95 VETERINARSKI ARHIV 73 (2), 95-102, 2003 * Contact address: Dr. Ramesh Chand Katoch, Department of Veterinary Microbiology, College of Veterinary and Animal Sciences, C.S.K. H.P.K.V., Palampur, Himachal Pradesh -176 062, India, Phone: +91 1894 230304(O)/242879; Fax: +91 1894 230327/230511; E-mail: sharmamandeep@hotmail.com ISSN 0372-5480 Printed in Croatia Brucellosis outbreak in an organized dairy farm involving cows and in contact human beings, in Himachal Pradesh, India Rajesh Chahota l , Mandeep Sharma l , R. C. Katoch l *, Subhash Verma l , M. M. Singh 2 , Vipasha Kapoor l , and R. K. Asrani 3 1 Department of Veterinary Microbiology, College of Veterinary and Animal Sciences, Krishi Vishvavidyalaya, Palampur, Himachal Pradesh, India 2 Department of Gynaecology and Obstetrics, College of Veterinary and Animal Sciences, Krishi Vishvavidyalaya, Palampur, Himachal Pradesh, India 3 Department of Veterinary Pathology, College of Veterinary and Animal Sciences, Krishi Vishvavidyalaya, Palampur, Himachal Pradesh, India CHAHOTA, R., M. SHARMA, R. C. KATOCH, S. VERMA, M. M. SINGH, V. KAPOOR, R. K. ASRANI: Brucellosis outbreak in an organized dairy farm involving cows and in contact human beings, in Himachal Pradesh, India. Vet. arhiv 73, 95-102, 2003. ABSTRACT Brucellosis is an important disease of livestock species and wild animals, as well as a significant health hazard in contact human beings, causing a variety of reproductive disorders in cattle under intensive farming. This report is about an outbreak of brucellosis in an organized dairy farm, leading to abortions, retained placenta and stillbirths in cows. The Brucella abortus biotype-I was isolated from placentas, uterine discharges, vaginal swabs and foetal stomach contents collected from infected animals. The serological study, employing rose bengal plate test (RBPT) and serum agglutination test (SAT), revealed involvement of both B. abortus and B. melitensis in all affected cows. Seropositive cases for B. melitensis were also found among 10% of contact animal handlers, having a history of human brucellosis-like symptoms. The isolates were found sensitive to streptomycin, chlortetracycline, ciprofloxacin, ampicillin, tetracycline and gentamicin. The haematological study revealed severe monocytosis averaging 33% and lymphocytosis averaging 32.8% in all infected animals. Key words: abortion, Brucella abortus biotype-I, Brucella melitensis, cows, human beings