Increase in testing alone cannot explain an increase in the number of cases during the lockdown. It is also possible that the surveillance systems in some States might have missed a cluster or two of infections during the earlier phase of the outbreak, which has resulted in a large number of cases now being detected, says Giridhara Babu.
Even after more than six weeks of national lockdown, there is no sign of any flattening of the curve but instead the number of new novel coronavirus cases reported each day continues to increase. Expanded and increased testing alone cannot be the reason. Prof. Gridhara R. Babu, Head-Lifecourse Epidemiology, Indian Institute of Public Health, PHFI, Bengaluru and Intermediate Fellow, Wellcome Trust DBT India Alliance, says States should look for active cases through house-to-house search using the syndrome approach and isolate every person who has two COVID-19 symptoms.
What is the reason why we see thousands of cases each day despite India being under a lockdown since March 24?
In absolute numbers, India’s case burden has increased by 1.8 times (180%) in the last two weeks alone. However, considering the infection period of 14 days, the Ro [the number of people one person can infect] has decreased from 2.13 to 1.82 from April 24 to May 8, with doubling time has increased from 6.59 to 7.69 days.
The increase in absolute numbers is due to states with higher population reporting cases. Apart from small States, the greatest increase in reporting is seen in the States of Punjab (5.9 times), Tamil Nadu (3.2 times), Bihar (3.1 times), West Bengal (3 times); these have increased more than three times in last two weeks. Increase in the testing alone cannot explain such an increase. Similarly, Delhi, Odisha and Jharkhand have around 250% increase in cases. It is also possible that the surveillance systems in these States might have missed a cluster or two of infections during the earlier phase of the outbreak, which has resulted in a large number of cases now being detected.
How valid is the government’s version that more cases seen now is due to increased testing?
I agree partly; India’s expanded testing (including random testing in red zones and surrounding areas) has indeed resulted in a spike in cases, as earlier testing criterion was centered mostly around people with symptoms. However, if lockdown was successful and containment measures were also successful, we could have picked up these cases earlier on. When you increase testing, you will not get many positives if there is no extensive spread of infection. When you expand testing, you get more new cases only when more people are infected around you, only when the infection has spread either in clusters or beyond. I am concerned about the increase in Bihar and West Bengal, which have a relatively poor health-care system to cater to the surge in cases. Let me repeat for clarity — it is only improved surveillance measures that will get us to minimise casualties.
Countries that had gone under lockdown, including Italy, saw a flattening of the curve in about three weeks. Why is India not seeing any flattening even after six weeks of lockdown?
It is wishful to think that lockdown alone will flatten the curve. For flattening to occur, the Ro should be less than 1. To achieve that, the focus of the surveillance system should be to find every case. Lockdowns are necessary only to mount the health system’s response and accomplish successful containment. We have not done a great job in surveillance in some States and some districts of every State. Even now, the focus is to identify every case in this country and isolate. We should have a success story; that success comes with hard work of finding every case and isolating the person.
Each State is a different country with different level of preparedness and varied response. But it is the States with weak surveillance systems which will have more deaths and will result in spreading the infection to other States. Kerala did well because of its humane approach to isolation and quarantine due to a strong surveillance system. Our future depends on reflecting and reviewing the underlying surveillance system. Also, we should look at the right metric. It is straight forward and intuitive. States/Union Territories that have higher ILI/SARI reporting and a higher number of contacts traced per confirmed case should guide future reviewers. Better quarantine measures coupled with identification and isolation of all cases is the only vaccine we have for now.
Should India restrict itself to testing contacts and SARI AND ILI cases alone?
No, it is also imperative to treat every person with a particular symptom complex in a syndromic approach. In my view, anyone who has two of these symptoms should be isolated as COVID-19 unless otherwise proved — fever, cough, shortness of breath or difficulty breathing, chills, muscle pain, sore throat, new loss of taste or loss of smell. Since a vast majority of the infections are mild or asymptomatic, we should develop plans for home isolation of cases, wherever possible. It is essential to review regularly the performance of districts and States based on the syndrome-based surveillance.
What different strategy should India adopt to make testing more targeted?
A good surveillance system is like a great surfer, one which goes in search of the tide to take control over it. The reality is that in the absence of strong district-level planning, we will get caught and make us a sitting duck. We need to decide whether to tame the tide or be a sitting duck.
We should find active cases through the house-to-house search using the syndrome approach and isolate every person who has two COVID-19 symptoms. Governments should use the tests judiciously to test people who have symptoms, and their contacts. After the contacts are quarantined, test between five-seven days from the day of onset of the symptoms in people who they were in contact with. Besides, it is essential to offer testing to health workers.
Like pulse polio program, door-to-door surveillance to check the health status of the public is needed. This requires a lot of workforce, which the government should pay heed to. Without health workforce and active testing we cannot say the curve will flatten anytime soon. District-level task forces should be formed to plan and improve surveillance and testing, and step up preparedness.
We still see many States, including Madhya Pradesh and Karnataka, reporting fewer cases each day. Is it because there truly is less virus spread?
Test positivity in Madhya Pradesh and Karnataka is 5.58% and 0.79%, respectively. It varies from zero to 8.29% across the States in India. Decreasing test positivity rate can indicate many things. First, there is less virus spread in the State, which is an implausible scenario. Second, it suggests that we are not testing the right kind of people and randomly testing. In many districts, the number of SARI and ILI cases tested are very few. Through improved surveillance, all the high-risk persons need to be tested. For now, we can think at our peril that the epidemic is over, given that there is a huge cohort of susceptible persons throughout the country.
What is the reason why we see a high case fatality rate in Maharashtra and Gujarat?
The possible reasons for the high fatality in these two States might be due to different reasons. The disease can worsen fast, sometimes within a few hours to one day. People might reach health facility late by which time their condition is already serious. Further, a higher proportion of co-morbidities like diabetes and hypertension might lead to fatalities. Reporting late to health system can also indicate stigma. Improving communication to reach people and addressing their fear and stigma can resolve some of these challenges.
On the other hand, if surveillance is poor, we might miss cases in the initial phases and only deaths occurring later will draw the system’s attention. By then, the infection would have spread wider, resulting in more deaths. Death is an unfortunate wake-up call to improve surveillance in that area.