Factors Associated With Single and Recurrent Bacteremia in Childhood Brucellosis

Data regarding risk factors of bacteremic brucellosis, and specifically recurrent bacteremia, are scarce. We assessed patients with childhood brucellosis, differentiating between those having culture-negative, single-bacteremic, and recurrent-bacteremic episodes.

The medical files of pediatric brucellosis patients, from 2005 through 2014, were reviewed retrospectively. Univariate and multivariate analyses were performed to compare demographic and clinical characteristics of culture-negative, single-bacteremic, and recurrent-bacteremic (≥30 days between positive cultures) episodes.

Of all 436 brucellosis cases, 22% were culture-negative, 72% were single-bacteremic, and 6% were recurrent-bacteremic. In a univariate analysis, single-bacteremic episodes were associated with fever (90% vs 65% and 40% in culture-negative and recurrent bacteremia, respectively) and elevated glutamic oxaloacetic transaminase (GOT) levels. Recurrent-bacteremic episodes were associated with anemia (26% vs 14% and 9% in single bacteremia and culture negative, respectively), elevated GOT, low immunoglobulin M (IgM) titers (56% vs 89% and 99%, respectively), and lower levels of adequate treatment (74% vs 94% and 86%, respectively). In multivariate analyses, single bacteremia was associated with fever (odds ratio [OR], 3.595, compared with culture negative), while recurrent bacteremia was inversely associated with IgM titers ≥1:160 (OR, 0.022 and 0.226 compared with culture negative and single bacteremia, respectively) and fever (OR, 0.108 compared with single bacteremia).

Brucellosis episodes are commonly complicated with bacteremia. Single-bacteremic episodes were associated with high-grade fever and elevated liver enzymes, possibly indicating high bacterial virulence. Recurrent-bacteremic episodes were associated with poor treatment at initial diagnosis, along with low rates of fever, low IgM titers, and high anemia rates, possibly indicating impaired host response. Physicians should consider treatment modifications for suspected recurrent-bacteremic brucellosis, including monitoring treatment adherence, and possibly administering prolonged treatment.