Emergence of dengue virus serotype 3 on Mayotte Island, Indian Ocean.

A serosurvey carried out in 2006 in Mayotte, a French overseas collectivity in the Indian Ocean, confirmed previous circulation of dengue virus (DENV) on the island, but since the set up of a laboratory-based surveillance of dengue-like illness in 2007, no case of DENV has been confirmed. In response to an outbreak of DENV-3 on Comoros Islands in March 2010 surveillance of dengue-like illness in Mayotte was enhanced. By September 15, 76 confirmed and 31 probable cases of DENV have been identified in Mayotte. In urban and periurban settings on the island, Aedes albopictus is the predominant Aedes species, but Ae. aegyptii remains the most common species in rural areas. Given the epidemic potential of dengue virus in Mayotte, adequate monitoring including early detection of cases, timely investigation and sustained mosquito control actions remain essential.

[Influenza A (H1N1) 2009 surveillance on Mayotte island: the challenge of setting up a new system facing the pandemic]. / La grippe A (H1N1) 2009 à Mayotte: mise en place d'une surveillance épidémiologique face à la menace de pandémie.

In response to the threat of the pandemic influenza A (H1N1) 2009 virus in Mayotte Island, influenza surveillance needed to be set up in a matter of weeks, to detect the introduction of the pandemic virus and monitor its spread and impact on public health. Surveillance was based on different systems, including a sentinel practitioner network for influenza-like illness, surveillance of the activity at the hospital emergency departments, virological surveillance, surveillance of severe and fatal cases, and data collection on sale of antipyretic and anti-viral drugs. Despite some weaknesses of the surveillance, results showed a good correlation between all systems, describing an epidemic period of approximately 8-9 weeks, with a peak between weeks 37 and 40, followed by a rapid decrease. Besides allowing monitoring and describing the impact of pandemic H1N1 2009 virus in Mayotte, the surveillance system provided an opportunity to create networks and globally strengthened surveillance of infectious diseases in the Island.