Unspecified cases indicate community transmission

Unspecified coronavirus cases recorded by ICMR indicates community transmission

The Indian Council of Medical Research has reported that it does not know the source of infection for 44 per cent of the patients tested positive for COVID-19 till April 30.

In an analysis of more than one million tests (1,021,518 to be exact) carried out till April 30, the ICMR team found 40,184 positive cases, out of which as many as 17,759 cases (44%) belong to the “Not Specified” category.

Majority of such cases were reported between April 15 and April 30 when lockdown 2.0 was in place.

While analysing the results, the ICMR scientists categorised the positive cases in seven groups – (1) symptomatic international travelers in the last 14 days (2) symptomatic contacts of laboratory confirmed cases (3) symptomatic healthcare workers (4) hospitalised SARI (severe acute respiratory illness) patients (5) asymptomatic direct and high risk contacts of laboratory confirmed case – family members (6) asymptomatic healthcare workers in contact with confirmed case and (7) ILI (influenza like illness) identified in hot zones.

But as these 17,759 cases did not fall in any such category, they were grouped under “Not Specified” category about which ICMR scientists did not offer any explanation in the paper published in the Indian Journal of Medical Research.  

They, however, admitted that “the surveillance data had a large proportion of tests with missing information on exposure history".

“Also cases were reported from all over India, and travel was no longer the primary means of exposure,” they reported. The medical researchers also noted that they were “uncertain about the transmission among unlinked individuals in the community.”

“There could be multiple reasons behind such cases ranging from people not belonging to any of these categories to community transmissions,” ICMR scientist Tarun Bhatnagar, one of the members of the team, told DH.

Furthermore, the analysis found 4,204 cases of SARI (10.5%) and 1,199 (3%) cases of ILI that are also indicative of the COVID-19’s silent spread into the community.

Looking for COVID-19 positives among SARI and ILI cases is part of ICMR’s strategy to look for the signatures of community transmission in India.

While the government has not admitted the pandemic virus’s community transmissions in India, doctors and health department officials were categorical in admitting that the pandemic has moved from local transmission to community transmission.

Asked why the government was silent on the community transmissions, eminent virologist T Jacob John said it could be due to the officials' lack of epidemiological understanding of epidemics.

“Perhaps the need to assert that government knows 'all sources of infection' - an obviously untenable claim - may have made them (the Govt) deny community transmission defined as 'unknown person(s) transmitting infection'. Such claim also shows lack of deep understanding of the dynamics of introduced epidemics,” said John, a retired professor of clinical virology at the Christian Medical College, Vellore.

Get a round-up of the day's top stories in your inbox

Check out all newsletters

Get a round-up of the day's top stories in your inbox