New Delhi: As dengue season sets in across large parts of India with the onset of the monsoon, scientists warn that COVID-19 and the mosquito-borne disease have overlapping symptoms and worry the country's healthcare infrastructure won't be able to cope with this double whammy.
The impact of a dengue-COVID-19' season would entail two different diagnostic tests and extract a huge toll on patients too, each disease making the other more complicated to deal with and perhaps more fatal. While the COVID-19 tally crossed the eight-lakh mark on Saturday to reach 8,20,916 cases with 22,123 fatalities, the incidence of dengue is also high.
Based on 2016-2019 data, virologist Shahid Jameel estimated that India gets about 100,000 to 200,000 confirmed cases of dengue each year.
According to the National Vector Borne Disease Control Programme (NVBDCP), 1,36,422 dengue cases were diagnosed in 2019 and an estimated 132 people died.
The virus is endemic and present around the year in southern India, and in monsoon and early winter in northern India, Jameel, CEO at DBT/Wellcome Trust India Alliance, a public charity that invests in building biomedical sciences and health research framework, said. Both COVID-19 and dengue have symptoms such as high fever, headache and body pain.
The dengue season may aggravate the COVID-19 situation as both viruses may supplement each other, warned Dhrubjyoti Chattopadhyay, virologist and vice chancellor of the Amity University in Kolkata.
This situation is not yet well studied. But the information available from South America is dangerous and found to create a major challenge to their medical infrastructure, he said.
The effect will be very critical. As major symptoms are overlapping, simultaneous infection will be much more fatal. Weakened immune systems will help the other to be more fatal. Once the dengue season starts, added virologist Upasana Ray, the infection spreads aggressively due to high prevalence of its mosquito vector, aedes aegypti.
Each season, we experience heavy loads in the hospital wards due to dengue outbreak and those times it gets almost unmanageable. So, have we thought about what will happen when we have two menaces to handle together? Both of them have overlapping symptoms. Are we geared to distinguish if a person has dengue or COVID 19? asked the senior scientist, CSIR-IICB, Kolkata.
The challenges are many.
Almost each patient with a three-day fever would need to undergo a test for dengue and another for the SARS-CoV-2 virus which causes COVID-19.
Considering the current numbers of COVID-19 patients, will our hospitals have beds available for dengue patients? Or will only severe dengue cases be handled at hospitals? she asked.
As both viruses infect via different pathways and different cell types. There would of course be overlaps in physiological effects and immunological responses. They would most likely make each disease worse than either infection alone, Jameel noted.
We need to be careful and deploy tests for dengue also for febrile illness. Thankfully, India makes some very good tests for dengue virus, e.g. NS1 antigen test that is positive on the first day of fever, said Jameel.
Ray pointed out that there is no vaccine available clinically for either and no specific antiviral to treat them.