title: Quantitative risk assessment of entry of contagious bovine pleuropneumonia through live cattle imported from northwestern Ethiopia.
abstract: Contagious bovine pleuropneumonia (CBPP) is a highly contagious bacterial disease of cattle caused by Mycoplasma mycoides subspecies mycoides small colony (SC) bovine biotype (MmmSC). It has been eradicated from many countries; however, the disease persists in many parts of Africa and Asia. CBPP is one of the major trade-restricting diseases of cattle in Ethiopia. In this quantitative risk assessment the OIE concept of zoning was adopted to assess the entry of CBPP into an importing country when up to 280,000 live cattle are exported every year from the northwestern proposed disease free zone (DFZ) of Ethiopia. To estimate the level of risk, a six-tiered risk pathway (scenario tree) was developed, evidences collected and equations generated. The probability of occurrence of the hazard at each node was modelled as a probability distribution using Monte Carlo simulation (@RISK software) at 10,000 iterations to account for uncertainty and variability. The uncertainty and variability of data points surrounding the risk estimate were further quantified by sensitivity analysis. In this study a single animal destined for export from the northwestern DFZ of Ethiopia has a CBPP infection probability of 4.76×10(-6) (95% CI=7.25×10(-8) 1.92×10(-5)). The probability that at least one infected animal enters an importing country in one year is 0.53 (90% CI=0.042-0.97). The expected number of CBPP infected animals exported any given year is 1.28 (95% CI=0.021-5.42). According to the risk estimate, an average of 2.73×10(6) animals (90% CI=10,674-5.9×10(6)) must be exported to get the first infected case. By this account it would, on average, take 10.15 years (90% CI=0.24-23.18) for the first infected animal to be included in the consignment. Sensitivity analysis revealed that prevalence and vaccination had the highest impact on the uncertainty and variability of the overall risk.
authors.affiliation: College of Veterinary Medicine and Agriculture, Addis Ababa University, P. O. Box 34, Debre Zeit, Ethiopia; College of Veterinary Medicine, Nursing and Allied Health, Tuskegee University, Tuskegee, AL 36088, USA. Electronic address: yilkalasfaw@gmail.com.
authors.forename: Yilkal Asfaw
authors.initials: YA
authors.lastname: Woube
authors.affiliation: College of Veterinary Medicine, Nursing and Allied Health, Tuskegee University, Tuskegee, AL 36088, USA.
authors.forename: Asseged Bogale
authors.initials: AB
authors.lastname: Dibaba
authors.affiliation: College of Veterinary Medicine, Nursing and Allied Health, Tuskegee University, Tuskegee, AL 36088, USA.
authors.forename: Berhanu
authors.initials: B
authors.lastname: Tameru
authors.affiliation: College of Veterinary Medicine, Nursing and Allied Health, Tuskegee University, Tuskegee, AL 36088, USA; Animal and Plant Health Inspection Service (USDA/APHIS), 4700 River Road, Riverdale, MD 20737, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Fite
authors.affiliation: College of Veterinary Medicine, Nursing and Allied Health, Tuskegee University, Tuskegee, AL 36088, USA.
authors.forename: David
authors.initials: D
authors.lastname: Nganwa
authors.affiliation: College of Veterinary Medicine, Nursing and Allied Health, Tuskegee University, Tuskegee, AL 36088, USA.
authors.forename: Vinaida
authors.initials: V
authors.lastname: Robnett
authors.affiliation: Ministry of Agriculture, P. O. Box 62347, Addis Ababa, Ethiopia.
authors.forename: Amsalu
authors.initials: A
authors.lastname: Demisse
authors.affiliation: College of Veterinary Medicine, Nursing and Allied Health, Tuskegee University, Tuskegee, AL 36088, USA.
authors.forename: Tsegaye
authors.initials: T
authors.lastname: Habtemariam
mesh_terms: D000822:Animal Husbandry / Q000379:methods*; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000382:microbiology; D003132:Commerce; D005002:Ethiopia / Q000453:epidemiology; D008962:Models, Theoretical; D009176:Mycoplasma mycoides / Q000502:physiology; D011002:Pleuropneumonia, Contagious / Q000453:epidemiology* / Q000382:microbiology; D015995:Prevalence; D018570:Risk Assessment / Q000379:methods
keywords: CBPP; Cattle; Disease free zone; Ethiopia; Export trade; Import risk assessment