A 5-year study of dengue seropositivity among suspected cases attending a teaching hospital of North-Western region of India.

Dengue virus infection is estimated to cause infection in approximately 390 million people globally each year, of which 96 million develop clinical disease. Dengue serotype 2 (DEN-2) is the most prevalent serotype over the past 50 years in India, but serotypes 3 and 4 have appeared in some epidemics as well. A retrospective study was conducted in a teaching hospital, western India, between January 2014 and December 2018. The records of dengue serological test were analyzed. In total, 40 randomly selected nonstructural protein 1 (NS1) antigen-positive samples were analyzed by a reverse transcription-polymerase chain reaction. The demographic data, that is, age and sex, along with geographic location and platelet count level, were recorded from the Serology laboratory register and Hospital Information System. In total, 14.85% (735/4948) samples tested positive for dengue serology. Most of the laboratory-confirmed dengue cases, 34.97% (257/735), were observed in the 21-30 years of age group. The most common serotype detected in the tested samples was DEN-3 in 55% cases (22/40, 13 monoinfection and 9 coinfection with DEN-1 and DEN-2). The present study gives an insight into the trend of dengue seropositivity among suspected cases in the western part of Rajasthan, India. This study showed a higher seroprevalence of dengue infection as well as a gradual increase in the seroprevalence in this part of India.