Neoascaris Vitulorum Research Articles

Infectious Rotavirus and Coronavirus of Calves

Recently, some progress has been made in the study of bacterial and viral infectious diseases of calves. However, as effective systems and methods are put in place to control these diseases, other new emerging diseases will also become important. Among diseases of the neonatal period in calves, diarrhea, which causes significant economic damage, is one of the main problems in cattle breeding. Calves diarrhea is divided into two groups: infectious and non-infectious. Diarrhea of infectious origin is mainly caused by Escherichia coli, Salmonella sp., Campylobacter sp., Clostridium perfringens type C, Rotavirus, Coronavirus, Parvovirus, Astrovirus, Calicivirus, Breda virus, Cryptosporidium, Coccidia, Giardia and Neoascaris vitulorum. During field studies, it was found that 75-95% of infectious diarrhea in calves is caused by enterotoxic Escherichia coli, rotaviruses, coronaviruses, cryptosporidium, including 27-36% rotaviruses, 20-26% coronaviruses. These diseases are often registered in livestock farms of the republic of Azerbaijan and cause the death of newborn calves.

Haemoparasites and Polyparasitism of Intestinal Helminths among Cattle Slaughtered in Selected Abattoirs in Abeokuta, Ogun State.

Background: Haemoparasites and intestinal helminths are significant constraints to livestock production resulting in substantial economic loss, and some helminth parasites of cattle are of serious public health concern. This study investigated the prevalence of haemoparasites and polyparasitism of intestinal helminths amongst cattle slaughtered in two major abattoirs of Abeokuta metropolis and their implications for public health. Methods: Blood and faecal samples were randomly collected from 256 cattle less than two and greater than two years of age. Blood samples were screened for Packed Cell Volume (PCV) using the haematocrit centrifuge technique and parasites were detected by microscopy using a wet mount, buffy coat and stained thin smear. Helminth eggs and oocysts were detected using centrifugal sedimentation and centrifugal faecal flotation method. Results: Results showed prevalence for Trypanosoma spp., Babesia spp., Anaplasma spp. and Theileria spp. to be 8.3%, 27.34%, 20.7% and 0.39%, respectively. For intestinal parasites, the prevalence for Strongyle eggs is 73.82%, Neoascaris vitulorum 0.8%, Fasciola spp. 10.15%, Moniezia spp. 4.3%, Eimeria oocyst 35.94% and Cryptosporidium oocyst was 1.17%. The total prevalence of coinfection of haemoparasite and intestinal helminths was 42.6%. Breed-specific prevalence for co-infection of haemoparasites and intestinal parasites showed 55.96%, 37.6% and 6.4% for White Fulani, Red Bororo and Sokoto Gudali, respectively which was statistically insignificant (p > 0.05). With regards to sex, females had a higher prevalence of 92 (84.4%) of coinfection of haemoparasites and intestinal helminths than males 17 (15.6%), which was statistically significant (p<0.05). Conclusion: This study revealed a high prevalence of haemoparasites and intestinal parasites in cattle slaughtered in Abeokuta, Nigeria. Therefore, the study recommends strict compliance with meat inspection at abattoirs and the need for immediate operationalisation and implementation of a sustainable Preventive One Health intervention to mitigate against the outbreak of zoonoses in Abeokuta.

Prevalence and Therapeutic Efficacy of Anthelmintic against Neoascaris vitulorum in Buffalo Populations from Sylhet District of Bangladesh

Background and Objectives: The epidemiological features of Neoascaris vitulorum infection in buffaloes are important to know their transmission and risk factors assessment as well treatment regimens. This study was conducted with the objectives of determining the prevalence of Neoascaris vitulorum infection in buffaloes in Sylhet district of Bangladesh and to evaluate the efficacy of anthelmintics against the parasite. Materials and Method: A total of 211 fecal samples were collected from buffaloes and examined for the detection of parasitic eggs during the period from July 2017 to June 2018. For the determination of therapeutic efficacy, animals were randomly divided into 6 groups (T0, Ti, T1, T2, T3, T4) where each group consisting of 3 buffaloes. The group T0 (negative control-non infected) and Ti (positive control-infected) were treated only with phosphate buffer saline (PBS). The other four infected groups were treated as T1 with albendazole, T2 with piperazine citrate, T3 with ivermectin and T4 with combination of tetramisole HCL and oxyclosanide. Before trials day 0 and after treatment of 7th, 14th, 21st and 28th days fecal samples examined using McMaster technique. Results: The overall prevalence was estimated 17.06% (36/211). The prevalence was higher among buffalo calves of below six months (39.28%) followed by 6 months to 1 year, 1 to 2 years and above 2 years as 25%, 22.5% and 7.20% respectively. The infection rate was high in females (20.0%) than males (13.18%). The parasite was more prevalent in rainy (21.42%) than summer (16.67%) and winter (14.29%) seasons. The EPG results revealed piperazine citrate was the most effective (100%) against Neoascaris vitulorum. The percent efficacies of other anthelmintic used in this study were albendazole, ivermectin and combination of tetramisole HCL and oxyclozanide as 95.49%, 86.20% and 95.58% respectively. Conclusion: The prevalence of Neoascaris vitulorum infection in buffalo at Sylhet district of Bangladesh was relatively high. The results revealed that piperazine citrate, tetramisole HCL and oxyclozanide combination are highly effective for the reduction of egg per gram (EPG) of Neoascaris vitulorum infection in buffalo. On the other hand ivermectin and albendazole were also around ninety percent effective respectively.

Features of the epizootiological process for the main helminthiasis in cattle in the Amur region

The effectiveness of the fight against helminthiases depends on the knowledge of their epizootology, age and seasonal dynamics. The Amur Region is located in a sharp continental climate zone, which affects the living conditions and health status of farm animals, including the development of various parasitic diseases that negatively affect the productivity of farm animals. The biological cycles of helminths are characterized by seasonal dynamics of development, since most of them take place with the participation of intermediate hosts that are sensitive to changes in climatic conditions (temperature, amount of precipitation), as well as to other factors. The determination of the onset of infection timing, the most unfavorable seasons and the main types of helminths are necessary for the prevention of helminthiasis in each specific region. It has been established that the basis of the population structure of helminthiases in cattle under the conditions of the Amur Region is trongylatoses, strongyloidiasis, neoascariasis and moniesiasis. The first eggs and larvae of Strongylata spp. Found in February – April. The greatest extent of invasion was observed in the winter period (February). Moniezia benedeni, as well as Neoascaris vitulorum, had the highest infection rates in the autumnwinter period. At the same time, in the annual dynamics, the first eggs of helminths in both species were found in February. Cases of detection of other helminths in cattle were first recorded mainly in the spring. Thus, the infection of cattle with helminths in the Amur Region does not depend on the grazing season, which should be taken into account when developing plans for anthelmintic measures in livestock farms.

Prevalence and severity of gastro-intestinal parasites in buffalo calves at Sylhet division of Bangladesh.

Gastrointestinal (GI) parasites are one of the most widely recognized health problems of buffalo calves in Bangladesh. The study was undertaken to investigate the prevalence of GI parasitic infestation in buffalo calves at Sylhet division of Bangladesh. Fecal samples of 200 buffalo calves under 1year of age (76 males and 124 females) were collected from Sylhet, Maulvibazar, Habiganj, and Sunamganj districts, and from each of the four regions, 50 samples were collected. Samples were examined through simple flotation, sedimentation, and McMaster techniques. The overall prevalence of GI parasites in Sylhet division was 65.5%. Among the samples, the highest prevalence of GI parasite was found in Sylhet (78%), followed by Sunamganj (68%), Maulvibazar (66%), and Habiganj (50%) districts.Among the identified GI parasites, the highest prevalence was observed in case of Neoascarisvitulorum (26.5%). The highest prevalence of GI parasite was observed in summer (69.84%), followed by rainy (69.62%) and winter (55.17%) seasons. Males and females were almost equally susceptible to GI parasitic infestation. Older calves (9-12months, 77.14%) were most vulnerable to GI parasites. Egg per gram (EPG) of feces was additionally counted in the current study to know the severity of infestation. The range of EPG varied from 50 to 900 among the identified parasites. Among them, the highest count was found in the case of Neoascarisvitulorum (100-900). It may be concluded that aggregated policies and actions need to be taken to control the GI parasitic infestation in buffalo calves atSylhet Division and elsewhere in developing countries like Bangladesh.

Diagnosis of bovine gastrointestinal parasites: comparison of different techniques and different solutions.

Cattle are important livestock species for protein and income supply. But disease agents, including gastrointestinal (GI) parasites, hinder their productivity. For effective GI parasites control, there is need for rapid, highly sensitive and specific diagnostic techniques and tools, lack of which poses problem to clinician, diagnostic staff and livestock owners. One hundred cattle faeces were analyzed through Simple Faecal Flotation (SFF), Modified Centrifugal Faecal Flotation (MCFF) and Mini-FLOTAC techniques (MFT) using sodium chloride, brine, sugar, salt/sugar and zinc sulphate at specific gravity of 1.2, 1.23, 1.25, 1.3 and 1.3 respectively as Flotation Solutions (FS). Overall GI parasite prevalence was 100%. Parasite elements identified were: Strongyle eggs (99%), Strongyloides papilosus (97%), Neoascaris vitulorum (78%), Trichostrongylus (56%), Nematodirus (46%), Capillaria spp. (14%) and Trichuris spp. (6%), Moniezia benedeni (24%), Moniezia expansa (16%), Taenia-like eggs (3%), Schistosoma eggs (3%) and Eimeria oocysts (100%). Sensitivity of 61.99%, 58.49% and 54.24%. for MFT, SFF and MCFF respectively was gotten using Salt/Sugar. With these techniques, Salt/Sugar availability with affordability; its use as a routine FS in diagnosis of GI parasite is advocated. The ease and rapid of use of Mini-FLOTAC diagnostic Kit can be adopted in low economic countries like Nigeria where power supply is limited as well as the safety of user and possibility of re-usage.

Contamination of animal-keeping premises with eggs of parasitic worms

Today, one of the important problems in the cultivation and maintenance of agricultural and domestic animals, both in industrial and private farms, is the spread of ecto- and endoparasites, which cause a significant decline in animal productivity, endanger their health and cause economic losses. The study of the level of distribution and conducting of diagnostic studies on parasitoses of animals in farms with different production orientation is an important and integral part of the overall complex of preventive and health-improving measures. The research was carried out during 2007–2017 in livestock enterprises of Kharkiv Oblast. As a part of the research work, 540 samples were collected from livestock farms, of which 180 were from the premises for keeping pigs, 100 from premises for keeping sheep, 120 from premises for keeping cattle, 80 from premises for dogs and 60 – from the surrounding territories of the livestock enterprises. We found that the objects of livestock rearing (pig complex, sheep farm, dairy farm, cynological center) in Kharkiv Oblast have a significant level of sanitary contamination with exogenous forms of helminths (21.7–45.6%) and the soil of the territories (20.0–36.6%). From samples taken from premises for pigs, eggs of four morphotypes were isolated (Ascaris suum – 5.3%, Trichuris suis – 14.6%, Oesophagostomum dentatum – 60.6%, Strongyloides ransomi – 19.4%), from premises for sheep – three morphotypes (Dicrocoelium lanceatum – 3.8%, Trichuris ovis – 29.3%, Strongylata spp. – 46.9%), from premises for cows – three morphotypes (Neoascaris vitulorum – 2.7%, Trichuris skrjabini – 12.9%, Strongylata spp. – 34.5%), premises for dogs – four morphotypes (Toxocara canis – 6.1%, Toxascaris leonina – 5.4%, Trichuris vulpis – 20.6%, Ancylostoma caninum – 17.5%). It should be noted that the places most contaminated with eggs of helminths were manure gutters (100%) and the floor of livestock buildings (50.0–86.7%). It has also been determined that, in the conditions of the cynological center, the Musca domestica was the source of environmental contamination with exogenous forms of Toxocara canis and Trichuris vulpis, and that the Muscina stabulans and Stomoxys calcitrans can be the source of spread of larvae of Ancylostoma caninum and eggs of Trichuris vulpis respectively.

Prevalence of gastrointestinal parasites of cattle in Greece

In this study, 600 faecal samples, collected from cattle of various parts of Greece, were examined with two different parasitological methods (sedimentation and flotation). The prevalence of the infection with one or more parasitic species was 53.5%. The animals were found to be infected with the following parasitic species: Entamoeba bovis (0.5%), Eimeria spp. (11.83%), Buxtonella sulcata (7.5%), Dicrocoelium dendriticum (4.5%), Fasciola hepatica (0.16%), Paramphistomum cervi (4.66%), Moniezia benedeni (1.83%), Strongyloidea (41.66%), Neoascaris vitulorum (3.33%) and Trichuris spp. (0.83%). The results are compared to those from similar studies in Greece or abroad. Suggestions for the prevention and control of cattle parasites are discussed.

Assessment of roundworm species prevalence in cattle, sheep and goats slaughtered at Lafia Abattoir, Nasarawa State, Nigeria

Intestinal parasites pose a great constraint to livestock production and cause high incidence of mortality and low production in livestock. This study was designed to identify the roundworm species infections in cattle, sheep and goats that were slaughtered at Lafia abattoir during the rainy seasonwithr  theidespread of the infections  and the methodology used was  (April to June, 2016). The aim was to sensitize livestock stakeholders to strategize effective means of disrupting the life cycles of the roundworms in order to prevent their widespread within the herds. Faecal samples were collected from 22 cattle, 25 sheep and 23 goats and were examined by simple floatation method and microscopy for the presence of roundworms. Results showed that out of a total of 70 animals examined, 36 representing 51.4% of the animals were infected with various species of roundworms. Those found in the animals examined included Haemonchus contortus, Bunostomum phlebotomum, Ascaris suum and Neoascaris vitulorum. It was observed that both sexes of all the animal breeds examined were infected, though males were more susceptible than the females. Animals in all the age categories were infected and those on extensive management system were more infected than those in semi-intensive. Since different species of roundworms were found in cattle, sheep and goats slaughtered at Lafia abattoir, it indicated that there was probably high prevalent rate of roundworms in the area. More so, mixed species infection of Ascaris suum and Neoascaris vitulorum were recorded in goats, suggesting severe burden that may hinder optimum physiological performance. It could be necessary therefore to advise that careful disposal of the gastrointestinal contents, regular deworming, implementation of strict biosecurity measures and intensive animal production system should be adopted in the study area. This may disrupt the life cycles of the roundworm species thus, preventing parasitic infections from spreading to other animals in the study area.

Prevalence of gastrointestinal helminthes in buffaloes in Barisal district of Bangladesh

A total 270 samples were collected from July 2012 to December 2012 from three upazilas (Barisal sadar, Bakergonj and Mehendigonj) of Barisal district to know the prevalence of gastrointestinal helminthes. Samples were collected in 10% neutral buffered formalin and shifted to Parasitology laboratory of the department of Pathology and Parasitology under the Animal Science and Veterinary Medicine (ANSVM) faculty of Patuakahli Science and Technology University. Samples were examined by direct smear method and simple sedimentation method of fecal sample examination technique. Among 270 samples 107 (39.6%) samples were found positive for gastrointestinal helminthes. Five types of helminthes were identified namely Fasciola gigantica (26.17%), Amphistomes (60.75%), Neoascaris vitulorum (1%), Schistosoma bovis (1%), Trichostrongylus axei (2%). The prevalence of mixed infection with Fasciola gigantica and Amphistomes was 9.34%. No cestode was found in this study. Comparative study among three different upazila shows highest prevalence in Barisal sadar (44%) and lowest in Mehendigonj (25%). Geographical location of different char island of Sadar upazila and season of sample collection may be the cause of highest prevalence of gastrointestinal helminthes in Sadar upazila of the district. Study period covered rainy season and part of winter season only. Highest parasitic ova were found in rainy season (44.32%) than winter season (29.41%). The age specific prevalence were 12.15%, 14.02%, 40.19%, 33.65% in 0-6 months, 7 months-2 years, 3 years- 6 years & 7 years - above respectively. History of administering anthelmintic (Levamisole hydrochloride) to the calf may be the cause of lowest prevalence of parasitic infection at early age in the study area. In this study, highest number (60.75%) of Amphistomes was found among positive cases. Some important Amphistomes of buffalo are Paramphistomum, Cotylophoron, Gigantocotyle, Gastrothylax etc. are difficult to differentiate through fecal sample examination. So, to understand the detail epidemiology, at least a year study using gross morphological examination with molecular characterization of helminthes is needed.DOI:http://dx.doi.org/10.3329/bjvm.v11i2.19137Bangl.J.Vet.Med. (2013).11(2): 131-135

Observation on the age at initial infection of Zebu Calves by <i>Toxocara vitulorum</i> in Northern Nigeria

A study was carried out to determine the mode of infection of neonatal zebu calves by Toxocara vitulorum in Northern Nigeria under both the extensively nomadic and the semi-intensively Institutional or Private Managements. Of the 90 calves from the 12 nomadic and 70 calves from the 8 Institutional/Private herds sampled, 20 and 10 respectively were positive for Toxocara (Neoascaris) vitulorum eggs in their faeces by the age of one week. This is a strong indication of the early infection of zebu calves by T. vitulorum, in Northern Nigeria as reported for calves of similar ages in other countries. This early infections could have been through intra-uterine route or postnatally via colostrum. Some of the calves voided mature stages of the helminth in their faeces between the ages of 7 and 8 weeks, which might be suggestive of either prenatal (intra-uterine) or postnatal (intra-mammary) modes of infections. Also, an infection rate among the calves of 91.1% for the nomadic and 61.4% for the Institutional/Private farms were observed in this study. The implications of these findings for the success of the cattle industry in Nigeria are discussed. Key Words: Toxocara vitulorum, neonatal zebu-calves; Initial age of infection. Trop. Vet. Vol. 21: (3) 124-128 (2003)

Comparison of isolates and species ofToxocaraandToxascarisby biosynthetic labelling of somatic and ES proteins from infective larvae

Infective-stage larvae of three different isolates of Toxocara canis were intrinsically ([35S]methionine) labelled in culture, to determine the presence of similarities or differences in the somatic and ES antigens expressed between larvae derived from different hosts and different geographical regions. Two other closely related ascaridids, Toxascaris leonina which infects cats and dogs, and Toxocara vitulorum (Neoascaris vitulorum) which infects cattle, were also compared to T. canis larvae by this method. Overall comparisons were made by 1- and 2-dimensional electrophoresis, while immunological cross-reactivities between the different species were analysed by radio-immunoprecipitation. Our results show that extensive physicochemical characteristics are shared between T. canis isolates, both from different hosts and different geographical locations. A substantial overlap was revealed when T. canis and T. vitulorum antigens were compared, whereas Toxascaris was found to produce a distinct antigen profile: this result was independent of whether methionine- or Iodogen-labelled products were being considered. Antigen recognition by polyclonal antibodies raised to all three species and to the cat ascaridid Toxocara cati, revealed considerable cross-reactivities. The cross-reactions were especially prominent between the Toxocara species, a fact further substantiated when reactivity of T. canis ES-specific monoclonal antibodies were tested against T. leonina and T. vitulorum antigens. The ES antigens of T. leonina were not recognized by the T. canis monoclonals, whereas the majority of these antibodies precipitated antigens of T. vitulorum. One which did not react with T. vitulorum was monoclonal antibody Tcn 2, indicating its species-specific reactivity and therefore its potential for the specific diagnosis of human toxocariasis.

Efficacy of ivermectin against mange and gastrointestinal nematodes of buffalo ( Bubalus bubalis)

The incidence of mange in dairy buffalo in India has increased significantly in recent years. The authors record an outbreak of mange affecting a dairy herd stocking about 30 000 buffalo and 1000 cows. The mange mites were either Sarcoptes scabiei or Psoroptes ovis, or a mixed infestation of both. The morbidity rate was 5–30% varying from group to group, with 100% in a severely affected group. Signs noticed were progressive dermatitis, alopecia, keratinization, skin thickened and wrinkled, intense itching and marked loss of condition often ending in death. Great losses of young animals from mange and gastrointestinal nematodes are very common in dairy herds in India. In view of their economic importance, the activity of ivermectin against naturally occurring mange and parasitic infections of adult buffalo and buffalo calves was determined. Ivermectin was administered by subcutaneous injection (IVOMEC 1% w/v - MSD AGVET) at a dose of 200 mcg kg −1 body weight. The efficacy was ascertained from the disappearance of mites from skin scrapings and the reduction in numbers of worm eggs in the faeces. The results of the treatment were dramatic: the mites disappeared within 2 weeks of the drug being administered in the majority of animals, with marked improvement in skin lesions. Four buffalo which had their entire body surface affected with mange needed a second dose on Day 28 for complete recovery. The effect on the nematodes was equally spectacular, with infections of Neoascaris vitulorum, Trichostrongylidae, Oesophagostomum spp. and Bunostomum being eliminated within 1 week of treatment.

Maternal Transmission by Alaria marcianae (Trematoda) and the Concept of Amphiparatenesis

The term amphiparatenic host was coined originally for hosts of Alaria marcianae that as adults are paratenic hosts, but as juveniles serve as definitive hosts. In this study the concept of amphiparatenesis is placed in a theoretical context, maternal transmission shown to be the basic mechanism, and the concept extended to include Toxocara canis, T. cati, T. pteropodis, Neoascaris vitulorum, Ancylostoma caninum, Uncinaria lucasi, various species of Strongyloides, Pharyngostomoides procyonis, and P. adenocephala. Alaria marcianae mesocercariae were used in a feline model to show that male and nonlactating female cats are definitive hosts, but lactating cats are primarily paratenic hosts. Inoculation of 1 female cat resulted in the infection of 21 of her offspring via the milk over the course of 5 litters and after a 3-yr period she still had viable larvae in her tissues. The ability of parasites to remain immature in amphiparatenic hosts is believed to be an adaptation on the part of the parasite to promote dissemination through maternal transmission and not the result of resistance, immunological or otherwise, on the part of the host. The amphiparatenic concept has important implications that include: the use of pregnant and lactating females as reservoirs of infection for the offspring; infection transmitted through a contagious transplacental or transmammary pathway; a parasite population structure in which adult worms are in greater abundance in neonate than adult hosts; and the effective control of parasites utilizing this strategy proving to be very difficult.

GENETIC VARIATION OF ASCARIDOID WORMS WITH DIFFERENT LIFE CYCLES.

The hypothesis that genetic variation of populations is positively related to the degree of environmental variation they experience was tested by several authors (e.g., Bryant, 1974a, 1974b; Hedrick et al., 1976; Valentine, 1976; Steiner, 1977; Nevo, 1976, 1978; Mitter and Futuyma, 1979; Nevo et al., 1984). These studies yielded contradictory results, partly because of the experimental design and/or the organisms compared. For example, some animal groups are physiologically more buffered than others against environmental variation, and this can affect their levels of genetic variability (Selander and Kaufman, 1973). The effect of environmental variation might be detectable only when the organisms studied are closely related and ecologically similar. In the present study, the genetic structure of several Ascaridoid worms is compared by means of multilocus electrophoresis. Evidence is given that species whose life cycle is carried out on a single homeothermic host show lower genetic variability (by a factor of about 1/3) than do those needing both poikilothermic and homeothermic hosts. Natural selection is suggested to be the major factor promoting and maintaining the different patterns of genetic variability found in these parasites. The 17 species studied belong to the superfamily Ascaridoidea; nine of them (i.e., Ascaris lumbricoides, A. suum, Parascaris univalens, P. equorum, Neoascaris vitulorum, Toxocara canis, T. cati, Toxascaris leonina, Baylisascaris transfuga) are single-host species, while eight (i.e., Anisakis simplex A, A. simplex B, A. physeteris, Phocascaris cystophorae, Contracaecum osculatum A, C. osculatum B, C. rudolphii A, C. rudolphii B) are multiple-host species. The former parasitize terrestrial mammals, whereas the latter live as larvae on poikilothermic hosts (first on crustaceans, later on fishes or squids of various size) and as adults on homeothermic hosts (marine mammals or fish-eating birds). Horizontal starch gel electrophoresis was performed on single specimens, both larvae and adults, for the following enzymes: octanol dehydrogenase (ODH), a-glycerophosphate dehydrogenase (a-GPDH), sorbitol dehydrogenase (SDH), lactate dehydrogenase (LDH), malate dehydrogenase (MDH), malic enzyme (ME), isocitrate dehydrogenase (IDH), 6-phosphogluconate dehydrogenase (6-PGDH), glucose-6-phosphate dehydrogenase (G6PDH), glyceraldheyde-3-phosphate dehydrogenase (G3PDH), xanthine dehydrogenase (XDH), superoxide dismutase (SOD), nucleoside phosphorylase (NP), glutamate oxaloacetate transaminase (GOT), hexokinase (HK), adenylate kinase (ADK), phosphoglucomutase (PGM), esterase (EST), acid phosphatase (ACPH), leucine aminopeptidase (LAP), aldolase (ALD), carbonic anhydrase (CA), triose phosphate isomerase (TPI), mannose phosphate isomerase (MPI), and glucose phosphate isomerase (GPI). The buffer systems used were: 1) tris-versene-borate (Brewer and Sing, 1970) for ODH, G6PDH, SOD, NP, CA, MPI, and GPI; 2) tris-versene-maleate (Brewer and Sing, 1970) for LDH and PGM; 3) phosphate-citrate (Harris, 1966) for a-GPDH, MDH, 6-PGDH, and ACPH; 4) discontinuous tris-citrate (Poulik, 1957) for EST and LAP; 5) continuous tris-citrate-II (Selander et al., 1971) for SDH, ME, IDH, G3PDH, XDH, GOT, HK, ADK, ALD, and TPI. The staining techniques were, with minor modifications, those described by Brewer and Sing (1970; LDH and PGM), Shaw and Prasad (1970; SDH, MDH, IDH, 6-PGDH, G6PDH, and XDH), Selander et al. (1971; SOD, GOT, and GPI), Ayala et al. (1972; ODH, a-GPDH, ME, G3PDH, HK, ADK, EST, LAP, ALD, and TPI), and Harris and Hopkinson (1976; NP, ACPH, CA, and MPI). Each species was tested for a number of loci ranging from 18 to 28, 12 of which (Ldh, Mdh-1, Idh-1, 6-Pgdh, G3pdh, Got-i, Adk-2, Pgm-1, Est-], Est-2, Mpi, and Gpi) were the same for all the species studied. The following parameters were used to estimate genetic variability: expected mean heterozygosity per locus (He); proportion of polymorphic loci, according to

Diseases and parasites of cattle in Vanuatu.

A study of cattle diseases was carried out in Vanuatu from 1971 to 1981. Tuberculosis was discovered in 4 herds and eradication was completed by 1981. The number of farms with brucellosis reactors increased from 2 in 1976 to 7 in 1978 despite eradication measures. Antibodies to serovars Leptospira icterohaemorrhagiae, australis, sejroe and canicola were demonstrated by the microscopic agglutination test. Antibodies were demonstrated against infectious bovine rhinotracheitis/infectious pustular vulvovaginitis and bovine virus diarrhoea/mucosal disease complexes. Of the 18 parasites identified, Haemaphysalis longicornis, Haemonchus, sp, Oesophagostomum phlebotomum and Neoascaris vitulorum were the most prevalent. As brucelossis is the only serious disease present, Vanuatu is in a favourable situation with regard to cattle diseases.

An Epidemiological Study On Zoonoses In Korea

Helminthic zoonoses are of significant importance to the public health and to the socioeconomic consequences especially in lost-meat, animal products and animal labor. For past several decades in Korea, it has been recognized that endoparasitic infections among domestic animals are extremely common and many of the helminth parasites of man have been acquired from, or are shared with domestic animals. However, there was no survey of a nationwide scale on the prevalence of animal helminthiasis; and control measures are also not satisfactory. Furthermore, because of the remarkable increase in the demand, number of domestic animals and pets is rapidly increasing in these days. Therefore, an extensive study on zoonotic helminths was carried out from July 1980 throughout August 1981 to understand the present status and parasite-host relationship from the epidemiological viewpoont. A total of 13,685 fecal specimens of cattles, sheeps, pigs, dogs and cats was collected from 26 localities in the country. The specimens were examined by formalin-ether centrifugal sedimentation technique. The results are summarized as follows: 1. Of 13,685 specimens examined, 9,808(71.7 %) were positive for helminth parasites. The positive rates were 99.0 % in cattles, 86.5 % on sheeps, 85.4 % in pigs, 35.4 % in dogs, 15.1 % in cats. 2. Single infection showed the highest rate (60.0 %), and double infection(27.5 %), triple(8.1 %), quadruple(2.8 %), quintuple(1.5 %) and hexad(0.1 %) were in decreasing order. 3. In the present study, 18 species zoonotic helminths were found: 11 nematodes, 6 trematodes and 1 cestode. 4. According to province, Cheju revealed the highest rate 84.8 %, then Kyungnam 77.5 %, Jeonnam 75.6 %, Jeonpuk 75.4 %, Kyonggi 75.2 %, Chungnam 71.7 %, Chungpuk 70.6 % and Kangwon 64.2 % were in decreasing order and Busan and Seoul showed 70.4 % and 58.1 %, respectively. 5. Rural area showed slightly higher rate (74.7 %) than urban area (68.5 %), and rates of mountainous area (70.4 %) and plain area (71.1 %) are very similar. 6. According to animal, helminths species and positive rates appeared in: Cattles: 6 nematodes and 3 trematodes; Strongyles 26.4 %, Neoascaris vitulorum 24.1 %, Trichuris ovis 12.0 %, Nematodirus sp. 6.3 %, Srongyloides papillosus 5.1 %, Capillaria bovis 0.02 %, Paramphistomum sp. 41.5 %, Fasciola hepatica 33.2 % and Eurytrema pancreaticum 29.7 %. Sheeps: 3 nematodes and 2 trematodes: Strongyles 33.0 %, S. papillosus 26.9 %, Nematodirus sp. 14.6 %, F. hepatica 31.7 % and E. pancreaticum 19.6 %. Pigs: 5 nematodes and 2 trematodes: Strongyles 43.1 %, Ascaris suum 29.0 %, Metastrongylus apri 20.3 %, Trichuris suis 14.0 %, Strongyloides ransomi 12.1 %, Clonorchis sinensis 1.4 % and Paragonimus westermani 0.9 %, Dogs: 4 nematodes and 3 trematodes and 1 cestode: Toxocara canis 14.4 %, Trichuris vulpis 9.5 %, Ancylostoma caninum 8.0 %, Toxascaris leonina 4.0 %, C. sinensis 2.4 %, Metagonimus yokogawai 1.3 %, P. westermani 0.8 % and Spirometra sp. 0.9 %, Cats: 2 nematodes, and 3 trematodes and 1 cestode: Toxocara cati 7.7 %, Ancylostoma tubaeforme 3.1 %, C. sinensis 1.9 %, P. westermani 1.4 %, M. yokogawai 1.2 % and Spirometra sp. 0.7 %.

Cholinesterases in Paramphistomum microbothrium, Ascaris suum and Neoascaris vitulorum

1. The protein fractions, soluble in 0.15 M NaCl, of Paramphistomum microbothrium, Ascaris suum and Neoascaris vitulorum each contain at least two cholinesterases. 2. This is deduced from the degree of inhibition by 0.0-dimethyl-2,2-dichlorovinyl phosphate (DDVP) which is different when measured with acetylthiocholine than with butyrylthiocholine as substrate.

On the Life Cycle of Strongyloides westeri in the Equine

Adult Strongyloides westeri infections in foals appear to originate mainly from larvae passed in the milk of mares. Larvae were found in milk samples of 32 mares for 4 to 47 days postpartum. No larvae were found in colostrum samples. There was no evidence of prenatal infection of foals. Periodicity was observed in the number of larvae passing in the milk; for 5 mares, sampled over 24-hr periods, 65.5 to 88.9% of the larvae were found in the AM and 11.1 to 34.5.% were found in the PM. The prepatent period of S. westeri in worm-free foals was 10 to 14 days when free-living third-stage larvae were given and 8 to 12 days when parasitic third-stage larvae were given. Most naturally infected foals sampled began passing eggs at about 2 weeks of age and they lost infections of adult worms at about 20 to 25 weeks of age. Under natural conditions, free-living third-stage larvae appear to play a minor role in producing infections of adult worms in foals. Three wormfree foals died after being given several million free-living third-stage larvae. Administering high numbers of freeliving third-stage larvae to preparturient mares did not noticeably increase the numbers of larvae shed in the milk. Slight differences were noted in measurements of free-living and parasitic third-stage larvae. It has long been known that foals pass eggs of Strongyloides westeri at a very young age. Since eggs of this parasite are not found in feces of adult horses and an environmental source of infection appeared unlikely (Russell, 1948), the means of transmission was unclear until recently when a few preliminary observations were reported (Lyons, Drudge, and Tolliver, 1969) on larvae of S. westeri being found in milk of mares. Other reports of passage of larval nematodes through the mammary system include Uncinaria lucasi of fur seals (Olsen and Lyons, 1962, 1965), Strongyloides ransomi of pigs (Moncol and Batte, 1966), and Ancylostoma caninum of dogs (Stone and Girardeau, 1966) found in the colostrum, and Toxocara canis of dogs (Stone and Girardeau, 1967), Neoascaris vitulorum of cattle (Warren, 1969), Strongyloides papillosus of cattle and sheep (Lyons, Drudge, and Tolliver, 1970), and Toxocara cati of cats (Swerczek, Nielsen, and Helmboldt, 1971) found in the milk. The object of the present paper is to provide more details concerning the earlier observations on S. westeri and to present new data on the life cycle of this parasite. Received for publication 6 March 1973. * The investigation reported in this paper (73-4-48) was made in connection with a project of the Kentucky Agricultural Experiment Station and is published with the approval of the Director. Supported in part by a grant from The Grayson Foundation, Inc., Lexington, Kentucky 40501. MATERIALS AND METHODS This investigation included Thoroughbreds, Standardbreds, Shetland Ponies, Hackney Ponies, draft horses, and mixed light horse breeds. Natural infection of foals kept with mothers Feces was examined daily from 83 naturally infected foals from 7 through 16 days of age to establish when S. westeri eggs were first present. Fecal egg counts were determined for 27 other foals at weekly intervals up to 19 to 34 weeks of age and for 24 additional foals, either weekly or biweekly, through 23 to 45 weeks of age. Natural infection of foals taken from mothers soon after birth A total of 157 pony foals were removed from their mothers at 1 to 11 days after birth. Eightythree of the foals were taken from their dams at 1 day of age, 44 at 2 days, 15 at 3 days, 4 at 4 days, and the other 11 at 5 to 11 days. Fecal samples were examined, usually at weekly intervals, for presence of S. westeii eggs in order to determine the incidence of infection. Another pony foal (68-OL-3) was taken from its mother at birth, before it nursed. It was fed colostrum collected fresh from its mother for 19 hr and then fed other mare milk that had been collected previously and frozen for at least 3 weeks. The purpose of this diet was to simulate the natural diet. Daily fecal samples were examined for eggs. At 19 days of age it was killed and the small intestine was examined for S. westeri adults and larvae. Parturition of mares in isolation To evaluate whether foals become infected by their dams, 7 pregnant mares were put in isolation where free-living third-stage larvae were unlikely to be present. Two of the mares were put in stalls previously uninhabited by horses, 2 in concrete-

Studies on the epizootiology of Neoascaris vitulorum in Nigeria.

1. The effect of relative humidity on the survival and development of Neoascaris vitulorum eggs to the infective stage is described.2. Tables showing the percentages of eggs at different stages of development and dead eggs at weekly interval for two different sizes of faecal masses are constructed and the results discussed.3. Detailed weather graphs showing daily rainfall, average daily relative humidity and evapotranspiration for Ibadan and Obudu during the rainy season of 1964 are constructed and the effect of the weather on survival of Neoascans vitulorum eggs in pasture at these places is discussed.4. The minimum relative humidity for the survival and development of Neoascaris vitulorum eggs to the infective stage is found to be 80%. The period of survival of eggs in a dry atmosphere depends on the size of the faecal mass containing the eggs. The critical relative humidity for Neoascaris vitulorum eggs is compared with values for other ascarids of domestic animals.