Varicella outbreak at the Itamaraju Indigenous Health Base Center: a descriptive study, Bahia, 2024

Objective: To investigate varicella cases in the Itamaraju indigenous territory base center and calculate the varicella vaccination coverage in the Tawá village, Bahia, 2024. Methods: Descriptive study of case series and census vaccination survey in children from the Tawá village conducted between June 6 and July 3, 2024, on the secondary survey database released by the General Coordination for Immunopreventable Diseases. We used descriptive statistics with measures of absolute and relative frequency and central tendency and dispersion. Results: We identified 42 cases, equally distributed between the sexes, with 27 indigenous persons and 19 children aged 7-13 years, and 14 cases received no varicella vaccine. There were 23 cases in the Tawá, Mucujê, Canto da Mata and Corumbauzinho villages, and 25 cases were associated to a school in the Tawá village, with indigenous and non-indigenous students, with an attack rate of 6.2% (25/403). In another indigenous school (Mucujê village), the attack rate was 7.0% (3/43). For the cases with available information (n=31), the most frequent symptoms were exanthema (31/31), pruritus (24/31) and fever (21/31). The varicella vaccination coverage was 90.0% (54/60) for the 1st dose and 70.3% (26/37) for the 2nd dose. Sixteen children received varicella vaccine after the outbreak began: seven received the first dose and nine received the second dose. Immunoglobulin was used for one pregnant woman. The outbreak was controlled 101 days after the first case. Conclusion: The occurrence of the outbreak in the indigenous territory was confirmed. The varicella vaccination status in the Tawá village was below the target recommended by the National Immunization Program. Vaccine updating and active case search were implemented.