Bovine thelaziasis: a re-emerging parasitic disease of cattle and buffaloes.

Fascioliasis is a common disease of sheep and other ruminants caused by F. hepatica and F. gigantica. The disease is worldwide in distribution and is liable for causing extensive economic losses to the livestock industry encompassing reductions in weight gain, wool production and fertility. It is caused by two members of genus Fasciola; Fasciola (F.) gigantica and F. hepatica. Fasciolosis is also known as, fasciolasis, distomatosis and liver rot. It occasionally affects humans, hence considered as a zoonotic disease. The life cycle of these trematodes involves snail as an intermediate host (IH). The epidemiology of fascioliasis is strictly linked to the geographical and environmental characteristics of the area where transmission occurs. The disease mostly diagnosed by prior knowledge of the epidemiology of the disease in a given environment; observation of clinical signs, information on grazing history, seasonal occurrence and standard examination of feces in the laboratory. The affected sheep should be effectively treated with oral administration of a narrow spectrum anthelmintic such as Triclabendazole in addition to reducing the population of the intermediate host to control the disease. Now a days, fasciolosis is recognized as emerging human disease over the world even if only few case reports of human fascioliasis are available in Ethiopia, as the disease mostly affects animals in the country. It causes several economic losses. The losses may be direct or indirect. Treatment of infected animals will largely depend on the correct use of appropriate and registered anthelmintics. Ovine fasciolosis may be controlled by reducing the populations of the intermediate snail hosts and by appropriate anthelmintic treatment. Key words: Anthelmintic, Ethiopia, Fasciola, Ovine

Fasciolosis is one of the major constraint factors for ovine production development in Ethiopia by inflecting direct and indirect loss at different parts of the country. Ovine fasciolosis is an economically important parasitic disease of sheep caused by tr ematodes species of the genus Fasciola , which migrate in the hepatic parenchyma and establish and develops in the bile ducts. In Ethiopia, both species co - exist at different altitudes. The snails of the genus lymnae are mainly involved as an intermediate host in the life cycle of fasciolosis. Ovine fascioliasis in Ethiopia were losses annually estimated at 48.4 million Ethiopian birr due to mortality, productivity (weight loss and reproductive wastage), and liver condemnation at slaughter. This fasciola di sease has three phases of clinical sign acute, sub - acute and chronic forms. Acute fasciolosis occurs as disease outbreak following a massive, but relatively short - term, intake of metacercariae. Death usually results from blood loss due to hemorrhage and ti ssue destruction caused by the migratory juvenile flukes in the live resulting in traumatic hepatitis. Diagnosis of Fasciolosis is based on clinical sign, grazing history, and seasonal occurrence, examination of feces by laboratory tests and post mortem ex amination. Treatment of infected animals will largely depend on the correct use of appropriate and registered anthelmintic. Triclabendazole is the most effective anthelmintic drug which can be destroys or kills all stage of fasciola. Fasciolosis may be con trolled by reducing the populations of the intermediate snail host, or by appropriate anthelminthic treatment and the population of snail should be destroyed by applying Molluscicide and destroying the environment that suit for snail’s reproduction.

Purpose. The purinergic P2Y 2 receptor agonists stimulate active Cl - transport across the excised rabbit conjunctival tissue in vitro. We determined whether UTP or ATP could increase the tear volume and change tear fluid composition in normal rabbits in vivo. Methods. Fifty µL was applied to rabbit eyes of UTP, ATP at concentrations of 0.1, 0.3, 1, 3, 8.5% (1.8–154 mM) or saline. A modified Schirmer test with topical anesthesia was performed 5, 15, 30 and 60 min after the instillation. In studies lasting 30 days, 50 µL of 0.5% UTP was applied 6 times a day for 4 weeks. Tear samples were collected from the conjunctival sac with a glass microcapillary. The protein profile of the tear fluid was analyzed by SDS-polyacrylamide gel electrophoresis and total protein was measured with the Bradford assay. The Easy-Titer rabbit IgG assay kit was used for the determination of immunoglobulin G (IgG). Results. UTP had dose-dependent stimulatory effects on tear secretion. It maximally increased tear secretion about 4-fold 15 min after its application. Similar effects were obtained with ATP. Repeated treatment with UTP reproducibly increased tear volume. Furthermore, UTP did not decrease total protein and IgG concentration in tear fluid and it had no effect on the protein profile. Conclusion. These data indicate that activation of P2Y 2 receptor increases tear fluid secretion accompanied with some proteins in normal rabbits. The purinergic agonists, UTP and ATP, have potential therapeutic value in the treatment of dry eye.

Globally, nematode parasites are arguably the most important causes of suboptimal productivity in sheep and cattle, albeit that they often occur concurrently with other problems. The control of nematode parasites...

Shedding of feline lungworm larvae and their infectivity to snail intermediate hosts after anthelmintic treatment

A computer simulation model of ovine fascioliasis

Parasitic helminths exhibit remarkable diversity in their life cycles, although few parasite species have their whole life cycles resolved. Owing to the fact that parasite life stages within hosts are often not comparable using morphological data, genetic data provides convincing evidence of transmission pathways between intermediate and definitive hosts. We took this approach to an ecosystem level, genetically matching parasite (acanthocephalan, cestode, nematode and trematode) life stages across a broad taxonomic range of intermediate and definitive hosts (invertebrates, seabirds, elasmobranchs and teleost fish) in Otago’s (New Zealand) coastal marine ecosystem. We identified which transmission routes are utilized by the most parasite species and assessed which intermediate hosts are most important in facilitating the transmission of parasites in this ecosystem. Our findings reveal 59 new records of larval parasites infecting their respective intermediate hosts and 289 transmission pathways utilized by 35 helminth species to complete their life cycles. Sprat, triplefin and arrow squid all hosted the highest number of larval parasite species, suggesting they play important roles as intermediate hosts. We then used the new life cycle data to provide a synthetic overview of the life cycles known for various parasite groups in New Zealand. This study highlights how studying parasite life cycles can enhance our understanding of the ecology and evolution of parasites and hosts in natural systems, beyond simply resolving life cycles.

To the Editor: The emergence and reemergence of infectious diseases are major problems for healthcare systems worldwide. Unfortunately, because accurate prediction of the occurrence of such diseases is difficult, if not impossible, surveillance and control can be carried out only after the outbreak has occurred. Predicting the likelihood of a disease outbreak should make it possible to start surveillance programs before outbreaks occur and to initiate control programs before the population has become seriously affected. We used data on changes in land use patterns to predict the likelihood of malaria reemergence in northeastern Thailand. Because natural rubber is of major economic importance and cannot be replaced by synthetic alternatives, the demand for and production of this commodity has consistently increased (1). This situation has led to changes in agricultural practices in various countries in Southeast Asia; rubber production has increased in Myanmar, Laos, Thailand, and Vietnam (1,2). Northeastern Thailand (Isaan) is a relatively poor area, and most rubber plantations belong to smallholders and provide them with a large source of income (3). In 1993, ≈284 km2 of northeastern Thailand were covered by rubber plantations; this area increased to 422 km2 in 1998 and to 948 km2 by 2003 (3). Since then, planting has increased exponentially so that, by 2006, the total area planted with rubber was >2,463 km2; new plantings expanded another ≈1,345 km2 from 2004 to 2006 and increased to a total of 5,029 km2 in 2007 (3). The plants mature ≈6 years after planting; at that stage, the trees can reach 10–12 m in height, although the growth rate depends on the physical and biotic environment (4). Deforestation in northeastern Thailand early in the last century led to an extreme reduction in the incidence of malaria (5) because the main vector mosquito in this area, Anopheles dirus sensu stricto, is forest dwelling and requires a shaded environment for its survival and reproduction (6). Currently, the northeastern part of the country is relatively free of autochthonous malaria cases except for 3 provinces that border Cambodia and Laos (5), Srisaket, Ubon Ratchathani, and Surin. In Srisaket and Ubon Ratchathani, 25% and 31%, respectively, of malaria cases are imported, particularly from Cambodia (7). Mosquitoes are sensitive to changes in environmental conditions, such as shade, temperature, and humidity. These conditions are often influenced by land use change, such as conversion of rice paddies to rubber plantations (8). In addition to providing economic benefits for the population, rubber plantations also provide suitable habitats for A. dirus s.s., perhaps even better habitats than those found in the original rain forest; new plantations lead to increased mosquito density and disease incidence (8). Thus, planting large tracts of rubber potentially increases the likelihood of the reemergence of malaria in northeastern Thailand, although a malaria vector such as A. dirus s.s. could return without reemergence of the disease (9). Should malaria return, the greatly reduced contact between the local Isaan population and Plasmodium spp. over the past ≈50 years suggests that malaria would enter a highly susceptible population, potentially leading to major health problems at the individual and regional levels. This possibility is of particular concern because several strains of Plasmodium in Thailand and surrounding countries are multidrug resistant, which leads to treatment difficulties (5). Each land use change creates different microclimatic conditions, which directly and indirectly affect the occurrence and distribution of malaria (10). Whether malaria will return as a major health threat likely depends on the size and fragmentation of the individual plantation areas. The required size of a plantation for the survival of the vector population is unclear, but large areas of plantation tend to offer dense vegetation and, therefore, high humidity and shade, which provide suitable environmental conditions for larval habitats, even during the dry season (8). Conversely, during the rainy season, conditions at the edges of fragmented forests, where human settlements are often located, become favorable for larval habitats, rendering villagers susceptible to the disease (6). In addition to changes in habitat and microclimate, social or political changes in the region may affect the transborder movement of malaria into Thailand with consequences for potential reemergence (7). Although the association between rubber plantations and malaria is well known in Southeast Asia, the potential for reemergence should receive substantially more attention from economic, agricultural, and environmental planning bodies. Changes in land use and land cover have the potential to facilitate the transmission of disease to humans. Understanding the influence of land use change on malaria occurrence is critical for shaping future surveillance and control strategies.

To determine morbidity and mortality from cholera during different segments of the period 1991-2011 in the countries of Latin America. Using information sources from a nonsystematic literature search for works on cholera epidemics, a mixed ecological study was conducted aimed at a time series analysis of morbidity, mortality, and case-fatality in cholera-related health events between 1991 and 2011 in 18 Latin American countries. During the period 1991-2011, 1 839 037 cases of cholera were reported in Latin America, with 19 538 deaths and a case fatality rate of 1.06%. The most affected countries were Peru between 1991 and 2002-with a maximum annual cumulative incidence of 1 452.72 cases per 100 000 population but a low case fatality rate (0.72%)-and Haiti between 2010 and 2011, with a maximum annual cumulative incidence of 3 319.13 per 100 000 population and a case fatality rate of 1.32%. The cholera epidemic has resulted in high morbidity, mortality, and case fatality in some Latin American countries, due largely to basically socioeconomic and climatic factors. The reemergence of this disease and the many factors related to how cholera outbreaks evolve call for the development and strengthening of regional prevention and control strategies in the countries as well as a study on the determinants that influence the emergence and reemergence of infectious diseases in Latin America.

BackgroundWhile the dispersal of hosts and vectors—through active or passive movement—is known to facilitate the spread and re-emergence of certain infectious diseases, little is known about the movement ecology of Oncomelania spp., intermediate snail host of the parasite Schistosoma japonicum, and its consequences for the spread of schistosomiasis in East and Southeast Asia. In China, despite intense control programs aimed at preventing schistosomiasis transmission, there is evidence in recent years of re-emergence and persistence of infection in some areas, as well as an increase in the spatial extent of the snail host. A quantitative understanding of the dispersal characteristics of the intermediate host can provide new insights into the spatial dynamics of transmission, and can assist public health officials in limiting the geographic spread of infection.Methodology/Principal findingsOncomelania hupensis robertsoni snails (n = 833) were sampled from 29 sites in Sichuan, China, genotyped, and analyzed using Bayesian assignment to estimate the rate of recent snail migration across sites. Landscape connectivity between each site pair was estimated using the geographic distance distributions derived from nine environmental models: Euclidean, topography, incline, wetness, land use, watershed, stream use, streams and channels, and stream velocity. Among sites, 14.4% to 32.8% of sampled snails were identified as recent migrants, with 20 sites comprising >20% migrants. Migration rates were generally low between sites, but at 8 sites, over 10% of the overall host population originated from one proximal site. Greater landscape connectivity was significantly associated with increased odds of migration, with the minimum path distance (as opposed to median or first quartile) emerging as the strongest predictor across all environmental models. Models accounting for land use explained the largest proportion of the variance in migration rates between sites. A greater number of irrigation channels leading into a site was associated with an increase in the site’s propensity to both attract and retain snails.Conclusions/SignificanceOur findings have important implications for controlling the geographic spread of schistosomiasis in China, through improved understanding of the dispersal capacity of the parasite’s intermediate host.

Echinococcosis, a neglected zoonotic disease caused by Echinococcus tapeworms, presents significant public health challenges worldwide. Cystic and alveolar echinococcosis has substantial health and economic impacts, necessitating effective prevention and control strategies. The present review provides a framework to expand our knowledge regarding key components of echinococcosis prevention and control, including phases, options, targets and available tools as well as current gaps and challenges in the field. Furthermore, we discuss the progress made in developing vaccines for the intermediate and definitive hosts and review the limitations and obstacles in vaccine development for definitive hosts. Abundant information is available on various aspects of the Echinococcus vaccine in sheep. Livestock vaccination effectively reduces Echinococcus transmission to sheep, offering a feasible control measure in intermediate hosts. However, vaccine development for the definitive host, i.e. dogs, exhibits significant challenges. Information gaps regarding the immune-mediated protective responses in dogs, repeatability of results, factors influencing the immune response, reinfection resistance, potential age-related decreases in worm burden and factors associated with the antifecundity effect are key challenges that should be addressed in canine vaccine development, and research collaboration, innovative technologies, and a deeper understanding of transmission dynamics are crucial. Multisectoral coordination under the One Health framework, with long-term political commitment and national and international cooperation, is critical for effective control in endemic areas.Graphical abstract

Background Cattle are economically the most important livestock for farmers in Sweden. However, both dairy and beef production has been subjected to considerable structural change over recent decades. Currently, there are approximately 1.5 million cattle, including ≈370 000 dairy cows producing milk worth 1 m€ [1]. The trend is that the numbers of dairy cows are decreasing slowly, while beef cows are somewhat increasing. At the same time as the productivity has been intensified since the 1950’s in the cattle sector, herd size has increased and the number of production units, especially the number of dairy farms, have been dramatically reduced. In contrast, the numbers of organic farms are steadily increasing. The goal of the Swedish government is to increase the Swedish organic production of agricultural commodities to 20% within a three-year period. According to the Swedish animal welfare regulations, both conventional and organic cattle must have access to pasture for a period of 2–3 months per year [2]. The grazing season normally occurs between early May and October. As pasture-borne parasites are ubiquitous wherever animals are grazing, they remain one of the most important productivity constraints in Swedish cattle production. These parasites have in common that they often exhibit simple direct life cycles with infective stages transmitted on pasture by the faecal–oral route. The most important pasture-borne parasites of grazing cattle in Sweden are the gastrointestinal (GI) nematodes Ostertagia ostertagi and Cooperia oncophora. To a lesser degree, the lungworm Dictyocaulus viviparus, and also the coccidian Eimeria alabamensis, are important pathogens. Furthermore, in wet areas the liver fluke Fasciola hepatica, with a complex life cycle, sometimes cause problems. The importance of GI-nematodes and lungworms on the productivity in first-season grazing (FSG) cattle has been demonstrated in a range of independent grazing trials conducted at SWEPAR over the last decade [3-8]. According to the results, the weight-gain penalties in unprotected set stocked FSG animals were on an average in the range of 20 to 65 kg, compared to simultaneously grazed calves but that were fully protected from parasites by the use of effective anthelmintics. Combined, these trials demonstrate the importance of nematode parasites on animal productivity under Swedish climatic and management conditions. They also show that good levels of nematode control can be achieved through the correct use of anthelmintics. However, at the same time there are concerns that over-dependence on ‘chemical’ control may lead to long-term difficulties. This occurs partly through development of anthelmintic resistance, but also because these substances are not widely accepted among consumers. Routine prophylactic use of anthelmintics is not accepted in organic livestock farming [9]. However, “blanket” treatment of the whole grazing group or herd is accepted, even on organic farms, in response to a worm problem after it has been diagnosed. Although the results from our grazing trials also have shown that good levels of parasite control can be achieved without anthelmintics, some of the alternative non-chemical parasite control approaches that we have tested are impractical. For example, when it comes to the use of natural pasturelands there are situations where high grazing pressure must be maintained in order to maintain a profile necessary for the generation of subsidies. Young and adult stock on Swedish dairy Department of Biomedical Sciences and Veterinary Public Health, Div. of Parasitology and Virology (SWEPAR), Swedish University of Agricultural Sciences (SLU), SE-751 80 Uppsala, Sweden Hoglund Acta Veterinaria Scandinavica 2010, 52(Suppl 1):S25 http://www.actavetscand.com/content/52/S1/S25

To investigate the effectiveness of lacrimal gland ultrasonography in the assessment of chronic ocular graft-versus-host-disease (oGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and to establish the correlation between the ocular surface and ultrasonographic results. The cross-sectional study included 57 participants aged 18 and older, who were at least 100 days after allo-HSCT. The study was conducted at the oGVHD clinic of Peking University People's Hospital between March to June 2023. Patients were categorized into groups according to the International Chronic oGVHD (ICCGVHD) consensus group diagnostic criteria or the 2005 National Institutes of Health (NIH) classification criteria for Chronic GVHD. Demographics and transplantation-related information were collected for all participants, including age, gender, donor-recipient HLA matching, donor-recipient ABO matching, donor-recipient gender combination and duration after allo-HSCT. The disease activity of oGVHD and the severity of ocular surface involvement were assessed using various parameters such as Ocular Surface Disease Index (OSDI), Schirmer test, tear film break-up time (BUT), tear meniscus height, corneal/conjunctival staining and meibomian gland dropout. Lacrimal gland structures were assessed by B-mode and Doppler ultrasonography to measure parameters such as the long diameter, thick diameter, homogeneity and parenchymal vascularization. Statistical analyses were performed to determine differences in ocular surface conditions and lacrimal gland ultrasonographic parameters between groups as well as to determine the correlation between ocular surface condition and lacrimal gland ultrasonographic findings. (1) Patients with definite and probable oGVHD exhibited a significantly longer duration after allo-HSCT compared to non-oGVHD patients (H=11.264, p<0.01), The median durations were 247(164,894) days and 525(310,928) days, respectively, compared to 204(169,323.25) days for non-oGVHD patients. (2) Compared to non-oGVHD patients, both definite oGVHD patients and probable oGVHD patients showed lower average of Schirmer test (H=31.188, p<0.01), TBUT (H=11.853, p<0.01), tear meniscus height (H=13.630, p<0.01) and higher average of OSDI (F=27.992, p<0.01), corneal staining scores (χ²=23.66, p<0.05) and temporal conjunctival staining scores (χ²=14.84, p<0.05). (3) The B-mode and Doppler ultrasonography parameters in lacrimal glands including long diameter, thick diameter, homogeneity and parenchymal vascularization did not exhibit significant differences between the three groups. (4) The long diameter in lacrimal ultrasonography had significantly positive correlations with tear meniscus height (r=0.297, p<0.05) and significantly negative correlations with temporal conjunctival staining scores (r=-0.313, p<0.05) and staining total scores (r=-0.285, p<0.05). The thick diameter in lacrimal ultrasonography demonstrated significantly positive correlations with tear meniscus height (r=0.404, p<0.01), and significantly negative correlations with OSDI (r=-0.273, p<0.05), corneal staining scores (r=-0.264, p<0.05), nasal conjunctival staining scores (r=-0.271, p<0.05) and staining total scores (r=-0.312, p<0.05). Homogeneity and parenchymal vascularization were not found to be significantly correlated with ocular surface status. The ocular surface condition in oGVHD patients is worse than that observed in non-GVHD patients. The main manifestations include keratoconjunctival injury and a reduction in tear secretion and tear film stability. These effects appear to be a common result of chemoradiotherapy-induced inflammation and rejection-associated responses. There were no significant differences in the morphology of lacrimal glands as revealed by ultrasonography. This suggests that ocular rejection may not be the primary cause of lacrimal gland changes in oGVHD patients. While ultrasonography can provide insight into tear secretion, its efficacy in diagnosing oGVHD appears limited.

Purpose: To assess the prevalence of dry eye disease (DED) and ocular surface conditions in patients before cataract surgery at a tertiary hospital in South Korea.Methods: This retrospective study included 96 eyes of 96 patients scheduled for cataract surgery from March to June 2023. The primary metrics of DED, including the Symptom Assessment in Dry Eye (SANDE) score, tear film breakup time (TBUT), tear secretion (Schirmer test), and ocular staining score (OSS, Oxford grading), were investigated. The proportion of patients with DED was determined according to the Asia Dry Eye Society (ADES) and revised Korean DED guidelines.Results: The patients’ mean age was 65.9 ± 8.3 years, with a mean SANDE score of 55.6 ± 30.5. The mean TBUT, OSS, and tear secretion were 3.5 ± 1.2 seconds, 1.3 ± 0.8 points, and 7.0 ± 5.4 mm, respectively. Among the patients, 85.4% exhibited a SANDE score of 20 or higher, 99% had a TBUT of &lt; 7 seconds, and 88.4% exhibited one or more points on the OSS. According to the ADES and revised South Korean guidelines, 79.2% and 86.5% of patients were diagnosed with DED, respectively. Furthermore, all 96 patients exhibited at least one abnormal dry eye sign, regardless of symptoms.Conclusions: The prevalence of DED in patients before cataract surgery was &gt; 80%, with all patients exhibiting at least one ocular surface abnormality. Therefore, identifying and managing ocular surface abnormalities before cataract surgery is imperative.

The nematode species that are of most clinical significance to the horse owner are the large redworms (particularly Strongylus vulgaris) small redworms (Cyathostomins), ascarids (particularly Parascaris equorum) and the pinworm (Oxyuris equi). They have a direct life cycle (no intermediate host) and the females are capable of producing thousands of eggs that can pass out in the faeces and then subsequently contaminate pasture and cause infection in susceptible horses. There are many factors that contribute to the clinical relevance of these species and much research has been undertaken into the factors that cause disease in susceptible equine populations. Many control strategies (for example faecal egg counts) and anthelmintic treatment programmes have been recommended in order to limit the clinical effects of these intestinal parasites; however due to the lack of clinical signs seen in horses most owners have relied on the routine prophylactic use of anthelmintics, and as a result anthelmintic resistance has become a growing concern. A better understanding by veterinary staff of the current research in this area would give them the ability to provide targeted therapeutic advice so that owners have a cost-effective and efficacious means of parasite control.