40 COVID-19 +ve cases with unknown source of infection, finds ICMR study
New Delhi: Forty SARI (Severe Acute Respiratory Illness) patients have tested positive for COVID-19, without a known source of infection, according to an ongoing study being conducted by the top scientists of the Indian Council of Medical Research (ICMR) and their COVID-19 response team. The study tracks the prevalence of the disease caused by the novel Coronavirus SARS-CoV-2 in all hospitalised SARI patients across the country to check whether the country has entered the stage of community transmission.
While the Ministry of Health and Family Welfare on Friday once again reiterated that India was yet to enter the stage of community transmission, the research paper, authored by ICMR DG Dr Balram Bhargava and the head of the COVID-19 team Dr Raman R Gangakhedkar among many others, said that many areas in India were already showing signs of community transmission.
The study has selected what it calls 41 sentinel hospitals (government hospitals predominantly in urban areas) where samples from admitted SARI patients were tested for COVID-19. According to the research paper, a total of 5,911 samples from across the nation were tested between February 15 and April 2, of which 1.8 per cent or 104 patients had tested positive for COVID-19.
The study considered that random testing of SARI patients would give them an accurate representation of whether community transmission has begun and take strategic measures accordingly. Interestingly, the study had revealed a prevalence of only two positive cases in a sample size of 965 between February 15 to March 19. But after the testing strategy was revised by the ICMR to include testing of all SARI patients admitted at these sentinel hospitals, the prevalence of the disease jumped to 2.1 per cent. Among the 4,946 samples tested under the new testing strategy, 102 samples were found COVID-19 positive.
Of these 102, 39.2 per cent did not have any travel history to COVID-19 affected countries nor did they come in contact with any laboratory-confirmed COVID-19 cases - meaning they contracted the infection from the community.
Interestingly, the study showed that some areas in the country could have entered community transmission as early as March 22. If the study is tracked between February 15 and April 2, it can be seen that by March 21, two out of 106 samples tested had already tested positive for COVID-19 (1.9 per cent).
In addition, that number increased to 54 samples testing positive out of over 2,000 samples tested yielding prevalence rate of about 2.6 per cent. The prevalence rate finally settled at 1.8 per cent by the week ending on April 2.