[Clinical, serological and polymerase chain reaction follow-up of a family with brucellosis]. / Seguimiento clínico, serológico y mediante la reacción de polimerasa en cadena de una familia con brucelosis.

INTRODUCTION: 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. AIM: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Seguimiento clínico, serológico y mediante la reacción de polimerasa en cadena de una familia con brucelosis / Clinical, serological and polymerase chain reaction follow-up of a family with brucellosis

Introduction: 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. Aim: 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. Methods: 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. Results: 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. Conclusion: 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.

Introducción: El diagnóstico de brucelosis humana es difícil pues los cultivos de sangre y tejidos tienen un rendimiento limitado (40-70%) y usualmente se recurre a la serología como recurso complementario; últimamente se han desarrollado técnicas de biología molecular que intentan optimizar la confirmación etiológica. Objetivo: Comparar la reacción de la polimerasa en cadena (RPC) con las pruebas de diagnóstico serológicas en el seguimiento clínico de una familia con brucelosis. Métodos: Siete integrantes de una familia con brucelosis que habitaban la zona urbana de Ciudad de México fueron monitoreados mediante aglutinación con antígeno Rosa de Bengala, prueba de aglutinación, aglutinación en presencia de 2 mercapto-etanol, hemocultivos y RPC en suero durante 27 meses. La probable fuente de infección de los pacientes fue el consumo de queso fresco de cabra originario de una zona endémica. Resultados: Brucella melitensis se obtuvo del hemocultivo de dos pacientes. Todos los pacientes fueron positivos a las pruebas serológicas y al RPC al inicio del seguimiento. Tres pacientes respondieron bien al tratamiento y mostraron resultados negativos en serología y RPC al final del estudio. Mientras que en dos pacientes con diabetes mellitus tipo 2 la sintomatología fue persistente, serología positiva y RPC positivos al finalizar el estudio. Conclusión: El seguimiento clínico de pacientes con brucelosis es muy importante para valorar el tratamiento, en este sentido la RPC es una herramienta que puede apoyar a otras pruebas de diagnóstico.