Some months ago, an ICMR study had found that 40% of 102 patients with Severe Acute Respiratory Illness (SARI) reported no history of travel or contact with a known case of Covid-19.
Delhi health minister Satyendar Jain suggested that ‘community transmission’ of Covid-19 was under way when, in response to a question on this, he said the source of infection was not known for 50% of the cases detected. On the specific question of what this meant, he said declaring community transmission was the remit of the Union government. Deputy chief minister Manish Sisodia, in a press interaction later, said that the Centre’s officials have held so far that there is no community infection in national capital territory, as per agency reports.
Some months ago, an ICMR study had found that 40% of 102 patients with Severe Acute Respiratory Illness (SARI) reported no history of travel or contact with a known case of Covid-19. While this is a classic symptom of community transmission, experts had then argued that this could also be attributed to incomplete reporting and poor contact-tracing. If person A contracted the infection from person B whom she met without realising that the latter was infected – and B may also not know of her infection – this would be reported as ‘community transmission’ while, in fact, it is not.
The matter is also complicated by the fact that there is no official definition of community transmission. While WHO doesn’t demarcate a threshold level of unknown-contact-history infections as community transmission, Union health ministry officials said, as far back as late March, that a 20-30% reporting of cases with unknown contact history would be deemed community transmission; there is, however, no official guideline on this yet.