Epidemiological and virological influenza survey in Dakar, Senegal: 1996-1998.

Abstract

Abstract. An influenza survey was conducted in seven sentinel sites in Dakar, Senegal from June 1996 to December 1998. Throat or nasal swab cultures were randomly collected from 804 patients suffering from influenza-like symptoms. Influenza viruses were isolated at a similar proportion in adults and in children (P ϭ 0.29). Strains of influenza B viruses were isolated from sporadic cases in 1997, whereas type A virus was associated with an isolated peak. Proportions of influenza virus isolation varied from 17.5% to 40.0% between 1996 and 1998 during the peak period (July/September) of acute respiratory infection in Dakar. Rainfall, humidity, and temperatures rose during the same period. Influenza in Dakar seems to be an-all-age groups respiratory infection characterized by high transmission during the hot and rainy season. The antigenic similarity of the A(H3N2) and B viruses to those circulating elsewhere in the world at the same time was confirmed. However, the A(H1N1) strains were found to be more closely related to an Asiatic strain which had not been isolated outside Asia previously. Consequently, the strain close to the A(H1N1)/ Wuhan/371/95 strain isolated in Dakar was included in the composition of the 1998/1999 influenza vaccine. This reinforces the importance of setting up a national influenza control strategy in tropical regions.

Associations between seasonal influenza and meteorological parameters in Costa Rica, Honduras and Nicaragua

“…Some other studies of influenza activity in tropical and subtropical countries have also a observed proportional association with humidity (Dosseh et al, 2000;Tang et al, 2010). In addition, Tamerius et al (2013) report that in regions where specific humidity and temperature remain high, influenza peaks occurred during humid-rainy conditions.…”

A Subregional Analysis of Epidemiologic and Genetic Characteristics of Influenza A(H1N1)pdm09 in Africa: Senegal, Cape Verde, Mauritania, and Guinea, 2009–2010

“…A selection of the influenza-positive specimens was chosen for virus isolation attempts based on the real-time RT-PCR positive (lowest Ct values), timing (taking into account periods of detection for a better coverage), and country of sampling. Samples were inoculated onto monolayers of Madin-Darby canine kidney (MDCK) cells with a maintenance media supplemented with 2 μg/mL trypsin (TPCK; reference 93630; Sigma-Aldrich) as described previously 6 and incubated at 35 C for 3-7 days with daily monitoring of cytopathic effects (CPEs) by microscopy. After this step, tissue-culture fluids were harvested and screened for influenza virus by hemagglutination (HA) titration.…”

Virological surveillance in Africa can contribute to early detection of new genetic and antigenic lineages of influenza viruses

“…In Africa, surveillance schemes have been implemented in a very small number of countries such as Senegal [10], Ivory Coast [11] and Madagascar [12][13][14][15]. In these countries, IV circulation and ILI incidence were demonstrated to vary according to the climate and geographical position of the particular country.…”