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

ABSTRACT

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