Molecular surveillance of Dengue Virus (DENV) and its co-infection with Chikungunya Virus (CHIKV) among febrile patients: A comparative study from South Delhi, India

Abstract

Dengue and Chikungunya are two major arboviral infections transmitted worldwide by the mosquitoes, Aedes aegypti and Ae. albopictus. India suffers enormously with both Dengue and Chikungunya as they pose a great public health challenge. The present study aims to evaluate the prevalence of Dengue Virus (DENV), Chikungunya Virus (CHIKV) and DENV/CHIKV co-infection (by Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR)/Enzyme Linked Immunosorbent Assay (ELISA), their clinical features, DENV serotypes and CHIKV specific Immunoglobulin G (IgG) within a 7 years gap in the Delhi population. The study sample included clinically suspected febrile patients (?7 days) sera collected during 2017-2018 (n=87) and during 2008-2010 (n=623) from Delhi. Captured ELISA was performed for CHIKV IgG screening and nested PCR was done for DENV serotyping. The percentage prevalence for DENV was significantly higher than CHIKV with 41.38% (n=87) and 16.1% (n=87), respectively; interestingly, DENV/CHIKV co-infection was detected in 10.34% (n=9/87) cases during 2017-2018. Similarly, a high DENV prevalence was observed during 2008-2010 with the prevalence rate of 38.3% (69/180), 34.65% (35/101) and 47.07% (161/342), respectively. DENV 1 and DENV 3 were dominant serotype during 2008-2010 and 2017-2018 respectively. We have noticed a high prevalence (36.67%, 22/60) of the CHIKV IgG antibody in the 2017-2018 samples. Joint pain was more preferential to CHIKV mono-infection and DENV/CHIKV co-infection compared to DENV mono-infection. The present study highlights the need for active surveillance simultaneously for both DENV and CHIKV and to evaluate the role of CHIKV/DENV co-infections in disease severity in the endemic regions.

Concurrent dengue infections: Epidemiology & clinical implications

“…We also observed that in the year preceding 2016 there were reports of DENV-2 and 4 co-circulating which was also the case during 2009-2010 which showed a jump in chikungunya infections post-co-circulation of DENV-2 and 4 ( Table II ). The recent molecular surveillance study during 2017-18 from south Delhi comparing DENV/CHIKV co-infection and DENV mono-infection from 2008 to 2010 detected the high prevalence of CHIKV IgG antibody in 2017-18 and joint pain was particularly present in co-infection cases as compared to DENV mono-infection 113 . These observations prompt us to hypothesize that co-circulation of dengue serotypes may affect the occurrence of other arboviral infections, particularly CHIKV, and warrant detailed epidemiological surveillance of arboviral infections in a locality to understand the transmission dynamics of the infections ( Table II ).…”