CHENNAI: A childhood viral infection, long regarded as a routine, is quietly resurfacing in Tamil Nadu, reappearing in schools and communities with little public attention. A peer-reviewed study published in the Indian Journal of Public Health has reported renewed circulation of the mumps virus across South India, with Tamil Nadu among the affected states, raising concerns over immunisation gaps, delayed diagnosis and the tendency to dismiss the disease as mild.
The study, conducted between January and March 2024, analysed samples from patients presenting with basic mumps symptoms in Tamil Nadu, Karnataka, Kerala and Telangana. Of the 200 clinically suspected cases tested using molecular methods, 26 (approximately 13 per cent) were laboratory-confirmed. Children accounted for nearly 89 per cent of the infections, underlining the virus's renewed foothold among the paediatric population.
For Tamil Nadu, the findings carry added significance as the study period coincided with reported clusters in districts such as Sivaganga, pointing at active transmission within the state. Researchers note that several cases may previously have gone undetected or been misclassified as non-specific viral fever.
"This resurgence reflects both missed immunisation timelines and improved laboratory confirmation through RT-PCR, which is now identifying infections that were earlier overlooked," the authors, N Ashokumar, K Jaya Swathi, Senthilraja Ramalingam, G Srividya, Deepa Sankari and Mani Mariappa, wrote.
Crucially, the study challenges the widespread perception of mumps as a harmless childhood illness. Samples drawn from blood, cerebrospinal fluid and buccal swabs revealed neurological involvement in a subset of patients, including meningitis. "Detection of the virus in cerebrospinal fluid indicates central nervous system involvement, underscoring that mumps is not always self-limiting, " the authors cautioned.
Although no deaths were recorded, doctors warn that complications such as orchitis, encephalitis, pancreatitis and permanent hearing loss are well documented, particularly when infection occurs in adolescents and adults. "Low mortality should not be interpreted as low disease burden," the study noted, pointing to avoidable morbidity and long-term sequelae.
The researchers also flagged a long-standing policy gap: India's continued exclusion of the measles-mumps-rubella (MMR) vaccine from the Universal Immunisation Programme. In countries with sustained MMR coverage, mumps incidence has dropped to fewer than one case per 100,000 population, a level India has yet to reach. Disruptions to routine immunisation and surveillance during the COVID-19 pandemic, the authors said, may have widened existing immunity gaps.
The experts argue that the study should be read as an early warning. With children forming the bulk of confirmed cases in Tamil Nadu and complications already documented, they say prevention through vaccination and surveillance remains the most effective safeguard.
State health authorities, however, sought to downplay immediate concerns. Director of Public Health and Preventive Medicine, Dr A Somasundaram, said mumps typically shows seasonal peaks between January and March. "Mumps is not considered a problematic virus and usually resolves on its own," he told DT Next, adding that decisions on including MMR rest with the Government of India.