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Live animal markets are known hotspots of zoonotic disease emergence. To mitigate those risks, we need to understand how networks shaped by trading practices influence disease spread. Yet, those practices are rarely recorded in high-risk settings. Through a large cross-sectional study, we assessed the potential impact of live poultry trading networks' structures on avian influenza transmission dynamics in Bangladesh. Networks promoted mixing between chickens sourced from different farming systems and geographical locations, fostering co-circulation of viral strains of diverse origins in markets. Viral transmission models suggested that the observed rise in viral prevalence from farms to markets was unlikely explained by intra-market transmission alone, but substantially influenced by transmission occurring in upstream network nodes. Disease control interventions should therefore alter the entire network structures. However, as networks differed between chicken types and city supplied, standardised interventions are unlikely to be effective, and should be tailored to local structural characteristics., (© 2021. The Author(s).)

Zika virus (ZIKV) is an arthropod-borne RNA virus (arbovirus), belonging to the Spondweni serogroup. ZIKV was first described in Africa in 1947 and remained sporadic until Micronesia outbreak in 2007, which was followed by outbreaks in the Pacific Islands, Latin America, and the Caribbean. Subsequent to the epidemics, ZIKV revealed its severity as virus was sexually transmissible, and it was associated with serious fetal and neurological complications. ZIKV originated from Africa; however, little is known about the epidemiology of the virus in African populations. Following a recent study in Cameroon that evidenced low ZIKV epidemiology associated with a presumptive (peri-)sylvatic transmission, we performed a seroepidemiological study in Republic of the Congo, neighbor of Cameroon. To accomplish this, 386 serum specimens from volunteer blood donors collected in 2011 from rural and urban areas of Republic of the Congo were tested with ZIKV-specific methodology; primary screening with anti-NS1 ZIKV IgG ELISA followed by confirmation with cytopathic effect (CPE)-based virus neutralization test (VNT). ZIKV seropositivity was determined as low as 1.8%, varying slightly between urban and rural areas (1.7% and 3.6%). These results demonstrate that the majority of the population of Republic of the Congo is immunologically naïve against ZIKV with a presumptive (peri-)sylvatic transmission cycle, which emphasizes the importance of surveillance studies in Africa.

We conducted a cross-sectional study in live bird markets (LBMs) in Dhaka and Chittagong, Bangladesh, to estimate the prevalence of avian influenza A(H5) and A(H9) viruses in different types of poultry and environmental areas by using Bayesian hierarchical logistic regression models. We detected these viruses in nearly all LBMs. Prevalence of A(H5) virus was higher in waterfowl than in chickens, whereas prevalence of A(H9) virus was higher in chickens than in waterfowl and, among chicken types, in industrial broilers than in cross-breeds and indigenous breeds. LBMs with >1 wholesaler were more frequently contaminated by A(H5) virus than retail-only LBMs. Prevalence of A(H9) virus in poultry and level of environmental contamination were also higher in LBMs with >1 wholesaler. We found a high level of circulation of both avian influenza viruses in surveyed LBMs. Prevalence was influenced by type of poultry, environmental site, and trading.

Background: Since its first report in 2007, avian influenza (AI) has been endemic in Bangladesh. While live poultry marketing is widespread throughout the country and known to influence AI dissemination and persistence, trading patterns have not been described. The aim of this study is to assess poultry trading practices and features of the poultry trading networks which could promote AI spread, and their potential implications for disease control and surveillance. Data on poultry trading practices was collected from 849 poultry traders during a cross-sectional survey in 138 live bird markets (LBMs) across 17 different districts of Bangladesh. The quantity and origins of traded poultry were assessed for each poultry type in surveyed LBMs. The network of contacts between farms and LBMs resulting from commercial movements of live poultry was constructed to assess its connectivity and to identify the key premises influencing it., Results: Poultry trading practices varied according to the size of the LBMs and to the type of poultry traded. Industrial broiler chickens, the most commonly traded poultry, were generally sold in LBMs close to their production areas, whereas ducks and backyard chickens were moved over longer distances, and their transport involved several intermediates. The poultry trading network composed of 445 nodes (73.2% were LBMs) was highly connected and disassortative. However, the removal of only 5.6% of the nodes (25 LBMs with the highest betweenness scores), reduced the network's connectedness, and the maximum size of output and input domains by more than 50%., Conclusions: Poultry types need to be discriminated in order to understand the way in which poultry trading networks are shaped, and the level of risk of disease spread that these networks may promote. Knowledge of the network structure could be used to target control and surveillance interventions to a small number of LBMs.

Background/objectives: Void frequency (VF) is significantly correlated to hydration status, but it is unknown whether VF is reliable when an individual is repeatedly euhydrated (EU) or hypohydrated (HY). The purpose of this study was to test the reliability of VF when individuals were EU or HY on multiple occasions., Subjects/methods: Fourteen males (age 22±2 years, mass 79.1±12.8 kg) completed three EU trials achieved with 24-h ad libitum fluid intake, and 14 males (age 22±2 years, mass 78.6±10.4 kg) completed three HY trials achieved with 24-h fluid restriction. Twenty-four hour urine was collected and analyzed for specific gravity (USG) and VF. Subjects voided at a 'normal urgency' (rated a '2' on a 0-4 perceptual scale) throughout each 24-h period., Results: Twenty-four hour USG was greater and VF was lower when HY (1.026±0.003 and 5±2, respectively) versus EU (1.014±0.003 and 7±2; both P<0.05). Intra-class correlations for VF between the three trials at each hydration status were deemed acceptable (0.863 and 0.849 for EU and HY, respectively). Within-subject coefficients of variation for VF were 15±9 and 21±14% for the EU and HY trials., Conclusions: VF is a reliable index of 24-h hydration status when healthy young males are EU or HY and voiding at a consistent 'urgency'.

In non-smokers, passive heat stress increases shear stress and vasodilation, decreasing arterial stiffness. Smokers, who reportedly have arterial dysfunction, may have similar improvements in arterial stiffness with passive heat stress. Therefore, we examined the effects of an acute bout of whole-body passive heat stress on arterial stiffness in smokers vs. non-smokers. Thirteen smokers (8.8 ± 5.5 [median = 6] cigarettes per day for > 4 years) and 13 non-smokers matched for age, mass, height, and exercise habits (27 ± 8 years; 78.8 ± 15.4 kg; 177.6 ± 6.7 cm) were passively heated to 1.5 °C core temperature (T C) increase. At baseline and each 0.5 °C T C increase, peripheral (pPWV) and central pulse wave velocity (cPWV) were measured via Doppler ultrasound. No differences existed between smokers and non-smokers for any variables (all p >  .05), except cPWV slightly increased from baseline (526.7 ± 81.7 cm · s(-1)) to 1.5 °C ΔT C (579.7 ± 69.8 cm · s(-1); p < 0.005), suggesting heat stress acutely increased central arterial stiffness. pPWV did not change with heating (grand mean: baseline = 691.9 ± 92.9 cm · s(-1); 1.5 °C ΔT C = 691.9 ± 79.5 cm · s(-1); p > 0.05). Changes in cPWV and pPWV during heating correlated (p < 0.05) with baseline PWV in smokers (cPWV: r = -0.59; pPWV: r = -0.62) and non-smokers (cPWV: r = -0.45; pPWV: r = -0.77). Independent of smoking status, baseline stiffness appears to mediate the magnitude of heating-induced changes in arterial stiffness.

Within the aging population, there exists a subset of individuals termed masters athletes (MA). As masters-level competition increases in popularity, MA must find methods to enhance individual athletic performance. Longitudinal beta-alanine (BA) supplementation is suggested to enhance physical capability during exercise; however, these effects have not been evaluated in MA. To examine the longitudinal effects of BA on time to exhaustion (TTE), total work completed (TWC), and lactate clearance in female MA cyclists. Twenty-two female MA (age = 53.3 ± 1.0) participated in this double-blind design. Subjects were randomly assigned to BA (n = 11; 800 mg BA + 8 g dextrose) or placebo (PLA; n = 11; 8 g dextrose) groups and supplemented 4 doses/day over 28 days. Every 7 days, subjects completed a cycling TTE at 120% VO2max, and TWC was calculated. Blood lactate was measured at baseline, immediate post, and 20-min post each TTE. No significant differences existed between groups for any variable at baseline (p > 0.05). After 28 days supplementation, BA had greater TTE (23 vs 1% change) and TWC (21 vs 2% change) than PLA (p < 0.05). Following the 20-min TTE recovery, lactate was 24% lower in BA compared to PLA (4.35 vs. 5.76 mmol/L, respectively). No differences existed for variables during intermittent weeks. 28 days of BA supplementation increased cycling performance via an enhanced time to exhaustion and total work completed with associated lactate clearance during passive rest in female MA.

Background: Ebola and Marburg viruses (family Filoviridae, genera Ebolavirus and Marburgvirus) cause haemorrhagic fevers in humans, often associated with high mortality rates. The presence of antibodies to Ebola virus (EBOV) and Marburg virus (MARV) has been reported in some African countries in individuals without a history of haemorrhagic fever. In this study, we present a MARV and EBOV seroprevalence study conducted amongst blood donors in the Republic of Congo and the analysis of risk factors for contact with EBOV., Methodology and Findings: In 2011, we conducted a MARV and EBOV seroprevalence study amongst 809 blood donors recruited in rural (75; 9.3%) and urban (734; 90.7%) areas of the Republic of Congo. Serum titres of IgG antibodies to MARV and EBOV were assessed by indirect double-immunofluorescence microscopy. MARV seroprevalence was 0.5% (4 in 809) without any identified risk factors. Prevalence of IgG to EBOV was 2.5%, peaking at 4% in rural areas and in Pointe Noire. Independent risk factors identified by multivariate analysis were contact with bats and exposure to birds., Conclusions/significance: This MARV and EBOV serological survey performed in the Republic of Congo identifies a probable role for environmental determinants of exposure to EBOV. It highlights the requirement for extending our understanding of the ecological and epidemiological risk of bats (previously identified as a potential ecological reservoir) and birds as vectors of EBOV to humans, and characterising the protection potentially afforded by EBOV-specific antibodies as detected in blood donors.

Background/objectives: Few user-friendly hydration assessment techniques exist for the general population to use on a daily basis. The present study evaluated void number over 24 h as a potential hydration assessment tool., Subjects/methods: Male and female subjects collected urine for 24 h while adequately hydrated (n=44; 22 ± 4 years, 168 ± 16 cm, 73 ± 15 kg) or fluid restricted (n=43; 22 ± 3 years, 175 ± 10 cm, 81 ± 24 kg). As a control, participants were asked to void when feeling the 'first urge to void' on a commonly used urge scale and noted the volume of each void. For each sample, 24-h urine volume, osmolality (U(OSM)), specific gravity (U(SG)) and color were measured in the laboratory., Results: As designed, the level of urge upon voiding was consistent throughout the study (2 ± 0; 'first urge to void'). Samples were classified by U(SG) as either euhydrated (U(SG)<1.020) or hypohydrated (U(SG) ⩾ 1.020). Grouping by U(OSM) did not change results. Euhydrated versus hypohydrated individuals had greater 24-h urine volume (1933 ± 864 versus 967 ± 306 ml, respectively) and lower urine color (2 ± 1 versus 5 ± 1), U(SG) (1.012 ± 0.004 versus 1.025 ± 0.004) and UOSM (457 ± 180 versus 874 ± 175 mOsm/kg H2O; all P<0.001). Euhydrated individuals voided more than hypohydrated individuals over the 24-h period (5 ± 2 versus 3 ± 1 voids; P<0.001). Additionally, void number inversely correlated with hydration status as identified by U(SG) (r=-0.50; P<0.05) and U(OSM) (r=-0.56; P<0.05)., Conclusions: In conclusion, over 24 h, individuals with a higher void number were euhydrated (that is, had less concentrated hydration biomarkers) than those with a lower void number. Based on these data, void number might be utilized as a simple and feasible hydration assessment for the general public, as it utilizes no equipment or technical expertise.

Background: Chikungunya is an Aedes -borne disease characterised by febrile arthralgia and responsible for massive outbreaks. We present a prospective clinical cohort study and a retrospective serological study relating to a CHIK outbreak, in the Republic of Congo in 2011., Methodology and Findings: We analysed 317 suspected cases, of which 308 (97.2%) lived in the city of Brazzaville (66.6% in the South area). Amongst them, 37 (11.7%) were CHIKV+ve patients (i.e., biologically confirmed by a real-time RT-PCR assay), of whom 36 (97.3%) had fever, 22 (66.7%) myalgia and 32 (86.5%) arthralgia. All tested negative for dengue. The distribution of incident cases within Brazzaville districts was compared with CHIKV seroprevalence before the outbreak (34.4% in 517 blood donors), providing evidence for previous circulation of CHIKV. We applied a CHIK clinical score to 126 patients recruited within the two first day of illness (including 28 CHIKV+ves (22.2%)) with sensitivity (78.6%) and specificity (72.4%) values comparing with those of the referent study in Reunion Island. The negative predictive value was high (92%), but the positive predictive value (45%) indicate poor potential contribution to medical practice to identify CHIKV+ve patients in low prevalence outbreaks. However, the score allowed a slightly more accurate follow-up of the evolution of the outbreak than the criterion "fever+arthralgia". The complete sequencing of a Congolase isolate (Brazza&#95;MRS1) demonstrated belonging to the East/Central/South African lineage and was further used for producing a robust genome-scale CHIKV phylogenetic analysis., Conclusions/significance: We describe the first Chikungunya outbreak declared in the Republic of Congo. The seroprevalence study conducted amongst blood donors before outbreak provided evidence for previous CHIKV circulation. We suggest that a more systematic survey of the entomological situation and of arbovirus circulation is necessary in Central Africa for better understanding the environmental, microbiological and sociological determinants of emergence.

Chikungunya virus (CHIKV) is the aetiological agent of the mosquito-borne disease chikungunya fever, a debilitating arthritic disease that, during the past 7years, has caused immeasurable morbidity and some mortality in humans, including newborn babies, following its emergence and dispersal out of Africa to the Indian Ocean islands and Asia. Since the first reports of its existence in Africa in the 1950s, more than 1500 scientific publications on the different aspects of the disease and its causative agent have been produced. Analysis of these publications shows that, following a number of studies in the 1960s and 1970s, and in the absence of autochthonous cases in developed countries, the interest of the scientific community remained low. However, in 2005 chikungunya fever unexpectedly re-emerged in the form of devastating epidemics in and around the Indian Ocean. These outbreaks were associated with mutations in the viral genome that facilitated the replication of the virus in Aedes albopictus mosquitoes. Since then, nearly 1000 publications on chikungunya fever have been referenced in the PubMed database. This article provides a comprehensive review of chikungunya fever and CHIKV, including clinical data, epidemiological reports, therapeutic aspects and data relating to animal models for in vivo laboratory studies. It includes Supplementary Tables of all WHO outbreak bulletins, ProMED Mail alerts, viral sequences available on GenBank, and PubMed reports of clinical cases and seroprevalence studies., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The CoPanFlu-France cohort of households was set up in 2009 to study the risk factors for infection by the pandemic influenza virus (H1N1pdm) in the French general population. The authors developed an integrative data-driven approach to identify individual, collective and environmental factors associated with the post-seasonal serological H1N1pdm geometric mean titer, and derived a nested case-control analysis to identify risk factors for infection during the first season. This analysis included 1377 subjects (601 households). The GMT for the general population was 47.1 (95% confidence interval (CI): 45.1, 49.2). According to a multivariable analysis, pandemic vaccination, seasonal vaccination in 2009, recent history of influenza-like illness, asthma, chronic obstructive pulmonary disease, social contacts at school and use of public transports by the local population were associated with a higher GMT, whereas history of smoking was associated with a lower GMT. Additionally, young age at inclusion and risk perception of exposure to the virus at work were identified as possible risk factors, whereas presence of an air humidifier in the living room was a possible protective factor. These findings will be interpreted in light of the longitudinal analyses of this ongoing cohort.