Cystic echinococcosis in cattle slaughtered at a slaughterhouse in Gessa, southern Ethiopia

Risk factors and economic losses associated with cystic echinococcosis among livestock in selected pastoral and agro-pastoral areas of Uganda

BACKGROUND

Cystic echinococcosis is a parasitic cyclo-zoonotic disease caused by the taeniid Echinococcus and causes significant economic losses in livestock production, yet its impact is often overlooked and under estimated.

METHODS

This study investigated the risk factors and economic impact of cystic echinococcosis in livestock, in Uganda's pastoral and agro-pastoral communities. In the study, 14,937 livestock were examined at selected slaughterhouses in Moroto, Kumi, Luwero and Nakasongola districts from March 2019 to February 2020. The visceral organs were examined for hydatid cysts during slaughter and the prevalence correlated with the risk factors got from livestock traders and livestock owners through questionnaire survey. Production losses and economic losses due to organ condemnations were also estimated.

RESULTS

This is the first study to provide insights into the financial impacts and risk factors towards Cystic Echinococcosis (CE) in livestock in Uganda. The key significant risk factors for the persistence of CE in goats were place of origin from Lira (P ≤ 0.000), Nakasongola (P ≤ 0.002), Luwero and Bukedea (P ≤ 0.002), and tethering (P ≤ 0.001); in cattle was communal grazing (P ≤ 0.0000); and in sheep was being kept in large flocks (P ≤ 0.004). The total annual economic losses due to CE on livestock inspected in abattoirs in the study districts was USD 21,352.7 (1 USD = 3,809.3 UGX) of which 11.7% was due to organ condemnation and 88.3% due to livestock production losses. More significant mean annual economic losses per livestock species examined occurred in Moroto district among Zebu cattle USD 8.4, goats USD 1.4 and sheep USD 1.4 than other districts.

CONCLUSION

Results show that CE is a disease of significant economic and public health importance in PAP areas in Uganda with urgent need to create awareness and institute community-based control measures involving multistakeholder particiapation.to break livestock-dog cycle.

Analysis of post-mortem inspection outcomes in water buffalo (Bubalus bubalis) slaughtered in the province of Caserta (Campania region, southern Italy)

To date, data on post-mortem inspection outcomes in water buffaloes are absent. The present study aimed to analyze the prevalence of lesions recorded in buffaloes slaughtered from 2018 to 2022 in the province of Caserta by analyzing the data extracted from the Management Information System for Food Safety and Veterinary Public Health (GISA Campania). Between 2018 and 2022, 185,583 buffaloes were slaughtered, with a growing trend from 2018 (n=29,705) to 2022 (n=47,366). A total of 3985 lesions were recorded. At least one lesion was found in 2846 animals (1.53%). The area most frequently affected by lesions was the reproductive system (n=1046/3985; 26.24%) followed by the udder (n=929/3985; 23.31%), liver (n=511/3985; 12.82%), lungs (n=386/3985; 9.69%) and musculoskeletal system (n=192/3985; 4.82%). Degeneration was the most commonly observed condition in the liver (n=387/511; 75.73%), while pneumonia and pleuritis were frequently reported in the lungs (n=197/386; 51.04%). Additionally, traumatic injuries to the musculoskeletal system were also prevalent (n=152/192; 79.17%), while pericarditis and myocarditis were commonly found in the heart (n=64/102; 62.74%). During the period analyzed, a tuberculous-related lesion was found in 186 animals (15.41%), with a decreasing trend observed over the years. The number of lesions observed in this study is relatively low and has been decreasing over the years. This decline may be related to the adoption of stricter biosecurity measures for controlling infectious diseases and the modernization of livestock practices toward precision farming. This study demonstrates how the slaughterhouse can be an important epidemiological tool. Incorporating increasingly specific data at the slaughterhouse provides epidemiological information that can be used to understand disease trends and causes.

Prevalence of cystic echinococcosis among livestock in pastoral and agro-pastoral areas in Uganda

Cystic echinococcosis (CE) remains a significant challenge in Uganda with precise status largely undocumented in most communities. To determine CE prevalence, post-mortem examination was done on 14 937 livestock (5873 goats, 1377 sheep, 3726 zebu cattle and 3054 Ankole cattle) slaughtered in abattoirs in the districts of Moroto in Karamoja region, Kumi in Teso region and Nakasongola and Luwero in Buganda region. The overall CE prevalence was 21.9% in sheep, 15.2% in zebu cattle, 5.5% in goats and 2.1% in Ankole cattle. Moroto district had a higher prevalence of CE than other districts with 31.3% in zebu cattle, sheep 28%, goats 29.1% and (0%) in Ankole cattle. On organ locations, the lungs were the most affected in all livestock in all the study areas. Considering cyst fertility, 33.9, 1.7 and 6.4% of Ankole cattle, sheep and zebu cattle respectively had fertile cysts in the liver while 4.5% of goats and 4% Ankole cattle had fertile cysts in the lungs. In conclusion, CE is widespread and occurs among cattle, sheep and goats in pastoral and agro-pastoral areas in Uganda. Therefore, there is an urgent need to create awareness among the communities on role of livestock in CE epidemiology and transmission.

Evaluation of the Local Immune Response to Hydatid Cysts in Sheep Liver

In order to characterize the inflammatory phenotype of livers of sheep naturally infected by cystic echinococcosis, 100 sheep livers have been macroscopically assessed for the presence of hydatid cysts and sampled for histopathological and molecular analysis. According to gross and microscopic examination, livers were subsequently classified into three groups: normal liver (Group A), liver with the presence of fertile hydatid cysts (Group B), and liver with the presence of sterile hydatid cysts (Group C). Immunohistochemical analyses were accomplished using primary antibodies anti-Iba1, anti-CD3, anti-CD20, anti-TGF-β, and anti-MMP9. Finally, real-time PCR was performed in order to estimate the concentration levels of tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ), interleukin (IL)-12, IL-10, and TGF-β. Immunohistochemical analysis showed a diffuse immunolabelling of mononuclear cells for Iba-1 and TGF-β and a higher amount of CD20+ B cells compared to CD3+ T cells in both Groups B and C. The expression levels of Th-1-like immune cytokines TNF-α, INF-γ, and IL-12 did not show significant statistical differences. However, we found a significant increase in expression levels of Th-2 immune cytokines TGF-β and IL-10 in Groups B and C compared to Group A. Taken together, our findings suggest that macrophages have a predominant role in the local immune response to cystic echinococcosis. Moreover, we can speculate that Th2 immunity may be dominant, corroborating the idea that B cells are decisively essential in the control of the immune response during parasitic infection and that the immunomodulatory role of IL-10 and TGF-β may ensure the persistence of the parasite within the host.

IEg67 kDa Bovine Hydatid Cyst Antigen: A Candidate for Developing Sero-Diagnostic Assays for Cystic Echinococcosis, a Disease of One Health Importance

Cystic echinococcosis (hydatidosis) is a world-wide zoonotic disease of mainly humans, livestock and dogs, caused by Echinococcus granulosus. The disease can negatively impact food production and animal welfare and causes socio-economic hardship. Here, we aimed to identify the local bovine hydatid cyst fluid (BHCF) antigen for developing a sero-diagnostic assay to be used for the pre-slaughter screening of food animals. In total, 264 bovines approved for slaughter in Pakistan were subjected to serum collection and post-mortem screening for hydatid cysts. These cysts were assessed microscopically to assess fertility and viability, and by PCR for molecular confirmation of species. A BHCF antigen was identified from positive sera via SDS-PAGE, confirmed by Western blot, and quantified via a bicinchoninic acid (BCA) assay. The quantified crude BHCF antigen (iEg67 kDa) was then used in ELISA screening to test all sera collected from known positive and negative animals based on hydatid cyst presence/absence. Of the 264 bovines examined, 38 (14.4%) showed hydatid cysts during post-mortem examination. All of these individuals, plus an additional 14 (total: 52; 19.6%) tested positive based on less time-consuming ELISA examination. Based on ELISA, occurrence in females (18.8%) was significantly higher than in males (9.2%) and was higher in cattle (19.5%) compared to buffalo (9.5%). The infection rate increased with age in both host species: cumulatively, 3.6% in animals aged 2-3 years, 14.6% in 4-5-year-olds and 25.6% in 6-7-year-olds. The occurrence of cysts in cattle was significantly higher in the lungs (14.1%) compared to their livers (5.5%), whereas the opposite was true in buffalo (6.6% livers, 2.9% lungs). For both host species, most cysts in the lungs were fertile (65%), while the majority in the liver were sterile (71.4%). We conclude that the identified iEg67 kDa antigen is a strong candidate for the development of a sero-diagnostic screening assay for the pre-slaughter diagnosis of hydatidosis.

The Importance of the Slaughterhouse in Surveilling Animal and Public Health: A Systematic Review

From the point of public health, the objective of the slaughterhouse is to guarantee the safety of meat in which meat inspection represent an essential tool to control animal diseases and guarantee the public health. The slaughterhouse can be used as surveillance center for livestock diseases. However, other aspects related with animal and human health, such as epidemiology and disease control in primary production, control of animal welfare on the farm, surveillance of zoonotic agents responsible for food poisoning, as well as surveillance and control of antimicrobial resistance, can be monitored. These controls should not be seen as a last defensive barrier but rather as a complement to the controls carried out on the farm. Regarding the control of diseases in livestock, scientific research is scarce and outdated, not taking advantage of the potential for disease control. Animal welfare in primary production and during transport can be monitored throughout ante-mortem and post-mortem inspection at the slaughterhouse, providing valuable individual data on animal welfare. Surveillance and research regarding antimicrobial resistance (AMR) at slaughterhouses is scarce, mainly in cattle, sheep, and goats. However, most of the zoonotic pathogens are sensitive to the antibiotics studied. Moreover, the prevalence at the slaughterhouse of zoonotic and foodborne agents seems to be low, but a lack of harmonization in terms of control and communication may lead to underestimate its real prevalence.