Morphological identification and molecular characterization of economically important ticks (Acari: Ixodidae) from North and North-Western Egypt.

Ticks represent a major source of growing economic and public health concern, especially in the tropics and sub-tropics. Towards evidencing ticks' invasion in the North and North-Western parts of Egypt, the present study aimed to investigate the morpho-molecular aspects of those ectoparasites using stereomicroscopy, scanning electron microscopy (SEM) and sequencing of the mitochondrial 16S ribosomal DNA gene (rDNA) and nuclear second internal transcribed spacer (ITS2). Our analysis confirmed the presence and well-distribution of Rhipicephalus sanguineus s.l. infesting dogs and sheep (Alexandria governorate), Rhipicephalus annulatus infesting cattle (Beheira governorate), and Hyalomma dromedarii infesting camels (Marsa Matruh governorate) from North/North-Western Egypt. 16S rDNA and ITS2 sequences of the ticks were amplified using universal and gene-specific sets of primers, sequenced and analyzed. Lengths of amplified 16S rDNA sequences in all examined tick species were found to be similar in size (approximately 460 bp); however, they differed in base pair constitutions, whereas ITS2 lengths were 1,500 bp, 1,550 bp, and 1,800 bp for Rh. annulatus, Rh. sanguineus s.l., and Hy. dromedarii, respectively. Phylogenetically, based on the 16S rDNA results, Rh. sanguineus s.l. ticks clustered with the southeastern Europe lineage from Romania and Greece, Rh. annulatus ticks were similar to Turkish populations, and Hy. dromedarii were close to the isolates from Tunisia. Similarly, based on ITS2 sequences, Rh. sanguineus s.l. from dogs were showing 99% similarity to Nigerian populations; however, those collected from sheep were closer to Iranian populations with 4.1% nucleotide divergence between the two populations of different hosts. Rh. annulatus ticks were identical to a population from Romania, whereas Hy. dromedarii was close by 99.7% similarity to a population from Kenya. This is the first study reporting nucleotide sequences of 16S rDNA and ITS2 in integration with morphological identification of ticks from this part of Egypt.

Epidemiology of bovine cysticercosis and associated economic losses in the state of Rio Grande do Sul, Brazil.

Bovine cysticercosis (BCC) is the most frequently detected zoonosis in Brazilian slaughterhouses and is considered a problem for public health and beef production chain, requiring epidemiological studies focusing on evaluating its prevalence, spatial distribution, and economic losses in order to improve and adopt specific strategies for BCC control. Thus, this study focused to establish BCC prevalence and spatial distribution in the state of Rio Grande do Sul, Brazil, and estimate the economic losses for cattle farmers suppliers of one exporter slaughterhouse. A set of 70,591 bovine carcasses were postmortem inspected from 2019 to 2020, which came from 134 municipalities located in eight distinct regions in the state of Rio Grande do Sul. The prevalence found was 3.44% (C.I. 95% 3.30-3.57%), and animals infected with unviable cysticerci were more frequently detected (70.56%) than those carrying viable ones (29.44%). The most frequent destination of carcasses and viscera was non-export (65.48%), followed by freezing/salting (25.41%), heat treatment (8.74%), and rendering (0.37%), resulting in a total economic burden of at least US$ 167,868.53 for cattle farmers. Some regions had higher risk for BCC occurrence, such as Porto Alegre, Caxias do Sul, Santa Maria, Ijuí, and Passo Fundo (OR > 1, p < 0.05), respectively. These results highlight the need of adopting prophylactic measures, mainly in specific areas, in order to control BCC and reduce the economic losses for beef production chain.

Economic model of bovine fasciolosis in Nigeria: an update.

Bovine fasciolosis is a zoonotic infection transmitted by infected freshwater snail-Lymnaea (Radix) natalensis-in tropical regions. The prevalence of bovine fasciolosis in Nigeria is overwhelming with huge financial cost. In the chronic form of the disease, hyperplastic cholangitis and calcification of bile ducts occur with severe liver damage. The aim of the study was to estimate annual economic losses of bovine fasciolosis in Nigeria. Disease prevalence was estimated at 18.3% (8.5-30.6), average annual disease incidence is maintained at 2.5%, an estimated mortality rate of 1.5%, a total liver condemnation rate of 11.1% were estimated from affected liver due to fasciolosis, annual slaughter rate of 10.5% and a total cattle population of 20 million. A total of 7.3% livestock owners consider fasciolosis as a threat, while only 4.3% have ever used molluscicide. Treatment cost of controlling fasciolosis is estimated at US$375,000, which puts the total annual loss due to fasciolosis at US$26.02 million. Both direct and indirect sources of production losses have an impact on the livestock industry in Nigeria. Bovine fasciolosis threatens food security in Nigeria; therefore, further awareness among livestock owners is needed on control strategies to improve the income base for small-scale livestock farmers.

Menace of acaricide resistance in cattle tick, Rhipicephalus microplus in India: Status and possible mitigation strategies.

Livestock in general and dairy sector in particular plays a vital role in the Indian economy and in the socio-economic development of millions of people. Rhipicephalus microplus, a one-host and the most prevalent cattle tick in various agro climatic zones of India. This tick species is responsible for severe economic losses to livestock owners both through the direct effects of blood sucking, injection of toxins and indirectly by transmitting pathogens. Due to inadvertent and indiscriminate use of chemicals to kill ticks, field tick population has developed resistance to almost all chemicals that are used to manage them. The intention of this review is to provide the current status of resistance in ticks, the possible mechanisms of resistance operating in the tick population, factors contributing to the development of resistance and the managemental strategies.

Breeding objectives of Brangus cattle in Brazil.

Our goal was to define a breeding objective for Brangus beef cattle in Brazil. Bioeconomic models were produced and used to estimate economic values (EVs). The scenarios simulated were typical full-cycle beef production systems that are used in tropical and subtropical regions. The breeding objective contained pregnancy rate (PR), warm carcass weight (WCW), mature cow weight (MCW), number of nematode eggs per gram of faeces (EPG) and tick count (TICK). Two models were used in series to estimate the EV. A deterministic model was used to simulate effects of PR, WCW and MCW on profitability with a constant parasite load. Subsequently, stochastic models were used to estimate economic values for TICK and EPG as consequences of their environmental effects on weight gains, mortality and health costs. The EV of PR, WCW, MCW, EPG and TICK, was US$1.59, US$2.11, -US$0.24, -US$5.35 and -US$20.88, respectively. Results indicate positive emphasis should be placed on PR (12.49%) and WCW (65.07%) with negative emphasis on MCW (13.92%), EPG (2.77%) and TICK (5.75%). In comparison with the indexes usually used, these results suggest a reformulation in the selection indexes of the beef production system in tropical and subtropical regions in order to obtain greater profitability.

Economic efficiency of Rhipicephalus microplus control and effect on beef cattle performance in the Brazilian Cerrado.

The cattle tick Rhipicephalus microplus causes significant economic losses to cattle production systems and is a main barrier to the introduction of Bos taurus breeds and their crosses in Brazil. These breeds have the genetic potential to generate animals that are more productive, but they are also more susceptible to R. microplus. One of the alternatives for conventional tick control is the use of strategic control, aiming at delaying or even preventing the development of its resistance to acaricides. The present study aimed to evaluate the economic losses caused by tick infestation on the productive performance of two breeds of beef cattle and to evaluate the economic efficiency of tick strategic control and its impacts on beef cattle production systems. Animal weights were obtained from the literature and were used to calculate the weight loss in kilograms (kg) and the economic loss (US$) caused by R. microplus infestation. The cost/loss ratio of performing strategic control was also calculated. The data show that tick infestation causes economic losses to the breeds and groups of animals evaluated and reduces animal performance (weight loss). The results show a loss of US$34.61/animal in the backgrounding phase and US$7.97/animal in the finishing phase for Brangus animals and its crosses. In conclusion, the data show that strategic control is economically efficient for Brangus animals in the backgrounding phase, independent of the methods used for acaricide application.

Rapid assessment of faecal egg count and faecal egg count reduction through composite sampling in cattle.

BACKGROUND: Faecal egg counts (FEC) and the FEC reduction test (FECRT) for assessing gastrointestinal nematode (GIN) infection and efficacy of anthelmintics are rarely carried out on ruminant farms because of the cost of individual analyses. The use of pooled faecal samples is a promising method to reduce time and costs, but few studies are available for cattle, especially on the evaluation of different pool sizes and FECRT application. METHODS: A study was conducted to assess FEC strategies based on pooled faecal samples using different pool sizes and to evaluate the pen-side use of a portable FEC-kit for the assessment of FEC on cattle farms. A total of 19 farms representing 29 groups of cattle were investigated in Italy and France. On each farm, individual faecal samples from heifers were collected before (D0) and two weeks after (D14) anthelmintic treatment with ivermectin or benzimidazoles. FEC were determined individually and as pooled samples using the Mini-FLOTAC technique. Four different pool sizes were used: 5 individual samples, 10 individual samples, global and global on-farm. Correlations and agreements between individual and pooled results were estimated with Spearman's correlation coefficient and Lin's concordance correlation coefficients, respectively. RESULTS: High correlation and agreement coefficients were found between the mean of individual FEC and the mean of FEC of the different pool sizes when considering all FEC obtained at D0 and D14. However, these parameters were lower for FECR calculation due to a poorer estimate of FEC at D14 from the faecal pools. When using FEC from pooled samples only at D0, higher correlation and agreement coefficients were found between FECR data, the better results being obtained with pools of 5 samples. Interestingly, FEC obtained on pooled samples by the portable FEC-kit on-farm showed high correlation and agreement with FEC obtained on individual samples in the laboratory. This field approach has to be validated on a larger scale to assess its feasibility and reliability. CONCLUSIONS: The present study highlights that the pooling strategy and the use of portable FEC-kits on-farm are rapid and cost-effective procedures for the assessment of GIN egg excretion and can be used cautiously for FECR calculation following the administration of anthelmintics in cattle.

Spatial seroepidemiology, risk assessment and haemato-biochemical implications of bovine trypanosomiasis in low lying areas of Punjab, India.

A cross-sectional study was carried out on 594 bovines (341 buffalo adults, 31 buffalo calves, 163 cattle adults, and 59 cattle calves) to assess the exposure of native bovine population to T. evansi elicited trypanosomiasis in the low-lying areas of Punjab (India). We ruled out the endemicity of the disease with 10.77% (95%CI = 8.53-13.52) sero-positive and 23.56% (95%CI = 20.33-27.15) suspected cases by card agglutination assay. We have presented the spatial distribution of these cases as a guideline to local veterinary practitioners and policy-makers. The categorical assessment of risk factors revealed buffalo adults are the most susceptible group in the state despite insignificant differences in farm management practices. A significant increase in the WBC, platelet, AST and serum iron, and decrease in haemoglobin, haematocrit volume, and serum glucose was recorded in both T. evansi positive and suspected animals.

Simulation tools for assessment of tick suppression treatments of Rhipicephalus (Boophilus) microplus on non-lactating dairy cattle in Puerto Rico.

BACKGROUND: The southern cattle fever tick (SCFT), Rhipicephalus (Boophilus) microplus, remains endemic in Puerto Rico. Systematic treatment programmes greatly reduced and even eradicated temporarily this tick from the island. However, a systemic treatment programme that includes integrated management practices for livestock against SCFT remains to be established in the island. We describe a spatially-explicit, individual-based model that simulates climate-livestock-SCFT-landscape interactions. This model was developed as an investigative tool to aid in a research project on integrated management of the SCFT that took place in Puerto Rico between 2014 and 2017. We used the model to assess the efficacy of tick suppression and probability of tick elimination when applying safer acaricides at 3-week intervals to different proportions of a herd of non-lactating dairy cattle. RESULTS: Probabilities of eliminating host-seeking larvae from the simulated system decreased from ≈ 1 to ≈ 0 as the percentage of cattle treated decreased from 65 to 45, with elimination probabilities ≈ 1 at higher treatment percentages and ≈ 0 at lower treatment percentages. For treatment percentages between 65% and 45%, a more rapid decline in elimination probabilities was predicted by the version of the model that produced higher densities of host-seeking larvae. Number of weeks after the first acaricide application to elimination of host-seeking larvae was variable among replicate simulations within treatment percentages, with within-treatment variation increasing markedly at treatment percentages ≤ 65. Number of weeks after first application to elimination generally varied between 30 and 40 weeks for those treatment percentages with elimination probabilities ≈ 1. CONCLUSIONS: Explicit simulation of the spatial and temporal dynamics of off-host (host-seeking) larvae in response to control methods should be an essential element of research that involves the evaluation of integrated SCFT management programmes. This approach could provide the basis to evaluate novel control technologies and to develop protocols for their cost-effective use with other treatment methods.

Prevalence of Gastrointestinal Parasitic Infections and Assessment of Deworming Program among Cattle and Buffaloes in Gampaha District, Sri Lanka.

Gastrointestinal (GI) parasitic infection is a serious issue in cattle management. The effects of GI parasites may vary with age, sex of cattle, nutritional condition, and severity of infection. Prevalence of GI parasites among cattle population in Gampaha District has not been studied and there is no published study available. A total of 45 farms rearing cattle were selected randomly in three areas, namely, Kelaniya, Ganemulla, and Welisara, under three Veterinary Surgeon Divisions (VSD) in Gampaha District (Mahara, Gampaha, and Welisara). Freshly voided cattle fecal samples were collected randomly from the selected farms during March 2017-December 2017. Out of 163 cattle and buffaloes examined, 13.39% (n=22) were positive for eggs of one or more species of GI parasites. The prevalence of parasitic infection was higher in buffaloes (31.25%, 5/16) as compared to that of cows (11.56%, 21/147), but the difference was not significant (P >0.05). Hookworms (Bunostomum spp.), whipworms (Trichuris spp.), digenetic trematodes (Paramphistomum spp.), cestodes (Moniezia spp.), and oocysts of protozoans (coccidians) were found during the study. The nontreated animals indicated the highest percentage of parasitic infections accounting for 46.67% (n= 14), followed by partially treated individuals (15.15%, n= 5). GI parasite prevalence in males was higher when compared to that of females, but the difference was nonsignificant (P >0.05). General Linear Modelling (GLM) revealed that the effect of treatment status was significantly associated with the prevalence of GI parasites. The calves and yearlings had the highest rate of GI parasitic infections. The highest infection rate was observed at Kelaniya, followed by Welisara. Future investigations are necessary to evaluate the economic impact of GI parasites in the study areas.

In vitro assessment of the acaricidal activity of carvacrol, thymol, eugenol and their acetylated derivatives on Rhipicephalus microplus (Acari: Ixodidae).

This study reports the comparative evaluation of the activity of carvacrol, thymol, eugenol and their respective acetylated derivatives (carvacrol acetate, thymol acetate and eugenol acetate) on Rhipicephalus microplus, to verify the possible influence of the acetate group. The acetylated derivatives were prepared from reactions of the phenolic compounds with acetic anhydride/pyridine. The formation of the products was confirmed by analysis of hydrogen and carbon-13 nuclear magnetic resonance (1H and 13C NMR) spectra. The larval packet test was used to evaluate the acaricidal activity, with concentrations of 0.312, 0.625, 1.25, 2.5, 5.0, 7.5, 10.0 and 15.0 mg/mL. Thymol and carvacrol resulted in 100% mortality starting at the concentration of 2.5 mg/mL, while the same was observed for carvacrol acetate starting at the concentration of 5.0 mg/mL. For the other treatments, 100% mortality was only achieved in the groups treated with the highest concentration (15.0 mg/mL). The LC50 and LC90 values (mg/mL) of carvacrol acetate (2.49, 4.21), thymol acetate (2.97, 8.52) and eugenol acetate (4.25, 13.10) were higher than those for the corresponding precursor molecules carvacrol (0.83, 2.02), thymol (1.26, 2.21) and eugenol (2.77, 5.35). The acetylation process did not enhance the activity of these substances on unengorged larvae of R. microplus, since the precursor substances (carvacrol, thymol and eugenol) had greater efficacy.

Gastro-intestinal parasite infections of Ankole cattle in an unhealthy landscape: An assessment of ecological predictors.

The distribution of gastro-intestinal (GI) parasites across landscapes is closely related to the spatial distribution of hosts. In GI parasites with environmental life stages, the vitality of parasites is also affected by ecological and landscape-related components of the environment. This is particularly relevant for domestic livestock species that are often kept across habitats with varying degrees of degradation, exposing them to a wide range of environmentally robust parasite species. In our study, we examined the effect of environmental and anthropogenic factors on the prevalence and intensity of GI parasites across a free-ranging stock of Ankole cattle in the Mutara rangelands of northeastern Rwanda. Prevalence and intensity of each parasite type (i.e., strongyle-type nematodes, Strongyloides spp., Moniezia spp., and Eimeria spp.) were used as dependent variables. Two fixed factors related to season and conservation-political history, together with three principal components (condensed from nine ecological variables) were used as independent covariates in a univariate General Linear Model (GLM). Major effects on the prevalence and intensity of strongyle-type nematodes and on the intensity of Eimeria spp. were found in that vegetation-related effects such as above-ground grass biomass in conjunction with a high degree of soil compaction had a negative relationship with these parasite types. These unexpected findings suggest that strongyle-type and coccidian infections increase with increasing rangeland degradation. Strongyle-type nematode prevalence and intensity were also negatively related to goat/sheep density, indicating a 'dilution effect' of GI infections between domestic livestock species.

Genetic assessment of leech species from yak (Bos grunniens) in the tract of Northeast India.

Yak is an iconic symbol of Tibet and high altitudes of Northeast India. It is highly cherished for milk, meat, and skin. However, yaks suffer drastic change in milk production, weight loss, etc, when infested by parasites. Among them, infestation by leeches is a serious problem in the Himalayan belt of Northeast India. The parasite feeds on blood externally or from body orifices, like nasopharynx, oral, rectum, etc. But there has been limited data about the leech species infesting the yak in that region because of the difficulties in morphological identification due to plasticity of the body, changes in shape, and surface structure and thus, warrants for the molecular characterization of leech. In anticipation, this study would be influential in proper identification of leech species infesting yak track and also helpful in inventorying of leech species in Northeast India. Here, we investigated, through combined approach of molecular markers and morphological parameters for the identification of leech species infesting yak. The DNA sequences of COI barcode fragment, 18S and 28S rDNA, were analyzed for species identification. The generated sequences were subjected to similarity match in global database and analyzed further through Neighbour-Joining, K2P distance based as well as ML approach. Among the three markers, only COI was successful in delineating species whereas the 18S and 28S failed to delineate the species. Our study confirmed the presence of the species from genus Hirudinaria, Haemadipsa, Whitmania, and one species Myxobdella annandalae, which has not been previously reported from this region.

A review of bovine fasciolosis and other trematode infections in Nigeria.

Trematode infections cause serious economic losses to livestock worldwide. Global production losses due to fasciolosis alone exceed US$3 billion annually. Many trematode infections are also zoonotic and thus a public health concern. The World Health Organization has estimated that about 56 million people worldwide are infected by at least one zoonotic trematode species, and up to 750 million people are at risk of infection. Fasciolosis caused by the fluke Fasciola gigantica is endemic in Nigeria and is one of the most common causes of liver condemnation in abattoirs. Total cattle losses from Fasciola infection in Nigeria have been estimated to cost £32.5 million. Other trematode infections of cattle, including paramphistomosis, dicrocoeliasis and schistosomiasis, have all been reported in various parts of Nigeria, with varying prevalence. Most publications on trematode infections are limited to Nigerian local and national journals, with very few international reports. This paper therefore summarized the current data on distribution, control and zoonotic trematode infections in Nigeria and other African countries. We also identified research gaps and made recommendations for future research and areas for funding for policy/planning.

Assessing the performance of multiplexed tandem PCR for the diagnosis of pathogenic genotypes of Theileria orientalis using pooled blood samples from cattle.

Oriental theileriosis caused by multiple genotypes of Theileria orientalis is an important tick-borne disease of bovines. Here, we assessed the performance of an established multiplexed tandem PCR (MT-PCR) for the diagnosis of the two recognized, pathogenic genotypes (chitose and ikeda) of T. orientalis in cattle using pooled blood samples. We used a total of 265 cattle blood samples, which were divided into two groups according to previous MT-PCR results for individual samples. Samples in group 1 (n = 155) were from a herd with a relatively high prevalence of T. orientalis infection; and those in group 2 (n = 110) were from four herds with a low prevalence. For group 1, 31 and 15 batches of five- and ten-pooled samples (selected at random), respectively, were formed. For group 2, 22 and 11 batches of five- and ten-pooled samples (selected at random), respectively, were formed. DNAs from individual pooled samples in each batch and group were then tested by MT-PCR. For group 1, the apparent prevalences estimated using the 31 batches of five-pooled samples (97%) and 15 batches of ten-pooled samples (100%) were significantly higher compared with individual samples (75%). For group 2, higher apparent prevalences (9% and 36%) were also recorded for the 22 and 11 batches of pooled samples, respectively, compared with individual samples (7%). Overall, the average infection intensity recorded for the genotypes of chitose and ikeda were considerably lower in pooled compared with individual samples. The diagnostic specificities of MT-PCR were estimated at 95% and 94%, respectively, when batches of five- and ten-pooled samples were tested, and 94% for individual samples. The diagnostic sensitivity of this assay was estimated at 98% same for all individual, five- and ten-pooled samples. This study shows that screening batches of five- and ten-pooled blood samples from cattle herds are similar to those obtained for individual samples, and, importantly, that the reduced cost for the testing of pooled samples represents a considerable saving to herd managers.

[Monitoring of sentinel mice and risk assessment of schistosomiasis transmission in key regions of Yunnan Province in 2014].

OBJECTIVE: To establish and perfect the surveillance and forecast system of schistosomiasis, and timely discover the suspicious high risk environments for preventing the human and livestock from schistosomiasis. METHODS: Eight villages of three counties were selected as survey points. Then, the surveillance and forecast of sentinel mice were carried out in the key water regions. The recovered sentinel mice were dissected in laboratory. The sentinel mouse serum antibodies against schistosome were detected by ELISA, the suspicious water contacts of residents and livestock were investigated and the results were analyzed, and the epidemic risk was assessed. RESULTS: Totally 300 sentinel mice were placed, the recovery rate was 94.67%, and the mortality rate was 8.80%. There were no mice with positive serum antibodies against schistosome, and the results of the dissection of all the sentinel mice were negative. The humans who contacted with the suspicious water were mainly villagers, students, children and fishermen by washing hands and feet, washing vegetables, harvesting, fishing and swimming. The Oncomelania hupensis snail areas, human infection rates, and cattle infection rates were obviously declined in recent 3 years. However, the epidemic risks still existed. CONCLUSION: Although schistosomiasis transmission was effectively controlled in the three counties, the comprehensive control measures still should be strengthened.

Echinococcus granulosus and other intestinal helminths: current status of prevalence and management in rural dogs of eastern Australia.

OBJECTIVES: Ascertain the prevalence of intestinal helminths in rural dogs from eastern Australia and Tasmania. Identify farm management practices contributing to the perpetuation and transmission of Echinococcus granulosus. METHODS: Helminth infection in dogs was determined microscopically through faecal flotation. Infection with E. granulosus was determined via faecal antigen-capture ELISA and coproPCR. Taeniid eggs were identified using molecular methods. Data on dog management and owner understanding of hydatid disease were collected via questionnaire. RESULTS: Faeces were collected from 1425 Australian rural dogs (1119 mainland; 306 Tasmania). Eggs of hookworms were most prevalent, up to 40.2%, followed by whipworms (Trichuris vulpis), up to 21.2%. Roundworms (Toxocara canis and Toxascaris leonine) were least common, up to 6.1%. Taeniid eggs were found in 11 dogs (5 Taenia pisiformis; 2 T. serialis; 4 T. hydatigena); 2 of the T. hydatigena-infected dogs were also E. granulosus coproantigen-positive. Of the 45 dogs found to be E. granulosus coproantigen-positive, 24 were in Tasmania, 16 in NSW, 3 in Victoria and 2 in Queensland. Three Tasmanian coproantigen ELISA-positive dogs were also coproPCR-positive. The most common dog ration was commercial dry food, but half the owners fed raw meat to their dogs and some fed offal of lambs (8.9%) or mutton (7.8%). More than half (69%) of owners weighed their dogs before deworming. Few dewormed their dogs often enough to ensure they remained cestode-free and owners hunting wildlife usually left carcases where they were shot. CONCLUSIONS: E. granulosus is still present in Australian rural dogs, including Tasmania, but at low levels. Owner behaviour perpetuates transmission of cestodes.

Reassessment of the potential economic impact of cattle parasites in Brazil.

The profitability of livestock activities can be diminished significantly by the effects of parasites. Economic losses caused by cattle parasites in Brazil were estimated on an annual basis, considering the total number of animals at risk and the potential detrimental effects of parasitism on cattle productivity. Estimates in U.S. dollars (USD) were based on reported yield losses among untreated animals and reflected some of the effects of parasitic diseases. Relevant parasites that affect cattle productivity in Brazil, and their economic impact in USD billions include: gastrointestinal nematodes - $7.11; cattle tick (Rhipicephalus (Boophilus) microplus) - $3.24; horn fly (Haematobia irritans) - $2.56; cattle grub (Dermatobia hominis) - $0.38; New World screwworm fly (Cochliomyia hominivorax) - $0.34; and stable fly (Stomoxys calcitrans) - $0.34. The combined annual economic loss due to internal and external parasites of cattle in Brazil considered here was estimated to be at least USD 13.96 billion. These findings are discussed in the context of methodologies and research that are required in order to improve the accuracy of these economic impact assessments. This information needs to be taken into consideration when developing sustainable policies for mitigating the impact of parasitism on the profitability of Brazilian cattle producers.

Reassessment of the potential economic impact of cattle parasites in Brazil / Reavaliação do potencial impacto econômico de parasitos de bovinos no Brasil

The profitability of livestock activities can be diminished significantly by the effects of parasites. Economic losses caused by cattle parasites in Brazil were estimated on an annual basis, considering the total number of animals at risk and the potential detrimental effects of parasitism on cattle productivity. Estimates in U.S. dollars (USD) were based on reported yield losses among untreated animals and reflected some of the effects of parasitic diseases. Relevant parasites that affect cattle productivity in Brazil, and their economic impact in USD billions include: gastrointestinal nematodes - $7.11; cattle tick (Rhipicephalus (Boophilus) microplus) - $3.24; horn fly (Haematobia irritans) - $2.56; cattle grub (Dermatobia hominis) - $0.38; New World screwworm fly (Cochliomyia hominivorax) - $0.34; and stable fly (Stomoxys calcitrans) - $0.34. The combined annual economic loss due to internal and external parasites of cattle in Brazil considered here was estimated to be at least USD 13.96 billion. These findings are discussed in the context of methodologies and research that are required in order to improve the accuracy of these economic impact assessments. This information needs to be taken into consideration when developing sustainable policies for mitigating the impact of parasitism on the profitability of Brazilian cattle producers.

A rentabilidade da atividade pecuária pode ser diminuída significativamente pelos efeitos dos parasitos que afetam o gado. As perdas econômicas causadas pelos parasitos dos bovinos, no Brasil, foram estimadas em uma base anual, considerando-se o número total de animais em risco e os efeitos negativos do parasitismo sobre a produtividade do gado. Estimativas em dólares baseiam-se em perdas de rendimento conhecidas em animais não tratados, e refletem alguns dos efeitos de doenças parasitárias. Aqui, tais perdas são referidas como perdas potenciais. Parasitos relevantes que afetam o bem-estar do gado e a produtividade no Brasil e seu impacto econômico em dólares incluem: nematódeos gastrintestinais - $7,11 bilhões; carrapato bovino (Rhipicephalus (Boophilus) microplus) - $3,24 bilhões; mosca-dos-chifres (Haematobia irritans) - $2,56 bilhões; berne (Dermatobia hominis) - $0,38 bilhões; mosca-da-bicheira (Cochliomyia hominivorax) - $0,34 bilhões; e a mosca-dos-estábulos (Stomoxys calcitrans) - $0,34 bilhões. A perda econômica anual combinada, devido aos parasitos internos e externos dos bovinos aqui listados, foi estimada em pelo menos $13,96 bilhões. Tais resultados são discutidos no contexto de metodologias e pesquisas necessárias, como a que envolve os efeitos da resistência aos parasiticidas de uso veterinário, para melhorar a precisão de tais avaliações de impacto econômico. Essa informação deve ser considerada pelos tomadores de decisão para influenciar programas de investigação e regulação, a fim de desenvolver políticas sustentáveis que reduzam o impacto do parasitismo sobre a rentabilidade dos pecuaristas brasileiros.

Prevalence of Fasciola species in ruminants under extensive management system in Ibadan southwestern Nigeria.

BACKGROUND: Fasciolosis is a zoonotic trematode of ruminants and a common parasite in cattle in Nigeria. With the increasing numbers of small household cattle herds kept under extensive management system as well as the more usual small ruminants, there is a possibility therefore that parasites common to these ruminants but better adapted to cattle such as Fasciola may also be on the increase within the small ruminant population as they graze freely over the same wide area and sometimes freely mix. AIM: The aim of the study is to determine the prevalence of Fasciola spp in sheep, goats and cattle in Ibadan during the short wet season, (August-October 2011). METHODS: Faecal samples were collected per rectum from 440 each of goats and sheep and 291 cattle. Helminth ova were recovered using sedimentation technique for faecal examination. RESULTS: A total of 40 goats (9.1%), 53 sheep (12.0%) and 158 cattle (54.3%) were positive for Fasciola ova which reflects an increase in prevalence in small ruminants. CONCLUSION: This implies that the entire Ibadan is endemic for Fasciola spp and small ruminants may serve as an important link in the epidemiology of Fasciola spp infection. More so, this has implications for the scavenging household animals which receive little or no medical attention and man that may acquire this trematode by inadvertently eating vegetables with encysted Fasciola metacercariae.