ABSTRACT
Problem:Evaluation of influenza surveillance systems is poor, especially in Africa.ApproachIn 2007, the Institut Pasteur de Madagascar and the Malagasy Ministry of Public Health implemented a countrywide system for the prospective syndromic and virological surveillance of influenza-like illnesses. In assessing this system's performance, we identified gaps and ways to promote the best use of resources. We investigated acceptability, data quality, flexibility, representativeness, simplicity, stability, timeliness and usefulness and developed qualitative and/or quantitative indicators for each of these attributes.Local settingUntil 2007, the influenza surveillance system in Madagascar was only operational in Antananarivo and the observations made could not be extrapolated to the entire country.Relevant changes By 2014, the system covered 34 sentinel sites across the country. At 12 sites, nasopharyngeal and/or oropharyngeal samples were collected and tested for influenza virus. Between 2009 and 2014, 177718 fever cases were detected, 25 809 (14.5%) of these fever cases were classified as cases of influenza-like illness. Of the 9192 samples from patients with influenza-like illness that were tested for influenza viruses, 3573 (38.9%) tested positive. Data quality for all evaluated indicators was categorized as above 90% and the system also appeared to be strong in terms of its acceptability, simplicity and stability. However, sample collection needed improvement.Lessons learnt:The influenza surveillance system in Madagascar performed well and provided reliable and timely data for public health interventions. Given its flexibility and overall moderate cost, this system may become a useful platform for syndromic and laboratory-based surveillance in other low-resource settings
Subject(s)
Influenza, Human/epidemiology , Madagascar , Nasopharynx/virology , Program Evaluation , Sentinel SurveillanceABSTRACT
La grippe est une maladie virale saisonniere qui peut etre benigne ou redoutable du fait du taux de morbidite et de mortalite occasionne lors des epidemies. En absence de donnees epidemiologiques et virologiques en Cote d'Ivoire; un reseau de surveillance de la grippe a ete mis en place a Abidjan pour determiner le niveau de circu-lation de virus grippaux et caracteriser les virus isoles. De janvier 2003 a decembre 2004; soit pendant 24 mois; des secretions nasales ont ete collectees dans les formations sanitaires de la ville d'Abidjan. L'identification des virus grippaux au laboratoire a ete realisee par technique ELISA utilisant des anticorpsmonoclonaux anti-A et anti-B (immunocapture) et par isolement sur cellulesMDCK. Une partie des echantillons d'origine et les isolats ont ete envoyes pour confirmation a l'Institut Pasteur de Paris (2003) et au National Institute for Communicable Diseases (NICD) a Johannesburg. Parmi les 211 echantillons analyses; 30 (12;8) se sont reveles positifs : 22 isolats de virus InfluenzaA dont 21 de typeA (H3N2) et une souche de typeA (H1N1); et 8 isolats de virus Influenza B. Ces souches ont ete isolees majoritairement chez des patients de 0-5 ans (34) et 15-59 ans (47). Bien que plus de 60des souches aient ete isolees en juin et en octobre; il est difficile de definir une saisonnalite du fait de la courte duree de l'etude. La poursuite de cette etude permettra une meilleure appreciation de la saisonnalite; des caracteristiques virologiques et cliniques pour envisager une prevention par la vaccination