Most of asymptomatic patients didn�t transmit virus while at home quarantine: Study

GUWAHATI, July 26 - In what can arouse curiosity, a sample study among 86 home quarantined persons in Guwahati who were later found to be COVID-19 positive, has found that only four of them seemingly transmitted the infection to their family members. This was despite the fact that the quarantined persons were with their families for an initial crucial infectivity time, till the RT-PCR results came and they were shifted to Covid care centres or hospitals.

Those people directly quarantined at home used to get their swab test reports after four to fourteen days and in positive cases, it is generally less than ten days. It means some of the positive persons were with their families for even a week, and yet did not transmit it to their family members. The revelation of the study is in line of recommendation of the Indian Council of Medical Research for home quarantine of asymptomatic or mildly symptomatic persons under certain conditions. None of the symptomatic persons later required any intensive care at hospital.

Of the 86 persons studied, 68 were asymptomatic persons and 18 had mild symptoms, principal investigator of the study Dr Gayatri Gogoi said. Dr Gogoi, an assistant professor of pathology (AMCH), was supported by Dr Dhananjay Ghanwat, SP, Dhemaji in this endeavour.

�We wanted to understand whether during the period � till they receive the reports � they had transmitted the virus to another person living closely with them in home environment. Is it safer for Covid positive persons to be home quarantined? Whether the family members have risk of getting infection?� Dr Gogoi said, adding that an appropriate questionnaire tool was prepared to find the probable answers.

The study found only four cases in which the positive persons transmitted the virus.

�In the first case, the symptomatic positive person while travelling with family was quarantined with two small children and wife. During quarantine he developed fever and cough. His report came as positive after six days and second tests for two children and wife were done. The children�s report came as positive after 13 days but were asymptomatic and yet wife was negative in spite of living with children,� Dr Gogoi said, elaborating on one instance.

The three other cases where the virus was transmitted, including one at the CRPF�s quarantine centre, it was found that there was a common toilet which could be the source of transmission. In all four cases, the independent risk factor was use of common toilet by them.

�There have been a series of debate whether asymptomatic cases spread the virus to others or not. Once WHO commented that asymptomatic rarely transmit and then later changed its stand. The caveat was basically pulling of data from multiple hurried studies where asymptomatic cases were designated as asymptomatic at the time of sample collection or initial assessment,� Dr Gogoi said.

�It is likely that a proportion of cases later become symptomatic and wrongly categorised as asymptomatic due to lack of a system to follow up to correct it. But our early data � though small � contained all complete follow-up information of not only index positive persons but also family members of close contacts,� she continued.

�Scientific data indicate that droplet is the source of infection in symptomatic cases during coughing/sneezing or through saliva contact, etc. However, in asymptomatic cases shedding by respiratory route is unconfirmed. Our data correlating the nature of transmission of four families suggest a strong risk factor through use of common toilet. Multiple families were using common toilets,� Dr Gogoi added.

Assam Police is taking support from community organisation Pratishruti Cancer and Palliative Trust (supervised by Dr Gogoi), in monitoring the home quarantined people in the city as a joint venture. Till date, some 23,000 people within Guwahati have been home quarantined and around 19,000 completed the mandatory period. Approximately 300 volunteers are involved in the project in distance mode operation from across the State.