Dengue and COVID-19 Co-infection or Cross-reactivity: Retrospective Study from a Tertiary Care Hospital

Dengue virus (DENV) and SARS-CoV-2 are single, positive-stranded RNA viruses infecting humans. The early clinical presentation of both viral diseases is quite similar, creating a serious challenge for healthcare providers to discriminate between the two diseases. Recent studies report cases of co-infection as well as cross-reactivity of DENV and COVID-19. Therefore, a retrospective study was designed to identify cases of co-infection/cross-reactivity and its severity based on Liver Function Tests (LFTs). We identified 38 cases of co-infection in a tertiary care hospital in Karachi, Pakistan during the year 2020. These cases were dengue NS-1 Ag or IgM/ IgG antibody-positive along with SARS-CoV-2 RT-PCR positive. The serological profile of co-infected cases revealed that the pattern of dengue serology is mainly based on IgG positivity followed by IgG & IgM positivity. Whereas, a single case of positive NS-1 and a single case of only IgM positive were found. The finding supports that if it is co-infection then might be more common in secondary as compared to primary dengue infection and not causing severe liver damage. This study strongly suggests, to exclude the possibility of cross-reactivity of antibodies in this pandemic condition, dengue infection should be confirmed by using accurate methods (RT-PCR or Virus isolation). Secondly, this study alarms that the dengue-endemic countries are at a higher risk of misdiagnosis of viral infection. Therefore, precautionary measures by the government agencies should be taken in this pandemic situation to reduce dengue infection in future.