Test was based on random sampling 

Yangchen C Rinzin 

The Ministry of Health has completed random testing of communities and collected a total of 8,400 samples from Thimphu Thromde as of yesterday.

Mass screening began from December 24.

However, many residents said that they were not tested even after the completion of mass screening. Many were left confused, as they did not receive a call for testing when the health ministry’s notification on mass screening said that a sample would be collected from each household.

Some residents shared that while their neighbours received a call for testing, they did not. Others said that only one person from the building was tested. Still others said that while a few people from one building were called for testing, not a single person was called for the test from the next.

“I went for a test, but I was asked to wait for a call. I was never called for the test,” Ugyen Dorji, a resident in Debsi said. “I don’t know how a test of one person can determine that the entire building is not infected.”

However, Technical Advisory Group (TAG) head and epidemiologist, Dr Sithar Dorjee, said that everyone doesn’t need to be tested.

Dr Sithar Dorjee clarified that the mass screening was based on the randomly selected household and people should not worry if they are not tested or did not receive a call for the test.

He added that samples were proportionately divided into different zones based on the total households needed in each zone.

The required number of households from each zone was randomly selected from a list of households using computer software. After that, from each selected household only one most active and high-risk individual is selected.

“Since it’s a random selection there is no uniformity, which is why some people did not receive a call for the test,” Dr Sithar said. “People must understand that it’s worked out scientifically and all households need not be sampled.”

He added that about 10 percent of those selected were also tested using the rapid antibody test (blood sample) besides the usual antigen test (swab sample), which is also collected for RT-PCR.

“The 8,400 samples collected are sufficient to give us the situation on how the virus is spreading in the community and how far it has spread,” Dr Sithar said. “This mass screening is to assess the situation that would also help in decide the duration of lockdown.”

He added that people must comply with the lockdown strictly and should not mix with people inside the same building irrespective of whether you are tested or not.

However, some did not turn up for the test. Many could not be reached on their mobile number. The mass screening team made sure to test other people to ensure enough samples are collected.

Thimphu has 95 Covid-19 positive cases from the community since December 20.