The COVID-19 pandemic (caused by severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) has increased the burden on healthcare systems in dengue endemic regions.

Harapan et al. reviewed the issues of misdiagnosis of COVID-19 and dengue, and antibody cross-reactivity and its potential consequences. Shared symptoms and clinical manifestations, and serological cross-reactivity (between the viruses) can result in misdiagnosis. Difficulties accessing COVID-19 tests and inadequate laboratories in dengue endemic countries like Indonesia make an accurate diagnosis even more challenging.

Antibody-dependent enhancement (ADE) leading to cytokine storm is characteristic of both severe COVID-19 infection and dengue and may be triggered by low levels of non-neutralizing, neutralizing or low affinity antibodies in the serum.

Since there is cross reactivity between anti-SARS-CoV-2 antibodies and dengue serotype antigens in rapid serological kits, a COVID-19 vaccine could theoretically elicit ADE and worsen dengue disease severity. The authors concluded that a simple, affordable diagnostic test capable of differentiating between COVID-19 and dengue is urgently needed in Asian countries, as well as better equipped testing laboratories.