Clinical, serological and polymerase chain reaction follow-up of a family with brucellosis

Abstract

Human brucellosis diagnosis is based on isolation of Brucella spp. from blood or tissue cultures with a positivity rate of 40-70% and serology techniques are used as complementary tools; recently molecular biology diagnostic techniques have been developed intending to optimize the etiological confirmation. The main objective of this work was to compare the polymerase chain reaction (PCR), against serological diagnostic tests during the clinical follow-up of a family presenting brucellosis. Seven family members who lived in the urban area of Mexico City, were monitored using the Rose Bengal test, the agglutination test as well as agglutination with 2 mecapto ethanol, blood cultures and serum PCR for a period of 27 months. The suspected source of infection was fresh goat cheese from a known endemic zone. Brucella melitensis was isolated from the blood cultures of two patients. All of the patients were positive in serological and PCR tests at the beginning of this follow-up. At the end of the study, three patients responded well to the treatment and showed negative results in the serological and PCR tests. While two patients with diabetes mellitus type 2, showed positive results in the serological and PCR tests as well as persistent symptoms. Clinical follow-up of patients with brucellosis is of great importance, to properly evaluate the given treatment. In this sense the PCR is a great supporting tool in diagnostic testing.