Seroprevalence of Chikungunya Virus Infection on Grande Comore Island, Union of the Comoros, 2005

Abstract

An outbreak of Chikungunya virus (CHIKV) illness associated with high fever combined with prolonged and severe arthralgias occurred on Grande Comore Island from January through May 2005; 5,202 cases were reported. A seroprevalence study was conducted to define the extent of transmission on the island. We conducted a cross-sectional survey using a multistage sampling technique. A total of 481 households were sampled. In each household, one resident was selected randomly for interview and blood collection. We administered questionnaires and tested 331 sera for CHIKV-specific IgM and IgG antibodies by capture enzyme-linked immunosorbent assay. Infection with CHIKV infection (seropositivity) was defined as presence of IgG and/or IgM antibodies to CHIKV. A total of 331 (69%) of 481 survey participants consented to blood collection. Antibodies to CHIKV were detected in 63% of sera; IgM antibodies were found in 60% of specimens and IgG antibodies were detected in 27% of specimens. Extrapolation of the findings to the entire Grande Comore population suggested that nearly 215,000 people were infected with CHIKV during the outbreak. A total of 79% of the seropositive persons were hospitalized or stayed at home in bed for a mean of 6 days (range = 1-30 days); 52% missed work or school for a mean of 7 days (range = 1-40 days). The findings suggest that CHIKV was broadly transmitted during the outbreak with a high attack rate. Although not fatal during this outbreak, CHIKV infection caused significant morbidity and decreased economic productivity.

Aedes albopictus, vecteur des virus du chikungunya et de la dengue à la Réunion : biologie et contrôle

“…Par la suite, de nouvelles épidémies ont été décri-tes dans ce pays ainsi qu'aux Cambodge, Vietnam, Laos, Myanmar, Philippines, Inde et Indonésie (Jupp & McIntosh, 1988;Johnston & Peters, 1996). Après 20 ans d'absence, le virus est réapparu à Java, en Indonésie, en 2001(Laras et al, 2005 (Sergon et al, 2007). La circulation du CHIKV parmi les îles de la zone SOOI ne semble cependant pas nouvelle puisque la présence du virus avait déjà été notifiée aux Seychelles en 1979 (Calisher et al, 1981).…”

Re-emergence of Chikungunya virus in South-east Asia: virological evidence from Sri Lanka and Singapore

“…In 2005, CHIKV emerged in Comoros (Sergon et al, 2007) followed by Reunion Island, the Seychelles, Mauritius and Mayotte. In Reunion Island alone, more than a third of the total population (267 000 individuals) was debilitated (Schuffenecker et al, 2006).…”

Outbreak of Chikungunya Fever, Dakshina Kannada District, South India, 2008

“…1,11 The high seroprevalence of anti-CHIKV IgM antibodies (62.2%) and attack rate (58.3%) observed in the present study is comparable with the figures documented during earlier outbreaks in Africa, Grande Comore Island, and other parts of India. [12][13][14] However, the seroprevalence studies done in these territories have shown large variations between regions in the prevalence rate. 15 It was 38.2% in La Reunion Island and 63% in Grande Comore Island.…”

“…15 It was 38.2% in La Reunion Island and 63% in Grande Comore Island. 13,15 The current serosurvey was conducted at the end of outbreak, avoiding the risk of underestimating the number of cases that might occur if serosurveys are conducted during epidemic.…”