Since 2010, WHO has recommended oral cholera vaccines as an additional strategy for cholera control. During a cholera episode, pregnant women are at high risk of complications, and the risk of fetal death has been reported to be 2-36%. Due to a lack of safety data, pregnant women have been excluded from most cholera vaccination campaigns. In 2012, reactive campaigns using the bivalent killed whole-cell oral cholera vaccine (BivWC), included all people living in the targeted areas aged ≥ 1 year regardless of pregnancy status, were implemented in Guinea. We aimed to determine whether there was a difference in pregnancy outcomes between vaccinated and non-vaccinated pregnant women.
METHODS AND FINDINGS
From 11 November to 4 December 2013, we conducted a retrospective cohort study in Boffa prefecture among women who were pregnant in 2012 during or after the vaccination campaign. The primary outcome was pregnancy loss, as reported by the mother, and fetal malformations, after clinical examination. Primary exposure was the intake of the BivWC vaccine (Shanchol) during pregnancy, as determined by a vaccination card or oral history. We compared the risk of pregnancy loss between vaccinated and non-vaccinated women through binomial regression analysis. A total of 2,494 pregnancies were included in the analysis. The crude incidence of pregnancy loss was 3.7% (95%CI 2.7-4.8) for fetuses exposed to BivWC vaccine and 2.6% (0.7-4.5) for non-exposed fetuses. The incidence of malformation was 0.6% (0.1-1.0) and 1.2% (0.0-2.5) in BivWC-exposed and non-exposed fetuses, respectively. In both crude and adjusted analyses, fetal exposure to BivWC was not significantly associated with pregnancy loss (adjusted risk ratio (aRR = 1.09 [95%CI: 0.5-2.25], p = 0.818) or malformations (aRR = 0.50 [95%CI: 0.13-1.91], p = 0.314).
CONCLUSIONS
In this large retrospective cohort study, we found no association between fetal exposure to BivWC and risk of pregnancy loss or malformation. Despite the weaknesses of a retrospective design, we can conclude that if a risk exists, it is very low. Additional prospective studies are warranted to add to the evidence base on OCV use during pregnancy. Pregnant women are particularly vulnerable during cholera episodes and should be included in vaccination campaigns when the risk of cholera is high, such as during outbreaks.
Cholera remains a public health threat but is inequitably distributed across sub-Saharan Africa. Lack of standardized reporting and inconsistent outbreak definitions limit our understanding of cholera outbreak epidemiology.
METHODS
From a database of cholera incidence and mortality, we extracted data from sub-Saharan Africa and reconstructed outbreaks of suspected cholera starting in January 2010 to December 2019 based on location-specific average weekly incidence rate thresholds. We then described the distribution of key outbreak metrics.
RESULTS
We identified 999 suspected cholera outbreaks in 744 regions across 25 sub-Saharan African countries. The outbreak periods accounted for 1.8 billion person-months (2% of the total during this period) from January 2010 to January 2020. Among 692 outbreaks reported from second-level administrative units (e.g., districts), the median attack rate was 0.8 per 1000 people (interquartile range (IQR), 0.3-2.4 per 1000), the median epidemic duration was 13 weeks (IQR, 8-19), and the median early outbreak reproductive number was 1.8 (range, 1.1-3.5). Larger attack rates were associated with longer times to outbreak peak, longer epidemic durations, and lower case fatality risks.
CONCLUSIONS
This study provides a baseline from which the progress toward cholera control and essential statistics to inform outbreak management in sub-Saharan Africa can be monitored.
Lassa fever (LF), a haemorrhagic illness caused by the Lassa fever virus (LASV), is endemic in West Africa and causes 5000 fatalities every year. The true prevalence and incidence rates of LF are unknown as infections are often asymptomatic, clinical presentations are varied, and surveillance systems are not robust. The aim of the Enable Lassa research programme is to estimate the incidences of LASV infection and LF disease in five West African countries. The core protocol described here harmonises key study components, such as eligibility criteria, case definitions, outcome measures, and laboratory tests, which will maximise the comparability of data for between-country analyses.
METHOD
We are conducting a prospective cohort study in Benin, Guinea, Liberia, Nigeria (three sites), and Sierra Leone from 2020 to 2023, with 24 months of follow-up. Each site will assess the incidence of LASV infection, LF disease, or both. When both incidences are assessed the LASV cohort (n min = 1000 per site) will be drawn from the LF cohort (n min = 5000 per site). During recruitment participants will complete questionnaires on household composition, socioeconomic status, demographic characteristics, and LF history, and blood samples will be collected to determine IgG LASV serostatus. LF disease cohort participants will be contacted biweekly to identify acute febrile cases, from whom blood samples will be drawn to test for active LASV infection using RT-PCR. Symptom and treatment data will be abstracted from medical records of LF cases. LF survivors will be followed up after four months to assess sequelae, specifically sensorineural hearing loss. LASV infection cohort participants will be asked for a blood sample every six months to assess LASV serostatus (IgG and IgM).
DISCUSSION
Data on LASV infection and LF disease incidence in West Africa from this research programme will determine the feasibility of future Phase IIb or III clinical trials for LF vaccine candidates.
Introduction
Médecins Sans Frontières (MSF) est présent Kouroussa depuis juin 2017 et a fourni des services de soutien aux structures de santé publiques (l'hôpital préfectoral de Kouroussa, les 13 centres de santé de la préfecture et 6 postes de santé), ainsi que des services de santé communautaires pour les enfants de 0 à 5 ans. Au niveau de l'hôpital préfectoral MSF, assure la prise en charge gratuite des cas de paludisme simple et grave, de la malnutrition et autres pathologies. Au niveau des centres de santé et des postes de santé, MSF assure le traitement gratuit des cas simples de paludisme, de la malnutrition, de la diarrhée et d'infections des voies respiratoires, mais aussi assure le transport des cas graves de ces structures vers l'hôpital préfectoral de la préfecture. Au niveau communautaire, MSF assure à travers des agents et relais communautaires, la prise en charge gratuite des cas simples de paludisme, le dépistage de la malnutrition, la prise en charge des cas de diarrhée, le suivi du calendrier de vaccination des enfants et le transfert des cas complexes vers les formations sanitaires. Afin d'améliorer et d'évaluer l'impact de ses activités dans la préfecture, MSF réalise chaque année une enquête rétrospective sur la mortalité avec un volet qui évalue le comportement par rapport à la recherche des soins dans la communauté. MSF mène également des activités de recherche opérationnelle visant à améliorer la santé des habitants de la préfecture.
Méthodologie
Une enquête de mortalité rétrospective (avec une composante sur la recherche des soins) en grappe à 2 degrés, a été réalisée dans les 12 sous-préfectures de Kouroussa du 7 au 14 Juin 2019. 45 grappes ont été enquêtées. La période de rappel s’étendait du 15 Juin 2018 (fête de Ramadan 2018) au jour de l’enquête. La population cible était constituée par l’ensemble des personnes résidant dans la préfecture de Kouroussa. L’évaluation de recherche de soins par rapport à la fièvre/paludisme a été réalisée pour les enfants de 0 à 5 ans.
Résultats
5 510 personnes ont été recensées dans 541 ménages, dont 5 283 étaient présentes et vivantes dans les ménages à la fin de l'enquête. La taille moyenne des ménages était 9,8 personnes et les enfants âgés de moins de 5 ans ont représenté 18,8% (95% IC : 17,3-20,3) de l’ensemble des personnes inclus. Pendant la période de rappel, 66 décès ont été rapportés : le taux brut de mortalité était estimé à 0,35 décès/10 000/jour [95% IC: 0,23-0,46; Deff : 1,20] et le taux de mortalité chez les enfants de moins de 5 ans était estimé à 0,81 décès/10 000/jour [95% IC: 0,40-1,20; Deff : 1,89]. Les
décès du a la fièvre/paludisme ont représenté 24,2% (IC 95%: 14,5-36,4) des décès rapportés. 68,2 % (IC 95%: 55,6-79,1) décès ont été survenus dans les ménages. 21,5% (IC 95%: 19,3-23,8) des
enfants de 0 à 5 ans ont eu de la fièvre au cours de deux semaines précèdent le jour de l’enquête. 85,7%(IC 95%: 80,9 - 89,6) d’enfants fiévreux ont eu à rechercher les soins avec 69,1% (IC 95%: 62,9-74,7) dans une structures de santé (y compris les agents/relais communautaires). « L'enfant n'est pas assez malade », a été identifié comme la principale raison de non recherche de soins chez les enfants de moins de 5 ans. 61,4% [95% IC: 54,8-67,7]) des enfants de 0 à 5 ans ont eu accès à des soins de santé gratuits. 66,5% (95% IC : 60,1-72,6) ont eu accès à un test de dépistage du paludisme avec 87,1% (95% IC : 80,8 – 91,9) de ces tests réalisés dans une structure sanitaire. 95,1% (IC 95%: 90,2-98,0) des enfants dont le test de dépistage du paludisme était positif avaient accès à un traitement antipaludique.
Conclusion
Nos résultats montrent une réduction de taux brut de mortalité et taux de mortalité chez les enfants de moins de 5 ans. Le recours aux soins chez les enfants âgés de 0 à 5 ans était élevé, mais les répondants étaient plus susceptibles de rechercher des soins quand ils percevaient la maladie comme «grave». L'accès aux tests de dépistage du paludisme a grandement influencé les chances de
recevoir un traitement de qualité. La majorité des décès sont survenus au sein des ménages, la fièvre/paludisme étant la principale cause de décès.
To estimate the proportion of invalid results generated by a CD4+ T-lymphocyte analyser used by Médecins Sans Frontières (MSF) in field projects and identify factors associated with invalid results.
METHODS
We collated 25,616 CD4+ T-lymphocyte test results from 39 sites in nine countries for the years 2011 to 2013. Information about the setting, user, training, sampling technique and device repair history were obtained by questionnaire. The analyser performs a series of checks to ensure that all steps of the analysis are completed successfully; if not, an invalid result is reported. We calculated the proportion of invalid results by device and by operator. Regression analyses were used to investigate factors associated with invalid results.
FINDINGS
There were 3354 invalid test results (13.1%) across 39 sites, for 58 Alere PimaTM devices and 180 operators. The median proportion of errors per device and operator was 12.7% (interquartile range, IQR: 10.3-19.9) and 12.1% (IQR: 7.1-19.2), respectively. The proportion of invalid results varied widely by country, setting, user and device. Errors were not associated with settings, user experience or the number of users per device. Tests performed on capillary blood samples were significantly less likely to generate errors compared to venous whole blood.
CONCLUSION
The Alere Pima CD4+ analyser generated a high proportion of invalid test results, across different countries, settings and users. Most error codes could be attributed to the operator, but the exact causes proved difficult to identify. Invalid results need to be factored into the implementation and operational costs of routine CD4+ T-lymphocyte testing.