The epidemiology of Mycobacterium bovis infections in animals and man: A review

Responses to tuberculin among Zebu cattle in the transhumance regions of Karamoja and Nakasongola district of Uganda

“…Factors such as congregation of herds in grazing and watering areas, merging of different cattle herds during migration, high cattle density in cattle camps, overcrowded night kraals, large herd sizes (mean = 95 cattle) and cattle rustling could explain the high prevalence of positive herds in Karamoja districts (Neill et al, 1989;O'Reilly and Daborn, 1995). Of special importance are the rampant armed cattle raids between ethnic groups for enhancement of socioeconomic status, which move cattle from one district or area to another.…”

“…Adverse weather conditions such as high environmental temperatures (30-35•C), strong direct sunlight (specifically ultraviolet light) and dry weather conditions as experienced in Karamoja (500-700 mm) (Karamoja-Data-Centre, 2004) and Nakasongola (875 mm) are capable of reducing the survival of the bacilli in the environment (Menzies and Neill, 2000;Phillips et al, 2003) and the likelihood of its transmission (King, 1999;Phillips et al, 2003). Dry conditions also affect the critical size of aerosol droplets necessary to establish an infection (Chambers et al, 2001) and diminish the efficiency of infections by the respiratory route (O'Reilly and Daborn, 1995), which is of most importance in BTB transmission. Under these conditions, few M. bovis organisms would survive for long at concentrations above the minimum number of particles required to establish infection (Menzies and Neill, 2000).…”

“…There is no supplementary feeding and very limited veterinary care is provided. Although M. bovis transmission is reportedly low under such extensively managed systems compared to intensive ones (Francis, 1947;Steele and Ranney, 1958), documented practices that favour transmission, such as sharing of communal grazing and watering areas by livestock from different areas or herds (Phillips et al, 2003), heavy faecal contamination of a few stagnant water sources (Faries and Davis, 1997) and overcrowding in night enclosures (O'Reilly and Daborn, 1995), are routine and common in the transhumance system. Long-distance migrations, large herds (n > 35 cattle) and overcrowding in cattle camps during the dry season increase herd-to-herd contacts and create an ideal environment for transmission (Neill et al, 1989;Omer et al, 2001).…”

Introduction to this issue: Dealing with TB in wildlife

“…For TB eradication in cattle strategies that reduce pathogen transmission between wildlife and domestic animals and between non-bovine livestock and cattle must be developed [8]. This can be achieved by preventative actions, such as host population control through random or selective culling, or through habitat management, and by vaccination.…”

A descriptive spatial analysis of bovine tuberculosis in intensively controlled cattle farms in New Zealand

“…Bovine tuberculosis (TB), caused by Mycobacterium bovis, is an infectious disease that causes economic, public health [4,27], and ecological concerns around the world [2,7,15]. The incidence of bovine TB in New Zealand has been reduced through a national test-andslaughter policy which has been compulsory for all dairy and beef herds since the 1960s [1,10].…”