[Measles outbreak in the indian community of Yaitepec, Oaxaca, 1988]

A measles outbreak that involved 230 cases occurred in 1988 in Santiago Yaitepec, Oaxaca, had an attack rate of 14% and a case-fatality ratio of 3.9%. That community is relatively speaking isolated. A pre-outbreak measles vaccine coverage of 38.7% was found among children 1-15 years old. We compared attack rates among vaccines and non-vaccines and adjusted the figures for age and source of vaccine information. The vaccine efficacy based on this comparison was 72%. We classified cases as primary and secondary for household level. The secondary attack rate was 15.5%. The comparison based on secondary attack rates yield an estimate of vaccine efficacy about 95%. The implications of the epidemic recurrence of measles for attack rates yield an estimate of vaccine efficacy about 95%. The implications of the epidemic recurrence of measles for isolated communities due to suboptimal vaccine coverage are discussed.