Table 2. Risk assessment for exposure to brucellosis in the pastoralist’s production system of Kajiado County.

Risk analysis steps	Description of evidence for risk profile	Estimates of epidemiological data	Systems affected	Authors
Hazard identification	Sero-Prevalence of Brucella in animals and man.	17% in man (n=174), 13% in goats (n=400), 11% in cattle (n= 200)	Pastoralists system in North Turkana	Nanyende, 2007 (MSc Thesis)
	Sero-prevalence of brucellosis in animals and man	Overall sero-prevalence for the three counties (Kajiado, Kiambu and Marsabit) were:16% in humans and 8% in animals; human and livestock sero-prevalence was 3 and 4 times higher in Marsabit than in Kajiado, which was 6 and 3times higher than Kiambu respectively	Extensive production system (Kajiado and Marsabit) and intensive production system (Kiambu)	Ogola et al. (2014).
	Prevalence of Brucella in cattle milk;	Overall prevalence of 4.9% by indirect ELISA and 3.9% by milk ring test (MRT) at consumer level and 2.4% -ELISA and 3.4% - MRT at informal market.	Milk from Extensive production system (Narok and Nakuru) and intensive production system (Nairobi and Kiambu	Kang’ethe et al. (2007)
Hazard characterisation	Types of Brucella organisms isolated in Kenya: Brucella abortus in cattle milk Brucella melitensis biovar 1 and Brucella abortus biovar 3 isolated in cattle	Milk sampled from urban consumers in Nairobi and Nakuru showed prevalence of 4.7% (n=10) by MRT and 5.1% (n=11) by ELISA; and from Rural consumers: 3.2% (n=7) by MRT and 4.6% (n=10) by ELISA. Brucella melitensis biovar one isolated from cattle milk from Central Kenya, and Brucella abortus biovar 3 from aborted foetal materials from cattle in Central and Eastern provinces of Kenya	Milk from Extensive production system (Narok and Nakuru) and intensive production system (Nairobi and Kiambu; Central province is characterized by intensive production system while Eastern is mainly characterised by semi- extensive production system	Kang’ethe et al. (2007) Muendo et al. (2012)
Exposure assessment	Exposure factors were: •      Consumption of unpasteurized milk •      Consumption of raw meat •      Consumption of raw blood •      Handling infected aborted materials or assisting animals during parturition without protective gloves		Peri-urban pastoralism system and rural pastoralism system	Current study
Risk characterization and estimation	Risk of human infection with Brucella organisms is higher in rural pastoralism than in peri- urban areas		Peri-urban areas and rural pastoralism system	Current study

Key: number of study units or samples which were included for specific studies which were reviewed (n); Masters of Science (MSc); milk ring test (MRT); and enzyme linked immunosorbent assay (ELISA)