Microbiological and Immunological Studies on Brucellosis in a Hospital in Al-Madinah Al-Munawarah

Abstract

Purpose: The study was conducted to estimate the prevalence of brucellosis in Prince Sultan Armed Forces Hospital at Al-Madinah Al-Munawarah, Saudi Arabia. The aim was also to determine the most prevalent species of Brucella and to make a comparison between culture and serological methods in diagnosis and to evaluate the levels of sIL-2R and/or IFN-γ production to be used as markers of treatment efficacy. Study Design: Cross-sectional Study Subjects and Methods: This study was conducted on 65 patients with male: female ratio (2:1) suspected of having brucellosis. It was carried out using slide agglutination test for detection of anti-Brucella antibodies. Also, we estimated anti-Brucella IgG and IgM antibody levels in the sera of examined patients using ELISA. Quantization of human IFN-ɣ was performed. Results: The total incidence of brucellosis was 92.3%. The incidence among males (95.2%) was higher than that of female (87%). Brucellosis was detected in all age groups. Most of brucellosis patients were recovered during the period from January to June. Consumption of milk products, heating raw milk and milking animals were the highest risks with an incidence of 100% followed by drinking raw milk with an incidence of 95% while cutting raw meat and animal contact were the less risk with an incidence of 80% and 67%, respectively. The most prevalent species among examined patients was B. melitensis (86%) and B. abortus (6%). Brucellosis patients had 63% and 83%of anti BrucellaIg G and IgM, respectively. The highest (%) of patients having positive IgG and IgM levels in their sera were among 1/160 standard tube agglutination test (SAT) antibody titer group brucellosis patients were having positive levels of IFN-ɣ. All of them belonged to 1/80 antibody titer group. The mean IFN-ɣ levels according to SAT antibody titers were 224.25, 102 and 69.3 pg/ml, respectively. Conclusion: Eradication of human brucellosis depends on the eradication of animal brucellosis. In countries like the Kingdom of Saudi Arabia, where brucellosis is endemic; rapid, sensitive and highly specific diagnostic methods are required to make early diagnosis and prevent resistance as there is an overlap in therapy.