A cross-sectional study of bovine tuberculosis in the transhumant and agro-pastoral cattle herds in the border areas of Katakwi and Moroto districts, Uganda

Abstract

A study to determine the prevalence of bovine tuberculosis in the transhumant and agro-pastoral cattle herds in the border areas of Katakwi and Moroto districts in Uganda was carried out from July 2006 to January 2007 using comparative intradermal tuberculin test containing bovine and avian PPDs. A total of 1470 animals, 612 (41.6%) males and 858 (58.4%) females, 883 (60%) young, 555 (37.8%) adult and 32 (2.2%) old animals were included. The study involved a cross-sectional multistage sampling technique with random selection of individual animals from a herd. The results revealed a 1.3% overall prevalence of bovine tuberculosis in cattle herds in the study area, with a marked variation between sub-counties. The highest recorded prevalence was 6.0% in Kapujan, while no cases were recorded in Ongogonja, Magoro and Katakwi sub-counties. Distinctly different patterns in the avian-bovine reactions were also found in different sub-counties. A multivariate logistic regression showed more positive reactions (OR = 6.3; 95%CI (1.4-26.34) in females than males. BTB prevalence did not differ significantly between cattle maintained in pastoral and agro-pastoral production systems. The study demonstrated a relatively low prevalence of bovine tuberculosis in local zebu cattle reared under traditional husbandry systems in Uganda, suggesting low infectiousness of the disease under such mode of production. The risk associated with the consumption of raw milk among the pastoral communities and that, the pooling of milk together from different animals is a common practice, warrants more investigation into the zoonotic transmission of tuberculosis within these communities.

Prevalence of bovine tuberculosis in cattle in the highlands of Cameroon based on the detection of lesions in slaughtered cattle and tuberculin skin tests of live cattle

“…This finding is in agreement with Inangolet et al (2008), who suggested high levels of infectiousness of bovine TB under the common cattle management practices and humid tropical conditions. However, inefficient close contact between diseased and healthy animals in extensive systems, dairy herds and large herds, and possibly a decrease in virulence and transmission capacity of the causal strains due to adverse weather (Oloya et al 2006), and low infectiousness of the local zebu cattle (Ameni et al 2006(Ameni et al , 2007Inangolet et al 2008), were also characteristics in the study environments. A better resistance or adapted tolerance to bovine TB infection of some local breeds have been suggested (O'Reilly and Daborn 1995;Ameni et al 2008), and could have been the reasons for the lower prevalence rates recorded among the Namchi, Guadali and White Fulani compared to the Red Mbororo cattle.…”

“…In this study, animal environments were generally humid or wet and favourable for long survival of TB agents (Goodchild and CliftonHadley 2001;Philips et al 2003). However, contradictory results of lower bovine TB prevalence in cattle maintained in traditional pastoral systems in Uganda and Ethiopia were associated with the relatively dryer conditions of the environments (Oloya et al 2006;Ameni et al 2007;Inangolet et al 2008). Traditional pastoral systems in the tropics that create risks characteristic of intensive farming in relation to the transmission of bovine TB have been well documented (O'Reilly and Daborn 1995;Omer et al 2001;Ayele et al 2004).…”

“…Intensive management systems provide favourable conditions for bovine TB transmission by promoting closer and more prolonged contacts between animals than in extensive systems (Ayele et al 2004;Zinsstag et al 2006;Inangolet et al 2008). In this work, the spread of the pathogen in the extensive and semi-extensive systems could have resulted from the closer contact experienced during periods of drought at shared grazing, watering and salt leak points, "cattle markets", during veterinary interventions (vaccination campaigns), and other ventures that involved the gathering together of different herds of animals.…”

“…For both tests, the disease was more severe in the Western highlands compared to the Adamawa plateaux; age was a more significant risk factor than sex, and upgraded / exotic and Red Mbororo cattle showed the highest prevalence rates. Age and sex (Ameni et al , 2007Oloya et al 2006;Inangolet et al 2008), herd size and body condition , husbandry system and breed (Ameni et al 2006(Ameni et al , 2007, have been extensively reported as important risk factors influencing individual bovine TB prevalence rates. However, and Oloya et al (2006) suggested that sex was a weak risk factor similarly to this study where non-significantly more female than male animals were affected.…”

“…Anergy has been reported to cause false TST negative reactions but the reasons are still poorly understood (Inangolet et al 2008). However, recently infected cattle, cattle under stress due to malnutrition, gastrointestinal parasitoses and other concurrent infections and cattle with generalized TB would be anergic and fail to react to TST (Ameni and Medhin 2000;Inangolet et al 2008).…”