Parasitic infections in dairy cattle around Hanoi, northern Vietnam

Fasciola spp. in Southeast Asia: A systematic review

BACKGROUND

Fasciolosis is an emerging public health threat in a number of regions worldwide. To date, we lack an overview of both its occurrence and distribution in Southeast Asia across all actors involved in the life cycle, which impedes the development of disease control measures. Therefore, our objective was to collect recent information on the distribution and the prevalence of Fasciola spp. and the associated risk factors for infection in humans, animals, snails and plant carriers in Southeast Asia.

METHODOLOGY

Bibliographic and grey literature databases as well as reference lists of important review articles were searched for relevant records published between January 1st, 2000, and June 30th, 2022. The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for reporting systematic reviews. A total of 3,887 records were retrieved, of which 100 were included in the final analysis.

PRINCIPAL FINDINGS

The studies focused mainly on one host species (96.0%), with Fasciola spp. infection in animals being the most studied (72.0%), followed by humans (21.0%). Based on the used inclusion and exclusion criteria, reports were retrieved describing the presence of Fasciola spp. infection in seven out of 11 countries in Southeast Asia. Depending on the diagnostic tool applied, the prevalence of Fasciola spp. infection ranged between 0.3% and 66.7% in humans, between 0% and 97.8% in animals, and between 0% and 66.2% in snails. There were no studies reporting the presence of metacercariae on plant carriers.

CONCLUSIONS/SIGNIFICANCE

Our study reconfirms that Fasciola spp. infections are widespread and highly prevalent in Southeast Asia, but it remains difficult to accurately assess the true occurrence of Fasciola spp. in absence of well-designed surveys covering all hosts. As next steps we propose to assess the occurrence of the infection across all actors involved in the transmission, to identify associated risk factors and to estimate the burden of the disease to support national and international decision makers.

Rumen Fluke in Cattle and Buffaloes in Asia: A Review

Rumen fluke is a parasitosis that infects ruminant animals across a wide geographical range of countries. It is a severe infection in temperate and tropical climate regions of Asia, Australia, Africa, and Europe, which cause significant economic losses. In this review, the available information to date on rumen fluke species infecting cattle and buffaloes in Asian countries is evaluated. The citation search was performed through specific keywords, literature published from 1964 to 2021, retrieved from electronic databases: Scopus, Web of Science, Pub Med, Education Resources Information Center (ERIC), Science Direct, Elsevier, and Google Scholar. Twenty-six (26) rumen fluke species belonging to two families: Paramphistomidae 61.5% (16/26) and Gastrothylacidae 38.4% (10/26), were reported in cattle and buffaloes in fourteen Asian countries. Paramphistomum cervi and Cotylophoron cotylophorum are the most prevalent species with broader distribution in countries than the other genera. The coprological prevalence varies from 0.8% to 98.17% and 0.86% to 78.4% in cattle and buffaloes, respectively. The prevalence of rumen fluke by fluke counts method range between 6.45% to 90.6% and 4.29% to 75.07% in cattle and buffaloes, respectively. The sedimentation method and fluke count are reliable tests for detecting rumen fluke in live and slaughtered animals. In conclusion, the rumen fluke should be considered a critical production disease that affects cattle and buffaloes in Asia. Further studies are necessary to determine the rumen fluke-snail associations, develop diagnostic tests to detect prepatent infections in the definitive host, determine the economic importance of rumen fluke, and determine the efficacy of different anthelmintic in the treatment of patent infections in the definitive host.

Prevalence, risk factors, and infection intensity of fasciolosis in dairy cattle in Boyolali, Indonesia

Background and Aim

Fasciolosis is a significant problem in veterinary and public health, causing huge economic losses. Epidemiological studies of fasciolosis in dairy cattle in Indonesia are few and existing reports primarily focus on prevalence. This study aimed to determine the prevalence, risk factors, and infection intensity of fasciolosis in dairy cattle in Boyolali, Indonesia.

Materials and Methods

This cross-sectional study included 400 dairy cattle from 72 household farms in eight subdistricts. Fecal samples (n=400) were examined using the Flukefinder® kit and the simple sedimentation technique was the gold standard for fasciolosis. In-person interviews using questionnaires collected data on farmers, farms, and animal characteristics. Chi-square and logistic regression analyses were performed to evaluate the associated risk factors for fasciolosis, and p < 0.05 was considered statistically significant.

Results

The overall prevalence of fasciolosis in dairy cattle in Boyolali, Indonesia, was 16.50% (95% confidence interval [CI] 12.85-20.15) at the animal level (n = 400), whereas 40.28% at household farms (n = 72) level (95% CI 18.67-51.88). The relative sensitivity and specificity of the Flukefinder® kit compared with those of the gold standard were 79.49% and 92.52%, respectively, with a moderate agreement (kappa=0.59; p < 0.001). Fasciolosis was more likely in cattle originating from the Mojosongo subdistrict than from other subdistricts (odds ratio (OR)=5.28, 95% CI 1.22-22.94); from farms that did not process manure versus from those that did (OR = 3.03, 95% CI 1.43-4.71); and with farmers that had never attended extension programs compared with those who had (OR = 4.72, 95% CI 1.99-11.19). Studied cattle were mostly affected by light Fasciola spp. infections (92.4%, 95% CI 77.8-100%) followed by moderate (6.1%, 95% CI 0-22.2%) and heavy (1.5%, 95% CI 0-5.6%) infections.

Conclusion

Fasciolosis is prevalent in dairy cattle in Boyolali, Indonesia. Control efforts should target the high-risk Mojosongo subdistrict, emphasize the importance of processing manure, and encourage farmers to attend extension programs. Flukefinder® is a practical on-site diagnostic kit for fasciolosis in Indonesian dairy farms. Parasite species identification and a malacological survey of intermediate hosts of Fasciola spp. in the farming environment are required for further research.

Morphological, molecular and MALDI-TOF MS identification of ticks and tick-associated pathogens in Vietnam

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been reported as a promising and reliable tool for arthropod identification, including the identification of alcohol-preserved ticks based on extracted leg protein spectra. In this study, the legs of 361 ticks collected in Vietnam, including 251 Rhiphicephalus sanguineus s.l, 99 Rhipicephalus (Boophilus) microplus, two Amblyomma varanensis, seven Dermacentor auratus, one Dermacentor compactus and one Amblyomma sp. were submitted for MALDI-TOF MS analyses. Spectral analysis showed intra-species reproducibility and inter-species specificity and the spectra of 329 (91%) specimens were of excellent quality. The blind test of 310 spectra remaining after updating the database with 19 spectra revealed that all were correctly identified with log score values (LSV) ranging from 1.7 to 2.396 with a mean of 1.982 ± 0.142 and a median of 1.971. The DNA of several microorganisms including Anaplasma platys, Anaplasma phagocytophilum, Anaplasma marginale, Ehrlichia rustica, Babesia vogeli, Theileria sinensis, and Theileria orientalis were detected in 25 ticks. Co-infection by A. phagocytophilum and T. sinensis was found in one Rh. (B) microplus.

Multilocus Genotyping of Giardia duodenalis Occurring in Korean Native Calves

Giardia duodenalis is one of the most widely occurring zoonotic protozoan parasites causing diarrheal disease in calves. This study aimed to investigate the prevalence of G. duodenalis in Korean native calves and elucidate the causal factors associated with giardiasis in these animals. We investigated the sequences of three genes (ssu, bg, and gdh) of G. duodenalis in fecal samples collected from 792 Korean native calves during 2019–2020. Data were analyzed with regard to age, sex, sampling season, and the fecal sample type (based on its physical characteristics). The samples were screened for the three genes mentioned above, and 44 samples (5.6%) were G. duodenalis-positive. Polymerase chain reaction results showed a significantly higher prevalence of the infection in calves aged ≥1 month and in those with watery diarrhea in spring season. Screening for the gene sequences ssu (87.5%), bg (96.2%), and gdh (96.7%) revealed that most of the G. duodenalis-positive samples belonged to assemblage E. Four of the G. duodenalis-positive samples belonged to the zoonotic assemblage A. This study highlights the importance of continuous surveillance of genetic mutations in G. duodenalis for the detection of emerging variants of zoonotic G. duodenalis in calves.

Skewness in the literature on infectious livestock diseases in an emerging economy - the case of Vietnam

Livestock production has increased in many emerging economies, but productivity is often substantially impaired by infectious diseases. The first step towards improved livestock health and productivity is to map the presence of livestock diseases. The objective of this review was to summarize studies conducted on such diseases in an emerging economy, Vietnam, and thereby identifying knowledge gaps that may inform the design of surveillance and control programs. Few studies were found to evaluate the distribution of infectious livestock diseases other than avian influenza. Also, many regions with dense livestock populations had received little attention in terms of disease investigation. A large proportion of the studies dealt with zoonoses and food-borne infections which might be due to funding agencies priorities. On the contrary, studies targeting infections that affect livestock and their productivity were few. We think that this limitation in scientific reports on infectious diseases that only affect livestock productivity is a common phenomenon in low and lower middle income countries. More science-based data on such diseases would help policymakers to prioritize which livestock diseases should be subject to animal health programs aimed to support rural livelihoods and economic development.

Anaplasma platys-Like Infection in Goats, Beijing, China

As one of the important tick-borne zoonotic pathogens, Anaplasma has both veterinary and public health significance. Here, we performed a survey of Anaplasma infection in the goats from a farm in Beijing, China, and found 44.6% (41/92) were infected with Anaplasma capra, and 22.8% (21/92) were infected with Anaplasma sp. This Anaplasma sp. bacterium was close to a recently emerging Anaplasma platys strain based on gltA and groEL gene phylogenetic analysis. As to further understand the characteristics of Anaplasma sp., we raised a couple of positive goats (n = 2) in the laboratory with tick-free settings. We observed inappetence, vomiting, high fever, and weakness of limbs in the goat's offspring (n = 3). In addition, the blood samples from all offspring were all positive of this Anaplasma spp. We did not see any intracellular morulae in neutrophils, monocytes, and erythrocytes, but we identified some in the platelets of the blood smears from the positive goats by light microscopy. We named it A. platys-like and suggested it may infect platelets and be transmitted vertically through the placenta of goats. These findings deserve further evaluation.

An overview of rickettsiae in Southeast Asia: Vector-animal-human interface

Rickettsioses are emerging, and re-emerging diseases caused by obligate intracellular arthropod-borne bacteria that infect humans and animals worldwide. Various rickettsiae such as Orientia, Rickettsia, Anaplasma and Ehrlichia have been circulated in companion, domesticated and wild animals through bites of infected ticks, fleas, lice or mites. This review summarizes the infections of rickettsiae, including the newly discovered regional species Rickettsia thailandii, Candidatus Rickettsia sepangensis, Candidatus Rickettsia johorensis, Candidatus Rickettsia laoensis, Candidatus Rickettsia mahosotii, Candidatus Rickettsia khammouanensis, Candidatus Anaplasma pangolinii, and other novel genotypes in vectors, humans and animals in Southeast Asia. Issues on some unidentified rickettsiae that elicit immune responses and production of antibodies that are cross-reactive with the antigens used are discussed. Knowledge gaps which required attention are also identified in this review.

Effect of deworming on milk production in dairy cattle and buffaloes infected with gastrointestinal parasites in the Kavrepalanchowk district of central Nepal

Background

In Nepal, knowledge of proper handling, management and causes of cattle diseases is still limited. The main objective of this study was to explore the impact of deworming on milk production and its effect on milk qualities.

Methods

A total of 200 faecal samples (100 buffaloes and 100 cows) were collected and analysed for parasitic burden. Half of the infected cattle (buffaloes, Bos bubalis; cow native, B indicus; European, B taurus) were then dewormed with Levamisole Hydrochloride-Oxyclozanide bolus, and the remaining 50 per cent were left untreated. The milk yield from both infected and dewormed cattle was recorded for 30 days and the qualities of milk were analysed.

Results

The prevalence of parasitic infection was found to be 22.0 per cent. Fasciola hepatica was the predominant parasite (81.8 per cent), followed by Toxocara vitulorum (34.1 per cent), Strongyloidespapillosus (6.8 per cent) and Bunostomum phlebotomum (4.5 per cent). The average milk yield (litre/day/cow) significantly increased, which was 1.22 litres per day for treated cows and 1.06 litres for treated buffaloes. The intervention effect of deworming among cows was 0.79 (14.06 per cent increment) and for buffaloes was 0.42 (8.32 per cent increment). After deworming the infected cattle, the protein percentage was significantly improved in cows (P=0.035), whereas the lactose percentage and solid percentage had increased significantly in buffaloes (P=0.002 and P=0.028).

Conclusion

Antiparasitic treatment in cattle had positive effects on milk qualities such as solid non-fat, lactose, solid percentage and total protein percentage.

An in vitro confirmation of the ethonopharmacological use of Senna plants as anthelmintic against rumen fluke Paramphistomum gracile

BACKGROUND

Paramphistomosis is a pathogenic disease of domesticated ruminants, causing great economic loss in dairy industry and meat production. It is considered as a neglected tropical disease with highest prevalence throughout tropical and subtropical regions, particularly in Africa, Asia, Europe, and Australia. There are few trematocidal drugs available in the market. Most are resistant and have elevated side effects. Therefore, alternative trematocidal drugs need to discover. This study was conducted to evaluate three plants leaf extracts (from Senna alata, S. alexandrina, and S. occidentalis) as effective remedies against gastrointestinal trematode parasite (Paramphistomum gracile) of ruminants. Live adult parasites were collected in 0.1 M phosphate-buffered saline (PBS) from fresh autopsied goat's rumen. Parasites were incubated in leaf extracts of S. alata, S. alexandrina and, S. occidentalis individually and in combination (1:1) ratio at 37 ± 1°C. Treatment media contain extracts at different concentrations (10, 20 and 40 mg/mL) in 10 mL of 0.1 M PBS with 1% dimethylsulphoxide (DMSO). Parasites in control group were incubated in PBS without extract. The efficacy of three Senna extracts was evaluated on the basis of dose-dependent motility and mortality of the trematode. Immediately after paralysis, all treated parasites were collected for histology, SEM and biochemical study.

RESULTS

Dose-dependent efficacy was observed in terms of motility and time of mortality in all treated parasites after exposure in various concentrations of the Senna plant extracts. S. occidentalis and S. alexandrina showed better efficacy in combination than comparing with individual treatment groups. Histological study and scanning electron microscopic observations revealed conspicuous deformity of surface architecture in all treated parasites. Scanning electron micrographs also revealed shrinkage, vacuolization, infoldings and blebbings on the body surface of treated worms. Activities of tegumental enzymes were inhibited in all treatment groups compared to control.

CONCLUSION

The overall findings from this study revealed that all three Senna leaf extracts individually and in combination showed potential antitrematocidal activity against Paramphistomum gracile by damaging body tegument and neural propagation. Thus, this study confirmed that all three Senna extracts can be considered as a potential drug-like candidate in indigenous system of traditional medicine against trematode infections in livestock.

Anaplasma marginale and A. platys Characterized from Dairy and Indigenous Cattle and Dogs in Northern Vietnam

Anaplasma marginale and A. platys were detected and characterized (16S rDNA sequence analysis) from dairy and indigenous cattle, and the latter in domestic dogs in Vietnam. A phylogenetic tree was inferred from 26 representative strains/species of Anaplasma spp. including 10 new sequences from Vietnam. Seven of our Vietnamese sequences fell into the clade of A. marginale and 3 into A. platys, with strong nodal support of 99 and 90%, respectively. Low genetic distances (0.2–0.4%) within each species supported the identification. Anaplasma platys is able to infect humans. Our discovery of this species in cattle and domestic dogs raises considerable concern about zoonotic transmission in Vietnam. Further systematic investigations are needed to gain data for Anaplasma spp. and members of Anaplasmataceae in animal hosts, vectors and humans across Vietnam.

Detection and Phylogenetic Characterization of Anaplasma capra: An Emerging Pathogen in Sheep and Goats in China

Anaplasma capra is an emerging pathogen, which can infect ruminants and humans. This study was conducted to determine the occurrence of A. capra in the blood samples of sheep and goats in China. Using nested polymerase chain reaction (nested-PCR) targeting the gltA gene and conventional PCR targeting the heat shock protein (groEL) gene and the major surface protein4 gene (msp4), A. capra was detected in 129 (8.9%) of 1453 sheep and goat blood samples. The positive rate was higher in goats (9.4%, 89/943) than in sheep (7.8%, 40/510) (χ² = 1.04, p > 0.05, df = 1). For sheep, A. capra was found in 17 sites from 2 provinces. The prevalence was 28.6% in sheep from Liaoning province, which was higher than in Henan Province (7.3%). For goats, A. capra was detected in 35 sites from 7 provinces. The prevalence varied from 0 to 19.4% in the goat sites examined. The prevalence rates were 19.4, 19.3, 10, 8.8, 6.8, 1.8, and 0% in goats from Guizhou province, Henan Province, Inner Mongolia Autonomous Region, Shanxi Province, Xinjiang Uygur Autonomous Region, Yunnan province, and Gansu province, respectively. Based on the analysis of the A. capra citrate synthase gene (gltA), two variants were identified. Variant I showed a high sequence similarity to the A. capra, which were previously reported in sheep, goats, Ixodes persulcatus, Haemaphysalis longicornis, Haemaphysalis qinghaiensis, and humans. Variant II was only found in Luoyang, Anyang, and Sanmengxia, of Henan province. To our knowledge, this is the first detection of this variant of A. capra in sheep and goat blood in China. Phylogenetic analysis based on groEL and msp4 genes showed that the Anaplasma sp. sequences clustered independently from A. capra and other Anaplasma species with high bootstrap values. We found A. capra DNA in sheep and goats in China, providing evidence that sheep and goats can be infected by A. capra. We also found that this zoonotic pathogen is widely distributed in China. This study provides information for assessing the public health risks for human anaplasmosis.

Genomics and molecular epidemiology of Cryptosporidium species

Cryptosporidium is one of the most widespread protozoan parasites that infects domestic and wild animals and is considered the second major cause of diarrhea and death in children after rotavirus. So far, around 20 distinct species are known to cause severe to moderate infections in humans, of which Cryptosporidium hominis and Cryptosporidium parvum are the major causative agents. Currently, ssurRNA and gp60 are used as the optimal markers for differentiating species and subtypes respectively. Over the last decade, diagnostic tools to detect and differentiate Cryptosporidium species at the genotype and subtype level have improved, but our understanding of the zoonotic and anthroponotic transmission potential of each species is less clear, largely because of the paucity of high resolution whole genome sequencing data for the different species. Defining which species possess an anthroponotic vs. zoonotic transmission cycle is critical if we are to limit the spread of disease between animals and humans. Likewise, it is unclear to what extent genetic hybridization impacts disease potential or the emergence of outbreak strains. The development of high resolution genetic markers and whole genome sequencing of different species should provide new insights into these knowledge gaps. The aim of this review is to outline currently available molecular epidemiology and genomics data for different species of Cryptosporidium.

Prevalence, genotyping and risk factors of Giardia duodenalis from dogs in Vietnam

This study was carried out to determine the prevalence, genotypes/assemblages and possible risk factors associated with Giardia duodenalis infection in dogs in central Vietnam. A total of 209 dog fecal samples, randomly collected from private owned dogs (n=105) and dogs from stores (n=104), were examined for Giardia cysts by microscopy. Positive samples were genotyped by PCR-sequence analysis of β-giardin and triosephosphate isomerase genes markers. Risk factors were studied using a structured questionnaire and collected data were analyzed by univariate and multivariate logistic regression analyses. Results indicated that the overall infection rate was 8.6% (18/209) with the detected parasites were belonging to the non-zoonotic assemblages C and D. Age, gender and origin of animals were the main risk factors associated with G. duodenalis infection in dogs under study. Occurrence of infection was more likely in young animals compared to old ones and in females compared to males. Dogs originated from stores were more prone to Giardia infection compared to private owned counterparts.

A review on epidemiology, global prevalence and economical losses of fasciolosis in ruminants

Fasciolosis is an important plant borne trematode zoonosis in ruminants caused by the Fasciola hepatica and Fasciola gigentica, It is classified as a neglected tropical disease and found in more than 50 countries especially where sheep and cattle are reared. Fasciolosis is a serious animal health problems in many rural and urban areas of world, causing significant financial losses due to decrease in production and viscera condemnation in animals. Accurate diagnosis of fasciolosis is always remained a challenging task for the field practitioners. There is no comprehensive summary on the occurrence and distribution of the infection at international level. Therefore, we intended to provide a complete overview on the prevalence and epidemiology of fasciolosis in farm animals from a global prospective. It includes to map the global distribution of fasciolosis in different areas of the world to identify the endemic regions which may be a source of potential disease outbreak. The financial liability related to fasciolosis on the livestock production has also been addressed. For this purpose, the published data during 2000-2015 (15 years) on fasciolosis was reviewed and collected by electronic literature search of four databases including Google, PubMed, Science Direct, and Web of Science. Data presented are contemplated to enhance our current understanding of the parasite's geographical distribution, host range, and economic losses. Information provided would be useful for the application of more effective control strategies against fasciolosis in different geo-economics regions of the world.

Integrated parasite management with special reference to gastro-intestinal nematodes

Domestic animals are susceptible to a large number of parasitic diseases, which lead to severe economic losses to livestock industry. So, it is necessary to control parasitic infections in these animals. Control of these helminths is undertaken mostly by anthelmintics, but because of their widespread use there is development of resistance across the globe. However, total dependence on a single method of control has proved to be non-sustainable and cost ineffective in the long term. A combination of treatment and management is necessary to control parasitism so that it will not cause further economic losses to producer as well as to livestock industry. To become practically and ecologically sustainable, parasitic control schemes need to be based on integrated parasite management.

The anthelmintic effects of the ethanol extract ofTerminalia catappaL. leaves against the ruminant gut parasite,Fischoederius cobboldi

Presently, no effective anthelmintic drugs have been used to treat and control paramphistomosis, a severe disease of ruminants. In this study, we have investigated thein vitroanthelmintic effect of the leaves ofTerminalia catappaL. crude extract (TcCE) and albendazole (ABZ) on adultFischoederius cobboldiafter incubating the flukes in RPMI-1640 medium containing the TcCE at various doses and times. The TcCE-treated flukes at all dosages exhibited rapid decrease of motility, and the relative motility (RM) values were decreased sharply from start to 3 h. Worms were killed after 6 and 12 h of treatment with 1000, 1500 and 2000µg mL−1as well as 500µg mL−1of TcCE, respectively. By light microscopy examination, the flukes exhibited the earliest alteration in a limited area of the tegument. At scanning electron microscopy level, the flukes’ tegument showed similar sequence of morphological alterations after treatment with ABZ and TcCE that consisted of swelling of ridges and folds, followed by blebbing and rupturing of the blebs, leading to the erosion, lesion and disruption of the tegument. Hence,in vivostudies should be performed to examine whether the TcCE may serve as a powerful anthelmintic drug for treatment of paramphistomosis.

Detection of Anaplasma sp. in Korean Native Goats (Capra aegagrus hircus) on Jeju Island, Korea

Anaplasma species are obligate intracellular pathogens that can cause tick-borne diseases in mammalian hosts. To date, very few studies of their occurrence in Korean native goats (Capra aegagrus hircus) have been reported. In the present study, we investigated Anaplasma infection of Korean native goats on Jeju Island, Republic of Korea, and performed phylogenetic analysis based on the 16S rRNA gene sequences. Our results showed that Anaplasma infection was found mostly in adult female goats. The phylogenetic tree revealed that the 7 sequences identified in Korean native goats could belong to Anaplasma sp. and were distinct from A. marginale, A. centrale, and A. ovis. The results indicated that the sequences identified to belong to Anaplasma were closely related to sequences isolated from goats in China and were clustered within the same group. To our knowledge, this is the first study to detect Anaplasma sp. infection in Korean native goats.

Current status of fasciolosis in Vietnam: an update and perspectives

Vietnam is recognized to be endemic for fasciolosis. However, most of the available publications have not been published in international journals. This review is based on national and international Vietnamese publications and highlights the current status of fasciolosis in Vietnam. It also provides some information available for neighbouring countries. Updated data on responsible species, distribution, transmission and control aspects are summarized. The central region of Vietnam is reported as being highly endemic for fasciolosis, with a high number of human patients (more than 20,000 in 2011). Fasciola gigantica is reported to be the main species in Vietnam. However, hybrids between F. gigantica and F. hepatica were identified. Both humans and animals are infected by the ingestion of raw vegetables and possibly contaminated drinking water. Three lymnaeid snail species (Austropeplea viridis, Radix auricularia and Radix rubiginosa) may act as intermediate hosts of Fasciola spp. However, due to the likely misidentification of snail species and cercariae during the past decade the critical analysis of published data is difficult. A better understanding of transmission aspects of fasciolosis would allow the implementation of preventive measures of this important neglected zoonotic disease.

Survey on gastrointestinal parasites and detection of Cryptosporidium spp. on cattle in West Java, Indonesia

OBJECTIVE

To evaluate the presence of gastrointestinal parasites on cattle in Indonesia because the prevalence of parasites varies between countries depending on the terrain surrounding livestock farms and investigations in Indonesia have never been performed.

METHODS

Fecal samples from cattle at 35 farms in 7 districts in West Java, Indonesia, has been examined using the floatation or sedimentation methods, and a immunofluorescence assay and experimentally inoculation to mice for Cryptosporidium or Giardia.spp.

RESULTS

153 of 394 examined cattle (38.8%) were infected with gastrointestinal parasites. The prevalence of Eimeria spp., Nematoda spp. (including Oesophagustomum and Bunostomum-like), Fasciola gigantica and Paramphistomum spp. was 22.4%, 11.2%, 12.5% and 3.8%, respectively. Cryptosporidium andersoni (C. andersoni) was also found in two samples. One isolate of this parasite was confirmed to be transmitted to mice, in contrast to the isolates from other countries.

CONCLUSIONS

although this survey is preliminary, the results shows that the infection of gastrointestinal parasites in Indonesia was not high, but these infected cattle could be as a potential source leading to economic losses in livestock production.

Multilocus genotyping of Giardia duodenalis in dairy cattle in Henan, China

Giardia duodenalis is a common and widespread intestinal protozoan parasite of both humans and animals. Previous epidemiological and molecular studies have identified Giardia infections in different animals and humans, but only limited information is available about the occurrence and genotypes of Giardia in cattle in China. In this study, we determined the occurrence of giardiasis and genetically characterized G. duodenalis in dairy cattle in Henan Province, central China. The overall prevalence of G. duodenalis was 7.2% (128/1777) on microscopic analysis, with the highest infection rate (22.7%) in calves aged less than 1 month. G. duodenalis assemblages and subtypes were identified with multilocus genotyping based on the SSU rRNA, β-giardin (bg), glutamate dehydrogenase (gdh), and triosephosphate isomerase (tpi) genes. Two assemblages were detected in the successfully sequenced samples: assemblage A (n = 58), assemblage E (n = 21), with a mixed E and A assemblage (n = 2). Four novel subtypes of the gdh gene and seven of the bg gene were found among the G. duodenalis assemblage E isolates. Using the nomenclature for the multilocus genotype (MLG) model, nine novel multilocus genotypes E (MLGs E1-E9) and three MLGs A (a novel subtype AI, previously detected subtype AII-1, and a combination of both) were identified. MLG AII-1 identified in this study may be an important zoonotic subtype. The dairy cattle in Henan are a potential public health concern.

A review of foodborne bacterial and parasitic zoonoses in Vietnam

Vietnam has experienced unprecedented economic and social development in recent years, and the livestock sector is undergoing significant transformations. Although food animal production is still dominated by small-scale 'backyard' enterprises with mixed crop-livestock or livestock-aquatic systems, there is a trend towards more intensive and vertically integrated operations. Changes in animal production, processing and distribution networks for meat and animal products, and the shift from wet markets to supermarkets will undoubtedly impact food safety risks in Vietnam in unforeseen and complex ways. Here, we review the available published literature on bacterial and parasitic foodborne zoonoses (FBZ) in Vietnam. We report on clinical disease burden and pathogen prevalence in animal reservoirs for a number of important FBZ, and outline opportunities for future research.

Internal parasite management in grazing livestock

It is a challenging task to control internal parasites in grazing livestock even by applying multi label and multi directional approach. It is impossible to draw general recommendations to control parasitic diseases due to varied geo-climatic conditions and methods adopted for rearing the livestock in the country like India. In view of increasing incidence of anti-parasitic drug resistance in animals, there is an urgent need to design sustainable parasite control strategy which must include on the host as well as off the host control measures to harvest the maximum productivity from the animal for an indefinite period.

Paramphistomum cervi: the in vitro effect of plumbagin on motility, survival and tegument structure

Paramphistomiasis causes enteritis and anemia in livestocks and result in substantial production and economic losses. It is considered a neglected tropical disease, with no effective trematodicidal compound for treatment. Plumbagin (PB), a compound founds to be rich in the roots of Plumbago indica, is a naphthoquinone derivatives which can induce oxidative stress in parasites. In this study we have evaluated the anthelmintic activity of PB against adult Paramphistomum cervi by incubating the parasites in M-199 medium containing 0.1, 1.0, 10 and 100 μg/ml of the PB, and albendazole (ABZ) at the concentration of 100 μg/ml as the positive control, for 3, 6, 12 and 24 h, using relative motility (RM) assay and observed by scanning electron microscopy (SEM). After 12 h exposure with 100 μg/ml ABZ, flukes showed decreased contraction and motility. At 24 h incubation they showed only active movement of some part of the body. The PB-treated flukes at all concentrations showed rapid decrease of motility at 3 h incubation. In 0.1, 1.0 and 10 μg/ml of PB, the RM values were decreased sharply from 3 to 12 h, and then they were killed since 12 h in the incubation with 10 μg/ml of PB. The highest parasite mortality was found as early as 3h when they were incubated with 100 μg/ml of PB. The morphological changes on the tegumental surface were similar in both flukes treated with ABZ and PB, which sequentially comprised of swelling, followed by blebbings that later ruptured, leading to the erosion and desquamation of the tegument syncytium. As the result, lesions were formed which exposed the basal lamina. The damage appeared more severe on the ventral than the dorsal surface, and earlier on the anterior part and lateral margins of middle third when compared to the posterior part of the parasites's bodies. The severity and rapidity of the damages were enhanced with increasing concentration of PB, which showed stronger activity than ABZ. Hence, PB has a potential to be an anthelmintic drug against adult P.cervi.

Prevalence of Fasciola in cattle and of its intermediate host Lymnaea snails in central Vietnam

The aims of this study were to investigate the prevalence of natural Fasciola infections in both the definitive hosts (cattle) and the intermediate hosts (Lymnaea snails) in central Vietnam. A total of 1,075 fecal samples, randomly collected from cattle in Binh Dinh, Khanh Hoa, and Phu Yen provinces, were examined for Fasciola eggs by a sedimentation method. The overall prevalence of Fasciola was 45.3 %. A subset of the animals (235) was also screened for antibodies against Fasciola by an enzyme-linked immunosorbent assay. Overall, 46.3 % of these animals were shedding Fasciola eggs while 87.2 % were Fasciola seropositive. A lower prevalence of Fasciola was observed in calves ≤ 2 years of age (37.6 %) compared to that in cattle >2 years of age (53.7 %) (p < 0.05). The prevalence in the rainy season (50.8 %) was significantly different to that in the dry season (38.1 %) (p < 0.05). Of the 3.269 Lymnaea viridis and 1.128 Lymnaea swinhoei examined, 31 (0.95 %) and seven (0.62 %), respectively, were found to be infected with Fasciola. This appears to be the first epidemiological survey of the prevalence of Fasciola in cattle and snails in these three provinces in central Vietnam.

Risk factors of Neospora caninum infection in dogs and cats in dairy farms in Western Thailand

The objectives of this study were to investigate the risk factors of Neospora caninum infection in dogs and cats found in dairy herds in western Thailand. A case-control study was conducted in dairy herds in three western provinces including Nakhon Pathom, Ratchaburi and Kanchanaburi. Blood samples of pets from 14 positive dairy herds and 26 herds from negative neighbouring farms which were randomly selected, in total blood samples from dogs and cats from 40 herds were collected and examined for antibodies against N. caninum infections using competitive ELISA and indirect fluorescent antibody test (IFAT). No seropositive cats were found. Of the 38 positive dogs, four (10.5%) were seropositive to N. caninum, which was higher than the proportion of seropositive in the negative herd population (one of 76, 1.3%). The higher proportion of seropositive farm dogs as compared with neighbouring dogs tended to be significant (P = 0.055).

Zoonotic potential and molecular epidemiology of Giardia species and giardiasis

Molecular diagnostic tools have been used recently in assessing the taxonomy, zoonotic potential, and transmission of Giardia species and giardiasis in humans and animals. The results of these studies have firmly established giardiasis as a zoonotic disease, although host adaptation at the genotype and subtype levels has reduced the likelihood of zoonotic transmission. These studies have also identified variations in the distribution of Giardia duodenalis genotypes among geographic areas and between domestic and wild ruminants and differences in clinical manifestations and outbreak potentials of assemblages A and B. Nevertheless, our efforts in characterizing the molecular epidemiology of giardiasis and the roles of various animals in the transmission of human giardiasis are compromised by the lack of case-control and longitudinal cohort studies and the sampling and testing of humans and animals living in the same community, the frequent occurrence of infections with mixed genotypes and subtypes, and the apparent heterozygosity at some genetic loci for some G. duodenalis genotypes. With the increased usage of multilocus genotyping tools, the development of next-generation subtyping tools, the integration of molecular analysis in epidemiological studies, and an improved understanding of the population genetics of G. duodenalis in humans and animals, we should soon have a better appreciation of the molecular epidemiology of giardiasis, the disease burden of zoonotic transmission, the taxonomy status and virulences of various G. duodenalis genotypes, and the ecology of environmental contamination.

Bovine fasciolosis in the human fasciolosis hyperendemic Binh Dinh province in Central Vietnam

A cross-sectional survey on bovine fasciolosis was conducted in the Binh Dinh province of Central Vietnam that was previously identified as hyperendemic for human fasciolosis. In Vietnam, both pure Fasciola gigantica and hybrid and/or introgressed populations of liverflukes bearing genetic material from both Fasciola hepatica and F. gigantica infect humans and animals. In this study, 825 cattle were randomly selected from 8 of the 11 provincial districts for faecal collection; blood samples were taken from 400 of these animals. Fasciola eggs and antibodies against Fasciola were detected by a quantitative sedimentation method and an Enzyme Linked Immunosorbent Assay, respectively. Overall, 54.9% of the animals were shedding Fasciola eggs while 72.2% were Fasciola seropositive. Animals under two years showed lower Fasciola infection rates than older animals. There were no differences in infection rates between districts. These results indicate a very high prevalence of Fasciola infections in cattle in Binh Dinh province. It is concluded that a fasciolosis control programme should be designed in this region aiming at reducing infection in both cattle and humans.

Phylogenetic analysis of the genus Anaplasma in Southwestern China based on 16S rRNA sequence

To identify the species within the genus Anaplasma circulating among ruminants in the Southwest of China, we performed the phylogenetic analysis of the 16S rRNA gene of two Anaplasma isolates from cattle and seven from goats. The two sequences obtained from cattle strains belonged to the A. marginale cluster, whereas the other seven sequences from caprine strains formed two Anaplasma spp. clusters, which diverged earlier than the clusters of A. marginale, A. centrale and A. ovis. These results indicate that there are at least two Anaplasma species circulating among ruminants in Southwestern China.

Is Giardia a significant pathogen in production animals?

Although Giardia duodenalis is recognised worldwide as the most important parasitic cause of gastro-intestinal disorder in human patients, the relevance of infection in production animals is prone to debate. Since the 1980s, clinical disease has been associated with giardiasis in production animals, both in natural conditions and in experimental studies. However, most Giardia research is focussed on the relevance of production animals as a reservoir for zoonotic transmission. In this study, the current knowledge on clinical relevance of giardiasis in production animals is reviewed, along with the diagnosis, treatment and control of infection. Furthermore, future research objectives are discussed.

Monthly changes in body condition scores and internal parasite prevalence in Nguni, Bonsmara and Angus steers raised on sweetveld

The objective of the study was to determine monthly changes in body condition scores, body weights and on the prevalence of internal parasites in Nguni, Bonsmara and Angus steers raised on sweetveld. Body condition scores (BCS), body weights (BW), packed cell volume (PCV) and monthly faecal egg counts (FEC) were determined in 25 Nguni, 15 Bonsmara and 15 Angus steers. Nguni and Bonsmara steers maintained their body condition throughout the study, while the Angus lost condition. The Nguni had the highest PCV levels. The PCV levels tended to decline during the rainy season for all the breeds. The FEC were generally low. Fasciola spp. and strongyle eggs were found in 16.3 and 54.6% of the collected faecal samples, respectively. Of the three breeds, Nguni steers had the lowest parasite infestation levels, with the Bonsmara being more susceptible than the other two breeds. Generally, the egg counts observed throughout the study were low.