How will Covid-19 interact with India’s infection season?
According to the NSO report, the share of infections in reported ailments increases by 1.5 times between the June and September quarters.Updated: Jul 31, 2020 12:48 IST
Infections are the single biggest ailment reported by Indians and they peak during the monsoon, the July-September quarter. Infections are the lowest during peak summer; the April-June quarter. Nine out of ten people who get infections also report a fever. These statistics are based on an HT analysis of unit level data from a 2017-18 National Statistical Office (NSO) survey on consumption of health services in India.
When read with the ongoing pandemic, these statistics should ring alarm bells. August and September are still to come. India’s daily confirmed cases of the coronavirus disease and positivity rate – confirmed cases as a proportion of tests – are still rising. A spike in infection-driven fevers means that more symptomatic suspected Covid-19 patients are likely to land at hospitals/testing centres even if they don’t have that illness.
The pros and cons of different kinds of tests could also create a policy dilemma. The RT-PCR tests are the gold-standard when it comes to detecting Covid-19, but they take more time to give results. Antigen tests produce quick results, but they are more susceptible to generating false negatives (which means they may show people to be uninfected when they are actually infected). At a time when symptomatic suspected cases are expected to rise, should India prioritise RT-PCRs over antigen tests? Not necessarily, suggests experience from many countries in the southern hemisphere.
According to the NSO report, the share of infections in reported ailments increases by 1.5 times between the June and September quarters. The share of persons reporting infections more than doubles between June and September , from 1.6% to 3.6%. The nearly 2 percentage point difference here means a difference of about 25 million people in a country of roughly 1.3 billion people. The share of persons reporting an infection was the second-highest in the post-monsoon season, from October to December. The share of persons reporting ailments other than an infection was roughly the same across the year. This pattern is seen in both rural and urban areas of India.
See Chart 1: Share of Indians reporting infections and other ailments
In normal circumstances ( the survey was conducted at such a time), 61% of those who reported infections sought treatment at a private clinic, a private hospital or with an informal healthcare provider. Nearly 24% sought treatment at a government hospital. Because most infection patients are likely to show Covid-19 symptoms such as fever, this means an increase in suspected cases at hospitals and clinics.
Fifteen percent of infected patients did not seek any treatment. Of those who did not seek treatment, an overwhelming 79% did not consider the ailment serious enough. As is to be expected, the headline numbers hide significant state-wise divergence: 43% people suffering from infections did not seek any treatment in Bihar. This number was only 3.2% in Tamil Nadu. Similarly, 31% of the patients in Bihar did not consider the ailment serious enough, against only 3% in Tamil Nadu.
See Chart 2: Share of infection patients who did not consider the ailment serious enough to seek treatment
To be sure, it is entirely possible that the pandemic has changed this behaviour among people, and they are pro-actively seeking tests and treatments. Another possibility is that the lockdown and continuing mobility restrictions might have significantly enhanced precautionary measures and therefore reduced infections this monsoon. For example, community mobility data from Google until 21 July shows that people were spending significantly less time outside than the baseline scenario, which is based on median value during the five week period from 3 January to 6 February, 2020. That could mean less chance of an infection.
See Chart 3: Decline in outdoor mobility
International evidence also points towards such a possibility. Last week, the Wall Street Journal reported that countries across the Southern Hemisphere are reporting significantly lower cases of influenza, respiratory syncytial virus, and other seasonal respiratory viral infections this year. It attributed this to measures as mask use and restrictions on air travel amid the Covid-19 pandemic. Maybe India could catch a similar lucky break
Professor Indranil Mukhopadhyay, who teaches public health at Jindal School of Government and Public Policy, said decreased mobility and supposedly increased level of precautions that people take may not decrease the prevalence of other infectious diseases in India. “Had that been the case the Covid would have come down,” he said, adding that while it is possible that a higher number of people will seek treatment at a hospital if they show Covid-19 like symptoms, it is also likely that people won’t visit hospitals out of fear of catching the coronavirus there.
Mukhopadhyay said monsoon leads to a surge in waterborne diseases, many of which cause Covid-19 like symptoms. “Rapid tests need to be done, otherwise reach would be less,” he said.
Dr Sanghita Bhattacharyya, public health specialist at the Public Health Foundation of India, said that even as people are now likely to be more panicked with onset of symptoms such as fever, fear of catching the virus at hospitals can prevent some of them from seeking treatment. “It’s also due to the burden on the health system that people are not getting treatment for other non-covid infections,” she said while advocating for increased use of RT-PCR testing for foolproof diagnosis of symptomatic patients in case there is a surge in symptomatic patients who are actually suffering from other infectious diseases.