Background: Brucellosis is one of the endemic diseases in our country and it can be in the types of acute, sub-acute or chronic. It estimates that about 20% of Brucellosis may change from acute to chronic. Because cell mediated immunity (CMI) is the main defense of body against Brucella species, it seems that some degree of Immunologic disorders existed in the patients with chronic form of diseases and some supplements such as Vitamin A (Vit A) as an immunomodulator can stimulate CMI and may decrease the rate of chronicity.
Materials and methods: In a single-blind randomized clinical trial 120 patients with the clinical and serological diagnosed Brucellosis were randomized. A total of 60 patients received streptomycin and Doxycycline as standard therapy for 6 weeks and others in addition to this Regimen received Vit A for about 4 weeks.
Results: In the case group, only 1 case (1.6%) relapsed and in the control group 8 (13.5%) with significant difference (P < 0.005) between two groups. Morbidity of disease was different between two groups.
Conclusion: Vit A therapy in the patients with Brucellosis with may reduce the disease morbidity and rate of chronicity.
Keywords: Brucellosis; immunity; vitamin A.