By August, 0.8% of Kerala’s population may have been exposed to the SARS-CoV-2 virus that causes COVID-19, as per a sero-surveillance study carried out by the Indian Council of Medical Research (ICMR). This suggests that over 2.67 lakh people in Kerala were possibly infected by the coronavirus as per the survey.
The ICMR sero survey was carried out between August 24 and 26 to measure the extent of the spread of the COVID-19 infection and recommend containment measures. Blood samples were collected from 1,281 individuals from Ernakulam, Palakkad and Thrissur districts to check for IgG antibodies against the novel coronavirus. IgG or Immunoglobulin G antibodies usually develop within two weeks of an individual getting infected by the virus and remain in the blood long after the patient recovers, although it is unclear for just how long.
At 0.8%, Kerala’s sero prevalence was eight times lower than the national average of 6.6%. In the first sero survey carried out in May, 0.33% of Kerala’s population had possibly been exposed as against the national average of 0.73%.
“The state’s sero prevalence increased by 2.4 times over three months. National average increased by 9 times during the same period,” states the technical paper put out by the Kerala government based on the survey results.
“ICMR study suggests that the IgG positivity has gone up from 0.33% to 0.8%. This needs to be seen in context of the vulnerability in the state such as high density of population, inflow of people from outside the country and other states, high percentage of elderly population, high percentage of people with morbidity. In spite of all these adverse situations, the state is maintaining low infection transmission is reflected through ICMR study. It shows the sincere efforts of all at the grassroots,” observes the Kerala Health Department.
Speaking to TNM, Dr Arun NM, an internal medicine expert based in Palakkad who has been tracking and analysing Kerala’s COVID-19 data, says the sero prevalence results are reflective of the data of August 10-12 – two weeks before the blood samples were taken. “We didn’t have that many cases (in mid August). Our positivity rate then was only 3 or 4%. That means Kerala is in the early stage of an epidemic,” he tells TNM.
On August 12, Kerala had recorded 38,144 positive cases. Dr Arun says that based on the survey results, Kerala may be missing 10 positive cases for every positive result it records. While he notes that Kerala has witnessed a surge in COVID-19 cases in the last month, he points out that the peak may still be weeks or months away.
As of October 4, Kerala has reported a total of 2,29,886 COVID-19 cases. At present, over 84,500 cases are active. The state has recorded a total of 836 deaths due to COVID-19 till date.