Covid-19 negative? Stay cautious still

Medical experts say symptomatic individuals should isolate and treat themselves

In a recent incident in Noida, two patients who were tested negative for Covid-19 turned out to have the illness after a third test showed positive. Medical experts say that it is best to be extra cautious even if tested negative.

Two types of tests are available to diagnose Covid-19, one that checks the viral particle (Reverse Transcriptase-Polymerase Chain Reaction Test or RT-PCR) and the other which checks the antibodies in the blood (Rapid test), says Dr Vishwanath Bellad, consultant pulmonologist, BGS Gleneagles Global Hospital.

“The former is more standard and is taken as the reference point, while the other is referred to as a quick method,” he says.

Whenever one is infected with the virus, the body will harbor it in the nose and the throat.

“In the initial days, the body will not produce any antibodies against the infection, it usually takes time. The viral load increases in the first seven days of the infection. Post this, the probability of getting a positive antigen test is high,” he says.

Across the country, both tests are done. The RT-PCR is standardised but time-consuming and is available in fewer laboratories. “Even if the test is negative, one needs to be cautious in the minority of cases which are suggestive of Severe Acute Respiratory Infection. If symptoms continue, repeat the test again in about 3 to 4 days,” Dr Vishwanath says.

Symptomatic individuals should isolate and treat themselves. “Patients exposed to a positive case or having arrived from a foreign country need to take caution.”

Transmission to other people is a big concern still, he adds. Dr Manish Mattoo, zonal director, Fortis Hospitals says the level of alertness around low-suspicion patients has to be higher. Nurses at Fortis have been advised to wear proper protective equipment, even when around patients who are tested negative.

“Although the number of laboratories authorised to do the tests has increased and the time to get results has reduced, not everybody can be tested yet,” he says.

The testing guidelines have been defined by the ICMR.

“For patients with symptoms the testing protocol is easier but it is the asymptomatic carriers that we are concerned about,” he says.

What should one do?

• Sport a mask
• Maintain hand hygiene
• Wash utensils and clothes in hot water and detergent.
• If you live with family or friends, do not mingle with them.