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Background An exploratory household transmission study was nested in SPECTRA, the phase 2/3 efficacy study of the adjuvanted recombinant protein-based COVID-19 vaccine SCB-2019. We compared the occurrence of confirmed COVID-19 infections between households and household contacts of infected SPECTRA placebo or SCB-2019 recipients. Methods SPECTRA participants at 8 study sites in the Philippines who developed real-time reverse transcriptase–polymerase chain reaction (rRT-PCR)–confirmed COVID-19 were contacted by a study team blinded to assignment of index cases to vaccine or placebo groups to enroll in this household transmission study. Enrolled households and household contacts were monitored for 3 weeks using rRT-PCR and anti–SARS-CoV-2 N-antigen IgG/IgM testing to detect new COVID-19 infections. Results One hundred fifty-four eligible COVID-19 index cases (51 vaccinees, 103 placebo) were included. The secondary attack rate per household for symptomatic COVID-19 infection was 0.76% (90% CI:.15–3.90%) if the index case was an SCB-2019 vaccinee compared with 5.88% (90% CI: 3.20–10.8%) for placebo index cases, a relative risk reduction (RRR) of 79% (90% CI: −28% to 97%). The RRR of symptomatic COVID-19 per household member was similar: 84% (90% CI: 28–97%). The impact on attack rates in household members if index cases were symptomatic (n = 130; RRR = 80%; 90% CI: 7–96%) or asymptomatic (n = 24; RRR = 100%; 90% CI: −76% to 100%) was measurable but the low numbers undermine the clinical significance. Conclusions In this prospective household contact study vaccination with SCB-2019 reduced SARS-CoV-2 transmission compared with placebo in households and in household members independently of whether or not index cases were symptomatic. [ABSTRACT FROM AUTHOR]

Objective To estimate the global burden of cholera using population-based incidence data and reports. Methods Countries with a recent history of cholera were classified as endemic or non-endemic, depending on whether they had reported cholera cases in at least three of the five most recent years. The percentages of the population in each country that lacked access to improved sanitation were used to compute the populations at risk for cholera, and incidence rates from published studies were applied to groups of countries to estimate the annual number of cholera cases in endemic countries. The estimates of cholera cases in non-endemic countries were based on the average numbers of cases reported from 2000 to 20081 Literature-based estimates of cholera case-fatality rates (CFRs) were used to compute the variance-weighted average cholera CFRs for estimating the number of cholera deaths. Findings About 1.4 billion people are at risk for cholera in endemic countries. An estimated 2.8 million cholera cases occur annually in such countries (uncertainty range: 1.4-4.3) and an estimated 87000 cholera cases occur in non-endemic countries. The incidence is estimated to be greatest in children less than 5 years of age. Every year about 91 000 people (uncertainty range: 28 000 to 142 000) die of cholera in endemic countries and 2500 people die of the disease in non-endemic countries. Conclusion The global burden of cholera, as determined through a systematic review with clearly stated assumptions, is high. The findings of this study provide a contemporary basis for planning public health interventions to control cholera. [TEXT NOT REPRODUCIBLE IN ASCII.] Objectif Estimer le fardeau mondial du cholera en utilisant les rapports et les donnees d'incidence bases sur la population. Methodes Les pays recemment affectes par le cholera ont ete dasses comme pays endemiques ou non endemiques, selon qu'ils avaient signale des cas de cholera au cours d'au moins trois des cinq dernieres annees. Dans chaque pays, les pourcentages de la population n'ayant pas acces a des installations sanitaires ameliorees ont ete utilises pour calculer les populations exposees au cholera, et les taux d'incidence tires d'etudes publiees ont ete appliques a des groupes de pays afin d'evaluer le nombre annuel de cas de cholera dans les pays endemiques. Les estimations de cas de cholera dans les pays non endemiques etaient basees sur le nombre moyen de cas signales de 2000 a 2008. Les estimations du taux de Ietalite (TL) du cholera basees sur la documentation disponible ont ete utilisees pour calculer lesTL du cholera moyens de variante ponderee afin d'evaluer le nombre de deces imputables au cholera. Resultats Environ 1,4 milliard de personnes sont exposees au cholera dans les pays endemiques. Environ 2,8 millions de cas de cholera se produisent chaque annee dans ces pays (marge d'incertitude: 1,4-4,3), et quelque 87 000 cas de cholera sont enregistres dans les pays non endemiques. On estime que l'incidence est superieure chez les enfants de moins de 5 ans. Chaque annee, environ 91 000 personnes (marge d'incertitude: 28 000 a 142 000) meurent du cholera dans les pays endemiques et 2 500 personnes en meurent dans les pays non endemiques. Conclusion Le fardeau mondial du cholera, tel que determine par une revue systematique sur la base d'hypotheses clairement enoncees, est eleve. Les resultats de cette etude fournissent une base actuelle pour la planification des interventions de sante publique afin de lutter contre le cholera. [TEXT NOT REPRODUCIBLE IN ASCII.] Objetivo Calcular la carga global del colera empleando los informes y datos sobre su incidencia en la poblacion. Metodos Los paises con unos antecedentes recientes de colera se clasificaron como endemicos o no endemicos en funcion de si habian comunicado casos de colera en al menos, tres de los ultimos cinco anos, Se emplearon los porcentajes nacionales de poblacion sin acceso a una sanidad moderna con el fin de calcular la poblacion en riesgo de padecer el colera y se aplicaron las tasas de incidencia de los estudios publicados a los grupos de paises para calcular el numero anual de casos de colera en paises endemicos. El calculo aproximado del numero de casos de colera en paises no endemicos se baso en las cifras medias de casos comunicados entre 2000 y 2008. Se utilizaron los calculos aproximados de la tasa de mortalidad por colera (TMC) procedentes de la documentacion disponible para establecer la varianza ponderada de la TMC media para el colera y calcular de este modo el numero de defunciones por esta enfermedad. Resultados Aproximadamente 1,4 mil millones de personas estan en riesgo de padecer el colera en los paises endemicos. Se ha calculado que en dichos paises se registran aproximadamente 2,8 millones de casos de colera al ano (rango de incertidumbre: 1,4-4,3) asi como unos 87 000 casos de colera en los paises no endemicos. Se estima que la incidencia mas elevada se registra en los ninos menores de 5 anos. Cada ano mueren unas 91 000 personas (rango de incertidumbre: 28 000 a 142 000) de colera en los paises endemicos y 2500 personas fallecen por esta enfermedad en los paises no endemicos. Conclusien La carga global del colera es elevada, segun se ha determinado a traves de una revision sistematica con supuestos claramente definidos. Los resultados de este estudio ofrecen una base contemporanea para planificar las intervenciones de la sanidad publica dirigidas a controlar el colera., Introduction Cholera is an important public health problem worldwide. Although most cholera infections are not detected, large cholera outbreaks, such as those seen in Haiti, (1) Viet Nam (2) and [...]

Background: Japanese encephalitis (JE) is a flaviviral disease of public health concern in many parts of Asia. JE often occurs in large epidemics, has a high case-fatality ratio and, among survivors, frequently causes persistent neurological sequelae and mental disabilities. In 1997, the Vietnamese government initiated immunization campaigns targeting all children aged 1–5 years. Three doses of a locally-produced, mouse brain-derived, inactivated JE vaccine (MBV) were given. This study aims at evaluating the effectiveness of Viet Nam’s MBV. Methodology: A matched case-control study was conducted in Northern Viet Nam. Cases were identified through an ongoing hospital-based surveillance. Each case was matched to four healthy controls for age, gender, and neighborhood. The vaccination history was ascertained through JE immunization logbooks maintained at local health centers. Principal Findings: Thirty cases and 120 controls were enrolled. The effectiveness of the JE vaccine was 92.9% [95% CI: 66.6–98.5]. Confounding effects of other risk variables were not observed. Conclusions: Our results strongly suggest that the locally-produced JE-MBV given to 1–5 years old Vietnamese children was efficacious.

SARS-CoV-2 serological testing is useful to determine seroprevalence, epidemiological trends, and the extent of transmission. The collection and transport of serum samples can be logistically challenging, especially in remote underserved areas. Dried blood spots (DBSs) would allow easier sample collection and logistical handling compared with standard serum collection, particularly for extensive and repeated SARS-CoV-2 serosurveys. We evaluated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the IgG ELISA (Wantai, Beijing, China) using DBSs against sera for the quantitative detection of SARS-CoV-2 IgG antibody. The IgG ELISA was used to test paired sera and DBSs obtained from individuals with recent virologically confirmed COVID-19 illness and banked paired sera and DBSs collected before the COVID-19 pandemic. We found that 100/100 (100%) seropositive samples were positive using DBSs, and 193/194 (99%) seronegative samples were negative using DBSs. Compared with sera, the DBS method had a 100% sensitivity, 99% specificity, 99% PPV, and 100% NPV. Use of DBSs for SARS-CoV-2 household or population serosurveys may be considered in situations with limitations in sample collection, shipment, and storage.