As India crosses 6,000 COVID-19 cases, a new study by the Indian Council of Medical Research hints at early community transmission in the country. The study analysed 5,911 SARI (severe acute respiratory illness) patients who were tested for COVID-19, of which 104 (1.8%) tested positive in 52 districts in 21 states and union territories, and 39% of whom did not report a history of foreign travel or contact with an infected person.

India expanded its testing strategy to include all hospitalised SARI patients on March 20, 2020. After that, 4,946 SARI patients were tested for COVID-19. Of these, 102 (2.1%) tested positive in 36 districts of 15 Indian states, which “need to be prioritized to target COVID-19 containment activities”, the study said.

Forty, or more than one-third (39.2%), did not report any history of contact or international travel, two (2%) reported contact with a confirmed case and one (1%) reported recent history of international travel, indicating community transmission. Data on exposure history were not available for more than half the cases.

The study recommended that COVID-19 containment activities “need to be targeted in districts reporting COVID-19 cases among SARI patients”.

Sentinel surveillance of SARI patients can help identify the spread and extent of transmission of the disease, noted the study. COVID-19 has now killed 199 people in India. Tracking the spread is vital to strategise and prioritise testing, and mitigation measures. The ministry data from April 6 showed that 284 districts in India had at least one reported COVID-19 case.

The study analysed the SARI surveillance data (February 15 to April 2) to calculate the weekly COVID-19 detection rate, and COVID19+ SARI cases by place and individuals’ characteristics.

Of the 102 SARI patients who tested positive for COVID-19, 85 were male. Further, 83 were more than 40 years old. The median age of these patients was 54 years--that is, half of all patients were more than 54 years old.

The positivity--or the percentage of positive cases among SARI patients tested--was the highest in the 50-70 years age-group (4.4%), and less than 1% in the 0-30 age-group.

Nearly 1 in 4 COVID-19 patients in Maharashtra between the ages of 61 and 80 have died, as per an analysis of 860 cases and 52 deaths by the state govt announced on April 9.