Seroprevalence of Chikungunya virus infection on Grande Comore Island, union of the Comoros, 2005.
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.
Sergon
Kibet
K
Epidemiology and Laboratory Training Program, Nairobi, Kenya; Ministry of Health, Moroni, Comoros.
Yahaya
Ali Ahmed
AA
Brown
Jennifer
J
Bedja
Said A
SA
Mlindasse
Mohammed
M
Agata
Naphtali
N
Allaranger
Yokouide
Y
Ball
Mamadou D
MD
Powers
Ann M
AM
Ofula
Victor
V
Onyango
Clayton
C
Konongoi
Limbaso S
LS
Sang
Rosemary
R
Njenga
M Kariuki
MK
Breiman
Robert F
RF
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
D007074:Immunoglobulin G; D007075:Immunoglobulin M