Management factors associated with Babesia bovis seroprevalence in cattle from eastern Yucata Ân, Mexico Jose  L. Solorio-Rivera a , Roger I. Rodrõ Âguez-Vivas b,* , Enrique Pe Ârez-Gutierrez c , Gale Wagner d a Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicola Âs de Hidalgo, Av. Acueducto y Tzintzuntzan, C.P. 58000, Morelia, Michoaca Ân, Mexico b Facultad de Medicina Veterinaria y Zootecnia, Universidad Auto Ânoma de Yucata Ân, Km 15.5 carretera Me Ârida- Xmatkuil, Apartado Postal 116-D, Me Ârida, Yucata Ân, Mexico c Facultad de Medicina Veterinaria, Universidad Nacional, Apartado Postal 86-3000, Heredia, Costa Rica d Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, TX, USA Accepted 11 February 1999 Abstract The effect of management on the seroprevalence of Babesia bovis was studied in 399 Bos indicus cattle 1±2 years old from 92 farms in the eastern Yucata Ân, Me Âxico. The management factors studied were: farm-type, production system, herd size, farm size, stocking density, vector control, dipping interval, type of dipping, type of acaricide and cattle introduction to the farm. A cross-sectional study was carried out (2-stage cluster sampling). The number of serum samples was proportionally distributed according to the number of farms in the nine locations of eastern Yucata Ân, Me Âxico (399 animals from 92 farms). Antibody activity to B. bovis was tested using an indirect ELISA. The farms with a seroprevalence 75% were considered as cases and those with seroprevalence >75% were considered as controls. The variables with p  0.20 were included in fixed effects logistic regression. The seroprevalence of the zone was 73.8% (66.3±81.3%). The following risk factors were found: Stocking density (<1 head/ha, OR  4.04, CI (OR)  1.20±13.62) and dipping interval (>60 days, OR  5.07 CI (OR)  1.26±20.48). # 1999 Elsevier Science B.V. All rights reserved. Keywords: Babesia bovis; Clusters; Cattle-parasitological diseases; Cross-sectional studies; ELISA; Seropre- valence; Me Âxico Preventive Veterinary Medicine 40 (1999) 261±269 * Corresponding author. Tel.:+52-99-42-32-00; fax: +52-99-42-32-05; e-mail: rvivas@tunku.uady.mx 0167-5877/99/$ ± see front matter # 1999 Elsevier Science B.V. All rights reserved. PII:S0167-5877(99)00019-7