Evaluation of a measles vaccine campaign by oral-fluid surveys in a rural Kenyan district: interpretation of antibody prevalence data using mixture models.
We evaluated the effectiveness of a measles vaccine campaign in rural Kenya, based on oral-fluid surveys and mixture-modelling analysis. Specimens were collected from 886 children aged 9 months to 14 years pre-campaign and from a comparison sample of 598 children aged 6 months post-campaign. Quantitative measles-specific antibody data were obtained by commercial kit. The estimated proportions of measles-specific antibody negative in children aged 0-4, 5-9 and 10-14 years were 51%, 42% and 27%, respectively, pre- campaign and 18%, 14% and 6%, respectively, post-campaign. We estimate a reduction in the proportion susceptible of 65-78%, with approximately 85% of the population recorded to have received vaccine. The proportion of 'weak' positive individuals rose from 35% pre-campaign to 54% post-campaign. Our results confirm the effectiveness of the campaign in reducing susceptibility to measles and demonstrate the potential of oral-fluid studies to monitor the impact of measles vaccination campaigns.
Centre for Geographic Medicine Research - Coast, Kenya Medical Research Institute, Kilifi, Kenya. eohuma@kilifi.kemri-wellcome.org
E O
EO
Ohuma
E A
EA
Okiro
A
A
Bett
J
J
Abwao
S
S
Were
D
D
Samuel
A
A
Vyse
N
N
Gay
D W G
DW
Brown
D J
DJ
Nokes
D000293:Adolescent; D000914:Antibodies, Viral / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007630:Kenya; D008458:Measles Vaccine / Q000276:immunology*; D012424:Rural Population; D016036:Seroepidemiologic Studies; D013183:Sputum / Q000276:immunology*
D000914:Antibodies, Viral; D008458:Measles Vaccine