Modeling Optimal Laboratory Testing Strategies for Bacterial Meningitis Surveillance in Africa.

Since 2010, the introduction of an effective serogroup A meningococcal conjugate vaccine has led to the near-elimination of invasive Neisseria meningitidis serogroup A disease in Africa's meningitis belt. However, a significant burden of disease and epidemics due to other bacterial meningitis pathogens remain in the region. High-quality surveillance data with laboratory confirmation is important to monitor circulating bacterial meningitis pathogens and design appropriate interventions, but complete testing of all reported cases is often infeasible. Here, we use case-based surveillance data from 5 countries in the meningitis belt to determine how accurately estimates of the distribution of causative pathogens would represent the true distribution under different laboratory testing strategies. Detailed case-based surveillance data was collected by the MenAfriNet surveillance consortium in up to 3 seasons from participating districts in 5 countries. For each unique country-season pair, we simulated the accuracy of laboratory surveillance by repeatedly drawing subsets of tested cases and calculating the margin of error of the estimated proportion of cases caused by each pathogen (the greatest pathogen-specific absolute error in proportions between the subset and the full set of cases). Across the 12 country-season pairs analyzed, the 95% credible intervals around estimates of the proportion of cases caused by each pathogen had median widths of ±0.13, ±0.07, and ±0.05, respectively, when random samples of 25%, 50%, and 75% of cases were selected for testing. The level of geographic stratification in the sampling process did not meaningfully affect accuracy estimates. These findings can inform testing thresholds for laboratory surveillance programs in the meningitis belt.

[Study on the clinical and epidemiological characteristics of the first 1030 cases of covid-19 in Mali]. / Etude sur les caracteristiques cliniques et epidemiologiques des 1030 premiers cas de covid-19 au Mali.

AIMS: Since the confirmation of the first cases of COVID-19 in Mali in March 2020 and the outbreakspreading to the whole country, clinical and epidemiological data fromaffected patients are used to characterize the disease. This study was to describe the clinica lsigns and epidemiologicalparameters of COVID-19 in the Malian context. MATERIALS AND METHODS: This is a cross-sectional study. All confirmed cases of COVID-19 in Mali between March 25, 2020 to May 24, 2020 have been included. Clinical and epidemiological data from patients with COVID-19 were extracted from the official line list of cases and the national reference laboratory register. RESULTS: The mean age of the 1,030 patients was 45.6 ± 18.4 years; 67.2% of patients were men. Asymptomatic patients accounted for 31.1%. The most common symptoms on admission were cough (60.8%) followed by fever (47.6%). The largest number of cases was recorded in Bamako. CONCLUSION: SARS-CoV-2 infection of the first 1,030 cases in Mali was marked by the predominance of cough and fever.

BUTS: Depuis la confirmation des premiers cas de COVID-19 au Mali en Mars 2020 et sa propagation à tout le pays, des données cliniques et épidémiologiques des patients atteints sont utilisées pour caractériser la maladie. Cette étude avait pour objectif d'étudier les signes cliniques et épidémiologiques de la COVID-19 dans le contexte malien. MATÉRIELS ET MÉTHODES: Il s'agit d'une étude transversale. Tous les cas confirmés de COVID-19 du Mali entre le 25 Mars 2020 au 24 Mai 2020 ont été inclus. Les données cliniques et épidémiologiques des patients atteints de COVID-19ont été extraites. RÉSULTATS: L'âge moyen descas était de 45,6±18,4 ans ; 67,2% des patients étaient des hommes. Les patients asymptomatiques représentaient 31,1%. Les symptômes les plus courants à l'admission étaient la toux (60,8%) suivi de la fièvre (47,6%). Le plus grand nombre de cas a été enregistré à Bamako. CONCLUSION: L'infection par le SARS-CoV-2 des 1 030 premiers cas au Mali a été marquée par la prédominance de la toux et de la fièvre.

Bacterial Meningitis Epidemiology in Five Countries in the Meningitis Belt of Sub-Saharan Africa, 2015-2017.

BACKGROUND: The MenAfriNet Consortium supports strategic implementation of case-based meningitis surveillance in key high-risk countries of the African meningitis belt: Burkina Faso, Chad, Mali, Niger, and Togo. We describe bacterial meningitis epidemiology in these 5 countries in 2015-2017. METHODS: Case-based meningitis surveillance collects case-level demographic and clinical information and cerebrospinal fluid (CSF) laboratory results. Neisseria meningitidis, Streptococcus pneumoniae, or Haemophilus influenzae cases were confirmed and N. meningitidis/H. influenzae were serogrouped/serotyped by real-time polymerase chain reaction, culture, or latex agglutination. We calculated annual incidence in participating districts in each country in cases/100 000 population. RESULTS: From 2015-2017, 18 262 suspected meningitis cases were reported; 92% had a CSF specimen available, of which 26% were confirmed as N. meningitidis (n = 2433; 56%), S. pneumoniae (n = 1758; 40%), or H. influenzae (n = 180; 4%). Average annual incidences for N. meningitidis, S. pneumoniae, and H. influenzae, respectively, were 7.5, 2.5, and 0.3. N. meningitidis incidence was 1.5 in Burkina Faso, 2.7 in Chad, 0.4 in Mali, 14.7 in Niger, and 12.5 in Togo. Several outbreaks occurred: NmC in Niger in 2015-2017, NmC in Mali in 2016, and NmW in Togo in 2016-2017. Of N. meningitidis cases, 53% were NmC, 30% NmW, and 13% NmX. Five NmA cases were reported (Burkina Faso, 2015). NmX increased from 0.6% of N. meningitidis cases in 2015 to 27% in 2017. CONCLUSIONS: Although bacterial meningitis epidemiology varied widely by country, NmC and NmW caused several outbreaks, NmX increased although was not associated with outbreaks, and overall NmA incidence remained low. An effective low-cost multivalent meningococcal conjugate vaccine could help further control meningococcal meningitis in the region.

MenAfriNet: A Network Supporting Case-Based Meningitis Surveillance and Vaccine Evaluation in the Meningitis Belt of Africa.

Meningococcal meningitis remains a significant public health threat, especially in the African meningitis belt where Neisseria meningitidis serogroup A historically caused large-scale epidemics. With the rollout of a novel meningococcal serogroup A conjugate vaccine (MACV) in the belt, the World Health Organization recommended case-based meningitis surveillance to monitor MACV impact and meningitis epidemiology. In 2014, the MenAfriNet consortium was established to support strategic implementation of case-based meningitis surveillance in 5 key countries: Burkina Faso, Chad, Mali, Niger, and Togo. MenAfriNet aimed to develop a high-quality surveillance network using standardized laboratory and data collection protocols, develop sustainable systems for data management and analysis to monitor MACV impact, and leverage the surveillance platform to perform special studies. We describe the MenAfriNet consortium, its history, strategy, implementation, accomplishments, and challenges.