Serological cross-reaction and coinfection of dengue and COVID-19 in Asia: Experience from Indonesia.

Similar symptoms and laboratory findings between dengue and coronavirus disease 2019 (COVID-19) pose a diagnostic challenge in some dengue-endemic countries in Asia. In this study, we reported three cases of suspected COVID-19-dengue coinfection in hospitals of Bali, Indonesia. Serological data demonstrated that patients with positive results for dengue virus (DENV) NS1 antigen and anti-dengue IgM were also reactive to COVID-19 rapid antibody tests, suggesting dengue-COVID-19 coinfection. However, two patients were later confirmed negative for SARS-COV-2 by qRT-PCR, implying a plausible cross-reactivity of anti-dengue and anti-COVID-19 antibodies in the serological test. Coinfection of dengue and COVID-19 was evident in one patient, following confirmation of SARS-COV-2 by qRT-PCR and DENV infection using the NS1 antigen serology test. This case was the first case of dengue and COVID-19 coinfection in Indonesia and revealed possible cross-reactivity between SARS-COV-2 and DENV antibodies based on rapid serological tests. Our study indicates a public health concern regarding COVID-19 and dengue detection in Indonesia as well as in other dengue-endemic countries, and it is important for these nations to manage both pathogens concurrently.