Sero-epidemiology of measles--a three years prospective study in a rural population of Rajasthan.

A community based prospective study on measles was undertaken during 1986 to 1988 in Ramgarh village of Alwar district (Rajasthan) to elucidate epidemiological features of measles. The initial population of the village was 5258 with 2018 children (0-14 years) which rose to total population of 5923 with 2200 children in 1988. During the entire period of study, all the children (0-14 years) were covered regularly through monthly domicilliary visits by trained paramedical personnel under direct supervision of Medical Officers. A total of 208 measles cases were detected which gave an overall incidence rate of 31.5 per 1000 children (0-14 years) per year. Incidence rate was highest in children of 2-5 years of age group and lowest (4.6 per 1000) in 10-14 years of age group. The maximum number (86.5 per cent) of cases occurred during the first six months of year. The Kolmogrov-Smirnov statistical method validated the seasonal character of the disease (Vn = 5.36, p less than 0.01). A significant (P less than 0.005) rise in seropositivity with increase in age was observed in children (6-36 months) who had no previous history of measles and measles immunization during their life time. A higher rate of sero-conversion was observed in children vaccinated after 10-months of age than those before. No significant relationship of seroconversion following vaccination could be seen with age of vaccination (p greater than 0.50), sex and nutritional status (p greater than 0.10).