Emergence of chikungunya and Zika in a municipality endemic to dengue, Santa Luzia, MG, Brazil, 2015-2017.

The recent circulation of arboviruses transmitted by vectors, such as dengue, chikungunya, and Zika, is concerning due to the high morbidity rates, clinical complications, and increased demand on health services. The objective of this study was to analyze the clinical and epidemiological aspects of an epidemic caused by arboviruses in the municipality of Santa Luzia, Minas Gerais, Brazil. Longitudinal study of patients with acute febrile disease and suspected arbovirus infection reported to Brazilian Notifiable Disease Information System (Sistema de Informação de Agravos de Notificação) from the epidemiological week 44 of 2015 to epidemiological week 52 of 2016. Patients with confirmed chikungunya were followed-up for 18 months and those with Zika for 15 months. Additionally, we analyzed and described the temporal distribution of confirmed cases of these arboviruses in this municipality. Overall 3,531 arboviruses cases, including 3,481 (98.7%) cases of dengue, 38 (1.0%) cases of chikungunya, and 12 (0.3%) cases of Zika were confirmed. The highest incidence of arbovirus infection occurred in the first quarter of 2016 (epidemiological week 7 to 14). The most frequent symptoms were for dengue, which included fever, headache, retro-orbital pain, and exanthema. Chikungunya infection was associated with fever, myalgia, arthralgia, and rash while Zika infection with pruritus and rash. Given the similarities in the initial clinical profiles of these arboviruses, it is important to perform a detailed clinical analysis, laboratory diagnosis, and patient follow-up.