…says single episode of community detection should not compromise the 14-day clean sheet and that it should be case-dependent  

Younten Tshedup  

The recent positive cases from the community in Thimphu have left many asking how it all happened.

The confusion arose after a mobile flu clinic in Lungtenphu picked up a positive case on January 12. The incident took place 24 days after Thimphu was locked down. Also, on January 11, a frontline worker tested positive to the virus while getting tested before being deployed to the workplace.


How did this happen?

In an ideal situation, 21 days of lockdown is supposed to break the chain of transmission of the infection. With no or limited interaction triggered by the lockdown, the virus, if an individual had contracted it, would die within himself or herself, provided they don’t develop symptoms and become sick.

But Thimphu was still recording positive cases after 21 day.

Clinical microbiologist and member of the health ministry’s technical advisory group, Dr Tshokey, said that technically there was no reason for people to worry from such detections as Thimphu was still under lockdown.

Dr Tshokey explained that outliers were bound to happen. “These individuals might have been exposed to the virus just before the enforcement of the lockdown,” he said. “If they have followed the lockdown protocols, there should not be any issues.”

He said that the positive cases detected on day 22 or after, presumably from the community, were in the late stage of infection, meaning they were almost non-infectious and the possibility of transmitting the virus to others was minimal.

The microbiologist said that the individuals would have tested positive for the antibodies as a result of the long-term exposure to the virus and body’s natural reaction to the infection. And as a highly specific test, the RT-PCR would have picked up even a minute part of the virus, he added.

There are several literature that support that a PCR machine can show positive results due to the shedding of the dead virus particles. The index case that triggered the first nationwide lockdown in August was linked to a similar scenario. The woman had tested positive during the viral shedding phase.

A PCR test amplifies the genetic material of a virus or any pathogen exponentially by making exact copies of the molecule. The copies produced are then used to compare with the gene of the virus. The sample here can be dead or alive.

Dr Tshokey said that if these people had followed the lockdown protocols sincerely, the spread would be minimal. “At the max, they would have infected the family members, which is given. This is the basic idea of having a lockdown or placing people in quarantine, which is to contain the spread of the virus.”


Implication of unlocking Thimphu 

The current understanding is that for considering any form of relaxation in Thimphu, a red zone, the city has to maintain zero positive case from the community for 14 straight days.

However, Dr Tshokey said that going back to day one after each episode of ‘cases from the community’ would be impractical. “We have to consider this based on individual cases and how and when they have contracted the infection.” This means that unless it is a newly acquired infection from the community (acute phase), it would not interrupt the 14-day clean sheet for Thimphu.

The case definition and detection classification would, however, depend on the health ministry and experts.

It was learnt that any positive cases detected outside the quarantine and from within the close contacts, the ministry swept all those areas to identify potential transmission.

The ministry has also started a mass screening at household level in Thimphu since January 14 to check for possible active transmission of the virus.

As of yesterday, more than 10,000 individuals were tested in Thimphu. Sowai Lyonpo (health minister) Dechen Wangmo, said that no one had tested positive from the screening so far. “This is a good sign. We have two more days to carry out testing in Thimphu. Let us all pray there are no positive cases hereafter.”

Paro, which is also a red zone, has also not reported any positive case from the community during the mass screening. Over 12,000 people were tested in Paro as of yesterday.

Lyonpo said that the results from the mass screening would also be considered by the experts and Covid-19 national taskforce to deliberate on the possible relaxation in the two red zones.