KOLKATA: Doctors and hospitals across the city have reported several cases of repeat dengue infections – some patients even got it thrice – and have warned that such cases are generally more serious than the first time, often requiring intensive care, and could even prove fatal if not timely treated.
Taking the example of a 26-year-old Dhakuria resident who died on October 20 in a private hospital after getting dengue thrice in five years, experts explained that a repeat infection is generally caused by a different dengue serotype, as the patient would have antibodies for the original serotype of the virus. That’s why most hospitals in the city are taking into account past dengue infections. Data collated from various hospitals of patients have revealed that a significant number of them (5% was the lowest and 30% the highest) had a history of dengue infection.
“Around 30% of patients, whose past infection history could be traced, had had dengue previously,” said Nishant Agarwal, emergency medicine head, Charnock Hospital. “We have to be all the more cautious while taking care of these patients as they are at a higher risk,” he added.
And it’s not just adults, said Prabhas Prasun Giri, associate professor of paediatrics, Institute of Child Health, Kolkata. “More than 30% of dengue cases in children are re-infections,” he said, adding, “Tracing past infection is important as re-infections can be more aggressive in terms of morbidity and mortality.”
There are five serotypes of the dengue virus. An infected person develops protective immunity against that particular strain, but not to the others.
“Second-time dengue infection can be more serious than the first time around because of antigen-antibody immune complexes that are triggered when the patient is infected by a different strain,” said microbiologist Bhaskar Narayan Chaudhuri of Peerless Hospital.
Doctors said that since all patients had not tested for dengue during previous fever episodes, it was not always possible to trace their history. “Secondary dengue infection is very common among patients who need intensive care. In our unit, we could trace past infections in about 50% of patients,” said critical care specialist Rimita Dey of Ruby General Hospital. Amit Roy, deputy medical director at Medica Superspecialty Hospital, said the hospital could trace past infection history in about 10% of patients.
“Clinical assessment on admission of a patient includes knowledge of past history of any illness, record of any previous infection of dengue. At Woodlands, cases of dengue reinfection have been less than 5% this year,” said Rupali Basu, managing director & CEO, Woodlands Multispeciality Hospital.