Medical &Health

Variation between PCR and antigen test positivity rates hides true situation of Covid-19 in Chapainawabganj

District Civil Surgeon Dr Zahid Nazrul Chowdhury informed on Sunday that the infection rate of coronavirus is decreasing in Chapainawabganj, but it cannot be said with confidence that the situation has improved.

According to results reported from the RT-PCR Lab in Rajshahi, 107 people came out positive in 188 tests carried out on Saturday night. That is an extremely high positivity rate of 59%.

Dr Zahid said the samples were sent to the Rajshahi lab last Wednesday and Thursday.

Additionally on Saturday, 453 people were tested using the rapid antigen test in the district, where 54 of them came out positive, for a positivity rate of 12%. The overall positivity rate (RT-PCR and antigen tests combined) stands at 25% (161/641).

The RT-PCR test is the most sensitive type of test for the virus (sometimes too sensitive, as they can detect viral loads that are not expected to be harmful). The test actually detects RNA (or genetic material) that is specific to the virus and can detect the virus within days of infection, even in those who have no symptoms. This makes it important in the pandemic to prevent asymptomatic spread.

However, the PCR test has a longer turnaround time, which is where the antigen test, frequently known as a rapid test, comes in. It is meant to detect protein fragments specific to the Coronavirus. While the rapid test can get you results very quickly, the results may not always be accurate.

The WHO recommends having a confirmation PCR test performed if you still have symptoms despite a negative antigen test. But whether that is at all happening in Chapainawabganj is not known.

Meanwhile, the district observed the sixth day of its 'strict' lockdown on Sunday. Police are working in the field to implement the lockdown.

The district civil surgeon further said a decision on whether to extend the ongoing one-week lockdown in the district would be taken at a meeting of the district coronavirus prevention committee.

Earlier on Tuesday, authorities in Chapainawabganj imposed a week-long lockdown to break the chain of Covid transmission.

All intra-district and long-distance buses as well as private vehicles would stay off the roads during the lockdown. However, no such restrictions apply on the movement of vehicles ferrying goods.

Train services to and from the district have also been suspended in the wake of the recent surge in Covid cases in Chapainawabganj.

Moreover, all shops, markets and restaurants would remain closed, except for grocery stores and pharmacies. This would allow people to buy their daily essentials and medicines from their local grocers and chemists.

Officials of the local administration and police personnel have been deployed on all the major roads of the district to ensure strict compliance.

Besides, as many as 27 checkpoints have been set up across the district to curb the movement of people, unless for specific reasons. "Cops will also patrol the streets of the district to make the lockdown a success," said an official.

Source: United News of Bangladesh