The latest disease transmission trends in the State has given rise to hope that the current COVID-19 epidemic in the State could peak by mid-September and that the epidemic curve (which started on May 4) could peter out by November.
However, new outbreaks can continue to occur from areas that remain unaffected or less affected in the current epidemic, public health experts have warned.
The infection is expected to scale the peak at different points in time between September and October across the State. The epidemic curve will rise and peak but the curve is likely to remain stable for a while before it descends, global experience shows.
“There are also other variables related to heterogeneity of the population in various districts like age structure, geographical distribution, occupations and behavioural patterns affecting disease dynamics. These will reflect on the effective reproductive number (R) of the different geographical zones. Real life situation can differ vastly from our basic premises,” a senior epidemiologist says.
“According to the current disease trend, we expect COVID-19 to peak in the State around mid-September, with around 4,300 new cases and around 45,000 active cases. By November, we expect the epidemic to have resulted in over 2.55 lakh confirmed cases and around 1,000 deaths. When the curve descends will depend on the extent of population immunity we would have achieved by then,” he adds.
Given the change in disease trends in various districts, the disease will peak in districts at different points in time between September second week to October second week. Districts like Thiruvananthapuram and Kasaragod will see the disease peak early, while those like Ernakulam will have a later peak.
The Statewide epidemic pattern will later shift to focal outbreaks pattern, with sporadic cases and deaths.
“These are projections made on the basis of the actual disease trends, as seen on the official COVID-19 dashboard of the State Health department. The accuracy of these projections will depend on how reliable the State data is,” he adds.
Going by the global pattern, epidemiologists believe that the current outbreak will lose its momentum when the sero prevalence rate (proportion of a population which gets infected with a pathogen and develops antibodies, as measured by a survey testing blood samples) in the community reaches 10-20 %. The sero prevalence could of course be higher in pockets like Poonthura where huge clusters have formed.
Sero surveillance study needed
Many in the scientific community in the State are thus puzzled and frustrated by the government’s strange resistance to initiate a Statewide sero study, which is crucial at this stage of the pandemic .
A sero study would throw up better evidence on the actual proportion of the population in the State that has already been exposed to the virus and help the government in crucial decisions regarding the future.
“Already, Mumbai, Pune, Delhi, Chennai and Hyderabad have done sero surveillance studies. Kerala has successfully managed to delay the disease peak through its efficient containment measures but a sero surveillance studies will put an end to a lot of uncertainties and help the State adopt better strategies in the days ahead,” Rakhal Gaitonde, Professor, Achutha Menon Centre for Health Science Studies, says.
