Coronavirus in Delhi: Source of infection in 30% of patients unknown

NEW DELHI: The authorities fighting the spread of the novel coronavirus are now faced with another challenge. The source of infection in nearly 30% of patients is unknown. Over a month ago, it was easy to pinpoint the source. In many cases, the contacts of a Covid-19 positive person are testing negative.


Around 10 days ago, a middle-aged person tested positive for coronavirus. The location of this case wasn’t disclosed by the source. Adhering to protocol, around 15 contacts of the patient, including high-risk ones, were traced. However, none of them tested positive for the virus. This left the authorities baffled as they were unable to pinpoint the source of infection.

Delhi government has established a network of district surveillance officers, who are equipped with an extended team working on a micro-level plan to check transmission of the virus.

After the test report of a person is found positive, the elaborate exercise of contact tracing begins. “Once the contacts are listed, the supervisory officer informs the control room and gives their residential addresses. The control room, in turn, intimates the officers concerned for surveillance of the contacts. Local health workers, like ANM or ASHA personnel, monitor them for Covid-19 symptoms for 28 days. Those showing symptoms are tested,” said an official.

High-risk contacts are those who probably touched bodily fluids of the positive person, like through respiratory system by living close, having direct physical contact, etc.

“At the beginning of April, it was easy to trace a positive person’s contacts. Either they had foreign travel history or had come in direct contact with another Covid-19 positive person. At that time, the city was under lockdown and there were complete restrictions on the movement of people. Now that movement has increased, tracing of the source is getting tougher,” added the official.

A health department official said that it was too early to state that community transmission of the virus had started. Since the city’s population density is high and people have started moving, spiralling of cases is imminent. Many people who didn’t have any symptoms also turned Covid-19 positive. Over 1,000 fresh cases were reported on Friday. Sources said nearly 80% Covid-19 positive people have been showing no symptoms, while many have mild or very mild symptoms.