Prevalence of Bovine Trematodiases and Associated Risk Factors in Nyagatare District, Rwanda

Introduction

Trematodiases cause significant financial losses to livestock worldwide and some of which are zoonotic, raising public health concerns. In Rwanda, information on the prevalence of bovine trematodiases is scanty, and this hampers efforts to control and prevent them in the country.

Methods

This cross-sectional study aimed to determine the prevalence of bovine trematodiases in Nyagatare district and associated risk factors. One hundred cattle were randomly selected for this study and faecal samples were collected directly from the rectum to identify trematode eggs using a simple sedimentation technique. To analyze the data, frequencies, chi-square test, and binary logistic regression were computed.

Results

Overall, the prevalence of bovine trematodiases was 69%, and Paramphistomum spp. predominated (69%), followed by Dicrocoelium spp. (23%), Fasciola spp. (20%), and Echinostoma spp. (1.0%). The study also recorded mixed paramphistomiasis, fascioliasis and dicrocoeliasis (11.6%), paramphistomiasis and fascioliasis (15.9%) as well as paramphistomiasis and dicrocoeliasis (20.3%). The odds of having trematodiasis (mono or mixed fascioliasis and dicrocoeliasis) for the cow located in Barija cell (AOR = 0.143; 95% C.I. 0.026-0.793) were 14% lower compared to those of developing such parasitosis for the cow located in Bushoga cell.

Conclusion

Taken together, the study shows that trematodes are a significant contributor to lowering livestock production and productivity and pose a threat to human health. Different approaches should be applied to prevent and control the trematodiases in cows and other livestock (sheep and goats) and reduce the risk of contracting fascioliasis and echinostomiasis in humans in Nyagatare district, Rwanda.

A survey of sheep dicrocoeliosis in Sulaymaniyah slaughterhouse, northern Iraq in 2013-2014

Dicrocoelium dendriticum is a helminth which lives in the bile ducts and gall bladder of mammalian definitive hosts. Dicrocoeliosis is thought to be endemic in some countries and it has an increasing prevalence in Northern Iraq, potentially due to increased importation of infected animals, particularly sheep, in high numbers from neighboring countries. The parasite's ability to infect rodents, wild animals, livestock and humans means this parasite is of significant interest in veterinary and human medicine. While D. dendriticum causes relatively mild clinical disease in animals, infection leads to liver condemnation at slaughter and subsequent economic losses to farmers. In this study, the livers of 91,486 sheep slaughtered at Sulaymaniyah New Slaughterhouse (Northern Iraq) were visually inspected for D. dendriticum infection between November 2013 and March 2014, with 1269 livers rejected due to D. dendriticum in this period, representing 29.4% of all condemned livers. The highest rate of rejection due to D. dendriticum infection was seen in December, possibly linked to increased numbers of intermediate host snails during the wet season. Routine inspection of condemned livers revealed adult flukes of D. dendriticum and eggs were seen in the faeces of imported sheep, indicating these animals may be a vector for introduction of D. dendriticum to this region. Due to the complex life cycle and wide range of animals which it infects, we cannot establish the exact route of introduction into Iraq; however, our study suggests that slaughterhouse workers, farmers and local health authorities should be aware of the presence of D. dendriticum, and the potential risks it represents to both human and animal health. Our data also suggest that some level of quarantine or border checks may be useful to prevent further introduction of D. dendriticum or other pathogens into Iraq, although this may prove difficult until accurate diagnostic assays are developed.

Prevalence of Fascioliasis and Associated Economic Losses in Cattle Slaughtered at Lira Municipality Abattoir in Northern Uganda

Fascioliasis (liver fluke infestation) is one of the most important parasitic diseases affecting cattle, other ruminant animals and humans. Fascioliasis causes large, but usually neglected, economic losses to cattle farmers and traders. The objectives of this study were to assess the prevalence and associated risks for fascioliasis in slaughter cattle and estimate the financial losses due to liver condemnation at the Lira Municipal abattoir in Uganda. A total of 216 cattle were sampled during the study period. Animal breed and sex were determined by observing the phenotypic characteristics of the animals. Age was determined by assessing the eruption and wearing of permanent teeth. After slaughter, the liver was examined for presence of Fasciola spp. (liver flukes) by visual inspection, palpation, and incisions. The bile ducts and gall bladder were similarly examined for presence of mature Fasciola spp. The gross weight and amount of liver trimmed-off due to fluke infestation were determined. Of the 216 liver examined, 65.7% (n = 142) were infested with Fasciola spp. Cattle that were aged 4-5 years old at the time of slaughter had significantly greater odds (OR = 5.84; CI [2.79-12.22]) of being infested with Fasciola spp. compared to those that were younger than 3.5 years old. In contrast, cattle that had a body condition score of 3.5 or 4 had lower odds (OR= 0.42; CI [0.21-0.88] and OR = 0.22; CI [0.04-1.10]) of fascioliasis than those with a BCS of 3. Other tested variables including animal origin, breed, sex, and gross weight of the liver had no significant effect on the prevalence of fascioliasis. This study also revealed that the abattoir loses an estimated 38 million UGX annually due to condemnation of Fasciola-infested liver (one UGX= 0.00027 USD; July 2016). Our study showed that the prevalence of fascioliasis was high in Lira District, Uganda, which results in a large amount of liver being condemned and destroyed, leading to financial losses for affected farmers in the area. Therefore, there is a need to take the necessary preventive measures to control the disease and increase awareness among farmers and medical personnel in the area due to the zoonotic nature of fascioliasis.

Economic impact of the liver condemnation of cattle infected with Fasciola hepatica in the Peruvian Andes

Fasciolosis is a zoonotic food- and waterborne infection related to great economic losses on ruminant production. In order to determine the prevalence of bovine liver condemnations due to fasciolosis in an abattoir at the Central Andes of Peru, we evaluated the records of an authorized slaughterhouse in Huancayo, at 3300 m above sea level, over 16 months. Subsequently, the average weights of condemned viscera and carcasses were also estimated to determine the direct and indirect economic losses. Fasciolosis was the main cause of liver condemnation, with a prevalence of 55.72% (3926/7046; CI 95%: 56.88-54.56%). The livers infected were more than double the amount of livers supplied to markets in this period. Although the average price of liver in the Peruvian Andes is very cheap, approximately 16.45 tons of livers were destroyed, estimating a direct economic loss of US$ 35,080 (CI 95%: US$ 29,178-40,938). The indirect loss due to decreased body weight gain (calculated using 10% of the average weight of a healthy animal carcass) was estimated at US$ 354,570 (CI 95%: US$ 387,908-US$ 321,227). Fasciolosis is an important zoonotic disease that threatens food security in the Andean region, with major repercussions on the income of the livestock industry and the availability of cheap protein sources.

Dicrocoeliidae Family: Major Species Causing Veterinary Diseases

This chapter analyses the taxonomic position of Dicrocoeliidae family and several of its genus and species. The biology of the major species causing veterinary diseases such Dicrocoelium dendriticum, Dicrocoelium hospes, Dicrocoelium chinensis, Eurytrema pancreaticum and Platynosomum fastosum, has been reviewed. All these species have an indirect life cycle, involving two intermediate hosts (molluscs as first and ants, grasshoppers and lizards as second). Dicrocoelium dendriticum is a very widespread hepatic trematode in the ruminants of many countries in Europe, Asia, North Africa and North America, even affecting humans. Dicrocoelium hospes is widely distributed in the savanna areas of Africa south of the Sahara, whilst D. chinensis has mainly been found in ruminants in East Asia and some European countries (probably imported from Asia). Eurytrema pancreaticum is a common parasite whose adults live in ruminant bile ducts, gall bladder, pancreatic ducts and intestines in Europe, Madagascar, Asia and South America. Adult P. fastosum live in the liver, gall bladder and pancreas of birds and mammals in Europe, Africa, Asia, North, Central and South America. Information about the epidemiology, pathology, clinical aspect, diagnosis, treatment, control, prevention and economic impact mainly of Dicrocoeliosis produced by D. dendriticum, as well as of Eurytrematodosis and Platynosomiosis, has been included.