Measles, rubella cases in Karnataka rise by nearly 7 times

Measles and rubella cases reported in Karnataka increased by nearly seven times between 2021-22 and 2022-23, data prepared by the World Health Organisation (WHO) country office for the Union health ministry shows.

The immunisation gap during Covid, along with increased surveillance over the past year, are said to be the reasons for the spike. Due to movement restrictions and the healthcare system’s Covid focus, many children had missed their routine vaccinations.

Between May 2021 and April 2022, Karnataka reported 451 cases of measles and rubella combined. Whereas, between May 2022 and April 2023, the number shot up to 3,098. The difference is more stark in the case of measles, with the count increasing from 350 to 2,871.

Data also shows that outbreaks rose rapidly over this period. An outbreak is defined as five or more cases, or any death, confirmed from a small geographical area over four weeks.

Karnataka reported just one mixed outbreak of measles-rubella in 2021-22. But in 2022-23, the number increased to a whopping 17 -- two mixed outbreaks and 15 measles outbreaks. “Measles, mumps and rubella (MMR) vaccine is usually taken when the baby is nine months old,” says infectious diseases specialist Dr John Paul.

“Many don’t know that those who missed this shot can take it as a two-course vaccination at any point in life,” adds Dr Paul. A WHO official says that other than the immunisation gap, more cases are reported due to improved surveillance by Karnataka since last year to meet the Union government’s target of measles elimination by December 2023. Before this, the numbers were much fewer owing to low surveillance.

Data shows that surveillance has indeed improved in Karnataka, as indicated by a high non-measles non-rubella (NMNR) discard rate, that is, the number of samples testing negative per lakh of
population.

However, accoreding to both 2021-22 and 2022-23 data, Karnataka has the highest number of measles-rubella cases and outbreaks among all south Indian states. It is not clear if this is because of higher cases in the state or better surveillance, says the WHO official.

Dr Sudarshan, Reproductive and Child Health Officer at BBMP, says that increased hospital and community surveillance, along with the upcoming national MMR vaccination drive is expected to help achieve the measles elimination goal.