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Objective To analyze the epidemic characteristics of malaria cases in Wuhan before and after the assessment of malaria elimination in 2015 (2010-2015 and 2016-2023), providing a scientific basis for formulating malaria prevention and control policies and evaluating their effectiveness. Methods Data on malaria cases including epidemiological surveys and case reports from 2010 to 2023 were collected. The year 2015 was used as a time point to analyze the species of infecting parasites, sources of infection, and treatment conditions. Results A total of 547 malaria cases were reported in Wuhan from 2010 to 2023, with an incidence rate ranging from 0.05 to 0.74 per 100 000 people. Among these, 73.8% were caused by Plasmodium falciparum, 13.1% by Plasmodium vivax, 8.0% by Plasmodium ovale, 2.3% by Plasmodium malaria, and 2.5% involved mixed infections. Except for four locally transmitted cases reported in 2010, all other cases were imported, with Africa being the primary source (89.9%). In African cases, Plasmodium falciparum accounted for 79.6%, while non-falciparum species predominated in Asia and Oceania (77.7%). There were statistically significant differences in malaria parasite species from different source countries (x=83.6, P < 0.05). From 2010 to 2023, malaria cases predominantly affected males aged 20 to 49, with farmers and workers comprising 52.8% of the cases. The majority of cases were reported in the Dongxihu District (25.9%), Wuchang District (19.0%), and Jiang'an District (12.7%). Cases were reported throughout the year, with a peak in July from 2010 to 2015 (37 cases), and 59.2% of cases (197/302) occurring from April to September. Between 2016 and 2023, peaks were observed in February, August, and December. The initial diagnosis of reported cases was concentrated in county-level and higher medical institutions (77.2%), with higher accuracy rates in provincial, municipal, and county-level institutions compared to village clinics or individual practitioners (statistically significant differences, χ²=95.3, P<0.05). The accuracy of initial diagnoses for malaria significantly improved from 2016 to 2023 compared to 2010 to 2015 (χ²=4.4, P< 0.05). The proportion of cases diagnosed within 72 hours of seeking care was 63.9% for 2010-2015 and 71.8% for 20162023, with a statistically significant difference (χ²=3.87, P<0.05). The proportions of cases diagnosed within 24 hours differed significantly among Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, Plasmodium malariae, and mixed infections (χ²=13.9, P<0.05). Conclusion From 2010 to 2023, malaria cases in Wuhan were predominantly attributed to imported Plasmodium falciparum from Africa, primarily affecting young male farmers and workers, with a diversification of parasite species. Continued strengthening of epidemiological investigations, pathogen and vector monitoring, and transmission risk assessments is essential to prevent the reintroduction and spread of malaria. [ABSTRACT FROM AUTHOR]

Objective To analyze the epidemiological characteristics of reported cases of dengue fever in mainland China from 2019 to 2023 and provide a scientific basis for dengue prevention and control efforts. Methods The temporal, spatial, and population distribution characteristics, as well as the trends of dengue fever cases reported in the National Notifiable Disease Reporting System (NNDRS) of China were analyzed using software such as Joinpoint regression, SaTScan, and ArcGIS. Results From 2019 to 2023, a total of 43 095 cases were reported in China, with an average incidence rate of 61/100 000. The annual reported incidence rate fluctuated significantly (AAPC=-3.16%, 95%CI:-54.16%-91.47%), mainly concentrated in 2019 and 2023, accounting for 96.83% of the total reported cases over the past five years. All age groups were susceptible to the disease, with the 30 to <40 age group comprising 22.6% of cases. Cases were reported throughout the year, with a rapid increase starting in June and a peak period concentrated between August and October (n=34 780, RR=12.44, LLR=29 262.52, P<0.05). The epidemic was primarily characterized by imported cases leading to autochthonous transmission, with the majority of imported cases originating from Southeast Asia (86.56%), particularly from Cambodia (46.11%, 3 284 cases) and Myanmar (25.99%, 1 851 cases). The epidemic characteristics varied significantly across different years, with high risks of autochthonous transmission epidemics in Southwest, South, and Southeast China. High-risk local transmission were mainly distributed in Yunnan and Guangdong. The duration of the peak period of the epidemic was affected by the timeliness of early detection of local transmission, and the peak value of the epidemic was related to the effectiveness of prevention and control measures. The scale of the epidemic was influenced by the pressure of by cross-border transmission and the ability to implement local measures for dengue prevention and control. Conclusions With the increasing trend of global dengue transmission, the risk of autochthonous transmission of dengue in China is rising. It is recommended to strengthen proactive early outbreak surveillance, along with well preparation of personnel, technology, and resources for dengue prevention and control.According to autochthonous conditions, reasonable management and risk assessment of cross-border travelers should be explored to effectively. [ABSTRACT FROM AUTHOR]

BACKGROUND: The potential reappearance and/or expansion of vector‐borne diseases is one of the terrifying issues awaiting humanity in the context of climate change. The presence of competent Anopheles vectors, as well as suitable environmental circumstances, may result in the re‐emergence of autochthonous Malaria, after years of absence. In Morocco, international travel and migration movements from Malaria‐endemic areas have recently increased the number of imported cases, raising awareness of Malaria's possible reintroduction. Using machine learning we developed model predictions, under current and future (2050) climate, for the prospective distribution of Anopheles claviger, Anopheles labranchiae, Anopheles multicolor, and Anopheles sergentii implicated or incriminated in Malaria transmission. RESULTS: All modelled species are expected to find suitable habitats and have the potential to become established in the northern and central parts of the country, under present‐day conditions. Distinct changes in the distributions of the four mosquitoes are to be expected under climate change. Even under the most optimistic scenario, all investigated species are likely to acquire new habitats that are now unsuitable, placing further populations in danger. We also observed a northward and altitudinal shift in their distribution towards higher altitudes. CONCLUSION: Climate change is expected to expand the potential range of malaria vectors in Morocco. Our maps and predictions offer a way to intelligently focus efforts on surveillance and control programmes. To reduce the threat of human infection, it is crucial for public health authorities, entomological surveillance teams, and control initiatives to collaborate and intensify their actions, continuously monitoring areas at risk. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Purpose: Previous studies on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have focused on factors that influence the achievement of negative conversion of viral RNA. This study aimed to investigate the effects of the genetic mutations in different SARS-CoV-2 strains on the negative conversion time (NCT) among imported cases in Hangzhou, Zhejiang Province, China, in order to provide valuable insights for developing targeted epidemic prevention guidelines. Methods: This retrospective study involved 146 imported SARS-CoV-2 cases in Hangzhou from 8 April 2021 to 11 June 2022. We compared the SARS-CoV-2-specific indicators, clinical indexes, and NCT among the wild-type (WT), Delta, and Omicron groups. Spearman correlation analysis was used to identify the correlations of NCT with mutation types/frequencies. Results: The mean age of the imported cases was 35.3 (SD: 12.3) years, with 71.92 % males and 28.08 % females. The mean cycle threshold (Ct) values of open reading frame 1ab (ORF1ab) and nucleocapsid (N) RNA were 25.17 (SD: 6.44) and 23.4 (SD: 6.76), respectively. The mutations of SARS-CoV-2 strains were mainly located in N, membrane (M), spike (S), ORF1a, ORF1b, ORF3a, ORF6, and ORF9b genes among the WT, Delta, and Omicron groups. NCT was significantly prolonged in the WT and Delta groups compared to the Omicron group. T lymphocyte, white blood cell, eosinophil, and basophil counts were dramatically higher in the WT group than the Delta group. White blood cell, red blood cell, and basophil counts were significantly lower in the Delta group than the Omicron group. Spearman correlation analysis revealed a significant correlation between the NCT of viral RNA and mutation types of viral genes of WT and Omicron strains. Additionally, NCT was markedly negatively correlated with the frequencies of five mutations in Omicron strains (ORF1b:P1223L, ORF1b:R1315C, ORF1b:T2163I, ORF3a:T223I, and ORF6:D61L). Conclusions: This study indicates that five mutations in Omicron strains (ORF1b:P1223L/R1315C/T2163I, ORF3a:T223I and ORF6:D61L) shortened NCT in imported SARS-CoV-2 cases.

Background: Chikungunya is emerging and reemerging word-widely in the past decades. It is non-endemic in Zhejiang Province, Southeast China. Aedes albopictus, one of major vectors of chikungunya, is widely-distribution in Zhejiang, and autochthonous transmission is possible after introducing chikungunya virus. Methods: Retrospectively collected the epidemiological, clinical and genetic data of chikungunya and conducted the descriptive analysis and gene sequence analysis. Results: From 2008 to 2022, 29 chikungunya cases, including 26 overseas imported and 3 local cases, were reported and no cases died of chikungunya. More than half of the imported cases (53.85%) were from Southeast Asia. Seasonal peak of the imported cases was noted between August and September, and 42.31% cases onset in those 2 months. Eight prefecture-level cities and 16 counties reported cases during the study period, with Jinghua (27.59%) and Hangzhou (24.14%) reporting the largest number of cases. The 3 local cases were all reported in Qujiang, Quzhou in 2017. For imported cases, the male-female gender ratio was 2.71:1, 20–30 years old cases (46.15%) and commercial service (42.31%) accounted for the highest proportion. Clinically, fever (100%), fatigue (94.44%), arthralgia (79.17%), headache (71.43%) and erythra (65.22%) were the most common reported symptoms. Eight whole-genome sequences were obtained and belonged to East/Central/South African (ECSA) or Asian genotype. Conclusions: With the change of immigration policy, the surveillance of chikungunya should be strengthened and the ability of the case discovery and diagnosis should be improved in Zhejiang in the post-COVID-19 era.

Abstract Background The Hubei Province in China reported its last indigenous malaria case in September 2012, but imported malaria cases, particularly those related to Plasmodium vivax and Plasmodium falciparum, threaten Hubei’s malaria-free status. This study investigated the epidemiological changes in P. vivax and P. falciparum malaria in this province to provide scientific evidence for preventing malaria resurgence. Methods The prevalence, demographic characteristics, seasonal features, and geographical distribution of malaria were assessed using surveillance data and were compared across three stages: control stage (2005–2009) and elimination stages I (2010–2014) and II (2015–2019). Results In 2005–2019, 8483 malaria cases were reported, including 5599 indigenous P. vivax cases, 275 imported P. vivax cases, 866 imported P. falciparum cases, and 1743 other cases. Imported P. falciparum cases accounted for 0.07% of all cases reported in 2005, but increased to 78.81% in 2019. Most imported P. vivax and P. falciparum malaria occurred among males, aged 21–60 years, during elimination stages I and II. The number of regions affected by imported P. falciparum and P. vivax increased markedly in Hubei from the control stage to elimination stage II. Overall, 1125 imported P. vivax and P. falciparum cases were detected from 47 other nations. Eight imported cases were detected from other provinces in China. From the control stage to elimination stage II, the number of cases of malaria imported from African countries increased, and that of cases imported from Southeast Asian countries decreased. Conclusions Although Hubei has achieved malaria elimination, it faces challenges in maintaining this status. Hence, imported malaria surveillance need to be strengthened to reduce the risk of malaria re-introduction.

Background: The Hubei Province in China reported its last indigenous malaria case in September 2012, but imported malaria cases, particularly those related to Plasmodium vivax and Plasmodium falciparum, threaten Hubei's malaria-free status. This study investigated the epidemiological changes in P. vivax and P. falciparum malaria in this province to provide scientific evidence for preventing malaria resurgence. Methods: The prevalence, demographic characteristics, seasonal features, and geographical distribution of malaria were assessed using surveillance data and were compared across three stages: control stage (2005–2009) and elimination stages I (2010–2014) and II (2015–2019). Results: In 2005–2019, 8483 malaria cases were reported, including 5599 indigenous P. vivax cases, 275 imported P. vivax cases, 866 imported P. falciparum cases, and 1743 other cases. Imported P. falciparum cases accounted for 0.07% of all cases reported in 2005, but increased to 78.81% in 2019. Most imported P. vivax and P. falciparum malaria occurred among males, aged 21–60 years, during elimination stages I and II. The number of regions affected by imported P. falciparum and P. vivax increased markedly in Hubei from the control stage to elimination stage II. Overall, 1125 imported P. vivax and P. falciparum cases were detected from 47 other nations. Eight imported cases were detected from other provinces in China. From the control stage to elimination stage II, the number of cases of malaria imported from African countries increased, and that of cases imported from Southeast Asian countries decreased. Conclusions: Although Hubei has achieved malaria elimination, it faces challenges in maintaining this status. Hence, imported malaria surveillance need to be strengthened to reduce the risk of malaria re-introduction. [ABSTRACT FROM AUTHOR]

Copyright of China Tropical Medicine is the property of China Tropical Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BackgroundsThe coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a global threat since 2020. The emergence of the Omicron variant in 2021, which replaced Delta as the dominant variant of concern, has had a significant adverse impact on the global economy and public health. During this period, Zhejiang Province implemented dynamic zeroing and focused on preventing imported cases. This study aimed to gain clear insight into the characteristics of imported COVID-19 cases in Zhejiang Province.MethodsWe conducted a systematic molecular epidemiological analysis of 146 imported cases between July 2021 and November 2022 in Zhejiang Province. Virus samples with cycle threshold (Ct) value less than 32 were performed next generation sequencing. Basing the whole genome sequence obtained after quality control and assembly of reads, the whole genome variation map and phylogenetic tree were constructed and further analyzed.ResultsOur study identified critical months and populations for surveillance, profiled the variation of various lineages, determined the evolutionary relationships among various lineages of SARS-CoV-2, and compared the results in Zhejiang with those obtained worldwide during this period.ConclusionThe continuous molecular epidemiological surveillance of imported cases of COVID-19 in Zhejiang Province during 2021 to 2022 is consistent with the global epidemic trend.

Abstract Background Although China has entered the post-malaria-elimination era, imported cases remain a public health concern in China. Methods We retrospectively analyzed data from cases of imported malaria from January 2017 to December 2020 in Chengdu Public Health Clinical Center. We assessed potential clinical, epidemiological, geographical, and seasonal effects on duration of hospital stay. Cox proportional hazards model was used to identify predictive factors for prolonged hospital stay. Multivariate logistic regression was used to assess the potential risk factors associated with severe cases. Results The highest number of imported cases of malaria were from the Democratic Republic of the Congo (23%, 34/150) and most patients (74%, 26/34) were infected by Plasmodium falciparum. The Edwards test indicated no significant seasonality in imported cases of malaria (χ2 = 2.51, p = 0.28). Bacterial infection (adjusted hazard ratio [aHR] for discharge = 0.58, p = 0.01) and thrombocytopenia (aHR = 0.66, p = 0.02) were risk factors for prolonged hospital stay. The C-reactive protein (OR = 1.02, p = 0.01) and procalcitonin (OR = 1.03, p = 0.01) were risk factors for severe cases. Conclusions Bacterial infection and thrombocytopenia are risk factors for prolonged hospital stay among imported malaria cases. The C-reactive protein and procalcitonin level were risk factors for severe cases.

In 2013, an epidemic of falciparum malaria involving over 820 persons unexpectedly broke out in Shanglin County, Guangxi Zhuang Autonomous Region, China, after a large number of migrant workers returned from Ghana, where they worked as gold miners. Herein, we selected 146 isolates randomly collected from these patients to investigate the resistance characteristics of the parasite to sulfadoxine–pyrimethamine (SP) by screening mutations in the dhfr and dhps genes. All 146 isolates were successfully genotyped for dhps, and only 137 samples were successfully genotyped for dhfr. In the dhfr gene, point mutations occurred at three codons: 51 (83.2%, 114/137), 59 (94.9%, 130/137), and 108 (96.4%, 132/137). In the dhps gene, mutations occurred at four codons: 436 (36.3%, 53/146 for S436A, 0.7%, 1/146 for S436Y), 437 (95.2%, 139/146), 540 (3.4%, 5/146), and 613 (2.7%, 4/146). All 146 isolates had mutations in at least one codon, either within dhfr or dhps. Quadruple mutation I51R59N108/G437 (41.1%, 60/146) of partial or low resistance level was the most prevalent haplotype combination. Quintuple I51R59N108/G437E540 accounted for 2.1% (3/146). Sextuple I51R59N108/A436G437S613 was also found and accounted for 1.4% (2/146). A chronological assay incorporating two sets of resistance data from the studies of Duah and Amenga-Etego provided an overview of the resistance trend from 2003 to 2018. During this period, the results we obtained generally coincided with the total development tendency of SP resistance. It can be concluded that Plasmodium falciparum samples collected from Chinese migrant workers from Ghana presented prevalent but relatively partial or low resistance to SP. A chronological assay incorporating two sets of data around 2013 indicates that our results possibly reflect the SP resistance level of Ghana in 2013 and that the possibility of increased resistance exists. Therefore, reasonable drug use and management should be strengthened while also maintaining a continuous screening of resistance to SP. These findings also underscore the need to strengthen the prevention of malaria importation from overseas and focus on preventing its reintroduction and transmission in China.

Abstract Background In March 2020, the WHO declared the novel coronavirus outbreak a global pandemic. While great success in coronavirus disease 2019 (COVID-19) control has been achieved in China, imported cases have become a major challenge. This study aimed to describe the epidemiological and clinical characteristics of imported COVID-19 cases and to assess the effectiveness of screening strategies in Beijing, China. Methods This retrospective study included all imported cases transferred to Beijing Ditan Hospital from 29 February to 20 March 2020 who were screened by both chest computed tomography (CT) and reverse-transcriptase-polymerase chain reaction (RT-PCR) at the initial presentation. Demographic, clinical and laboratory data, in addition to chest CT imaging, were collected and analysed. Results In total, 2545 cases were included, among which 71 (2.8%) were finally diagnosed with laboratory-confirmed COVID-19. The majority 63 (88.7%) were from Europe. The most common initial symptoms were cough and fever, which accounted for 49.3% and 42.3%, respectively. Only four cases (5.6%) had lymphocytopenia, and thirteen cases (18.3%) demonstrated elevated levels of C-reactive protein (CRP). All cases had normal serum levels of procalcitonin (PCT). At initial presentation, among the 71 confirmed cases, 59 (83.1%) had a positive RT-PCR assay, and 35 (49.3%) had a positive chest CT. Twelve (16.9%) had a negative RT-PCR assay but a positive chest CT. Conclusions A combination of RT-PCR and chest CT is an effective strategy for the screening of imported COVID-19 cases. Our findings provide important information and clinical evidence about the infection control of imported COVID-19 cases.

Since the outbreak of COVID-19 in Wuhan, China in December 2019, it has spread quickly and become a global pandemic. While the epidemic has been contained well in China due to unprecedented public health interventions, it is still raging or not yet been restrained in some neighboring countries. Chinese government adopted a strict policy of immigration diversion in major entry ports, and it makes Suifenhe port in Heilongjiang Province undertook more importing population. It is essential to understand how imported cases and other key factors of screening affect the epidemic rebound and its mitigation in Heilongjiang Province. Thus we proposed a time switching dynamical system to explore and mimic the disease transmission in three time stages considering importation and control. Cross validation of parameter estimations was carried out to improve the credibility of estimations by fitting the model with eight time series of cumulative numbers simultaneous. Simulation of the dynamics shows that illegal imported cases and imperfect protection in hospitals are the main reasons for the second epidemic wave, the actual border control intensities in the province are relatively effective in early stage. However, a long-term border closure may cause a paradox phenomenon such that it is much harder to restrain the epidemic. Hence it is essential to design an effective border reopening strategy for long-term border control by balancing the limited resources on hotel rooms for quarantine and hospital beds. Our results can be helpful for public health to design border control strategies to suppress COVID-19 transmission.

The large-scale infection of COVID-19 has led to a significant impact on lives and economies around the world and has had considerable impact on global public health. Social distancing, mask wearing and contact tracing have contributed to containing or at least mitigating the outbreak, but how public awareness influences the effectiveness and efficiency of such approaches remains unclear. In this study, we developed a discrete compartment dynamic model to mimic and explore how media reporting and the strengthening containment strategies can help curb the spread of COVID-19 using Shaanxi Province, China, as a case study. The targeted model is parameterized based on multi-source data, including the cumulative number of confirmed cases, recovered individuals, the daily number of media-reporting items and the imported cases from the rest of China outside Shaanxi from January 23 to April 11, 2020. We carried out a sensitivity analysis to investigate the effect of media reporting and imported cases on transmission. The results revealed that reducing the intensity of media reporting, which would result in a significant increasing of the contact rate and a sizable decreasing of the contact-tracing rate, could aggravate the outbreak severity by increasing the cumulative number of confirmed cases. It also demonstrated that diminishing the imported cases could alleviate the outbreak severity by reducing the length of the epidemic and the final size of the confirmed cases; conversely, delaying implementation of lockdown strategies could prolong the length of the epidemic and magnify the final size. These findings suggest that strengthening media coverage and timely implementing of lockdown measures can significantly reduce infection.

During infectious disease outbreaks, inference of summary statistics characterizing transmission is essential for planning interventions. An important metric is the time-dependent reproduction number (Rt), which represents the expected number of secondary cases generated by each infected individual over the course of their infectious period. The value of Rt varies during an outbreak due to factors such as varying population immunity and changes to interventions, including those that affect individuals' contact networks. While it is possible to estimate a single population-wide Rt, this may belie differences in transmission between subgroups within the population. Here, we explore the effects of this heterogeneity on Rt estimates. Specifically, we consider two groups of infected hosts: those infected outside the local population (imported cases), and those infected locally (local cases). We use a Bayesian approach to estimate Rt, made available for others to use via an online tool, that accounts for differences in the onwards transmission risk from individuals in these groups. Using COVID-19 data from different regions worldwide, we show that different assumptions about the relative transmission risk between imported and local cases affect Rt estimates significantly, with implications for interventions. This highlights the need to collect data during outbreaks describing heterogeneities in transmission between different infected hosts, and to account for these heterogeneities in methods used to estimate Rt. This article is part of the theme issue 'Technical challenges of modelling real-life epidemics and examples of overcoming these'. [ABSTRACT FROM AUTHOR]

Copyright of China Tropical Medicine is the property of China Tropical Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Haiqian Chen,1 Leiyu Shi,2 Yuyao Zhang,1 Xiaohan Wang,1 Gang Sun1 1Department of Health Management, School of Health Management, Southern Medical University, Guangzhou, Guangdong, 510515, People’s Republic of China; 2Department of Health Policy and Management, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, 21205, USACorrespondence: Gang SunDepartment of Health Management, School of Health Management, Southern Medical University, Guangzhou, Guangdong, 510515, People’s Republic of ChinaTel +86 14103189758Email sunhoney163@163.com; gsun15@jhu.eduObjective: This study aimed to analyze the distribution characteristics and influencing factors for the interval between entering mainland China and the diagnosis of imported COVID-19 cases in Guangdong province, in order to provide valuable experience for global pandemic in prevention and control.Methods: We collected publicly reported data between March 1 and June 2, 2020. Univariate and multivariate regression analyses were performed to identify the significant associated factors with the interval between entering mainland China and diagnosis of imported COVID-19 cases.Results: As of June 2, 2020, a total of 200 imported cases were reported in Guangdong province. The average interval time was 4.25 days with a median of 2 days, the interval time of 68% cases was between 1 and 3 days. The multivariate model results show that the three following factors were critical influencing factors: nationality was foreign nationality (P = 0.037), results of initial nucleic acid detection were negative (P = 0.000) and the interval between entering mainland China and the detection of positive results (T) exceeded two days (P = 0.008).Conclusion: The results suggested that all travelers and returning resident should be taken strict sampling and testing, and isolation measures, improved the accuracy of the initial nucleic acid test results, and the detection efficiency and shortening the interval between entering mainland China and detection of positive results.Keywords: COVID-19, imported cases, Guangdong province, containment measures

This review aims to map the spread of the virus from Iran to the Middle East and the rest of the world and to help better understand the key trends that occurred during COVID-19 from this epidemic center. We performed a literature review which was undertaken from 16 June to 22 November 2020. We reviewed the available evidence on imported cases from Iran, in the electronic databases PubMed and Google Scholar, as well as gray literature. It is shown that 125 cases were imported from Iran, out of which most of the imported cases were asymptomatic, and PCR testing was the most common method of detection. It was also found that more than half of the imported cases were not quarantined or isolated at home. The review revealed that many countries, especially the Middle East had imported cases from Iran. The big gap between the date of arrival at the airport and the date of diagnosis emphasizes the importance of early detection and quarantine measures, to stop the spread of the virus.

• Mutations of SARS-CoV-2 strains were mainly located in eight viral genes among three groups. • The negative conversion time (NCT) of the WT and delta groups was significantly longer than the omicron group. • NCT was significantly negatively correlated with the frequencies of five mutations in omicron variants. Previous studies on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have focused on factors that influence the achievement of negative conversion of viral RNA. This study aimed to investigate the effects of the genetic mutations in different SARS-CoV-2 strains on the negative conversion time (NCT) among imported cases in Hangzhou, Zhejiang Province, China, in order to provide valuable insights for developing targeted epidemic prevention guidelines. This retrospective study involved 146 imported SARS-CoV-2 cases in Hangzhou from 8 April 2021 to 11 June 2022. We compared the SARS-CoV-2-specific indicators, clinical indexes, and NCT among the wild-type (WT), Delta, and Omicron groups. Spearman correlation analysis was used to identify the correlations of NCT with mutation types/frequencies. The mean age of the imported cases was 35.3 (SD: 12.3) years, with 71.92 % males and 28.08 % females. The mean cycle threshold (Ct) values of open reading frame 1ab (ORF1ab) and nucleocapsid (N) RNA were 25.17 (SD: 6.44) and 23.4 (SD: 6.76), respectively. The mutations of SARS-CoV-2 strains were mainly located in N, membrane (M), spike (S), ORF1a, ORF1b, ORF3a, ORF6, and ORF9b genes among the WT, Delta, and Omicron groups. NCT was significantly prolonged in the WT and Delta groups compared to the Omicron group. T lymphocyte, white blood cell, eosinophil, and basophil counts were dramatically higher in the WT group than the Delta group. White blood cell, red blood cell, and basophil counts were significantly lower in the Delta group than the Omicron group. Spearman correlation analysis revealed a significant correlation between the NCT of viral RNA and mutation types of viral genes of WT and Omicron strains. Additionally, NCT was markedly negatively correlated with the frequencies of five mutations in Omicron strains (ORF1b:P1223L, ORF1b:R1315C, ORF1b:T2163I, ORF3a:T223I, and ORF6:D61L). This study indicates that five mutations in Omicron strains (ORF1b:P1223L/R1315C/T2163I, ORF3a:T223I and ORF6:D61L) shortened NCT in imported SARS-CoV-2 cases. [ABSTRACT FROM AUTHOR]

Coccidioidomycosis is caused by the dimorphic fungi Coccidioides species which is endemic in the Western hemisphere. Reports on the characteristics of travel-related disseminated coccidioidomycosis in immunocompetent patients are rare, especially in non-endemic regions. The multifaceted symptoms of this condition present a diagnostic challenge to clinicians. This study aimed to review immunocompetent patients diagnosed with disseminated coccidioidomycosis in a tertiary hospital in Eastern China and other non-endemic areas, and to emphasize the importance of combining travel history with clinical manifestations and proper diagnostic examinations. This study retrospectively reviewed a case series of disseminated coccidioidomycosis diagnosed in an academic hospital in Eastern China. We conducted a global literature review of disseminated coccidioidomycosis in immunocompetent patients with travel history. We identified six patients in our case series and reviewed 42 cases in the literature. Travel history included Mexico, Arizona, California, and regions of low endemicity. Extrapulmonary sites of infection, which presented with diverse signs and symptoms, involved the skin and soft tissue, musculoskeletal system, lymph nodes, and central nervous system. Misdiagnoses and diagnostic delays were common. Next-generation sequencing substantially promoted precise diagnosis in our series. The overall prognosis for immunocompetent individuals was positive, mainly benefited from long-term azole therapies. The patients that succumbed had either central nervous system involvement or multiorgan dissemination. Progressive pneumonia with varied symptoms and travel history should alert healthcare professionals in non-endemic areas to consider the possibility of Coccidioides species infection. We recommend detailed history-taking and hypothesis-free detection of pathogens for cases with diagnostic delay. [ABSTRACT FROM AUTHOR]

Background: Although China has entered the post-malaria-elimination era, imported cases remain a public health concern in China.Methods: We retrospectively analyzed data from cases of imported malaria from January 2017 to December 2020 in Chengdu Public Health Clinical Center. We assessed potential clinical, epidemiological, geographical, and seasonal effects on duration of hospital stay. Cox proportional hazards model was used to identify predictive factors for prolonged hospital stay. Multivariate logistic regression was used to assess the potential risk factors associated with severe cases.Results: The highest number of imported cases of malaria were from the Democratic Republic of the Congo (23%, 34/150) and most patients (74%, 26/34) were infected by Plasmodium falciparum. The Edwards test indicated no significant seasonality in imported cases of malaria (χ2 = 2.51, p = 0.28). Bacterial infection (adjusted hazard ratio [aHR] for discharge = 0.58, p = 0.01) and thrombocytopenia (aHR = 0.66, p = 0.02) were risk factors for prolonged hospital stay. The C-reactive protein (OR = 1.02, p = 0.01) and procalcitonin (OR = 1.03, p = 0.01) were risk factors for severe cases.Conclusions: Bacterial infection and thrombocytopenia are risk factors for prolonged hospital stay among imported malaria cases. The C-reactive protein and procalcitonin level were risk factors for severe cases. [ABSTRACT FROM AUTHOR]

Leishmaniasis is a transmissible disease caused by Leishmania protozoa. Spain is endemic for both visceral and cutaneous leishmaniasis, the autochthonous aetiological agent being Leishmania infantum. Around the world, the L. donovani complex is associated with visceral symptoms, while any species of the Leishmania or Viannia subgenera affecting human can produce tegumentary forms. In a context of growing numbers of imported cases, associated with globalisation, the aim of this study was to analyse the aetiological evolution of human tegumentary leishmaniasis in a region of Spain (Catalonia). Fifty-six Leishmania strains, isolated from 1981 to 2018, were analysed using MLEE, gene sequencing (hsp70, rpoIILS, fh and ITS2) and MALDI-TOF. The utility of these different analytical methods was compared. The results showed an increase in leishmaniasis over the two last decades, particularly imported cases, which represented 39% of all cases studied. Leishmania infantum, L. major, L. tropica, L. braziliensis, L. guyanensis and L. panamensis were identified. The combination of molecular and enzymatic methods allowed the identification of 29 different strain types (A to AC). Strain diversity was higher in L. (Viannia), whilst the different L. major types were relatable with geo-temporal data. Among the autochthonous cases, type C prevailed throughout the studied period (39%). Minor types generally appeared within a short time interval. While all the techniques provided identical identification at the species complex level, MALDI-TOF and rpoIILS or fh sequencing would be the most suitable identification tools for clinical practice, and the tandem hsp70-ITS2 could substitute MLEE in the epidemiological field. [ABSTRACT FROM AUTHOR]

The scientific community knows little about the long-term influence of coronavirus disease 2019 (COVID-19) on olfactory dysfunction (OD). With the COVID-19 pandemic ongoing worldwide, the risk of imported cases remains high. In China, it is necessary to understand OD in imported cases. A prospective follow-up design was adopted. A total of 11 self-reported patients with COVID-19 and OD from Xi'an No. 8 Hospital were followed between August 19, 2021, and December 12, 2021. Demographics, clinical characteristics, laboratory and radiological findings, and treatment outcomes were analyzed at admission. We surveyed the patients via telephone for recurrence and sequelae at the 1-, 6-, and 12-month follow-up. Eleven patients with OD were enrolled; of these, 54.5% (6/11) had hyposmia and 45.5% (5/11) had anosmia. 63.6% (7/11) reported OD before or on the day of admission as their initial symptom; of these, 42.9% (3/7) described OD as the only symptom. All patients in the study received combined treatment with traditional Chinese medicine and Western medicine, and 72.7% (8/11) had partially or fully recovered at discharge. In terms of OD recovery at the 12-month follow-up, 45.5% (5/11) reported at least one sequela, 81.8% (9/11) had recovered completely, 18.2% (2/11) had recovered partially, and there were no recurrent cases. Our data revealed that OD frequently presented as the initial or even the only symptom among imported cases. Most OD improvements occurred in the first 2 weeks after onset, and patients with COVID-19 and OD had favorable treatment outcomes during long-term follow-up. A better understanding of the pathogenesis and appropriate treatment of OD is needed to guide clinicians in the care of these patients. [ABSTRACT FROM AUTHOR]

Following initiation of China's National Malaria Elimination Action Plan (NMEAP) in 2010, China's 1-3-7 surveillance and response approach was developed and rolled out in China to facilitate the malaria control programme and accelerate the progress of malaria elimination. Innovative strategies and interventions have been developed and implemented in Jiangsu Province to facilitate case-based malaria surveillance and response. A total of 9879 malaria cases were reported in Jiangsu Province from 2001 to 2020. Since 2012, no indigenous malaria cases have been reported in Jiangsu Province. However, in recent years, there has been a substantial increase of imported cases from abroad. To continue improving the malaria surveillance and response system, Jiangsu Province has conducted population-based health education to improve the healthcare seeking behaviour of malaria patients, strengthened the capacity of health facilities to improve the performance of malaria diagnosis and treatment, and strengthened health workforce capacity to improve the implementation of 1-3-7 approach. Continually improving surveillance and response system can play a critical role in the early detection and rapid response of individual malaria cases and prevent the re-establishment of malaria. [ABSTRACT FROM AUTHOR]

Abstract Background The novel coronavirus disease 2019 (COVID-19) confirmed cases overseas have continued to rise in the last months, and many people overseas have chosen to return to China. This increases the risk of a large number of imported cases which may cause a relapse of the COVID-19 outbreak. In order to prevent imported infection, the Shenzhen government has implemented a closed-loop management strategy using nucleic acid testing (NAT) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and requiring 14 days of medical observation for individuals with an overseas tour history (Hong Kong, Macao, Taiwan province and other countries). Our study aims to describe the status of COVID-19 infection among people entering Shenzhen, and to evaluate the effect of the closed-loop management strategy. Methods We undertook a descriptive study and risk analysis by the entry time, time of reporting, and local confirmed cases in countries of origin. The NAT were completed in Shenzhen Center for Disease Control and Prevention (CDC), ten district-level CDCs, and fever clinics. Results A total of 86,844 people from overseas entered Shenzhen from January 1 to April 18, 2020; there were 39 imported COVID cases and 293 close contacts. The infection rate of people entering was 4.49‰ [95% Confidence interval (CI): 3.26‰–6.05‰]. Fourteen imported cases (35.9%) came from the UK, and nine (23.08%) came from the USA. People entering from the USA since March 9 or from the UK since March 13 are the high-risk population. As of July 17, there have been no new confirmed cases in Shenzhen for 153 days, and the numbers of confirmed case, close contacts, and asymptomatic cases are 0. Conclusions The closed-loop management has been effective in preventing imported infection and controlling domestic relapse. The distribution of entry time and report time for imported cases overseas was similar. This shows that it is important to implement closed-loop management at the port of entry.

Background: As COVID-19 ravages continuously around the world, more information on the epidemiological characteristics and factors associated with time interval between critical events is needed to contain the pandemic and to assess the effectiveness of interventions. Methods: Individual information on confirmed cases from January 21 to March 2 was collected from provincial or municipal health commissions. We identified the difference between imported and local cases in the epidemiological characteristics. Two models were established to estimate the factors associated with time interval from symptom onset to hospitalization (TOH) and length of hospital stay (LOS) respectively. Results: Among 7,042 cases, 3392 (48.17%) were local cases and 3304 (46.92%) were imported cases. Since the first intervention was adopted in Hubei on January 23, the daily reported imported cases reached a peak on January 28 and gradually decreased since then. Imported cases were on average younger (41 vs. 48), and had more male (58.66% vs. 47.53%) compared to local cases. Furthermore, imported cases had more contacts with other confirmed cases (2.80 ± 2.33 vs. 2.17 ± 2.10), which were mainly within family members (2.26 ± 2.18 vs. 1.57 ± 2.06). The TOH and LOS were 2.67 ± 3.69 and 18.96 ± 7.63 days respectively, and a longer TOH was observed in elderly living in the provincial capital cities that were higher migration intensity with Hubei. Conclusions: Measures to restrict traffic can effectively reduce imported spread. However, household transmission is still not controlled, particularly for the infection of imported cases to elderly women. It is still essential to surveil and educate patients about the early admission or isolation.

Since December 2019, an outbreak of a novel coronavirus pneumonia (WHO named COVID-19) swept across China. In Shanxi Province, the cumulative confirmed cases finally reached 133 since the first confirmed case appeared on January 22 2020, and most of which were imported cases from Hubei Province. Reasons for this ongoing surge in Shanxi province, both imported and autochthonous infected cases, are currently unclear and demand urgent investigation. In this paper, we developed a SEIQR difference-equation model of COVID-19 that took into account the transmission with discrete time imported cases, to perform assessment and risk analysis. Our findings suggest that if the lock-down date in Wuhan is earlier, the infectious cases are fewer. Moreover, we reveal the effects of city lock-down date on the final scale of cases: if the date is advanced two days, the cases may decrease one half (67, 95% CI: 66–68); if the date is delayed for two days, the cases may reach about 196 (95% CI: 193–199). Our investigation model could be potentially helpful to study the transmission of COVID-19, in other provinces of China except Hubei. Especially, the method may also be used in countries with the first confirmed case is imported.

BackgroundTo limit the spread of COVID-19 due to imported cases, Burkina Faso has set up quarantine measures for arriving passengers. We aimed to determine the incidence and predictors of imported cases of COVID-19 in Burkina Faso.MethodsA prospective cohort study was performed using data from passengers arriving at the airport from April 9 to August 31, 2020. The data was extracted from the District Health Information Software 2 (DHIS2) platform. Cox regression was used to identify predictors of imported cases of COVID-19.ResultsAmong 6,332 travelers who arrived in the study period, 173 imported cases (2.7%) were recorded. The incidence rate was 1.9 cases per 1,000 traveler-days (95%CI: 1.6–2.2 per 1,000). Passengers arriving in April (Adjusted hazard ratio [aHR] = 3.56; 95%CI: 1.62–7.81) and May (aHR = 1.92; 95% CI: 1.18–3.12) were more at risk of being tested positive compared to those arriving in August, as well as, passengers presenting with one symptom (aHR = 3.71; 95% CI: 1.63–8.43) and at least two symptoms (aHR = 10.82; 95% CI: 5.24–22,30) compared to asymptomatic travelers.ConclusionsThe incidence of imported cases was relatively low in Burkina Faso between April and August 2020. The period of travel and the presence of symptoms at arrival predicted the risk of being tested positive to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This is essential in the context of the high circulation of virus variants worldwide and the low local capacity to perform genotyping tests to strengthen the surveillance and screening capacities at the points of entry into the country.

Background: We present a novel approach for exiting COVID-19 lockdowns using a 'risk scorecard' to prioritise activities to resume whilst allowing safe re-opening.Methods: We modelled cases generated in the community/week, incorporating parameters for social distancing, contact tracing and imported cases. We set thresholds for cases and analysed the effect of varying parameters. An online tool to facilitate country-specific use including the modification of parameters (https://sshsphdemos.shinyapps.io/covid_riskbudget/) enables visualisation of effects of parameter changes and trade-offs. Local outbreak investigation data from Singapore illustrates this.Results: Setting a threshold of 0.9 mean number of secondary cases arising from a case to keep R < 1, we showed that opening all activities excluding high-risk ones (e.g. nightclubs) allows cases to remain within threshold; while opening high-risk activities would exceed the threshold and result in escalating cases. An 80% reduction in imported cases per week (141 to 29) reduced steady-state cases by 30% (295 to 205). One-off surges in cases (due to superspreading) had no effect on the steady state if the R remains < 1. Increasing the effectiveness of contact tracing (probability of a community case being isolated when infectious) by 33% (0.6 to 0.8) reduced cases by 22% (295 to 231). Cases grew exponentially if the product of the mean number of secondary cases arising from a case and (1-probability of case being isolated) was > 1.Conclusions: Countries can utilise a 'risk scorecard' to balance relaxations for travel and domestic activity depending on factors that reduce disease impact, including hospital/ICU capacity, contact tracing, quarantine and vaccination. The tool enabled visualization of the combinations of imported cases and activity levels on the case numbers and the trade-offs required. For vaccination, a reduction factor should be applied both for likelihood of an infected case being present and a close contact getting infected. [ABSTRACT FROM AUTHOR]

Due to globalization, physicians have to be prepared with knowledge and understanding of cases and diseases from all over the world. Vector-borne diseases are a particular group of diseases for which the clinician should be prepared, especially in the context of returning travelers with tropical fever, as the symptoms are very similar among some of the pathogens. In this report we present a case of a returning traveler from Nigeria with fever as her chief complaint and with a final diagnosis of malaria and chikungunya. We discuss how co-infection with different pathogens could change the natural history or modify the clinical course of the disease.

Estimating the time-varying reproductive number, Rt, is critical for monitoring transmissibility of an infectious disease. The impact of imported cases on the estimation is rarely explored. We developed a model to estimate separately the Rt for local cases and imported cases, with accounting for imperfect contact tracing of cases. We applied this framework to data on COVID-19 outbreaks in Hong Kong. The estimated Rt for local cases rise above 1 in late March, 2020, which was undetected by other commonly used methods. When imported cases accounted for a considerable proportion of all cases, their impact on estimating Rt is critical. [ABSTRACT FROM AUTHOR]

Background: The novel coronavirus disease 2019 (COVID-19) confirmed cases overseas have continued to rise in the last months, and many people overseas have chosen to return to China. This increases the risk of a large number of imported cases which may cause a relapse of the COVID-19 outbreak. In order to prevent imported infection, the Shenzhen government has implemented a closed-loop management strategy using nucleic acid testing (NAT) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and requiring 14 days of medical observation for individuals with an overseas tour history (Hong Kong, Macao, Taiwan province and other countries). Our study aims to describe the status of COVID-19 infection among people entering Shenzhen, and to evaluate the effect of the closed-loop management strategy.Methods: We undertook a descriptive study and risk analysis by the entry time, time of reporting, and local confirmed cases in countries of origin. The NAT were completed in Shenzhen Center for Disease Control and Prevention (CDC), ten district-level CDCs, and fever clinics.Results: A total of 86,844 people from overseas entered Shenzhen from January 1 to April 18, 2020; there were 39 imported COVID cases and 293 close contacts. The infection rate of people entering was 4.49‰ [95% Confidence interval (CI): 3.26‰-6.05‰]. Fourteen imported cases (35.9%) came from the UK, and nine (23.08%) came from the USA. People entering from the USA since March 9 or from the UK since March 13 are the high-risk population. As of July 17, there have been no new confirmed cases in Shenzhen for 153 days, and the numbers of confirmed case, close contacts, and asymptomatic cases are 0.Conclusions: The closed-loop management has been effective in preventing imported infection and controlling domestic relapse. The distribution of entry time and report time for imported cases overseas was similar. This shows that it is important to implement closed-loop management at the port of entry. [ABSTRACT FROM AUTHOR]

In the era of coronavirus disease 2019 (COVID-19) pandemic, imported COVID-19 cases pose great challenges to many countries. Chest CT examination is considered to be complementary to nucleic acid test for COVID-19 detection and diagnosis. We report the first community infected COVID-19 patient by an imported case in Beijing, which manifested as nodular lesions on chest CT imaging at the early stage. Deep Learning (DL)-based diagnostic systems quantitatively monitored the progress of pulmonary lesions in 6 days and timely made alert for suspected pneumonia, so that prompt medical isolation was taken. The patient was confirmed as COVID-19 case after nucleic acid test, for which the community transmission was prevented timely. The roles of DL-assisted diagnosis in helping radiologists screening suspected COVID cases were discussed. [ABSTRACT FROM AUTHOR]

• At the beginning of the epidemic, measures to lockdown the city could reduce imported spread. • Household transmission is not yet controlled, particularly for the infection of imported cases to elderly women. • Patients who contacted with a confirmed case of family members were admitted to the hospital earlier. • Surveillance and education of immediate admission/isolation should be emphasized, after travel restrictions were taken. As COVID-19 ravages continuously around the world, more information on the epidemiological characteristics and factors associated with time interval between critical events is needed to contain the pandemic and to assess the effectiveness of interventions. Individual information on confirmed cases from January 21 to March 2 was collected from provincial or municipal health commissions. We identified the difference between imported and local cases in the epidemiological characteristics. Two models were established to estimate the factors associated with time interval from symptom onset to hospitalization (TOH) and length of hospital stay (LOS) respectively. Among 7,042 cases, 3392 (48.17%) were local cases and 3304 (46.92%) were imported cases. Since the first intervention was adopted in Hubei on January 23, the daily reported imported cases reached a peak on January 28 and gradually decreased since then. Imported cases were on average younger (41 vs. 48), and had more male (58.66% vs. 47.53%) compared to local cases. Furthermore, imported cases had more contacts with other confirmed cases (2.80 ± 2.33 vs. 2.17 ± 2.10), which were mainly within family members (2.26 ± 2.18 vs. 1.57 ± 2.06). The TOH and LOS were 2.67 ± 3.69 and 18.96 ± 7.63 days respectively, and a longer TOH was observed in elderly living in the provincial capital cities that were higher migration intensity with Hubei. Measures to restrict traffic can effectively reduce imported spread. However, household transmission is still not controlled, particularly for the infection of imported cases to elderly women. It is still essential to surveil and educate patients about the early admission or isolation. [ABSTRACT FROM AUTHOR]

Background The rapidly growing pandemic of coronavirus disease 2019 (COVID-19) has challenged health systems globally. Here we report the first identified infections of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; aetiology of COVID-19) among recent international arrivals to Sudan and their contacts. Methods Suspected cases were identified clinically and/or epidemiologically. Samples from suspected cases and their contacts were tested in the National Influenza Centre following World Health Organization protocols. Two real-time reverse transcription quantitative polymerase chain reaction assays were used to detect and confirm SARS-CoV-2 infection. Results Seven cases of COVID-19, including two deaths, were confirmed in Sudan between 27 February and 30 March 2020. Suspected cases were identified and tested. As of 30 March, no local transmission was yet reported in the country. Fifty-nine percent of the suspected cases were international travellers coming from areas with current COVID-19 epidemics. Cough and fever were the major symptoms, presented by 65% and 60% of the suspected cases, respectively. By early April, an additional seven cases were confirmed through limited contact tracing that identified the first locally acquired infections in recent contact with imported cases. Conclusions The high mortality rate of COVID-19 cases in Sudan might be due to limitations in test and trace and case management services. Unfortunately, infections have spread further into other states and the country has no capacity for mass community screening to better estimate disease prevalence. Therefore external support is urgently needed to improve the healthcare and surveillance systems. [ABSTRACT FROM AUTHOR]

Objective To analyze the imported malaria epidemic characteristics in Shanglin county, from 2010 to 2019, we provide reference basis for the formulation of prevention and control strategies. Methods The data of imported malaria were collected in Shanglin County, Guangxi, from 2010 to 2019, and descriptive analysis on the epidemical distribution of imported malaria case survey date, species, source of infection, three-dimensional distribution were conducted. Results A total of 2 319 cases of malaria were reported in Shanglin County, Guangxi, from 2010 to 2019, all of which were imported from abroad, with the largest number of cases detected in 2013 (1 052 cases, 45.4%). It included 1 774 cases (76.5%) with falciparum malaria, 112 cases (4.8%) with vivax malaria, 372 cases (16.0%) with ovale malaria, 26 cases (1.1%) with quartan malaria, and 35 cases(1.5%) with mixed infections. Most malaria cases were young men, and 2 286 cases (98.6%) were male, the ratio of males to females was 69:1; while 2 205 cases (95.1%) were at ages of 20 to 55 years. Gold mining was the predominant occupation (2 314 cases, 99.8%), the malaria cases were reported in each month across the year, with the largest number of cases detected in June (608 cases, 26.2%), followed by July (405 cases, 17.5%); The cases were distributed in 11 towns, with the largest number of cases detected in Mingliang town (870 cases, 37.5%), followed by Dafeng town (544 cases, 23.5%), and Xiangxian town (496 cases, 21.4%). The malaria cases were originated from 16 countries in Africa (2 293 cases, 98.9%), 3 countries in Southeast Asia (26 cases, 1.1%). The main species were falciparum malaria (1 766 cases, 77.0%) in Africa, and most malaria cases were from Ghana (1 761 cases, 76.8%); the main species were vivax malaria (14 cases, 53.8%) in Southeast Asia, most malaria cases were from Indonesia (53.8%). Conclusions The situation of prevention and control of imported malaria abroad is very serious in Shanglin county, strengthening the surveillance and management of migrant labors is the key to consolidate the achievements of malaria elimination. [ABSTRACT FROM AUTHOR]

Objective To analyze diagnosis of imported malaria in Zhejiang Province duiring 2012-2019, to prevent transmission after elimination of malaria, we provide the foundation for malaria prevention and control. Methods Malaria case information, epidemiological investigation data on imported malaria cases in Zhejiang Province from 2012 to 2019 were collected through Parasitosis Prevention and Control Information System of China Disease Prevention and Control Information System (CISDCP). The diagnostic methods, diagnostic institutions and onset - diagnosis time of imported malaria cases were described and analyzed. Results A total of 1 543 malaria cases were reported in Zhejiang Province during 2012-2019, and all of which were imported. Majority of the cases were Plasmodium falciparum (71.2%). The utilization rate of RDT increased from 62.86% (88/140) in 2012 to 88.76% (158/178) in 2019. The rate of diagnosis in CDC decreased from 35.7% (50/140) in 2012 to 9.6% (17/178) in 2019 (P<0.05), while that in medical institutions increased from 55% (77/140) in 2012 to 88.2% (157/178) in 2019. And the diagnosis rate of county-level medical institutions was statistically significant from 2012 to 2019 (P< 0.05). The median time from onset to initial diagnosis and from initial diagnosis to confirmation of malaria cases was 1 day, respectively. The time interval from initial diagnosis to confirmation was statistically different in each year (P<0.001). The interval from initial diagnosis to confirmation of Plasmodium falciparum was shorter than that of other species (P<0.001). The interval from onset to initial diagnosis of the institutions below county-level was shorter than that of the institutions at other levels (P<0.001). Conclusions The diagnostic awareness and capabilities of medical institutions should be further strengthened, and health education should be strengthened to increase awareness of medical treatment, to prevent retransmission of imported malaria after elimination. [ABSTRACT FROM AUTHOR]

Burkholderia pseudomallei and Burkholderia mallei are etiologic agents of glanders and melioidosis, the particularly dangerous infections of animals and humans, and are attributed to potential agents of bioterrorism. The manifestation of diseases ranges from acute septicemia to chronic infection, any organs and tissues are affected, andtreatment requires long intravenous and oral antibiotic courses. The endemic zone of glanders and melioidosis covers spacious regions in the world, and the number of imported cases to temperate regions is constantly increasing. For the Russian Federation, glanders and melioidosis are «forgotten» and «unknown» infections, and this review presents current data on their distribution in the world, epidemiological aspects, and laboratory diagnosis features.

Abstract Background Hubei Province, China, has been operating a malaria elimination programme. This study aimed at investigating the epidemiologic characteristics of malaria in Hubei Province (2005–2016) to plan resource allocation for malaria elimination. Methods Data on all malaria cases from 2005 to 2016 in all counties of Hubei Province were extracted from a web-based reporting system. The numbers of indigenous and imported cases during the disease control (2005–2010) and elimination (2011–2016) stages, as well as their spatiotemporal distribution, were compared. Results A total of 8109 malaria cases were reported from 2005 to 2016 (7270 and 839 cases during the control and elimination stages, respectively). Between 2005 and 2010, indigenous malaria cases comprised the majority of total cases (7114/7270; 97.9%), and Plasmodium vivax malaria cases accounted for most malaria cases (5572/7270; 76.6%). No indigenous malaria cases have been reported in Hubei Province since 2013. Imported malaria cases showed a gradually increasing trend from 2011 to 2016, Plasmodium falciparum was the predominant species in these cases, and the number of counties with imported cases increased from 4 in 2005 to 47 in 2016. During the control and elimination stages, the most likely spatial clusters for indigenous cases included 13 and 11 counties, respectively. However, the cluster of indigenous malaria cases has not been identified since September 2011. For imported cases, the most likely cluster and three secondary clusters during both stages were identified. Conclusions Hubei Province has made significant achievements in controlling and eliminating malaria; however, the region now faces some challenges associated with the increasing number and distribution of imported malaria cases. Priorities for malaria elimination should include better management of imported malaria cases, prevention of secondary malaria transmission, and ensuring the sustainability of malaria surveillance.

Objective: To ascertain the role of imported cases and serotypes on dengue outbreaks in Taiwan which have been sporadic yet highly volatile during the past two decades, exhibiting record-breaking magnitude in recent years. Methods: Confirmed case and serotype data from Taiwan Centers for Disease Control during 1998-2017 were fully examined, with fitting of weekly and daily case data of each city/county to a mathematical model to pinpoint the waves of cases and their locations. Moreover, we quantify the timing of turning point and transmission potential of each wave and determine its circulating serotype, to ascertain any pattern or connection between the variations in circulating serotypes and the magnitude/transmissibility of outbreak. Results: While the number of imported case increased steadily during past two decades, the yearly number of indigenous cases fluctuated wildly. Moreover, while yearly percentages of serotypes for imported cases remains steady, that of indigenous cases does not exhibit any clear pattern. There was at least one wave of reported cases somewhere in Taiwan every year from 1998 to 2015, except in 2016-2017. The effective reproduction number R for all waves in all locations ranged from 1.14 to 2.87, with the exception of two Tainan waves, in 2010 (3.95) and 2015 (6.84). Four major outbreaks of over 2000 cases reveal circulation of one dominant serotype. Conclusions: Correlation between imported cases and indigenous outbreak prove to be difficult to ascertain, even with the availability of serotype data. However, although there had been occasional co-circulation of serotypes in one location, and for some years with different serotypes circulating in different locations, all major outbreaks of over 2 000 cases during the past two decades are due to circulation of mainly a single serotype, perhaps indicating greater transmission potential with one dominating serotype.

Background We aimed to report the clinical characteristics of imported cases of coronavirus disease 2019 (COVID-19) in Jiangsu Province. Methods We retrospectively investigated the clinical, imaging, and laboratory characteristics of confirmed cases of COVID-19 with World Health Organization interim guidance in 3 grade IIIA hospitals of Jiangsu from 22 January to 14 February 2020. Real-time RT-PCR was used to detect the new coronavirus in respiratory samples. Results Of the 80 patients infected with COVID-19, 41 were female, with a median age of 46.1 years. Except for 3 severe patients, the rest of the 77 patients exhibited mild or moderate symptoms. Nine patients were unconfirmed until a third nucleic acid test; 38 cases had a history of chronic diseases. The main clinical manifestations of the patients were fever and cough, which accounted for 63 (78.75%) and 51 (63.75%) cases, respectively. Only 3 patients (3.75%) showed liver dysfunction. Imaging examination showed that 55 patients (68.75%) showed abnormal density shadow and 25 cases (31.25%) had no abnormal density shadow in the parenchyma of both lungs. Currently, 21 cases have been discharged from the hospital, and no patient died. The average length of stay for discharged patients was 8 days. Conclusions Compared with the cases in Wuhan, the cases in Jiangsu exhibited mild or moderate symptoms and no obvious gender susceptibility. The proportion of patients having liver dysfunction and abnormal CT imaging was relatively lower than that in Wuhan. Notably, infected patients may be falsely excluded based on 2 consecutively negative respiratory pathogenic nucleic acid test results. [ABSTRACT FROM AUTHOR]

For many diseases, the basic reproduction number (R 0) is a threshold parameter for disease extinction or survival in isolated populations. However no human population is fully isolated from other human or animal populations. We use compartmental models to derive simple rules for the basic reproduction number in populations where an endemic disease is sustained by a combination of local transmission within the population and exposure from some other source: either a reservoir exposure or imported cases. We introduce the idea of a reservoir-driven or importation-driven disease: diseases that would become extinct in the population of interest without reservoir exposure or imported cases (since R 0 < 1), but nevertheless may be sufficiently transmissible that many or most infections are acquired from humans in that population. We show that in the simplest case, R 0 < 1 if and only if the proportion of infections acquired from the external source exceeds the disease prevalence and explore how population heterogeneity and the interactions of multiple strains affect this rule. We apply these rules in two case studies of Clostridium difficile infection and colonisation : C. difficile in the hospital setting accounting for imported cases, and C. difficile in the general human population accounting for exposure to animal reservoirs. We demonstrate that even the hospital-adapted, highly-transmissible NAP1/RT027 strain of C. difficile had a reproduction number <1 in a landmark study of hospitalised patients and therefore was sustained by colonised and infected admissions to the study hospital. We argue that C. difficile should be considered reservoir-driven if as little as 13.0% of transmission can be attributed to animal reservoirs. [ABSTRACT FROM AUTHOR]

Introduction: An unprecedented outbreak of the novel coronavirus disease (COVID-19) has swept across the globe since the end of 2019. Shenzhen confirmed its first imported case from Wuhan on 19 January 2020. However, little is known regarding the epidemiological characteristics of COVID-19 in these imported cities. Methodology: Data of all 417 confirmed cases diagnosed in Shenzhen before 29 February were collected. The epidemiological characteristics of imported and local cases were compared. The resilience to COVID-19 was evaluated by discharge density. Results: All ten districts reported COVID-19 cases by 29 February, including 331 imported and 86 local cases. The Pearson linear correlation model showed the number of confirmed cases (r = 0.990, p < 0.001) as well as incidence of COVID-19 (r = 0.766, p = 0.010) was positively correlated with the gross domestic product of district. Family clusters were more commonly found in local cases. Imported patients had earlier onset (p < 0.001) and diagnosis (p < 0.001), but longer interval from onset to admission (p = 0.030), diagnosis (p = 0.003) and discharge (p = 0.016). Older and severe cases had lower discharge density (0.024 and 0.018, respectively); while cases with subclinical symptoms exhibited higher discharge density (0.052). Conclusions: COVID-19 patients were predominantly imported cases in Shenzhen and the spatial distribution was closely related to district GDP. Imported and local cases differed in the intervals from onset to admission, diagnosis and discharge. Moreover, family-based transmission should not be ignored, especially in local cases. [ABSTRACT FROM AUTHOR]

Background: Substantial limitations have been imposed on passenger air travel to reduce transmission of severe acute respiratory syndrome coronavirus 2 between regions and countries. However, as case numbers decrease, air travel will gradually resume. We considered a future scenario in which case numbers are low and air travel returns to normal. Under that scenario, there will be a risk of outbreaks in locations worldwide due to imported cases. We estimated the risk of different locations acting as sources of future coronavirus disease 2019 outbreaks elsewhere.Methods: We use modelled global air travel data and population density estimates from locations worldwide to analyse the risk that 1364 airports are sources of future coronavirus disease 2019 outbreaks. We use a probabilistic, branching-process-based approach that considers the volume of air travelers between airports and the reproduction number at each location, accounting for local population density.Results: Under the scenario we model, we identify airports in East Asia as having the highest risk of acting as sources of future outbreaks. Moreover, we investigate the locations most likely to cause outbreaks due to air travel in regions that are large and potentially vulnerable to outbreaks: India, Brazil and Africa. We find that outbreaks in India and Brazil are most likely to be seeded by individuals travelling from within those regions. We find that this is also true for less vulnerable regions, such as the United States, Europe and China. However, outbreaks in Africa due to imported cases are instead most likely to be initiated by passengers travelling from outside the continent.Conclusions: Variation in flight volumes and destination population densities creates a non-uniform distribution of the risk that different airports pose of acting as the source of an outbreak. Accurate quantification of the spatial distribution of outbreak risk can therefore facilitate optimal allocation of resources for effective targeting of public health interventions. [ABSTRACT FROM AUTHOR]

Following the importation of coronavirus disease (COVID-19) into Nigeria on 27 February 2020 and then the outbreak, the question is: How do we anticipate the progression of the ongoing epidemic following all the intervention measures put in place? This kind of question is appropriate for public health responses and it will depend on the early estimates of the key epidemiological parameters of the virus in a defined population. In this study, we combined a likelihood-based method using a Bayesian framework and compartmental model of the epidemic of COVID-19 in Nigeria to estimate the effective reproduction number (R(t)) and basic reproduction number (R0) – this also enables us to estimate the initial daily transmission rate (β0). We further estimate the reported fraction of symptomatic cases. The models are applied to the NCDC data on COVID-19 symptomatic and death cases from 27 February 2020 and 7 May 2020. In this period, the effective reproduction number is estimated with a minimum value of 0.18 and a maximum value of 2.29. Most importantly, the R(t) is strictly greater than one from 13 April till 7 May 2020. The R0 is estimated to be 2.42 with credible interval: (2.37–2.47). Comparing this with the R(t) shows that control measures are working but not effective enough to keep R(t) below 1. Also, the estimated fraction of reported symptomatic cases is between 10 and 50%. Our analysis has shown evidence that the existing control measures are not enough to end the epidemic and more stringent measures are needed. [ABSTRACT FROM AUTHOR]

Abstract Background Though there was the significant decrease in the incidence of malaria in central and southwest China during the 1980s and 1990s, there has been a re-emergence of malaria since 2000. Methods A cross-sectional survey was conducted amongst the staff of eleven Centers for Disease Control and Prevention (CDC) in China to gauge their perceptions regarding the impacts of climate change on malaria transmission and its control and prevention. Descriptive analysis was performed to study CDC staff’s knowledge, attitudes, perceptions and suggestions for malaria control in the face of climate change. Results A majority (79.8%) of CDC staff were concerned about climate change and 79.7% believed the weather was becoming warmer. Most participants (90.3%) indicated climate change had a negative effect on population health, 92.6 and 86.8% considered that increasing temperatures and precipitation would influence the transmission of vector-borne diseases including malaria. About half (50.9%) of the surveyed staff indicated malaria had re-emerged in recent years, and some outbreaks were occurring in new geographic areas. The main reasons for such re-emergence were perceived to be: mosquitoes in high-density, numerous imported cases, climate change, poor environmental conditions, internal migrant populations, and lack of health awareness. Conclusions This study found most CDC staff endorsed the statement that climate change had a negative impact on infectious disease transmission. Malaria had re-emerged in some areas of China, and most of the staff believed that this can be managed. However, high densities of mosquitoes and the continuous increase in imported cases of malaria in local areas, together with environmental changes are bringing about critical challenges to malaria control in China. This study contributes to an understanding of climate change related perceptions of malaria control and prevention amongst CDC staff. It may help to formulate in-house training guidelines, community health promotion programmes and policies to improve the capacity of malaria control and prevention in the face of climate change in China.