Despite spike in cases, Karnataka’s test positivity rate lower than national average

BENGALURU: While the number of Covid-19 cases and the number dead have been rising in recent weeks in Karnataka, the silver lining is that the state’s test positivity rate (number of positive cases per 100 tests conducted) is just 1% – far lower than the national average of 5%.
A low test positivity rate, experts say, suggests infection is not high or the spread of the virus spread is at a relatively low level.Since the state has scaled up testing to 3,209 tests per million people, the low test positivity rate suggests the state has not allowed the situation to spin out of control. For context, Kerala’s positivity rate is 2%, while Maharashtra is 14%.
Dr Giridhar R Babu, epidemiologist and member of Indian Council of Medical Research’s Covid-19 research group on epidemiology and surveillance, said: “Karnataka should be happy as a low positivity rate indicates background prevalence of infection is not increasing. With testing ramped up, the test positivity rate remaining the same indicates that the burden of infection is getting better.” Dr Babu is also part of the Bengaluru-based Public Health Foundation of India (PHFI).
Covid-19 experts across the world say test positivity rate is a huge parameter to determine if the incidence curve is flattening. “The number of positive cases has crossed 2,000 so far, but there is no need for alarm. There has been no major spread in the state so far,” a senior IAS officer said.
So, how has the state managed to keep the test positivity rate low?
Dr CN Manjunath, state Covid-19 taskforce nodal officer and cardiologist, said: “Tracing contacts and segregating people with exposure to positive patients through institutional quarantine is one of the best things the state has done. This has helped reduce the spread of the virus immensely. That’s one reason why Karnataka is reporting less than 1% of positive cases despite the number of tests crossing more than a lakh. The lockdown mandate by the government to curb the spread has also helped immensely with 75-80% of the population adhering to norms and staying at home. This could also be a major reason for the low positivity rate.”
Medical education minister (in-charge of Covid-19 issues) K Sudhakar concurred with Dr Manjunath, saying Karnataka was alert and prepared before the pandemic broke. “The state’s four-Ts strategy of tracing, tracking, testing and treatment has worked well so far,” Sudhakar said, adding: “Karnataka’s positivity rate is among the lowest in the world.”
Data from the state Covid-19 war room shows the test positivity rate in the US and the UK was 12% as on Sunday, while it was 7% in Italy and 6% in Japan and Germany. Only South Korea had 1% positivity rate.
However, the challenge now is to monitor those returning from other states.
“The test positivity rate is high in Mandya at 2.6% and this is attributed to those who returned from Maharashtra,” a senior bureaucrat said. Dr Babu suggested testing to be ramped up further. “Going forward the syndromic approach has to be better and we should test as many people with symptoms as possible.”