Background: Of 1115 measles outbreaks during 2015 in India, 61,255 suspected measles cases were reported. In 2016, a measles outbreak was reported at East and West Jaintia Hills districts in Meghalaya State, India.
Objectives: The outbreak was investigated to describe the epidemiology, estimate vaccination coverage and vaccine effectiveness (VE), determine risk factors for the disease, and recommend control and prevention measures.
Methods: A measles case was defined as new-onset fever with maculopapular rash occurring between May 1, 2016, and January 21, 2017, in a resident of East and West Jaintia Hills. Cases were identified by active and passive surveillance. Serum and urine samples were collected from cases with laboratory diagnosis for confirmation. A retrospective cohort study was conducted to estimate vaccination coverage, VE, and risk factors for the disease.
Results: We identified 382 cases (51% female). The attack rate was 24% with three deaths. The case fatality rate was <1%. The median age was 4 years (range: 3 months-12 years). Among children 12-60 months, 128 (56%) received measles-containing-vaccine first-dose (MCV1), 85 (37%) received measles-containing-vaccine second-dose (MCV2), and 80 (35%) received Vitamin A. VE for MCV1 was 78% and for MCV2 94%. Being unvaccinated for MCV1 (relative risk [RR] = 9.7, 95% confidence interval [CI] = 4.6-20.5) and MCV2 (RR = 17.4, 95% CI = 4.3-69.4) were both strongly associated with illness.
Conclusions: Poor vaccination coverage led to the measles outbreak in East and West Jaintia Hills districts of Meghalaya. Strengthening the routine immunization systems and improving Vitamin A uptake is essential to prevent further outbreaks.
Keywords: India; Vitamin A; measles vaccination; retrospective cohort study; risk factors.