Many Covid cases with no history of travel or contact, ICMR study shows

NEW DELHI: An ICMR study of patients admitted with Severe Acute Respiratory Disease (SARI) showed that 93% of those who tested positive for Covid-19 and for whom the information on exposure was known had not traveled abroad or had had contact with a person known to be infected.

According to the study, of 102 SARI patients who tested positive for Covid-19, no data was available for 59 (58%) regarding any contact they may have had with a Covid-19 positive person or from international travel. Of the remaining 43, for whom such exposure and history details were known, 40 (93%) had no history of travel or international contacts.

Some public health experts see it as an indication of spread. Dr., a public health expert who has worked with the Indian government, said: This is the definition of community outreach even by the WHO: cases with no history of contact with infected people or international travel. The community is only a particular stage in the transmission of the disease and does not mean that the government has failed or that the closure has not been successful. The reluctance to accept that community transmission has been established seems to come from insisting that the blockade be successful only if it has stopped community transmission. There will be no real change in strategy if community outreach has been extended. ”

According to the WHO, community transmission is evidenced by the inability to link confirmed cases through transmission chains for a large number of cases, or by increasing positive tests through sentinel samples (systematic systematic tests of laboratory respiratory samples). established). The ICMR study, of which the head of the institution was a co-author, also stated that Covid-19 positivity among SARI patients has increased from zero before March 14 to 2.6% for the week ending April 2. Between March 22 and April 2, when the testing strategy was expanded to include all SARI patients, 102 of 4,946 samples tested positive.

In listing the limitations of the study, he cautioned that since the data on SARI patients belonged to selected sentinel hospitals, predominantly from the public sector in urban areas, it may not be representative of the entire district, state, or country. However, he added that the trend of Covid-19 positivity among SARI patients could provide reliable information about its spread in the area.

The study also noted that the diagnosis of some Covid-19-positive SARI patients may have been missed due to false-negative results (when positive patients show negative in one test) of laboratory tests based on RT-PCR. He said that antibody-based testing among those who tested negative for RT-PCR could have increased the number of positive cases.

The study emphasized the importance of evaluating SARI patients to help decide response activities, including testing, containment, and mitigation measures.