Spatial Analysis of Risk Factors and their Effects on Peste des Petits Ruminants Control Strategies in Kajiado and Marsabit Pastoral Systems of Kenya

Gitonga, Pauline Njoki (2015) Spatial Analysis of Risk Factors and their Effects on Peste des Petits Ruminants Control Strategies in Kajiado and Marsabit Pastoral Systems of Kenya. Masters thesis, University of Nairobi.

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The contribution of sheep and goats to pastoralist livelihoods and economies is limited by the frequent occurrence of small ruminant diseases such as Peste des Petits Ruminants (PPR). PPR, also known as ‘goat plague’, is a highly contagious viral disease of sheep and goats characterised by sudden onset of depression, bilateral eye and nasal discharges, mouth sores , pneumonia, foul-smelling diarrhoea and death. In susceptible small ruminant herds, PPR virus infections result in high morbidity rates of 90 percent (%) and mortality rates of 70%. The disease is endemic across 70 countries in Africa, the Middle East and Southern Asia. Current global estimates indicate that PPR outbreaks in endemic countries results in an annual loss of close to 2 billion United State Dollar (USD). PPR was first introduced into Kenya in 2006, but despite vaccination control measures being in place, the disease has continued to spread and is now endemic throughout Northern Kenya. The underlying risk factors triggering outbreaks in Kenya are not well understood. A risk based cross-sectional study was therefore undertaken with an overall aim of improving the management of PPR disease in small ruminant pastoral production systems in Kenya. The study was carried out between January 2014 and March 2015 in Kajiado county which is a high risk PPR zone and Marsabit county which is an endemic PPR zone. The study used integrated approaches of questionnaire survey, laboratory and spatial statistical analysis to address three specific objectives, the first objective, characterised small ruminant disease control practices amongst Kajiado and Marsabit pastoral communities. The second, determined the seroprevalence of antibodies against PPR virus as well as the prevalence of intestinal parasites of sheep and goat herds in the study areas. The third, identified risk factors and their effects on PPR control strategies using spatial statistical techniques of a geographical information system (GIS). xvi Sixty three livestock owners were surveyed across 28 sites in Marsabit and 35 sites in Kajiado. Information concerning the small ruminant husbandry and disease control practices was gathered from livestock owners whose herds were sampled. A total of 535 animals consisting of 245 sheep and 290 goats were randomly sampled. In total, 1,070 blood and faecal samples were collected from 213 small ruminants in Kajiado and 322 in Marsabit. Prevalence of PPR antibodies was determined using the competitive Enzyme Linked Immunosorbent Assay (c-ELISA) laboratory procedure. Clinical indicators of intestinal parasitism were evaluated using Body Condition Score (BCS) chart, FAMACHA© anaemia score chart and Packed Cell Volume (PCV) determination. Prevalence of intestinal parasitism was then confirmed using McMaster and pooled faecal culture laboratory techniques. The study found that only 57% of livestock owners in Kajiado relied entirely on livestock keeping compared to 75% of livestock owners in Marsabit. All (100%) Kajiado livestock owners regularly purchased anthelmintic, antibiotic and tick control products for their small ruminant herds, while only 57% of invested in preventive vaccines. In contrast, all (100%) Marsabit livestock owners did not purchase tick control products or preventive vaccines. However, when available, 42.9% of Marsabit livestock owners occasionally purchased anthelmintic products while only 28.6% purchased antibiotic drugs for use in their small ruminant herds. An important finding with regard to PPR, was that all (100%) livestock owners in Kajiado and Marsabit study sites ranked Contagious Caprine Pleuropneumoniae (CCPP) disease in goats and helminthiasis infections in sheep as the most important small ruminant diseases associated with the highest production and mortality losses throughout the year. The three main constraints hindering livestock keepers’ disease control efforts in Marsabit were lack of veterinary services (52.4%), lack of veterinary drug outlets (35.7%) and lack of inclusion when planning livestock disease control programmes (7.1%). xvii In Kajiado, 60% of livestock owners felt that lack of quality veterinary drugs especially anthelmintics was the main hindrance this was followed by lack of veterinary services (31.4%) and lack of early warning information about disease outbreaks in their area (8.6%). The main policy interventions recommended by majority of Kajiado (90.5%) and Marsabit (84.5%) livestock owners was the provision of regular and timely veterinary services. Veterinary services were defined by the livestock owners as the provision of free vaccination services, extension services and rapid response to disease outbreaks. The overall PPR seroprevalence for Marsabit small ruminant herds was 22.4% (95% Confidence Interval (CI): 19.5 – 25.4) when compared to 37.1% (95% CI: 31.3 – 42.9) for Kajiado herds. PPR seropositivity in Kajiado was associated with geographical location of sheep and goat herds, animals from Lenkisem ward were 64.0 times (p< 0.0001) more likely to be seropositive when compared to animals from Bisil ward. Herd size of goats in Kajiado was also a significant predictor, goats sampled from large herds consisting of more than 100 goats were more likely to be seropositive when compared to medium sized herds composed of between 51 to 100 animals (β-estimate = - 2.19, O.R. = 0.112, p= 0.001). In addition, small ruminants herds in Kajiado that received regular doses of combined oral (Levamisole or Albendazole) and injectable (Ivermectin) anthelmintic products had a significantly (p=0.001) higher likelihood of being PPR seropositive when compared to animals receiving only oral Levamisole products (β-estimate = -1.623, O.R. = 0.197, p=0.001). Prevalence of intestinal parasites and age of animals in Kajiado were not significant predictors of PPR seropositivity. Geographical location of small ruminant herds was also significantly (p< 0.0001) associated with PPR seropositivity of animals in Marsabit, sheep and goat herds sampled from Loiyangalani ward had a 36.6 times (p<0.0001) probability of being PPR seropositive when compared to animals sampled from Dukana ward. xviii Animals sampled from herds that had reported past PPR outbreaks in Marsabit were 96.2 times (p<0.0001) more likely to be PPR seropositive when compared to those from herds that had not reported outbreaks. Further, Marsabit sheep and goat herds that had access to PPR vaccines had a 5.5 times (p= 0.002) probability of being seropositive when compared to herds that had no access to PPR vaccine. Age of animal was also significant (p<0.0001), adult animals that were above 3 years of age were 11.9 times more likely to be seropositive when compared to young animals between 6 and 12 months of age. Prevalence of intestinal parasites in Marsabit was not a significant predictor of PPR seropositivity. The average prevalence of intestinal parasites in Kajiado small ruminant herds was 54.5% (95% CI: 47.9 -61.0) for coccidia parasite and 82.2% (95% CI: 77.0 – 86.9) for helminth parasites. In Marsabit, the average prevalence of intestinal parasites was 48% (95% CI 42.2- 54.0) for coccidia and 30.7% (95% CI: 25.8 – 36.0) for helminths. Haemonchus nematode specie was the most common larvae identified after faecal culture. Co-infection prevalence for both helminth and coccidia intestinal parasite was 51.2% (95% CI: 44.6 -57.7) for Kajiado herds and 21.7% (95% CI: 17.1 -26.4) for Marsabit herds. The utility of GIS as a decision support tool when planning PPR control programmes was demonstrated using spatial statistical techniques of Boolean and overlay analysis, choropleth mapping, Euclidean distance calculation and Voronoi polygon development. GIS analysis found that access to veterinary services varied across Kajiado and Marsabit study areas with Marsabit herds being more disadvantaged due to terrain and long distances that needed to be covered. In conclusion, study findings indicate that small ruminant husbandry practices in Kajiado and Marsabit differed and the differences were due to the access levels to veterinary services, animal health inputs and livestock markets. The overall PPR seroprevalence in the study herds was lower than the recommended 70% that prevents PPR virus circulation in endemic and high risk areas. This means that majority of Kajiado and Marsabit small ruminant herds were not protected from future PPR outbreaks. Serosurveillance was found to be an important tool that can be used to monitor the effectiveness of existing vaccination control programmes as well as evaluate veterinary service delivery. The Five risk factors significantly associated with PPR seropositivity in the study were (1) Age of animal in Marsabit, adult animals were more likely to be PPR seropositive when compared to animals between 6 and 12 months of age. (2) Geographical location of herds in both study areas, that determined accessibility to veterinary services (3) herd size of goats in Kajiado, animals from large herds were more likely to be PPR seropositive due to the likelihood of their owners investing in PPR preventive vaccines (4) Past PPR outbreak incidences in Marsabit and (5) PPR vaccination status in Marsabit. GIS spatial analysis techniques were found to be useful tools that can support decision making when planning, implementing and monitoring PPR control strategies in endemic and high risk areas. The following recommendations should be considered, PPR control strategies in pastoral areas of Kenya should be tailored to specific geographical regions taking into consideration the prevalent small ruminant diseases, existing disease control practices, socioeconomic status of communities and access to veterinary services. Annual PPR vaccination activities should include CCPP vaccination for goats as well as target animals between 6 and 12 months of age. Policy makers should adopt the use of GIS and post vaccination serosurveys to monitor the effectiveness and coverage of PPR vaccination campaigns in pastoral areas in Kenya.

Item Type: Thesis (Masters)
Subjects: G Geography. Anthropology. Recreation > G Geography (General)
S Agriculture > S Agriculture (General)
S Agriculture > SF Animal culture
Divisions: Africana
Depositing User: NLANDU Ephraim DIKUIZA
Date Deposited: 10 Jan 2017 09:48
Last Modified: 12 Jan 2017 10:35

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