Foreign experts advise Vietnam to carry out serosurvey to find Covid infection rate

"It is likely that the total number of cases in Vietnam is 10 times higher than what has been announced," Dr Pandu Riono of the faculty of public health, University of Indonesia, said when asked about the Covid situation in the country.

He explained that the majority of infected people might not have had symptoms or been tested, and the PCR test might not even be available everywhere.

Vietnam has reported a total of 165,286 Covid infections, including 161,431 in the fourth wave that emerged in late April. HCMC is the epicenter of the latest wave with 100,557 of them.

People are waiting for Covid-19 test in Go Vap District, HCMC, July 6, 2021. Photo by VnExpress/Quynh Tran.

Riono suggested HCMC should conduct a serological survey to find out the rate of people infected in the city.

It is done by testing samples selected randomly from among the population to find out the rate of those who have Covid antibodies.

In Jakarta, the local government carried out a serosurvey of around 5,000 people in March and found 44 percent of them had antibodies, indicating nearly half the city's population could have had Covid, some 15 times the official figure, Jakarta Post reported.

After that similar surveys were done in other major areas, including Bali. Across the country, Indonesia estimated, 20 percent of the population was infected, meaning 80 percent remains vulnerable, making the need for quick vaccination imperative.

Riono said: "Serological surveys helped authorities understand the problem in reality. So Vietnam could consider doing it to find all positive cases."

It is important to detect the gap between testing and real infection rates, he said.

Riono said Vietnam should not mind asking its partners for financial and technical help.

Indonesia sought assistance from the U.S. Centers for Disease Control and Prevention (CDC) to perform the serological survey, and gave oxygen to India when it had a deficit, he said.

The healthcare system could be overloaded in many places since the Delta variant is more transmissible, he pointed out.

In Jakarta and Java island, many people died at home because hospitals could not accommodate them or lacked oxygen, and so the key is to prevent transmission and increase testing, contact tracing and isolation, he said.

Besides mandatory mask wearing, he said Vietnam should tighten regulations for people coming in from other countries.

Indonesia responded late when faced with community transmission, and that is why it has difficulty controlling it, he said.

Dr. Ali Mokdad, chief strategy officer, population health, University of Washington, the U.S., also said his team estimates that 2 percent of people in Vietnam, or nearly 2 million, have been infected as of July 26.

Vietnam needs to pay attention to the level of breakthrough infection, which is defined as the detection of Covid-19 in people who had been fully vaccinated, to see if the vaccine strategy needs to be changed since it is using various vaccines for Covid.

Besides, the country should continue surveillance of new cases, and investigation of outbreak.

The government has approved six vaccines: Pfizer/BioNTech, Moderna, Johnson Johnson, AstraZeneca, Sputnik V and Sinopharm.

Mokdad said though Vietnam has done better than other countries, it is still a big concern, and so it needs to take aggressive measures to control the pandemic.

"People need health education such as safe isolation, hand washing and mask wearing indoors, and keeping a distance. It is very important."

He predicted the mortality would increase in Vietnam until mid-August, peaking at 250 deaths a day, before starting to come down.

In the worst-case scenario, the death toll could be 26,000 by November 1, one of the causes being the low rate of vaccination, he said.

He said the country needs to control ports, airports and borders to keep out new variants.

Dr Chandrakant Lahariya, an epidemiologist in New Delhi, India, said from the ferocious second wave in India the key learning was that countries need to be prepared for the worst-case scenario.

There is a need to be alert and perform genomic sequencing, he said.

Triage, or preliminary assessment of patients, could help reduce the burden on the healthcare system, he said. Citizens have the very important role of ensuring they come forward for early testing and support contact tracing to ensure infections are detected in a timely manner, he said.

The emergence of secondary infections such as mucormycosis is a reminder that while focus has to be on the treatment of sickness, adherence to standard treatment guidelines is important, he pointed out.

The situation in Vietnam and many other countries that had successfully contained the spread of the virus until recently is a reminder of how the world is interconnected in this fight against the pandemic, he said.

"Cases may go down but being prepared for all eventualities, having sufficient Covid testing, contact tracing and treatment has to be the right approach as long as the world is in [the grip of] the pandemic."