Detection of SARS-CoV-2 IgM Antibodies in Febrile Patients From an Endemic Region of Dengue and Chikungunya

PURPOSE: The rapid expansion of the novel SARS-CoV-2 virus has raised serious public health concerns due to the possibility of misdiagnosis in regions where arboviral diseases are endemic. We performed the first study in northern Peru to describe the detection SARS-CoV-2 IgM antibodies in febrile patients from an endemic zone for dengue virus (DENV) and chikungunya virus (CHIKV). METHODS & MATERIALS: A cross-sectional study was performed in febrile patients attending primary healthcare centers from April 2020 through March 2021. This study was carried out jointly with the national surveillance system for the etiological identification of acute febrile illness (AFI). Patients are included if they attended outpatient clinics with AFI (axillary temperature greater than or equal to 38°C in the previous 7 days) along with one or more of the following symptoms: headache, myalgias, arthralgias, retro-ocular pain, lumbar pain, arthritis, nausea, rash, among others. Serum samples were collected from each patient, for the molecular and serological detection of DENV and CHIKV by RT-PCR and IgM ELISA-based assay, respectively. Also, the detection of IgM antibodies against SARS-CoV-2 with an ELISA-based assay was performed. RESULTS: 464 patients were included during the study period, of which 188 (40.51%) were positive for one pathogen, meanwhile 32 (6.90%) presented co-infections between 2 or more pathogens. The majority of patients with monoinfections were positive for SARS-CoV-2 IgM with 73.40%, followed by DENV 18.09% and CHIKV 8.51%. The most frequent co-infection was DENV + SARS-CoV-2 with 65.63%, followed by DENV + CHIKV and DENV + CHIKV + SARS-CoV-2, both with 12.50%. The presence of polyarthralgias in hands (p<0.01) and feet (p=0.05) were more frequently reported in patients with CHIKV monoinfection. Also conjunctivitis was more common in patients positive for SARS-CoV-2 IgM (p<0.01). The rest of the symptoms were similar among all the study groups. CONCLUSION: In conclusion, a high prevalence of SARS-CoV-2 IgM antibodies were frequently detected in acute sera from febrile patients with a clinical suspicion of arboviral disease. These results highlight the need to consider SARS-CoV-2 infection as a differential diagnosis of AFI in endemic areas for arbovirosis, as well as consider co-infections between these pathogens.