The epidemiology of seasonal influenza after the 2009 influenza pandemic in Africa: a systematic review

Background: Influenza infection is a serious public health problem that causes an estimated 3 to 5 million cases and 250,000 deaths worldwide every year. The epidemiology of influenza is well-documented in high- and middle-income countries, however minimal effort had been made to understand the epidemiology, burden and seasonality of influenza in Africa. This study aims to assess the state of knowledge of seasonal influenza epidemiology in Africa and identify potential data gaps for policy formulation following the 2009 pandemic. Method: We reviewed articles from Africa published into four databases namely: MEDLINE (PubMed), Google Scholar, Cochrane Library and Scientific Research Publishing from 2010 to 2019. Results: We screened titles and abstracts of 2070 studies of which 311 were selected for full content evaluation and 199 studies were considered. Selected articles varied substantially on the basis of the topics they addressed covering the field of influenza surveillance (n=80); influenza risk factors and co-morbidities (n=15); influenza burden (n=37); influenza vaccination (n=40); influenza and other respiratory pathogens (n=22) and influenza diagnosis (n=5). Conclusion: Significant progress has been made since the last pandemic in understanding the influenza epidemiology in Africa. However, efforts still remain for most countries to have sufficient data to allow countries to prioritize strategies for influenza prevention and control

Leveraging the Global Influenza Surveillance and Response System for global respiratory syncytial virus surveillance-opportunities and challenges

BACKGROUND: Respiratory syncytial virus (RSV)-associated acute lower respiratory infection is a common cause for hospitalization and hospital deaths in young children globally. There is urgent need to generate evidence to inform immunization policies when RSV vaccines become available. The WHO piloted a RSV surveillance strategy that leverages the existing capacities of the Global Influenza Surveillance and Response System (GISRS) to better understand RSV seasonality, high-risk groups, validate case definitions, and develop laboratory and surveillance standards for RSV. METHODS: The RSV sentinel surveillance strategy was piloted in 14 countries. Patients across all age groups presenting to sentinel hospitals and clinics were screened all year-round using extended severe acute respiratory infection (SARI) and acute respiratory infection (ARI) case definitions for hospital and primary care settings, respectively. Respiratory specimens were tested for RSV at the National Influenza Centre (NIC) using standardized molecular diagnostics that had been validated by an External Quality Assurance program. The WHO FluMart data platform was adapted to receive case-based RSV data and visualize interactive visualization outputs. RESULTS: Laboratory standards for detecting RSV by RT-PCR were developed. A review assessed the feasibility and the low incremental costs for RSV surveillance. Several challenges were addressed related to case definitions, sampling strategies, the need to focus surveillance on young children, and the data required for burden estimation. CONCLUSIONS: There was no evidence of any significant adverse impact on the functioning of GISRS which is primarily intended for virologic and epidemiological surveillance of influenza

Leveraging the Global Influenza Surveillance and Response System for global respiratory syncytial virus surveillance—opportunities and challenges

BackgroundRespiratory syncytial virus (RSV)‐associated acute lower respiratory infection is a common cause for hospitalization and hospital deaths in young children globally. There is urgent need to generate evidence to inform immunization policies when RSV vaccines become available. The WHO piloted a RSV surveillance strategy that leverages the existing capacities of the Global Influenza Surveillance and Response System (GISRS) to better understand RSV seasonality, high‐risk groups, validate case definitions, and develop laboratory and surveillance standards for RSV.MethodsThe RSV sentinel surveillance strategy was piloted in 14 countries. Patients across all age groups presenting to sentinel hospitals and clinics were screened all year‐round using extended severe acute respiratory infection (SARI) and acute respiratory infection (ARI) case definitions for hospital and primary care settings, respectively. Respiratory specimens were tested for RSV at the National Influenza Centre (NIC) using standardized molecular diagnostics that had been validated by an External Quality Assurance program. The WHO FluMart data platform was adapted to receive case‐based RSV data and visualize interactive visualization outputs.ResultsLaboratory standards for detecting RSV by RT‐PCR were developed. A review assessed the feasibility and the low incremental costs for RSV surveillance. Several challenges were addressed related to case definitions, sampling strategies, the need to focus surveillance on young children, and the data required for burden estimation.ConclusionsThere was no evidence of any significant adverse impact on the functioning of GISRS which is primarily intended for virologic and epidemiological surveillance of influenza.</p

Epidémiologie des infections respiratoires à Madagascar

En Afrique, la pathologie fébrile dominée par le paludisme avait laissé jusqu à présent peu de place à l étude des infections respiratoires aigües et à la circulation des virus grippaux. Mon travail de thèse a donc été consacré à ce champ de la santé laissé pour compte. Bénéficiant de la qualité d un système de surveillance sentinelle, j ai pu étudier la diffusion du virus A(H1N1) pandémique à travers le pays et m interroger aussi sur son impact en termes de mortalité sur la population malgache. Mais pour mieux documenter les infections respiratoires, je me suis aussi intéressé à développer une étude prospective en milieu hospitalier. Les résultats des deux premières années font l objet ce travail de thèse alors que l étude se poursuit. Mais déjà j ai pu documenter la fréquence plus importante d agents étiologiques pour lesquelles une vaccination est disponible et également la part des infections virales sur une plus forte activité d hospitalisation pour des infections respiratoires.The African continent is thought be burdened with a very heavy load of malaria. So, not surprisingly, acute respiratory infections and circulation of influenza viruses had received relatively little attention. My PhD work has been devoted to this specific field of the infectious diseases. With the support of the sentinel surveillance system, I was able to study the spread of influenza A (H1N1) pandemic through the country and also ask about its impact on the Malagasy mortality. But to better describe respiratory infections, I have carried out a prospective study in some hospital wards. The results of the first two years of the study are presented in this work although the study is not currently finished. However I have already been able to show the higher frequency of etiologic agents for which a vaccine is available and also the viral infection load in relation with a higher activity hospitalization for respiratory infections.VERSAILLES-BU Sciences et IUT (786462101) / SudocSudocFranceF

Data from: Has Madagascar lost its exceptional leptospirosis free-like status?

Background: Leptospirosis is a widespread but underreported cause of morbidity and mortality. It has rarely been reported in either humans or animals in Madagascar. Methods: We conducted a cross-sectional survey of the inhabitants in Moramanga, Madagascar, in June 2011, to estimate the prevalence of human infection using the microscopic agglutination test (MAT). This activity was carried out as part of a workshop implemented by the Pasteur Institute of Madagascar, focusing on surveillance with a one week field study and targeting the health staff of the district level. Results: In total, we sampled 678 inhabitants from 263 households. The sex ratio (M/F) was 0.65 and the mean age 26.7 years. We obtained a value of 2.9% for the first recorded seroprevalence of this disease in the human community of Moramanga. Questionnaire responses revealed frequent contacts between humans and rodents in Moramanga. However, activities involving cattle were identified as a risk factor significantly associated with seropositivity (OR=3). Conclusion: Leptospirosis remains a neglected disease in Madagascar. This study highlights the need to quantify the public health impact of this neglected disease in a more large scale, in all the country and to establish point-of-care laboratories in remote areas

Has Madagascar Lost Its Exceptional Leptospirosis Free-Like Status?

International audienceBackgroundLeptospirosis is a widespread but underreported cause of morbidity and mortality. It has rarely been reported in either humans or animals in Madagascar.MethodsWe conducted a cross-sectional survey of the inhabitants in Moramanga, Madagascar, in June 2011, to estimate the prevalence of human infection using the microscopic agglutination test (MAT). This activity was carried out as part of a workshop implemented by the Pasteur Institute of Madagascar, focusing on surveillance with a one week field study and targeting the health staff of the district level.ResultsIn total, we sampled 678 inhabitants from 263 households. The sex ratio (M/F) was 0.65 and the mean age 26.7 years. We obtained a value of 2.9% for the first recorded seroprevalence of this disease in the human community of Moramanga. Questionnaire responses revealed frequent contacts between humans and rodents in Moramanga. However, activities involving cattle were identified as a risk factor significantly associated with seropositivity (OR=3).ConclusionLeptospirosis remains a neglected disease in Madagascar. This study highlights the need to quantify the public health impact of this neglected disease in a more large scale, in all the country and to establish point-of-care laboratories in remote areas

Characteristics of the study population in Moramanga, 2011, and risk factors for leptospirosis.

<p>Characteristics of the study population in Moramanga, 2011, and risk factors for leptospirosis.</p

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<i>Leptospira</i> strains used in this study.

<p><i>Leptospira</i> strains used in this study.</p