title: 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.
authors.affiliation: Epidemiology and Laboratory Training Program, Nairobi, Kenya; Ministry of Health, Moroni, Comoros.
authors.forename: Kibet
authors.initials: K
authors.lastname: Sergon
authors.forename: Ali Ahmed
authors.initials: AA
authors.lastname: Yahaya
authors.forename: Jennifer
authors.initials: J
authors.lastname: Brown
authors.forename: Said A
authors.initials: SA
authors.lastname: Bedja
authors.forename: Mohammed
authors.initials: M
authors.lastname: Mlindasse
authors.forename: Naphtali
authors.initials: N
authors.lastname: Agata
authors.forename: Yokouide
authors.initials: Y
authors.lastname: Allaranger
authors.forename: Mamadou D
authors.initials: MD
authors.lastname: Ball
authors.forename: Ann M
authors.initials: AM
authors.lastname: Powers
authors.forename: Victor
authors.initials: V
authors.lastname: Ofula
authors.forename: Clayton
authors.initials: C
authors.lastname: Onyango
authors.forename: Limbaso S
authors.initials: LS
authors.lastname: Konongoi
authors.forename: Rosemary
authors.initials: R
authors.lastname: Sang
authors.forename: M Kariuki
authors.initials: MK
authors.lastname: Njenga
authors.forename: Robert F
authors.initials: RF
authors.lastname: Breiman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018354:Alphavirus Infections / Q000453:epidemiology* / Q000276:immunology / Q000821:virology; D002646:Chikungunya virus / Q000302:isolation & purification*; D002648:Child; D002675:Child, Preschool; D017507:Comoros / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D016036:Seroepidemiologic Studies
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M