Mumps cases in Tamil Nadu surge by eightfold in one year, experts call for MMR vaccine in immunization program

CHENNAI: From 61 cases in 2021-22 to 129 the following year, mumps cases in Tamil Nadu have surged to 1,091 cases in 2023-24. Considering the surge, health experts opined that the inclusion of MMR vaccine in Universal Immunization Program (UIP) would help to reduce the burden of mumps cases.

A DPH study published in the Tamil Nadu Journal of Public Health and Medical Research stated that the epidemiology pointed out that Chennai accounted for the highest percentage of mumps cases in 2023-24, mainly due the high population density and migration that can lead to higher transmission of disease.

As many as 31% cases were reported from Chennai. The overall incidence per lakh population has increased significantly with 0.07% in 2021 to 1.3% in 2024.

A recent article on the ‘Rising Mumps Cases in India – Need for inclusion of MMR vaccine in National Immunisation Program’ in the journal pointed out that orchitis was the most common complication of mumps in post-pubertal men, affecting about 20-30% of cases. The article co-authored by Nandhini Selvanesan highlighted that mumps vaccines were available as a monovalent vaccine, a bivalent measles-mumps vaccine, or as a trivalent measles-mumps-rubella vaccine (MMR).

The mumps vaccine, commonly administered as part of the measles, mumps, and rubella (MMR) combination, has shown high efficacy in preventing mumps and its complications. “One dose of MMR vaccine is 93% effective against measles, 78% effective against mumps, and 97% effective against rubella. Two doses of MMR vaccine are 97% effective against measles and 88% effective against mumps. The vaccine is well tolerated, with adverse events being rare and mild,” it stated.

Currently, bivalent measles-rubella vaccine is included in the UIP because mumps is not considered a serious public health issue. Lack of published data on the community burden of mumps and the higher cost of MMR are part of the problem.

Data from industrialised countries have proved the cost-effectiveness of mumps when translated to reduced school- and work-absenteeism and reduction in associated long term complications and costs of associated hospitalisation. The article concluded that epidemiological shifts in the affected age group and inadequate treatment practices can lead to significant harm to patients.

“The occurrence of repetitive mumps outbreaks and the epidemiological transition of disease affecting older age groups with a higher risk of complications emphasise the need for an effective vaccination policy of MMR vaccine in India,” said the study.

The article stated that given the potential complications of mumps orchitis, including subfertility, oligospermia, and infertility, vaccination was essential. Therefore, widespread vaccination is crucial to protect reproductive health and minimise long-term fertility issues.