Widespread Exposure to Human Parvovirus B19 in the Brazilian Amazon: Evidence from a Community-Based Seroprevalence...

Human parvovirus B19 (B19V) causes a broad spectrum of clinical manifestations but is often asymptomatic. In the Brazilian Amazon, where B19V may mimic endemic arboviral infections, epidemiological data remain limited. This study investigated B19V seroprevalence among residents of Manaus, Amazonas, Brazil.

A cross-sectional study included 450 age-stratified participants recruited from 2021 to 2023 across different zones of Manaus. Plasma samples were tested for anti-B19V IgG and IgM by enzyme-linked immunosorbent assay. Associations were estimated using Poisson regression with robust variance and reported as prevalence ratios (PRs) with 95% confidence intervals (95% CIs).

Anti-B19V IgG seroprevalence was 67.56% (304/450; 95% CI: 63.10-71.72), and IgM positivity was 2.89% (13/450; 95% CI: 1.70-4.88). In multivariable analysis, age group was the only independent factor associated with IgG seropositivity (p < 0.001). Seropositivity was not associated with sex, skin color, education, income, blood transfusion history, or geographic zone. IgG levels varied by age group (p = 0.0108) but not by sex (p = 0.33).

B19V exposure is widespread in Manaus, with approximately two-thirds of participants showing evidence of past infection, whereas serological evidence of recent infection was uncommon. Age was the only independent determinant of IgG seropositivity, consistent with the progressive accumulation of exposure across the life course. These findings establish a contemporary epidemiological benchmark for Manaus and highlight the need for targeted investigation of B19V in patients with febrile-exanthematous illness in arbovirus-endemic settings.