Do our virus curves reflect reality?

Highlight:

• Covid-19 curves showing upward/downward trends in a repetitive pattern
• Daily infection rate down to 16-18% this week, compared to 20-25% since June
• Govt argument says declining infection rate points to falling virus transmission
• Experts say rate is low because people with symptoms now uninterested in testing
• No data on patients testing for Covid-19 before other healthcare procedures
• Experts think such patients make up a significant share of total daily test counts
• No alternative to intensifying testing to break the chain of virus transmission

It has been more than five months, but the virus curves drawn from everyday test results are still unpredictable. They show upward and downward trends within a span of just 15 days, and then they repeat over a month.

For example, the daily death toll was 54 on August 26, the highest since July 26. The number of deaths caused by Covid-19 was 54 exactly a month ago. The daily infection rate, however, came down to 16-18 percent this week; though it had been hovering between 20-25 percent since June, except for a few exceptional figures.

While there is an argument from the government authorities that the declining infection rate points to falling virus transmission, experts say the rate is low because people with symptoms of the novel coronavirus are now uninterested in testing for the disease.

The government also introduced fees for Covid-19 tests at government hospitals or laboratories at the end of June, which played a part in discouraging people from getting tested.

There is a lack of measures to identify suspected Covid-19 patients at the community level then test and isolate them–as well as their contacts.

Additionally, public and private offices and businesses have opened to strike a balance between life and livelihoods. As a result, the virus may spread further. To keep it in check, the testing mechanism has to be intensified, followed by isolation, contact tracing, and quarantine of the contacts.

The number of daily tests has been ranging from 10,000 to 15,000 for nearly two months. But it is not only suspected patients who are getting tested now.

As hospitals have begun their operations in full swing for non-Covid-19 patients at a time when the coronavirus prevalence is high in the community, complicated medical procedures – C-sections, surgeries and kidney dialysis, for example – require patients to get a prior Covid-19 test report.  

Testing patients without Covid-19 symptoms

At the Dhaka Shishu Hospital–a testing centre–a majority of in-patients who now give samples fall into this category rather than that of those with Covid-19 symptoms.

Epidemiologist Kinkar Ghosh, of the hospital, said though there was an official instruction from the government authority that only the people with signs such as a cough, fever and respiratory problems are tested, the hospital collects samples of others on humanitarian grounds.

"This is because if they [patients] don't get the report, they will not get the treatment they need urgently," he added.

It is not the doctors' fault if they ask for Covid-19 reports because the concern over contamination of machines, like during kidney dialysis, and transmission of the coronavirus to other patients is valid.

Unexpectedly, many of those who seek treatment for other health complications turn out to be asymptomatic Covid-19-positive cases.

They are kept isolated until follow-up test results return negative. The asymptomatic patients get the required medical intervention when they are no longer contagious. However, if they need immediate attention, they get it at the coronavirus-dedicated units, said Shafi Ahmed, director of the Shishu Hospital.

At the National Institute of Cardiovascular Diseases (NICVD), no angiogram–a test done to see if there is any restriction in the flow of blood to the heart–and surgeries are conducted without a coronavirus test report, said Associate Prof Kazol Karmoker.

The specialised public hospital does not have negative Cath labs that can ensure the virus does not infect doctors, nurses and other technicians present in the lab during the procedure. Further, the machine, once contaminated, should not be run for at least the next 72 hours, Kazol said.

Every day, at least 20 patients, who need to undergo an angiogram, are referred from the NICVD to the National Institute of Laboratory Medicine and Referral Centre for a Covid-19 test. 

Active surveillance to identify people suspected of having Covid-19

There is no compilation of data of patients who were tested for Covid-19, without showing symptoms, before other complicated health care measures were administered.

Experts think they account for quite a significant share of the total daily test counts.

This raises a question as to whether the virus curves compiled from everyday test reports, infections and deaths paint the real picture of the country.

Be-Nazir Ahmed, former director, Communicable Disease Control of the Directorate General of Health Services (DGHS), said, "What we see is only the tip of the iceberg."

During a pandemic, he said, "Active surveillance should be in place, in which healthcare workers or volunteers identify suspected patients in their communities, isolate them and collect their samples for testing. Their contacts should also be traced and quarantined."

Instead, the labs are asking suspected patients to come to them voluntarily to give samples.

"All the contacts should be tested too, but if that is not possible, at least the people who have been at high risk of contracting the virus from the infected, should be tested," Be-Nazir said.

Contact tracing has not been done properly. To explain, he said the DGHS data shows about only five lakh people have been quarantined, so far, against the three lakh people who tested positive.

About one lakh people are yet to recover. If they came into contact with at least five people in their families who were at high risk, five lakh people should be tested.

There is no alternative to intensifying testing to break the chain of virus transmission, Be-Nazir said. In doing so, rapid antigen and antibody tests should be rolled out immediately to help understand the real picture of the pandemic in Bangladesh.

M Mushtuq Husain, adviser to the Institute of Epidemiology, Disease Control and Research, acknowledged that contact tracing has been done on a limited scale.

The authority should ramp up testing to flatten the virus curves, he said, adding that if the infection rate came down to below 10 percent, only then would it indicate a possible decline in virus transmission.