Search

Recently, severe cases of infection due to hypermucoviscous Klebsiella pneumonia (hmKP) have been reported in Japan. The Amami Islands in Japan are also endemic regions for Strongyloides stercoralis. Disseminated strongyloidiasis strain often causes severe enterobacteria infection; however, whether or not chronic strongyloidiasis induces it remains unclear. We herein report a 71-year-old man who developed meningitis and liver abscess due to hmKP complicated with chronic strongyloidiasis. He died on the seventh hospital day. Strongyloides stercoralis were only found around the polyp in the cecum. Chronic strongyloidiasis can also induce severe infection due to enterobacteria, especially hypervirulent pathogens like hmKP, through the induction of mucosal rupture.

The duration of viral shedding of SARS-CoV-2 is usually less than 10 days. We experienced a COVID-19 case with prolonged viral shedding for 2 months. His cell mediated immunity has been depressed (CD4+T cell

Enhanced global travel networks have heightened the risk of emerging infectious diseases escalating into pandemics in a short time. The COVID-19 pandemic in 2020 reminded us of the importance of peacetime efforts to establish a basis for responding to a pandemic. Kawasaki City, one of the government-designated cities in the Greater Tokyo area in Japan, has made continuous efforts to reinforce preparedness and response capacity for emerging diseases. City authorities have sought to enhance communication and foster trust between the public health authority and medical institutions through a real-time information sharing system. The City has built trustworthy relationships with multiple stakeholders through various forms of joint exercises. Kawasaki City has also effectively developed a human resource development program, the “Field Epidemiology Training Program-Kawasaki (FETP-K),” that collaborates closely with the national FETP. This chapter introduces the details of a series of activities and lessons for reinforcing pandemic and emerging disease preparedness in urban areas in Japan.

Seasonal influenza epidemics are associated with various meteorological factors. Recently absolute humidity (AH) has garnered attention, and some epidemiological studies show an association between AH and human influenza infection. However, they mainly analyzed weekly surveillance data, and daily data remains largely unexplored despite its potential benefits. In this study, we analyze daily influenza surveillance data using a distributed lag non-linear model to examine the association of AH with the number of influenza cases and the magnitude of the association. Additionally, we investigate how adjustment for seasonality and autocorrelation in the model affect results. All models used in the study showed a significant increase in the number of influenza cases as AH decreased, although the magnitude of the association differed substantially by model. Furthermore, we found that relative risk reached a peak at lag 10–14 with extremely low AH. To verify these findings, further analysis should be conducted using data from other locations.

In this study, we examined the molecular evolution of the fusion protein (F) gene in human respiratory syncytial virus subgroup B (HRSV-B). First, we performed time-scale evolution analyses using the Bayesian Markov chain Monte Carlo (MCMC) method. Next, we performed genetic distance, linear B-cell epitope prediction, N-glycosylation, positive/negative selection site, and Bayesian skyline plot analyses. We also constructed a structural model of the F protein and mapped the amino acid substitutions and the predicted B-cell epitopes. The MCMC-constructed phylogenetic tree indicated that the HRSV F gene diverged from the bovine respiratory syncytial virus gene approximately 580years ago and had a relatively low evolutionary rate (7.14×10-4substitutions/site/year). Furthermore, a common ancestor of HRSV-A and -B diverged approximately 290years ago, while HRSV-B diverged into three clusters for approximately 60years. The genetic similarity of the present strains was very high. Although a maximum of 11 amino acid substitutions were observed in the structural model of the F protein, only one strain possessed an amino acid substitution located within the palivizumab epitope. Four epitopes were predicted, although these did not correspond to the neutralization sites of the F protein including the palivizumab epitope. In addition, five N-glycosylation sites of the present HRSV-B strains were inferred. No positive selection sites were identified; however, many sites were found to be under negative selection. The effective population size of the gene has remained almost constant. On the basis of these results, it can be concluded that the HRSV-B F gene is highly conserved, as is the F protein of HRSV-A. Moreover, our prediction of B-cell epitopes does not show that the palivizumab reaction site may be recognized as an epitope during naturally occurring infections.

During the 2012-13 rubella outbreak in Japan, local governments implemented subsidy programs for catch-up vaccination to mitigate the rubella outbreak and prevent congenital rubella syndrome (CRS). In most local governments, to prevent CRS, eligible persons of the subsidy program were women who were planning to have a child and men who were partners of pregnant women. On the other hand, in Kawasaki City, unimmunized men aged 23-39 years were additionally included in the eligible persons, because they were included in an unimmunized men group resulting from the historical transition of the national routine vaccination in Japan. The number of rubella cases in the city decreased earlier than that in the whole Japan. First, in order to estimate the effect of the catch-up vaccination campaign in Kawasaki City on the epidemic outcome, we performed numerical simulations with a Susceptible-Vaccinated-Exposed-Infectious-Recovered (SVEIR) model incorporating real data. The result indicated that the catch-up vaccination campaign showed a beneficial impact on the early decay of the rubella cases. Second, we numerically compared several different implementation strategies of catch-up vaccinations under a fixed amount of total vaccinations. As a result, we found that early and intensive vaccinations are vital for significant reduction in the number of rubella cases and CRS occurrences. Our study suggests that mathematical models with epidemiological and social data can contribute to identifying the most effective vaccination strategy.

Enteroaggregative Escherichia coli (EAEC), an enteric pathogen, causes persistent diarrhea in children, HIV-infected individuals, and travelers in economically developing countries. However, the pathogenesis of EAEC infection is not well understood. This study aimed to characterize EAEC in Japan. Between 2012 and 2014, we identified 40 EAEC strains carrying the aggR gene at the Kawasaki City Institute for Public Health, Japan. We characterized these strains using O:H-antigen typing, polymerase chain reaction (for pCVD432, astA, extended-spectrum beta-lactamase, and 4 aggregative adherence fimbriae genes), HEp-2 cell adherence, clump formation, and antimicrobial susceptibility testing. We were able to classify the 40 EAEC strains into 20 O:H types. Although specific O:H types were not correlated with HEp-2 cell aggregative adherence, all the O99:H10, O131:H27, and O176:H34 EAEC strains that were the most frequent O:H types detected in this study showed co-resistance to ampicillin, sulfamethoxazole-trimethoprim, and tetracycline. Based on results of the adhesion assay and detection of virulence-related genes, no significant difference was found between asymptomatic and symptomatic cases. Irrespective of the origin, their potential for virulence was retained. Further characterization is vital to determine whether EAEC is virulent in Japan.

Objectives In Japan, nationwide data of the incidence of infectious diseases have been collected via the National Epidemiological Surveillance of Infectious Diseases (NESID) since 1981. In addition, since March 2014, Kawasaki City has operated its own real-time surveillance (RTS) system to collect data of the incidence of influenza from medical institutions across the city. This study aimed to describe the characteristics of the RTS system and compare the two surveillance systems to improve measures against infectious diseases in the future.Methods NESID and RTS data from March 2014 to October 2017 were obtained from the Kawasaki City Institute for Public Health. First, the operating methodologies of the two surveillance systems were compared. Second, RTS data were used to analyze the daily epidemic curve, and then the daily number of influenza cases was converted into weekly data for comparison with NESID data. Pearson's correlation coefficients and 95% confidence intervals (CIs) were calculated. Correlations were also analyzed after data for the last and first weeks of each year were excluded because few hospitals remain open around the New Year holiday, resulting in a disproportionately large number of patients visiting the few institutions that remain open.Results The NESID relies on data provided by a fixed number of medical institutions determined each fiscal year (mean: 56.0±4.2 institutions), while the number of institutions providing data for the RTS varies daily or monthly. In September 2017, 691 of the 1,032 eligible institutions (67.0%) were registered for the RTS. Pearson's correlation coefficient for the two surveillance systems was 0.975 (95%CI, 0.967-0.981); when data for the last and first week of each year were excluded, it was 0.989 (95%CI 0.986-0.992). In each of the three seasons that were investigated, an increase in the incidence of type A influenza preceded an increase in the incidence of type B influenza.Conclusion The operating methodologies of the two surveillance systems differed; however, the results identified a strong correlation, confirming the reliability of the RTS. The RTS collects daily data by influenza type; therefore, it detects epidemic onsets at an earlier stage, facilitating more detailed epidemiological analysis, compared with that of the NESID. It is necessary to understand differences in the characteristics between two surveillance systems when we analyze influenza surveillance data.

SUMMARYA large outbreak of enterohaemorrhagic Escherichia coli (EHEC) O111 and O157 occurred in Japan in April 2011. We conducted an unmatched case-control study and trace-back investigation to determine the source of EHEC O111 infection and risk factors for severe complications. Pulsed-field gel electrophoresis was performed to help define cases. A total of 86 individuals met the case definition. Of these, 40% experienced haemolytic uraemic syndrome (HUS), 24% acute encephalopathy, and 6% died. Illness was significantly associated with eating the raw beef dish yukhoe (odds ratio 19·64, 95% confidence interval 7·03–54·83), the likely food vehicle. EHEC O111 and its closely related stx-negative variants were found in the beef. HUS occurred most frequently in individuals aged 5–9 years, and this age group was significantly associated with acute encephalopathy. The prevalence of HUS and acute encephalopathy was higher than in previous non-O157-related outbreaks, indicating a high risk of severe complications.

Enteroaggregative Escherichia coli (EAEC), an enteric pathogen, causes persistent diarrhea in children, HIV-infected individuals, and travelers in economically developing countries. However, the pathogenesis of EAEC infection is not well understood. This study aimed to characterize EAEC in Japan. Between 2012 and 2014, we identified 40 EAEC strains carrying the aggR gene at the Kawasaki City Institute for Public Health, Japan. We characterized these strains using O:H-antigen typing, polymerase chain reaction (for pCVD432, astA, extended-spectrum beta-lactamase, and 4 aggregative adherence fimbriae genes), HEp-2 cell adherence, clump formation, and antimicrobial susceptibility testing. We were able to classify the 40 EAEC strains into 20 O:H types. Although specific O:H types were not correlated with HEp-2 cell aggregative adherence, all the O99:H10, O131:H27, and O176:H34 EAEC strains that were the most frequent O:H types detected in this study showed co-resistance to ampicillin, sulfamethoxazole-trimethoprim, and tetracycline. Based on results of the adhesion assay and detection of virulence-related genes, no significant difference was found between asymptomatic and symptomatic cases. Irrespective of the origin, their potential for virulence was retained. Further characterization is vital to determine whether EAEC is virulent in Japan.

アトピー性皮膚炎 (AD) はTh2型の炎症性疾患であり, Th2細胞に特異的に発現するケモカイン受容体CCR4のリガンド Thymus and activation-regulated chemokine/CCL17 (TARC/CCL17) が病態に関与するとの報告は多い. 本研究では小児ADにおける病勢指標としての血清TARC/CCL17値の有用性について検討した. 6ヵ月以上15歳未満のアレルギー性疾患患者140名 (AD65名, アレルギー性鼻炎32名, 喘息43名) および正常対照者62名につき, それぞれ, 血清TARC/CCL17, 血清IgE, LDH, 末梢血好酸球数を測定した. 正常対照者の血清TARC/CCL17値は, 2歳未満で有意に高値であったため, 正常上限値を6ヶ月～1才未満, 1～2才未満, 2才以上に分けて, それぞれ1367, 998, 743pg/mlと設定した. ADと喘息において血清TARC/CCL17値は, 正常対照者に比べて有意に高値であり, ADのみが重症度と有意な相関を認めた. 次に, ADにおける血清TARC/CCL17の臨床診断能を他のマーカーと比較してROC解析すると, 血清TARC/CCL17値は感度・特異度ともに血清IgE, LDH, 末梢血好酸球数よりも高かった. また, 血清TARC/CCL17値は, 皮膚症状スコアと有意な相関を示し, 治療にともなう変動 (改善) とも良く一致した. 以上の結果より, 血清TARC/CCL17測定はADの病勢を客観評価する臨床検査として有用であり, ガイドラインに基づく治療選択の一助となると考えられた.

We conducted a long-term follow-up study between December 2005 and February 2007 on 4 immunocompetent infants, who repeatedly presented with respiratory symptoms, using PCR-based techniques targeting 14 viruses related to acute respiratory tract infection. Of 38 specimens, 30 were collected from symptomatic infants and 8 were collected when respiratory symptoms were absent. Overall, one or more respiratory viruses were detected in 94.7% (36/38) of the specimens. Of the 36 PCR-positive specimens, 77.8% (28/36) were positive for more than one virus. Most of these co-infections were double infections (55.6% or 20/36). Of note, co-infections with 4 and 3 viruses were observed in 3 (8.3% or 3/36) and 5 (13.9% or 5/36) specimens, respectively. Of the 8 specimens collected from the 4 infants when apparent respiratory symptoms were absent, 7 (87.5%) were positive for respiratory viruses. Respiratory viral co-infections were also frequent and found in 5 of the specimens (62.5%). However, apparent correlation between disease severity and co-infection was undetectable due to the limit of the number of cases studied. Taken together, this longitudinal study revealed that respiratory viral co-infections were not infrequent in infants aged 0-2 years, regardless of the presence of respiratory symptoms (62.5-77.8%).

Objective: To elucidate the clinical and radiologic features and analyze factors associated with neurologic outcomes of encephalopathy secondary to Shiga toxin–producing Escherichia coli (STEC) O111. Methods: We reviewed medical records and neuroimaging in 22 patients with neurologic symptoms among 86 with STEC O111 infection. Results: Twenty-one (6 males and 15 females, 10 children and 11 adults) of the 22 patients were diagnosed with encephalopathy. All patients with encephalopathy also presented with hemolytic-uremic syndrome. Five patients died, from day 1 to 6 months (days 1–5 in 4 patients), due to progressive encephalopathy with severe cerebral edema observed in neuroimaging (4 patients). Fifteen of the 16 surviving patients clinically recovered completely. Statistical analysis revealed differences between patients with poor (n = 6) and good (n = 15) outcomes in the interval from hemolytic-uremic syndrome presentation to encephalopathy, creatinine levels, and the methylprednisolone administration ratio. Conclusion: We note a high incidence of encephalopathy in the Toyama STEC O111 outbreak. All fatal cases resulted from progressive encephalopathy. Methylprednisolone pulse therapy represents a possible therapeutic choice. Classification of evidence: This study provides Class III evidence that methylprednisolone pulse therapy increases the probability of a good outcome for patients with encephalopathy associated with STEC O111.

We report a case of X-linked alpha-thalassemia/mental retardation syndrome (ATR-X) with repeated apnea attacks dating from the patient's 12th year. We initially diagnosed them as obstructive apnea due to upper pharyngeal stenosis and laryngomalacia by polysomnography and laryngo-fiberscopy. However, reevaluation after one and a half years revealed that the boy had central and mixed apnea, as well as obstructive apnea. To date, few reports have been published on the causes of apnea attacks in ATR-X patients. We clinicians should therefore consider laryngomalacia as one cause of apnea attacks in ATR-X patients, and choose the appropriate therapy for a pattern of apnea that can change during its clinical course.