Delta variant may account for 90% of cases unless action is taken to curb its spread – expert

By Rathindra Kuruwita

The Delta variant of coronavirus would increase in the next few weeks and could account for 90% of all cases, Executive Director of the Institute for Health Policy (IHP), Dr Ravi Rannan-Eliya told The Island yesterday. He said that the actual Delta infection rate was probably four to six times higher than reported.

Soon the average transmission rate would be driven by Delta, which was 40%-60% more infectious than the alpha variant, and current measures taken by Sri Lanka were totally inadequate to control it, Dr. Rannan-Eliya said, adding that already, one in 10 samples, sequenced across the country, showed Delta varian infection.

“Whatever the current infection rate is today, it will almost certainly increase in the coming weeks. Most of our cases (90%) are probably still the Alpha variant,” Dr. Eliya said.

Commenting on the recent drop in COVID-19 cases in Sri Lanka, Dr. Eliya said that there were several reasons for that. He added that in almost all countries, most infections were never detected. Most people with COVID-19 were either asymptomatic or the infected person did not visit a doctor.

“At most, only 25-50% of infections are ever detected. In the case of India, the data suggest that fewer than 3% of infections were ever detected and reported. In the case of Sri Lanka, we probably did relatively well. If contact tracing was not efficiently done and most contacts were not tested, the number of reported cases could be lower, he said.

“Our test to case ratio (TCR) is now much worse than it was six months ago or even 4-5 months ago. All of this points to the actual infection rate being four to six times higher than reported cases”, he said, adding that the death rate bore evidence. The government was now reporting only deaths counted during the past 48 hours.

“I think the death rate may be closer to 100 a day. The death rate with COVID should be about 0.4–0.8%, and, therefore, if we are having 80 or more deaths a day, then the true infection rate could be around 10,000. Minister Fernandopulle said some time ago that actual infections could be several times the reported cases.”

Dr. Rannan-Eliya said that the countries that had controlled the Delta outbreaks at the community were China and Australia. They conducted aggressive testing. In the case of China, over 50 million tests were done in the province where the outbreak occurred, and as regards NSW in Australia, tests are being conducted at the rate of 50,000 a day. “With our current abysmal rate of testing and with the breakdown of the system of contact tracing and isolation, it is possible that Delta variant will spread faster.”