Cross-sectional study on bovine fasciolosis: prevalence, coprological, abattoir survey and financial loss due to liver condemnation at Areka Municipal Abattoir, Southern Ethiopia

Prevalence and associated economic losses of bovine fasciolosis from postmortem inspection in municipal abattoirs in Ethiopia: A systematic review and meta-analysis

Fasciolosis is a prevalent disease that significantly affects the health and productivity of cattle and causes significant economic loss. Beyond individually available studies with varying prevalence rates, there are no pooled national prevalence studies on bovine fasciolosis. Therefore, the aim of the current study was to determine the combined magnitude and economic significance of fasciolosis among cattle on postmortem examination. Inverse variance (I2), sensitivity analysis, funnel plots, Begg's test, and Egger's regression test were used to assess heterogeneity and publication bias. A random-effects model was used to calculate the pooled burden of fasciolosis among cattle. The pooled prevalence of fasciolosis among cattle on postmortem examination was 31.77 % (95 % CI=27.82-35.71). Among a total of 14,965 livers of slaughtered cattle examined in municipal abattoirs, Fasciola hepatica (54.4 %) was the predominant fluke identified compared to F. gigantica (24.6 %). Mixed infections of both species and unidentified immature flukes were detected in 12.4 % and 7.6 %, respectively, of affected livers. Regarding the severity of the pathological lesions observed, 30.5 %, 44.3 %, and 25.2 % of the livers were lightly, moderately, and seriously infested, respectively. The pooled annual economic loss attributed to fasciolosis-associated liver condemnation among cattle in 40 reported studies was approximately 40,833,983.15 ETB (6,417, 847.73 USD). Therefore, bovine fasciolosis requires integrated control methods to address its influence on animal health and economic impact.

Study on Cattle Trematodiasis and Related Risk Factors in Damot Sore District, Wolaita Zone, Southern Ethiopia

Trematodes are chronic, debilitating diseases in livestock, causing significant economic losses worldwide. From mid-December 2021 to May 2022, a cross-sectional study was carried out in the Damot Sore District to estimate the prevalence of trematode infections in cattle and associated risk factors. Trematode eggs were found in 100 of the 384 faecal samples tested, with an overall prevalence of 26.04% (95% CI: 21.88-30.69%). The prevalence for Fasciola, Paramphistome, and Schistosoma species were 12.50%, 5.21%, and 0, respectively. Moreover, the infection rate with two parasites was 8.33%. The data were then examined further using univariable and multivariable logistic regression analysis. As a result, age was the only potential predictor identified to influence trematode infections in cattle among the potential predictors considered. Furthermore, old cattle were more likely to be infected with trematodiasis nearly 12 times (OR = 11.5) that of young cattle, and this difference was statistically significant (p < 0.05), whereas other risk factors considered were statistically insignificant (p > 0.05). According to the findings of this study, cattle trematodiasis is a moderately common disease in the study area. As a result, additional research on the meteorological conditions of snail infection was forwarded, along with other points to reduce the disease problem in livestock production.

Potential Hybridization of Fasciola hepatica and F. gigantica in Africa-A Scoping Review

The occurrence of Fasciola gigantica and F. hepatica in Africa is well documented; however, unlike in Asia, there is a paucity of information on the existence of hybrids or parthenogenetic species on the continent. Nonetheless, these hybrid species may have beneficial characteristics, such as increased host range and pathogenicity. This study provides evidence of the potential existence of Fasciola hybrids in Africa. A literature search of articles published between 1980 and 2022 was conducted in PubMed, Google Scholar, and Science Direct using a combination of search terms and Boolean operators. Fasciola species were documented in 26 African countries with F. hepatica being restricted to 12 countries, whilst F. gigantica occurred in 24 countries, identified based on morphological features of adult Fasciola specimens or eggs and molecular techniques. The co-occurrence of both species was reported in 11 countries. However, the occurrence of potential Fasciola hybrids was only confirmed in Egypt and Chad but is suspected in South Africa and Zimbabwe. These were identified based on liver fluke morphometrics, assessment of the sperms in the seminal vesicle, and molecular techniques. The occurrence of intermediate host snails Galba truncatula and Radix natalensis was reported in Ethiopia, Egypt, South Africa, Tanzania, and Uganda, where F. hepatica and F. gigantica co-occurrences were reported. The invasive Pseudosuccinea columella snails naturally infected with F. gigantica were documented in South Africa and Egypt. In Zimbabwe, P. columella was infected with a presumed parthenogenetic Fasciola. This suggests that the invasive species might also be contributing to the overlapping distributions of the two Fasciola species since it can transmit both species. Notwithstanding the limited studies in Africa, the potential existence of Fasciola hybrids in Africa is real and might mimic scenarios in Asia, where parthenogenetic Fasciola exist in most Asian countries. In South Africa, aspermic F. hepatica and Fasciola sp. have been reported already, and Fasciola hybrids have been reported? in Chad and Egypt. Thus, the authors recommend future surveys using molecular markers recommended to identify Fasciola spp. and their snail intermediate hosts to demarcate areas of overlapping distribution where Fasciola hybrids and/or parthenogenetic Fasciola may occur. Further studies should also be conducted to determine the presence and role of P. columella in the transmission of Fasciola spp. in these geographical overlaps to help prevent parasite spillbacks.

Occurrence of Fasciola (Digenea: Fasciolidae) Species in Livestock, Wildlife and Humans, and the Geographical Distribution of Their Intermediate Hosts in South Africa—A Scoping Review

This review was conducted to provide an update on the status of the occurrence of Fasciola species in livestock, wildlife and humans, and the geographical distribution of snail intermediate host (IH) species in South Africa. The literature search was conducted on four electronic databases using the Boolean operators in combination with predetermined search terms for thematic analysis. Results showed that Fasciola species have been reported in six out of nine provinces of South Africa in the last six decades (1960–2021), with both F. hepatica and F. gigantica infecting vertebrate hosts and F. hepatica and Fasciola spp infecting humans. Results also showed that most studies relied on morphological identification of eggs and flukes without molecular confirmation, which might have led to the misidentification of specimens, especially when immature. Fasciola hepatica has been documented in Limpopo, Mpumalanga, and KwaZulu-Natal provinces. The occurrences of Galba truncatula as the probable snail IH for F. hepatica in the three provinces has been documented while Pseudosuccinea columella has only been documented in Mpumalanga and KwaZulu-Natal provinces. The occurrence of F. gigantica to date has been reported in Mpumalanga and KwaZulu-Natal provinces, with overlapping distribution with F. hepatica. Radix natalensis, the main IH of F. gigantica has been documented in all the three provinces, while the two alien Radix species (R. auricularia and R. rubiginosa) were documented in KwaZulu-Natal province and have been implicated elsewhere with the transmission of F. gigantica. The presence of Fasciola spp eggs and antibodies in humans were documented in the Eastern Cape and the Western Cape provinces, where both P. columella and G. truncatula are known to be present. The prevalence of Fasciola spp infection in livestock ranged from 9.1 to 37.67 %, with an estimated annual financial loss ranging from R44930.26-129901 in cattle production in the Eastern Cape province of South Africa. This review reaffirms the scarcity of information on the occurrence and burden of fasciolosis in South Africa, and further highlights the importance of future research covering all provinces of the country and assessing the public health significance of the disease in resource-poor livestock communities in the areas where the parasite is endemic.

Fasciola species and their vertebrate and snail intermediate hosts in East and Southern Africa: a review

A systematic review was conducted focusing on the distribution of Fasciola species and their snail intermediate hosts (IHs) in East and Southern Africa. The reviewed literature showed that both Fasciola hepatica and F. gigantica are present in East and Southern Africa, and infect a wide range of domestic and wild ruminants. Fasciola gigantica was reported in six East African and five Southern African countries, where Radix natalensis (found in low altitudes) was reported to be the main IH. Fasciola hepatica was reported in Tanzania and Ethiopia (East Africa), and in South Africa and Zimbabwe (Southern Africa), where Galba truncatula (found in high altitudes) was documented as the IH in all countries except in Zimbabwe. Both Fasciola species were documented in Tanzania, Ethiopia, Zimbabwe and South Africa. An overlap of the two was observed in areas with an intermediate altitude in Ethiopia and South Africa, where Pseudosuccinea columella was widespread and assumed to transmit both species. Pseudosuccinea columella has been reported in South Africa and Namibia, and proven to transmit F. gigantica in South Africa; its role in Namibia in the transmission of Fasciola species has not been reported. Other lymnaeid species such as R. rubiginosa were reported in South Africa, and R. auricularia in South Africa and Botswana; their role in the transmission of Fasciola species has not been proven. Future studies should aim to determine the role of P. columella in the geographical spread of the two species in East and Southern African countries.