Epidemiology of measles outbreaks in Kerala, India, during 2007-2008

Abstract

Context: Measles imparts high morbidity and mortality in low-income countries with weak health infrastructure. The coverage of measles vaccination in Kerala which is best performing state of India in indicators of health has also not reached the elimination level and outbreaks of measles continue to occur. Aim: The aim of the paper was to study the profile of measles outbreaks in Kerala during the years 2007-2008. Settings and Designs: The study design was cross-sectional and data of the measles surveillance project of Kerala were analyzed . Results: The total number of clinically suspected measles outbreaks in Kerala during the 2-year period of 2007 and 2008 was 29. But only 15(53.6%) were found to be 'measles only' outbreak. The total number of epidemiologically linked measles cases was 718 (314 in 2007 and 404 in 2008). The cases that were immunized but developed the disease were 187 (28.6%), the number of cases that were not immunized was 355 (54.3%) and those whose immunization status was unknown were 112 (17.1%). The mean age of occurrence of disease was higher in the vaccinated group as compared to not vaccinated group. Two deaths were recorded in the study. Conclusions: Significant morbidity and mortality due to measles do occur in the most developed state of India. The epidemics were clustered in some districts. The study indicated an age shift in occurrence of measles cases among who received the vaccination.