The southern island of Mayotte is administered by France and exhibits significantly higher development indices. The islands of the Union of Comoros are small and sparsely populated. of Comoros that ranks amongst the least developed countries in the world. The southern island of Mayotte is usually administered by France and exhibits significantly higher development indices. The islands of the Union of Comoros are small and sparsely populated. The largest island (1146Km2) sheltering the capital is named Ngazidja (Grande Comore in French) and has 380 000 inhabitants. The second larger island, Ndzouani (Anjouan) (424 Km2) has 300 000 inhabitants, while Mwali (Moheli) is the smallest island (290Km2) and is home to less than 45 000 inhabitants. The geographic proximity to Africa exposes the Comoros archipelago to arboviral emergence as evidenced by a number of epidemics recorded in the last decades. Hence, dengue, chikungunya and Rift Valley fever outbreaks flared up on the Comoros islands in first BFH772 place before spreading to other islands of the SWIO. Most interestingly, there is evidence that these epidemics have had contrasted courses and severity around the 3 islands of the Union of the Comoros, despite their cultural homogeneity and the frequent inter island mobility of people and livestock. The different exposure of the three islands to the arboviral risk is usually most evidenced by the last epidemics of dengue and chikungunya. In 1993, a large epidemic due to Dengue computer virus serotype 1 (DENV1) affected Ngazidja, with a prevalence of 26% of IgM antibodies to Dengue computer virus (DENV) [4]. In contrast, the outbreak was much less severe around the sister islands of Ndzouani and Mwali where a ten occasions lower IgM positivity rate was detected [4], and no dengue epidemic was reported at the same time on Mayotte. In March 2010, a Dengue computer virus serotype 3 (DENV3) epidemic was reported on Ngazidja where 1805 suspected cases were registered while the number of suspected cases was only 18 and 4 on Mwali and Ndzouani respectively, as informally reported by the Comorian Health Authorities (www.reseausega-coi.org/system/files/06-Mlindasse-DENV3_0.pdf15). Only 76 cases of dengue were confirmed on Mayotte despite an efficient surveillance system [5]. In 2004, a CHIK outbreak flared up in Lamu, Kenya [6] then spread to Ngazidja where 5202 cases were reported from January to May 2005. A sero-survey conducted around BFH772 the island during the epidemic showed an attack rate of 63% with 60% IgM and 27% IgG positive samples [7] According to the Comorian Health Authorities [8], the outbreak appeared much less severe around the other Comorian islands with 207 cases reported on Ndzouani and only 1 1 on Mwali. On Mayotte, the epidemic curve delineated two waves [9]: the first wave (April-June 2005) was concomitant to the epidemic on Ngazidja but of minor intensity as assessed by the very low prevalence (1.6%) detected on October 2005; the second wave was however explosive: it started on early 2006 and peaked on March-April with a dramatic rise of CHIK computer virus (CHIKV) seroconversion rate. This second wave then expanded into a huge epidemic that involved all the SWIO islands, spp., CHIKV, and DENV, revealed 4.5% positive cases, suggestive BFH772 of BFH772 recent RVFV infection, sampled throughout other islands of the South West Indian Ocean and these haplotypes may be associated with distinct morphological and ecological traits [39]. Such BFH772 information, as well as studies around the vector competence of these distinct lineages towards CHIKV and DENV are not available on the Union of the Comoros and should help understanding the human serological figures highlighted here. Today’s study demonstrates Mwali is more subjected to WNV infection compared to the two sister islands clearly. It really is unlikely that peculiarity depends on different contact with the bites of spp significantly., the most common vectors of WNV. It suggests rather, if one IkappaBalpha considers the main role performed by parrots in the transmitting of this disease, some specificities of Mwali in regards to to.