Dengue poses a significant threat in India during the COVID-19 epidemic

A view of dengue ward at Hindu Rao Hospital on 17 September 2015 in Delhi. Delhi was in a panic over dengue as the number of cases crossed 2,000 and hospitals across the city continued to reel under acute pressure.  Saumya Khandelwal/Hindustan Times

In the second week of September, India’s coronavirus numbers began falling from a peak of just above one lakh cases per day. The steady decline in cases brought hope that the worst might be over, till Delhi was hit by another nasty surge of infections in late October and November. This increase in Delhi is a reminder that India should not be complacent about coronavirus. Moreover, many infections that have occurred later in the year have been accompanied by a disease that Indians have battled for decades—dengue.

Every year, dengue poses risks to a large population in India where some are more equal than others when it comes to access to healthcare. The risk is larger this year with the complications due to COVID-19 and dengue co-infections, and more acute with an already inadequate public-health infrastructure crumbling under the strain of the epidemic. In late September, Delhi’s deputy chief minister, Manish Sisodia, was diagnosed with dengue while he was in hospital for treatment of a COVID-19 infection. Dr Randeep Guleria, the director of the All India Institute of Medical Sciences, India’s premier medical institution, pointed out that management of dengue-COVID-19 co-infection can be very challenging. 

Dengue has been a major threat in India for more than two decades. One of the worst outbreaks was in 1996, when there were more than sixteen thousand cases and more than five hundred deaths, most of them in and around Delhi. The government introduced a system of mandatory recording and reporting of laboratory-confirmed dengue cases from districts to states and from states to the centre after this outbreak. The numbers recorded show a few relatively quiet years, following which dengue infections in India rose dramatically. In 2017, India witnessed a big increase in dengue cases—1,88,401 cases and 325 deaths, according to the National Vector Borne Disease Control Programme. India saw comparably large numbers cases in 2018 and 2019. During 2019, the states of Karnataka, Andhra Pradesh, Tamil Nadu, Telangana, Gujarat, Maharashtra, Uttar Pradesh, Bihar, Rajasthan, Uttarakhand, Kerala and Delhi last year saw 1,28,582 dengue cases—almost 82 percent of the total case load. 

The NVBDCP’s dengue data captures only 0.35 percent of the clinically diagnosed dengue cases in India. The programme depends on hospital-reported data. It misses suspected cases having dengue symptoms at the community-level as most of these cases do not reach government laboratories. It also does not account for dengue case information from private healthcare providers, who are the most common first-contact providers in India. Private health providers avoid going through the cumbersome government laboratory system, and the NVBDCP reporting system does not include private labs. This implies that the risk of residents of cities of the 11 states and the union territory of Delhi getting infected with dengue is about 300 times higher than suggested by official data. These states also have a high load of COVID-19 cases—68 lakh as on 20 November—which has burdened their health systems. These twelve regions are also important health administrative units and home to 63.8 percent of the country’s population, according to the 2011 census.