Despite vaccination, 12 measles cases surface in 2 Mumbai wards

MUMBAI: Over a dozen fresh cases of suspected measles have been detected in children from two city wards. What has perplexed authorities, though, is that many of the affected children were vaccinated in the statewide measles-rubella vaccination campaign that ended on March 31.
The outbreaks in F south ward, which covers Parel, Sewri and Naigaum, and P north ward, that includes Malad, were detected during routine surveillance by BMC's health volunteers in the last two weeks.The area in F south, where 11 cases were found, is considered 'high-risk' due to dense slum pockets and a high refusal for vaccination. Intriguingly though, at least 10 of the children who developed fever and rashes-considered typical symptoms of measles-had received at least one dose of the measles-rubella vaccine. At Malad, however, many of these children had not taken the vaccine when the drive was carried out in the city from November 2018 till March this year.
With the fresh cases, the count of suspected measles outbreaks in the city this year has touched ten. In 2018, there were 32. The detection of more than five measles cases within a close geographical area is classified as an 'outbreak'. This year, close to 60 children are suspected to have contracted the viral infection that the Union government plans to eliminate by 2020.
"All measles cases have to be confirmed through blood tests, but we are facing some resistance from F south in taking the samples from children. Most of the affected children seem to have taken the vaccine, barring one. Some had also taken the measles dose prior to the campaign. In Malad, the cases were scattered and didn't come from one particular area," said Dr Chandrasekhar Chiplunkar, assistant health officer, BMC. During the campaign, the BMC could vaccinate 90% of the targeted 25 lakh children from the city. And that's what could hold a key to the reason why even vaccinated children got the viral infection, say experts.
Dr Nitin Shah, consultant paediatrician at PD Hinduja Hospital, said it's not impossible to get measles even if one has been vaccinated. "The efficacy of a single dose is 80-85%, while that of two doses is around 95%. Theoretically, if 70-75% of the targeted population is covered with one dose, it effectively means that only 60% are vaccinated. So, the chain of transmission will be there till the number of vaccinated children goes up to 95% and above," he said. WHO, too, says that at least two doses are ideal to provide over 97% protection. "Elimination is a process and just because we have run an MR campaign, cases will not disappear overnight," he said. "We can hope that will happen over the next few years as measles-rubella vaccination is made a part of the national immunisation schedule."
Meanwhile, in a positive sign, deaths caused by measles among children declined by nearly 60% in the state in 2018-19. Latest RTI data obtained by Chetan Kothari from the state's health services has revealed that between April 2018 to February 2019, seven children died of measles compared to 17 casualties in the corresponding period in 2017-18.
Dr Archana Patil, additional director of directorate of health services, said there has indeed been a decline in deaths and outbreaks. However, WHO's Dr Meeta Vashi said it may be premature to link the fall in deaths to the vaccine drive.