Outbreak of measles amongst vaccinated children in a slum of Chandigarh

Background: An outbreak of measles was reported from a slum, UT, Chandigarh in April 2003. Similar outbreak was also reported in less than three years from the same and adjoining areas. The present study was conducted to investigate and assess various epidemiological features associated with measles outbreak.
Material and Methods: Three cases of measles were admitted in Deptt. of Paediatrics, Govt. Medical College & Hospital, Chandigarh and were reported to the Deptt. of Community Medicine for an outbreak investigation. A trained team investigated the slum having a population of 25,000 and studied various features associated with epidemic between the period of April 22 to May 10, 2003.
Results: The study covered 484 houses having 1130 children. Among the children who developed measles 32.76% were vaccinated ones. In them attack rate was 3%. Attack rate in vaccinated children went on increasing as age increased. An overall attack rate of 5.13% (Peak incidence 6% in 1-4 years age group) was recorded. Among measles cases, one-fifth had post measles complications. As much as 32.76% children with measles had received measles vaccination in the past. Therefore something more than immunization by single dose of vaccine is required. Measles was reported to be higher amongst the children without Vitamin A supplementation (P<0.001).
Conclusion: There is need to store vaccine properly and to strengthen routine immunization coverage, Vitamin A supplementation and health infrastructure in underprivileged population. Serological studies among vaccinated children against measles should be undertaken to explore the possibility of second dose of measles in older children.