Epsilon Archive for Student Projects

Abstract

In Zambia, small ruminants play an important role in securing the livelihood of resourceconstrained smallholder farmers by contributing to income, social status and food security.
Infectious diseases, such as mange and orf, can be major challenges to small ruminant production as they can cause big economic losses. Both mange and orf are among the top constraints faced by the farmers in the country today with only a few studies done on the prevalence. The aim of this
study was to investigate the clinical presentation and occurrence of the contagious skin diseases mange and orf in goat herds in Zambia.
Skin scrapings were collected from goats with clinical signs of mange and eSwabs were taken from goats with clinical signs of orf in the Southern and Central province of Zambia. In total, twenty households were included in the study (10 in the Southern province and 10 in the Central
province) and at each household, 10 goats were randomly selected for clinical examination with focus on the skin for mange and areas around the mouth, nose, teats and feet for orf. The material collected by skin scraping was digested in 10% potassium hydroxide followed by microscopic
examination for detection of mange mites. For detection of parapoxvirus, DNA was extracted from the eSwabs followed by Real-Time PCR. For confirmation, a touch-down PCR was conducted followed by gel electrophoresis.
The herd occurrence of mange was 10% (1/10) in the Southern province and 10% (1/10) in the Central province of Zambia and the genuses of mange mite located were Sarcoptes spp. in the Southern province and Demodex spp. in the Central province. The major clinical sign of mange on the animals positive at microscopic examination was alopecia. The herd occurrence of orf virus was 10% (1/10) in the Central province and 0% in the Southern province. The clinical signs
present in the positive herd was small lesions and pustules in the mouth.
The study shows that both mange and orf are present in goat herds in Zambia. The low occurrence is likely due to challenges in diagnostic techniques, mild clinical signs present and unfavorable seasonal conditions for mange mites. The study also found widespread use of acaricides, unclear control strategies against ectoparasites and a possible perception among farmer conflating mange with other skin conditions that present with similar clinical signs. Further
research is recommended during the rainy season when conditions are more favorable for mange mites, along with investigations into the effectiveness of ectoparasite control strategies among farmers. The herd positive for parapoxvirus is most likely positive for orf virus but sequencing is needed for definite diagnosis. To better understand the distribution and impact of orf in goat herds
across Zambia, further research on the seroprevalence of the disease is recommended.