Strict lockdown needed, BD envoy on tests by Chinese expert
June 24th, 2020 at 1:17 pm
Strict lockdown needed, BD envoy on tests by Chinese expert

Nadeem Qadir;

There is no good news so far on COVID-19 so far for the world as Bangladesh is witnessing a steep climb of new cases but yet confusion reigns high on how to put a tab on it as far as experts are concerned.

Our two Dhaka mayors are either testing one area in red zone, while the other is waiting for government instructions.

However, what is shown on TV is not impressive as there has been a rise of new cases of coronavirus in East Rajabazar, a red zone under a three-week lockdown. Footages showed people getting in and out of the area for one reason or the other.

Experts told that one good news is that more people were now understanding the dangers of the disease and staying indoors which has forced railways and Biman or even inter-district buses to limit operations.

But, they feel that lockdowns must be tough with full preparations ahead like adequate supply of food, medicine and other essential daily needs, besides ensuring jobs of residents in those areas are secured.

“It (lockdowns) has to be foolproof,” one expert said, adding that would help tab the deadly disease.

Green area residents must be alerted against entry of non-residents, which this correspondent saw in some villages where leaders are tough on ensuring safety.

On the other hand, complaints on testing and results are quite common these days. We have an active ambassador in China who has an expert opinion on the issue.

Mahbub Uz Zaman, Bangladesh’s envoy to China, quoted one Chinese expert for “public sharing and awareness building” in a Facebook status.

Crowded ferry journey after Bangladesh lifted the virus lockdown on May 30, 2020- photo

He told this correspondent that he was sharing the information on COVID-19 received from Li Jinming, researcher at the National Council for Clinical Laboratories.

Zaman wrote: “Sharing herewith some view points and perspectives on how to handle and address the COVID situation in terms of NAT testing. This is related to the issue of false positives and negatives of some NAT test results.

I am sharing the experience of the Chinese health experts in this connection with his assessments and observations:

If close contacts of confirmed cases have tested negative in their first NAT, whether they still need to be placed under quarantine:

According to Li Jinming, close contacts of Covid-19 cases need to be placed in quarantine even if they have been tested negative in the first NAT because close contacts have a much higher risk of contracting the virus than others.

During the quarantine should the person develop symptoms, he or she will need to take another NAT test. Even if the person shows no symptoms during the quarantine, he or she will still need to take another NAT and if tested negative the quarantine can be lifted

Are false negative results avoidable?

Li Jinming said that false negative results cannot be ruled out completely due to factors that may affect accuracy, such as of sampling, types of samples and lab testing operation. A positive NAT result is usually the golden rule for detecting a virus infection, but there can be false positives. For example, when a sample has already been contaminated.

False positive can be avoided through re-testing. There is always a possibility of a false negative result. Take timing of sampling as an example. False negatives may happen to a close contact when samples are taken at the beginning of an infection, or in the case of long incubation. It may also happen at the late stage of incubation period or at the time of early symptoms. Incorrect operation of collecting a sample or mutation of the virus may also lead to testing inaccuracy.”