[Response to the treatment of brucellosis among children. Evaluation with Huddleson reaction and PCR].

Introduction: Brucellosis poses a significant public health problem and requires meticulous diagnosis; the outcome has frequent relapses even when the treatment is appropriate.

Objective: To evaluate the response to the treatment in children with brucellosis by means of Huddleson seroaglutination test and PCR.

Methods: Using a prospective design, a cohort of children with brucellosis was followed up by carrying out Huddleson seroaglutination test of and PCR for Brucella at 6, 12 and 24 weeks. Most of children were treated with trimetoprim + sulfametoxazole and rifampicine. The progress towards therapeutic failure or relapse was evaluated.

Results: Twenty-three children fulfilled the inclusion criteria. The median age was 4.7 years; 61 % had consumed potentially infected milk or dairy products. The duration of symptoms ranged from 7 days to 1 year. Brucella sp. was isolated in blood culture in two of 21 children and Brucella melitensis in myeloculture in one of four children. 69 % had positive Huddleson serological test from 1:160 to >1:12000. PCR tested positive in 100% of children when entering to the study. Six weeks after beginning treatment 17% of children had therapeutic failure. At 12 weeks, three children (13 %) persisted with positive PCR and their antimicrobial treatment was modified. At 24 weeks, five children (21.7 %) presented relapse. A child persisted positive in spite of modifying the antimicrobial scheme. The agreement between the two tests was low in the three follow-up periods (k = 0.08, k = 0.12 and k = 0.28 respectively).

Conclusions: A 6-week treatment cannot be enough to eliminate Brucella. PCR test can be used to early identify relapses.