Circulation of Chikungunya virus in Rio Grande do Norte from 2019 to 2020: epidemiological and molecular aspects

Abstract Background : Once considered a third-world disease, Chikungunya Fever is currently one of the main emerging arboviruses globally. Shortly after having been established as an autochthonous disease in Brazil, Chikungunya virus (CHIKV) spread in the State of Rio Grande do Norte, where it has caused recurrent outbreaks. This study aims to describe epidemiological aspects of Chikungunya in the State of Rio Grande do Norte during 2019 and 2021. Methods : Samples of suspected cases of chikungunya from different municipalities in Rio Grande do Norte were analyzed. A total of 540 samples were tested using the qRT-PCR. Results : 134 were chikungunya positive in 2019 (n = 82) and 2020 (n = 52), representing a total of 25% for both years. Most of those affected were female (60%) in the age group between 20 and 39 years old. The most frequent health issues associated with infection were fever (65%), headache (48%) and arthralgia (47%). We identified two (2/134) probable cases of congenital infection and two asymptomatic cases (1.5%). The highest mean viral load peak was found on the first day of symptom onset. The highest proportion of cases reported in 2019 was observed in Natal, in the Tirol neighbourhood (57%); and in 2020, in the municipality of Guamaré (33%). Conclusions : This study contributes to the Chikungunya population-based surveillance in urban centres of the state of Rio Grande do Norte, outlining higher incidence areas, which will serve as a basis for disease epidemiological control.