Mumps, an acute viral infection characterised by fever and swelling of the salivary glands and historically affecting children, has been spreading in epidemic proportions in many districts in Kerala, especially Malappuram and Kozhikode, for the past five months. As in the case of measles, cases are being reported in older children and adults also.
Though mumps is a vaccine-preventable disease, because of its low mortality profile, mumps vaccine has never been a part of the nation’s Universal Immunisation Programme (UIP). From a public health perspective, measles, a more infectious and severe disease, has always been considered a priority for elimination.
Mumps is a self-limiting, airborne disease and presents as fever and headache, with painful swelling of the salivary glands on both sides of the face. There is no specific treatment and the patient recovers with rest and symptomatic management.
However, with 6,348 cases reported so far this year (till February 19) in the State, several cases of acute pancreatitis and neurological complications due to mumps — encephalitis, epilepsy and aseptic meningitis — have also been reported at Government Medical College Hospital, Kozhikode.
With a large number of school-based outbreaks and an avalanche of cases in the periphery, it is highly likely that the disease is under-reported.
Paediatricians in the State are quite concerned that mumps may not be as harmless as it is made out to be, especially if it is occurring in epidemic proportions in an immunologically naive community.
Public health experts have also raised the question whether the Health department should be dismissive of a disease with potential long-term complications (like a drop in sperm count in males), however rare it might be. Especially so, when it is a vaccine-preventable disease.
In 2014, Kerala had on its own replaced the second dose of measles vaccination in the UIP with MMR (mumps-measles-rubella) vaccine, as part of an initiative against rubella.
However, when in 2017 the Union Health Ministry decided to introduce two doses of measles-rubella (MR) vaccine in the UIP, in place of the measles vaccine, MMR vaccinations were discontinued in public hospitals in Kerala too.
Today, only those vaccines supplied by the Centre are included for routine immunisation in Kerala
As an optional vaccine, MMR vaccine is available in the private health sector since 1985 and it has been advocated by the Indian Academy of Paediatrics (IAP) too.
K. K. Purushothaman, a former Professor of Paediatrics, Thrissur Government Medical College, maintains that the public health risk of mumps has remained underestimated in the absence of surveillance and epidemiological data. There is a total lack of documentation of mumps-associated complications or patients’ follow-up data, he says.
“Mumps may not be life-threatening but the virus is known to affect the gonads (reproductive hormone glands) in both males and females. Long-term complications such as infertility are considered to be rare but we have no follow-up data to say with certainty that the virus causes no harm at all. When there is a safe and effective vaccine against mumps, Kerala should explore this option,” Dr. Purushothaman feels.
Public health experts warn that mumps outbreaks are not going to be restricted to a few districts.
“Over time, in the absence of MMR vaccination in the public sector, the cohort of children unprotected against mumps has grown. In Malappuram, where the general immunisation cover is also low, this cohort of unprotected children and adults would have gone over the herd immunity threshold to result in such a huge outbreak. But this trend will soon show up in the rest of Kerala and we will be dealing with a large number of mumps-associated complications,” warns TS Anish, Additional Professor of Community Medicine, Manjeri Medical College.
The State asecretary of IAP, R. Krishnamohan, says that IAP has been very concerned about the huge mumps outbreak and the complications that have been reported.
“IAP has always pushed for the MMR vaccine and from a public health perspective, we think that a discussion on MMR vaccination should be re-opened in Kerala,” he said.
