Tracking source big challenge

The government's disease control agency, IEDCR, has been able to track down the patient zero in a cluster but failed to identify how he or she got infected with coronavirus in the first place.

A number of clusters have been identified in different districts, each with three to 30 patients, according to the Institute of Epidemiology, Disease Control and Research (IEDCR).

"We identified the clusters and how the virus spread at the community level but could not identify how the first person of a cluster got infected. It is worrisome for us," Prof Dr Meerjady Sabrina Flora, director of IEDCR, told The Daily Star yesterday.

Experts say contact tracing is the key to containing the virus spread and it is hardly impossible if the source of community transmission is not traced. 

"Community transmission began a few days ago and we are now at stage-4, which means an epidemic," Jahidur Rahman, virologist and assistant professor at Shahid Suhrawardy Medical College, told The Daily Star yesterday.

"The reason for worry is that if we cannot identify the source, how will the spread be contained?" he asked.

The virologist further said, "We have to impose strict lockdown and bring all symptomatic and asymptomatic cases under screening within the locked down areas."

Currently, people in almost every corner of the city and many districts across the country have been affected, he said.

Prof Flora also warned that the coronavirus outbreak in Bangladesh will become an epidemic if people do not follow the stringent guidelines on social distancing.

The number of new cases has been jumping daily since April 4, amidst a nationwide shutdown of offices and the public transport system.

Some 40 of the 64 districts have now confirmed Covid-19 patients.

Yesterday, 182 people tested positive for Covid-19 in the previous 24 hours. With this, the total number of infected reached 803 and the death toll now stands at 39.

That overcrowded Dhaka is the epicentre of the outbreak is not a surprise -- as of Sunday, 52 percent of total Covid-19 patients identified are in the capital.

"Dhaka is the worst hit because the coronavirus patients travelled through Dhaka and lockdown was not strictly followed here," said Prof Flora.

"We found that many people who came from abroad said they will stay in their village homes but we later found they stayed on in Dhaka," she added.

In Tolarbagh, the IEDCR tracked where the transmission began but could not identify how the first patient was infected. The same goes for Basabo -- patient zero has not been identified.

After Dhaka, Narayanganj is another virus hotspot with 107 patients testing positive for coronavirus, as of Sunday.

Health officials said the spread in the district was caused from mass gatherings but they were unable to identify how the first person was infected.

Prof Flora said all the catalysts for the outbreak, including gatherings and returnees from abroad, were present in the case of Narayanganj.

"We do not know and we are not working on it," said ASM Alamgir, principal scientific officer of IEDCR, when asked about this shortcoming in tracing the spread. He said they are focused on testing and treating patients now.

Narayanganj district has been locked down since April 8, as well as parts of the capital. But dodging the eyes of law enforcers, people are still on the streets, increasing the risk of further spread of the virus.

Health officials, requesting anonymity, said the country is at stage-4. According to the World Health Organisation (WHO), stage-4 means the spread of the virus is practically uncontrollable and there are many major clusters of infection all over the country.

"There is no confusion that we are at stage-4 and the situation is epidemic here," said Muzaherul Huq, former regional adviser of WHO's Southeast Asia.

If the government takes an appropriate strategy and fixes its priority areas, it will be easy to deal with and eventually overcome the crisis, he added.

Health Minister Zahid Maleque said yesterday, "Community transmission of the virus has already occurred in the country, but we have to be careful so that it does not grow."

The minister urged everyone to stay at home and abide by the guidelines to avoid contracting the virus.