Evaluation of the influenza sentinel surveillance system in Madagascar, 2009­2014

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

Comparing influenza positivity rates by real-time rt-pcr, elisa and viral culture methods in Cote d'Ivoire, West Africa, in 2009

Detection of circulating influenza strains is a key public health concern especially in limited-resource settings where diagnosis capabilities remain a challenge. As part of multi-site surveillance in Cote d'Ivoire during the 2009 influenza A(H1N1) pandemic; we had the opportunity to test respiratory specimens collected from patients with acute respiratory illness (ARI). We analyzed and compared the percentage of specimens testing positive using three laboratory methods (rtRT-PCR; ELISA; viral culture). From January to October 2009; 1;356 respiratory specimens were collected from patients with acute respiratory illness and shipped at the WHO NIC (Institut Pasteur) Cote d'Ivoire; and 453 (33) tested positive for influenza by one or more laboratory methods. The proportion of positive influenza tests did not differ by the sex or age of the patient or presenting symptoms; but did differ depending on the timing and site of specimen collection. Of the 453 positive specimens; 424 (93.6) were detected by PCR; 199 (43.9) by ELISA and 40 (8.8) by viral culture. While seasonal influenza A(H1N1) virus strains were prominent; only four 2009 pandemic influenza A(H1N1) cases were detected. Use of molecular biology method (rtRT-PCR) increased sensitivity and diagnosis capabilities. Among all three methods used; rRT-PCR was the most sensitive and rapid method. More capacity building is still required for viral culture. Need to collect denominator data in order to have an accurate estimate of the burden of influenza. There was delayed introduction of pandemic influenza A(H1N1)2009 in Cote d'Ivoire

Investigation of an outbreak of acute respiratory disease in Côte d'Ivoire in april 2007

Background: This study aim was to investigate an outbreak of human cases of unexplained influenza-like illness and fatal acute respiratory infection (ARI); with simultaneous poultry illness and high mortality raising concerns of possible influenza A (H5N1); virus in Cote d'Ivoire in February and March 2007. Materials and Methods: To investigate the outbreak; we conducted active surveillance in the community and reviewed health registries. Persons meeting the case definition were asked to provide nasopharyngeal specimens. On the basis of clinical and epidemiological information; specimens were tested using conventional RT-PCR for the M gene of the influenza viruses and hemagglutinin H5 of avian influenza A (H5N1); virus; negative samples were tested for other respiratory viruses. Specimens from healthy animals were also collected. Results: Between October 2006; and February 2007; 104 suspected cases of Acute Respiratory Disease that included; 31 deaths recorded. We collected and tested 73 nasopharyngeal specimens; of which; 2; were positive for human Coronavirus OC43 and 1 for influenza C virus. No pathogens were identified in animal specimens. Conclusions: The investigation quickly ruled out influenza A (H5N1); virus as the cause and found laboratory-confirmed cases of influenza C virus and human Coronavirus OC 43 for the first time in both Cote d'Ivoire and in a Sub-Saharan African country. However we were not able to show that these viruses caused the outbreak. Monitoring of influenza viruses must be a priority but other respiratory viruses and non-viral causes may be of interest too

Chlamydophila pneumoniae; Mycoplasma pneumoniae; and Influenza in Children with Respiratory Infections in Alexandria; Egypt

Introduction: Acute respiratory infections (ARI) are the leading cause of pediatric morbidity and mortality worldwide. Information about etiological agents of ARI in developing countries is still limited. Methodology: Throat swabs collected from children hospitalized with ARI between December 2009 and May 2010 were investigated for Chlamydophila pneumoniae; Mycoplasma pneumoniae; and influenza viruses by molecular analyses. Results: This study conducted in Alexandria; Egypt; was designed to determine the prevalence of several microorganisms in 156 children hospitalized with ARI. Overall; samples from 76 individuals (49) were found to be positive for at least one pathogen; and 10 of them were positive for two agents. C. pneumoniae was the most commonly detected agent; followed by M. pneumonia and H1N1 pandemic influenza virus. Positivity for C. pneumoniae was associated with colder months and mild disease of the upper respiratory tract such as laryngitis. Conclusions: Further studies are needed to identify other possible agents of ARI (e.g.; RSV; adenoviruses; other bacterial infections) in this population and to better understand the causal role of atypical bacteria detected in respiratory samples

Avian and human influenza pandemic; how prepared is the developing world?

The history of avian and human influenza pandemics showed a high case fatality and devastating socioeconomic impact on the developing world. The global epidemiology of the human influenza of 1918; 1957 and 1968 pandemics had few similarities. One of which was mass human migration; whether it being troop deployment or trade routes. How much the perennial flight patterns of wild bird had on its spread is another question for consideration? The avian influenza virus does not readily cross the species barrier; though there is a potential for genetic re-assortment and cross infection. The main finding of this review suggest a lack of historic epidemiological data from the developing world on previous influenza pandemics; a poorly developed surveillance system and lack of health service delivery capacity to effectively combat an outbreak of influenza; should it occur. The developing world already heavily burdened with endemic diseases such as malaria; HIV; Tuberculosis and other respiratory tract infections will find it difficult to cope with an influenza pandemic. A preparedness plan for developing countries should include health systems strengthening especially that providing expertise and improved surveillance tools

Bilan de deux années de surveillance de la grippe à Abidjan

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

Epidemies d'infections respiratoires aigues a Madagascar en 2002 : de l'alerte a la confirmation

Epidemics of acute respiratory infections in Madagascar in 2002 : from alert to confirmation : An epidemiological investigation (Ministry of Health/Institut Pasteur de dagascar (IPM)) was conducted in July 2002; in two districts of a same province (Fianarantsoa : Fianarantsoa II and Ikongo) considering the high frequency of deaths linked with acute respiratory infection (ARI). Morbidity and mortality data was collected in the Centre de Sante de Base (CSB) which gave the alert (village of Sahafata; district Fianarantsoa II). Analysis of monthly activity reports (MAR) allowed calculation of incidence rates of ARI/pneumonia in Fianarantsoa province. Virological data was based on the analysis of nasopharyngal samples collected during the investigations. Clinical symptoms and homogeneity of laboratory results are consistent with an origin of these epidemics being related to the circulation of an influenza virus A subtype H3N2. Attack rates were very high. CFR was significantly higher in individuals of less than 1 year and more than 65 years. This data was confirmed by posterior investigations of teams from MoH/WHO. Surprisingly; this large epidemic was due to a known influenza virus that previously circulated in countries of northern hemisphere (the year before) and even in Antananarivo weeks before. Different hypothesis could be proposed to explain such phenomenon : great restriction of exchanges between different geographical zones; nutritional status

Historique de la grippe a Madagascar

"The history of flu in Madagascar"" : The purpose of this paper is to actualize the historical data on influenza in Madagascar. The first outbreak of flu probably occured in 1890. The first epidemic fully described was in 1893. Between 1890 and 1957; 11 outbreaks of influenza were registered. Since 1978; the unit of virology of the Institut Pasteur de Madagascar is the National Reference Center of the World Health Organization for influenza in Madagascar. Between 1975 and 2002; 12 epidemics of flu were registered confirmed by viral isolation. Madagascan terms used to design fever diseases are discussed."

Surveillance epidemiologique et virologique de la grippe a Antananarivo de 1995 a 2002

"Influenza epidemiologic and virologic surveillance in Antananarivo from 1995 to 2002"" : The ""Institut Pasteur de Madagascar"" virology laboratory is the National WHOCentre for Influenza surveillance in Madagascar. On this surveillance collaborate the Ministry of Health with 9 sentinel centres. In the present article; the authors relate the results of influenza surveillance in Antananarivo between 1995 and 2002. Among 6341 patients with nasal and/or pharyngeal swabs; influenza virus were isolated from 427 patients (6.7"