Two in One Outbreak of Rubeola-Rubella in Tobacco Affected Maan Vajreshwari Nagarkot Dham-District Kangra of Northern Himanchal

Abstract

Background: A local community leader informed us about sudden increase in number of cases of fever and rash in five villages of district Kangra on 14th September 2006,. We investigated the suspected outbreak to confirm diagnosis and recommend for prevention and control. Methods: A case of rubeola was defined as occurrence of fever with rash in a child between from 3rd September to13th January, 2007. We collected information on age, sex, date of onset, residence, signs, symptoms, vaccination and cold chain and smoking status. We described the outbreak by place, time and person characteristics. We conducted a retrospective cohort study to estimate vaccine efficacy. We ascertained the measles immunization status by interviewing the mothers and reviewing immunization cards. We confirmed diagnosis clinically, epidemiologically and serologically. Results: Sixty case patients were identified in five villages (41/60 rubeola and 11/60 confirmed epidemiologically linked unvaccinated rubella). The overall attack rate (AR) was 9%. Sex specific AR was 11% for male. Majorities of cases were >5years of age. No death/minimal complications occurred. Of 60 case-patients, 42 (70%) were vaccinated for rubeola. The AR of rubeola among unvaccinated children was 25.8% as compared to AR among vaccinated of 4.5% (Relative risk: 5.75%; 95% confidence interval: 3.48–9.51 P <0.001). We estimated general vaccine efficacy (VE) to be 83% while gender based VE for male was 84%. Eight case-patients were confirmed serologically for measles IgM antibodies, two nasopharyngeal swabs positive by PCR. Rubeola virus was genotyped D4. Only 30% (18/60) of the cases took the treatment from modern system of medicine. Conclusion: A mixed outbreak of rubeola/rubella was confirmed clinically, epidemiologically and serologically. We recommend MR vaccination at the age of 18-24 months and aggressive IEC activities to modify help seeking behavior of community, especially in the measles affected areas. Key Message: In the outbreak setting, two viruses’- rubeola and rubella were investigated simultaneously in the district Kangra of Northern India in highly immunized mountainous area for rubeola but unvaccinated for rubella. The single virus of rubella has been investigated in 2006 and officially documented in the state of Himachal Pradesh. The attack rate was highest in older age group warranting the need for MR vaccination.