Inhabitants of the Greater Mekong Subregion in Cambodia are exposed to pathogens that might influence serologic cross-reactivity with severe acute respiratory syndrome coronavirus 2. A prepandemic serosurvey of 528 malaria-infected persons demonstrated higher-than-expected positivity of nonneutralizing IgG to spike and receptor-binding domain antigens. These findings could affect interpretation of large-scale serosurveys.
Keywords: COVID-19; Cambodia; SARS-CoV-2; coronavirus disease; cross-reactivity; malaria; serosurvey; severe acute respiratory syndrome coronavirus 2; vector-borne infections; viruses; zoonoses.