title: Understanding the poultry trade network in Kenya: Implications for regional disease prevention and control.
abstract: Infectious diseases in poultry can spread quickly and lead to huge economic losses. In the past decade, on multiple continents, the accelerated spread of highly pathogenic avian Influenza A (H5N1) virus, often through informal trade networks, has led to the death and culling of hundreds of millions of poultry. Endemic poultry diseases like Newcastle disease and fowl typhoid can also be devastating in many parts of the world. Understanding trade networks in unregulated systems can inform policy decisions concerning disease prevention and containment. From June to December 2008 we conducted a cross-sectional survey of backyard farmers, market traders, and middlemen in 5/8 provinces in Kenya. We administered a standardized questionnaire to each type of actor using convenience, random, snowball, and systematic sampling. Questionnaires addressed frequency, volume, and geography of trade, as well as biosecurity practices. We created a network diagram identifying the most important locations for trade. Of 380 respondents, 51% were backyard farmers, 24% were middlemen and 25% were market traders. Half (50%) of backyard farmers said they raised poultry both for household consumption and for sale. Compared to market traders, middlemen bought their poultry from a greater number of villages (median 4.2 villages for middlemen vs. 1.9 for market traders). Traders were most likely to purchase poultry from backyard farmers. Of the backyard farmers who sold poultry, 51% [CI 40-63] reported selling poultry to market traders, and 54% [CI 44-63] sold to middlemen. Middlemen moved the largest volume of poultry on a weekly basis (median purchases: 187 birds/week [IQR 206]; median sales: 188 birds/week [IQR 412.5]). The highest numbers of birds were traded in Nairobi - Kenya's capital city. Nairobi was the most prominent trading node in the network (61 degrees of centrality). Many smaller sub-networks existed as a result of clustered local trade. Market traders were also integral to the network. The informal poultry trade in Kenya is dependent on the sale of backyard poultry to middlemen and market traders. These two actors play a critical role in poultry movement in Kenya; during any type of disease outbreak middlemen should be targeted for control- and containment-related interventions.
authors.affiliation: US Centers for Disease Control and Prevention, Influenza Division, 1600 Clifton Rd. NE, Atlanta, GA 30333, USA. Electronic address: mmccarron@cdc.gov.
authors.forename: Margaret
authors.initials: M
authors.lastname: McCarron
authors.affiliation: Centers for Disease Control and Prevention-Kenya, KEMRI Complex, Mbagathi Road off Mbagathi Way PO Box 606-00621 Village Market, Nairobi, Kenya.
authors.forename: Peninah
authors.initials: P
authors.lastname: Munyua
authors.affiliation: US Centers for Disease Control and Prevention, Influenza Division, 1600 Clifton Rd. NE, Atlanta, GA 30333, USA; Battelle Memorial Institute, 2987 Clairmont Road, Suite 450, Atlanta, GA 30329, USA.
authors.forename: Po-Yung
authors.initials: PY
authors.lastname: Cheng
authors.affiliation: Department of Veterinary Services, Ministry of Livestock Development, P.Os. Box 34188-00100, Nairobi, Kenya.
authors.forename: Thomas
authors.initials: T
authors.lastname: Manga
authors.affiliation: Department of Veterinary Services, Ministry of Livestock Development, P.Os. Box 34188-00100, Nairobi, Kenya.
authors.forename: Cathryn
authors.initials: C
authors.lastname: Wanjohi
authors.affiliation: US Centers for Disease Control and Prevention, Influenza Division, 1600 Clifton Rd. NE, Atlanta, GA 30333, USA.
authors.forename: Ann
authors.initials: A
authors.lastname: Moen
authors.affiliation: US Centers for Disease Control and Prevention, Influenza Division, 1600 Clifton Rd. NE, Atlanta, GA 30333, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Mounts
authors.affiliation: US Centers for Disease Control and Prevention, Influenza Division, 1600 Clifton Rd. NE, Atlanta, GA 30333, USA; Centers for Disease Control and Prevention-Kenya, KEMRI Complex, Mbagathi Road off Mbagathi Way PO Box 606-00621 Village Market, Nairobi, Kenya.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Katz
mesh_terms: D000822:Animal Husbandry / Q000191:economics*; D000818:Animals; D003132:Commerce; D003430:Cross-Sectional Studies; D004196:Disease Outbreaks / Q000662:veterinary*; D007630:Kenya / Q000453:epidemiology; D011200:Poultry; D011201:Poultry Diseases / Q000453:epidemiology* / Q000517:prevention & control*; D011795:Surveys and Questionnaires
keywords: Disease control; Disease prevention; Kenya; Poultry; Social network analysis; Trade