Arboviruses in the COVID-19 era in the State of Maranhão, Brazil (2019–2021)

Chikungunya, Dengue, and Zika viruses are endemic to Brazil, with a high annual incidence rate. As COVID-19 emerged as a pandemic, the diagnosis of arboviruses was underestimated. Hence, this study aimed to characterize the sociodemographic and clinical aspects of arboviruses in the context of the COVID-19 pandemic in the state of Maranhão, Brazil. Sociodemographic and clinical data were obtained by applying questionnaires to 179 patients treated at health units in São José de Ribamar, Paço do Lumiar, Raposa, Santa Inês, and Vargem Grande municipalities. Serological and polymerase chain reaction analyses were performed do detect Chikungunya, Zika, Dengue, and COVID-19 infections. The Maranhão state registered 706 probable cases of Chikungunya from 2019 to 2020. In 2020, the cases were reduced by 74.8% compared to those reported in 2019. The test results were analyzed separately. Here, 46.3% of the Chikungunya virus test results were negative, and 36.8% were positive. For the Zika virus tests, most (79.9%) were positive, as well as the DENV1, DENV2, DENV3, and DENV4 tests (88.3%, 88.3%, 89.4%, and 65.9%, respectively). For the COVID-19 tests, of the 146 individuals tested, 52.7% were reactive when considering the anti-S test, and 17.8% were positive when considering the anti-N test. Fever and myalgia were the symptoms most frequently reported by patients. Our results emphasize the importance of continuous epidemiological surveillance of arboviruses in northeastern Brazil, and simultaneous testing for Chikungunya, Dengue, and Zika viruses among suspected patients.