Use epidemiology as a tool to fight Covid-19 | Opinion
A highly placed clinical specialist recently said that epidemiologists are busy projecting numbers because that is what they do. This is a misleading assumption. Epidemiologists aim to prevent and control epidemics of diseases. Epidemiology, as our doctoral mentor Dr Roger Detels defines it, is the basic science of public health, because it describes the relationship of health or disease with other health-related factors, like human pathogens, in human populations. The crisis caused by the coronavirus disease (Covid-19) is a good example to show that, if the epidemiology is not properly understood, it can bring lethal consequences.
Countering the adverse impacts of Covid-19 requires two types of measures: Containment and mitigation.
Consider, for example, the absolute burden of cases as a big balloon. Containment, in this case, refers to the amount of air added into the ballon, while mitigation means controlling the speed at which the air is filled into it. To prevent strain on the public health system with limited resources, we aim to ensure that the balloon is never full.
Containment ensures that we detect everyone infected with Covid-19. Once they are identified, they are isolated, and their contacts are identified and monitored properly. This process is referred to as quarantine, and after the passage of the quarantine period, they are not likely to be infectious.
Mitigation refers to the slowing down of the virus’ spread in the community by making it difficult for it to attack susceptible populations. It is important to underline that both, the containment and mitigation processes are equally necessary to ensure the balloon of disease does not burst.
For effective mitigation, Prime Minister Narendra Modi appealed to Indians to stay at their homes for the next 21 days. This lockdown has the potential to phenomenally alter the course of the pandemic, by effectively mitigating it.
Our next challenge is the containment of Covid-19. India’s inability to effectively detect and isolate cases hinders this process. Instead, we need what we call syndromic approach. Consider every case having fever, cough, tiredness or difficulty in breathing as that of Covid-19. This can, with or without testing, limit the virus’ spread.
Surveillance systems have thrown varied results across the country. While some states like Maharashtra and Kerala have identified and reported the maximum number of cases, others have been late in their response. Tracking and quarantining is a function of a good surveillance system. The national task force on Covid-19 that reviews containment measures daily should encourage states to get more proactive.
Despite India’s weak health care system, we are hopeful to keep the balloon from bursting because of the proactive steps the government has taken so far. Some areas, however, still require improvement. While most experts are calling in for intensive testing, we should not wait until the test results are available.
We should immediately implement complementary detection methods such as the syndromic approach to identify the most probable cases and isolate them. We are a country with software prowess, and that should help us start and scale mobile apps to track cases and their contacts, and map them.
Providing personal protective equipment and supporting the psychological well-being of health workers is a defining factor in tackling this. The PM needs to personally review these measures to lift and sustain the morale of frontline health workers. Implementing mass cough and fever screening using thermal temperature scanners or telephonic/app-based self-reporting will help expand containment measures.
The crisis allows us to boost the critical care bed capacity, and improve supplies and logistics. Though the government has allocated Rs 15,000 crore to address these issues, we need additional allocations to incentivise and hire health professionals. Finally, measures should be taken on a war footing to disinfect transport carriers, streets and manage hazardous waste.
We are dealing with a complex challenge that requires innovation and perseverance. But we are at our best when we are challenged. Covid-19 has challenged India’s resolve and capacity. While some of the experts predict a catastrophic end to the crisis, others think that flattening the curve is an urban myth. The number crunchers’ efforts matter, but as epidemiologists, our job requires us to offer solutions, not merely numbers.
We are interested in understanding herd immunity, in which an infection provides immunity for large groups of people. The virus is smart, but we are smarter and younger. The population dynamics do not support higher casualties in India as India’s mean age is in the 20s, with only 8% of Indians aged 60 and above. If we are to believe some of the recent reports suggesting that the virus cannot flourish in high temperatures, the soaring sun in the coming summer is good news. This, however, doesn’t absolve us of the responsibility of strengthening public health surveillance. The virus won’t go away, and many more of these may come. It is time we use the strength of epidemiology to take public health-related decisions.
Giridhara R Babu is professor and head of life-course epidemiology at PHFI, Bengaluru. Tarun Bhatnagar is a scientist with ICMR-NIE, Chennai
The views expressed are personal