Anthelmintic efficacy of oral trichlorfon solution against ivermectin resistant nematode strains in cattle

Infected calves from two different rural estates in Brazil were studied to assess the anthelmintic efficacy of oral trichlorfon against naturally occurring ivermectin resistant parasitic nematode strains. In experiment 1, infected animals were from a region where ivermectin resistant populations of Haemoncus placei, Cooperia punctata,Cooperia spatulata and Trichuris discolor have recently been identified. Six calves with natural gastrointestinal nematode infections were treated with 48.5 mg/kg aqueous trichlorfon administered orally and six calves acted as a non-treated control group. In experiment 11 24 naturally infected calves were selected to enter one of four treatment groups, six animals each received: 48.5 mg/kg oral trichlorfon; 200 mu g/kg subcutaneous 1% ivermectin; 630 mu g/kg subcutaneous 3.15% ivermectin; or no treatment (control group). Gastrointestinal helminths were counted and identified post-mortem at 7 days (trichlorfon and 1% ivermectin treated and untreated animals) or 14 days (3.15% ivermectin treated and untreated animals) after administration of the test agents. Experiment I identified a high level efficacy for oral trichlorfon against four helminth species that have previously been shown to be ivermectin resistant in this geographical region: percentage efficacy was 99.82% against adult H. placei, 99.18% against C. punctata, 99.33% against C. spatulata, 81.06% against T. axei, 98.46% against Oesophagostomum radiatum and 100% against T. discolor. Trichlorfon also showed activity against the ivermectin (1% and 3.15%) resistant helminth species identified in experiment 11, attaining efficacy levels of 99.17% against H. placei, 98.46% against C punctata and 100.00% against T. discolor. These findings indicate that oral trichlorfon is an effective treatment option in the management of cattle infected with ivermectin resistant helminths. (C) 2009 Elsevier B.V. All rights reserved.

Infecções por helmintos em Javalis (Sus scrofa scrofa) criados em cativeiro na região Noroeste do Estado de São Paulo, Brasil

O estudo foi desenvolvido no período de outubro de 2001 a maio de 2002, com 51 javalis (Sus scrofa scrofa) proveniente de duas propriedades situadas nos municípios de Mirassol e Fernandópolis, Estado de São Paulo, sendo 18 animais variando de 150 a 360 dias (Grupo I) e 33 animais entre 30 a 120 dias de vida (Grupo II). O objetivo da investigação foi identificar a helmintofauna e obter subsídio para melhor conhecimento da instalação das infecções helmínticas. Foram identificadas nos dois grupos, respectivamente, oito espécies de nematódeos com as seguintes prevalências: Trichuris suis (16,7% e 30,3%); Metastrongylus salmi (50,0% e 15,2%), Metastrongylus pudendotectus (5,6% e 3,0%); Strongyloides ransomi (27,8% e 12,1%); Ascaris suum (0,0% e 3,0%), Ascarops strongylina (27,8% e 0,0%); Physocephalus sexalatus (5,6% e 0,0%); Oesophagostomum dentatum (22,2% e 0,0%). O total de nematódeos colhidos e identificados nos dois grupos de animais foi de 7958, assim distribuídos: 6573 no intestino grosso (82,6%), 1246 no pulmão (15,7%), 89 no intestino delgado (1,1%), e 50 no estômago (0,6%). As maiores variações de intensidade foram obtidas por T. suis de 1 a 1764 e por M. salmi 1 a 248 exemplares.

Helminth fauna of bovines from the Central-Western region, Minas Gerais State, Brazil

A prevalência e a intensidade de parasitismo por diferentes espécies de helmintos foram estudadas em bovinos da microrregião de Formiga, região Centro-oeste de Minas Gerais. Para tanto, foram necropsiados 76 bovinos naturalmente infectados, machos e fêmeas, SRD (sem raça definida) e de oito a 12 meses de idade. Os resultados necroscópicos revelaram a presença de nove gêneros e 16 espécies de helmintos, com a seguinte prevalência e média de intensidade de infecção: Haemonchus placei (100,0%; 3895,5); Haemonchus similis (29,0%; 159,6); Cooperia punctata (100,0%; 5595,0); Cooperia spatulata (32,9%; 137,8); Cooperia pectinata (34,2%; 1010,5); Trichostrongylus axei (69,7%; 239,2); Trichostrongylus colubriformis (10,5%; 10,8); Trichostrongylus longyspicularis (2,6%; 0,5); Ostertagia ostertagi (2,6%; 3,1); Ostertagia lyrata (2,6%; 1,5); Ostertagia trifurcata (1,3%; 0,3); Oesophagostomum radiatum (94,7%; 470,9); Trichuris discolor (47,4%; 32,5); Strongyloides papillosus (1,3%; 0,1); Capillaria bovis (9,2%; 10) e Bunostomum phlebotomum (2,6%; 0,3). A carga parasitária média foi de 11.558,5 helmintos por animal. Dos 76 bovinos necropsiados, 92,1% estavam infectados por três a sete espécies de helmintos. Apenas 7,9% dos hospedeiros mostravam-se parasitados por oito espécies diferentes de helmintos. Este estudo mostra o primeiro relato das espécies Ostertagia lyrata e Ostertagia trifurcata no Estado de Minas Gerais. É importante ressaltar que, no presente trabalho, por meio da identificação dos helmintos colhidos nas necropsias, foi possível observar que está ocorrendo uma inversão na intensidade parasitária média, com uma diminuição no número de Cooperia e um aumento nos valores de Haemonchus, em comparação com os valores relatados na literatura.

Eficácia anti-helmíntica comparativa da associação albendazole, levamisole e ivermectina à moxidectina em ovinos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Correlação entre condições de saneamento básico e parasitoses intestinais na população de Assis, Estado de São Paulo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Classic and molecular study of Giardia duodenalis in children from a daycare center in the region of Presidente Prudente, São Paulo, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Prevalence of intestinal parasites in dogs from São Paulo State, Brazil

The prevalence of gastrointestinal parasites in stray dogs, and dogs with owners was investigated by fecal examinations from 271 dogs employing sedimentation, simple flotation and centrifugation-flotation methods. The centrifugation-flotation method, when compared to simple flotation or sedimentation methods was generally more accurate in the diagnosis of all intestinal parasites, but statistical differences were detected only in relation to Giardia spp. and Cystoisospora spp. (synonym Isospora spp.). The following parasites, with their respective prevalence, were diagnosed in the fecal samples: Ancylostoma spp. (23.6%); Toxocara canis (5.5%); Trichuris vulpis (4.8%); Spirocerca lupi (1.9%); Dipylidium caninum (0.7%); Giardia spp. (12.2%); Hammondia heydorni (2.6%); Cystoisospora spp. (8.5%); and Sarcocystis spp. (2.2%). The prevalence of most parasites was similar for dogs of mixed-breed and for dogs of a defined-breed, except for Cystoisospora spp. and T canis which showed a significantly higher prevalence in mixed-breed dogs. The prevalence of Ancylostoma spp. (17.1%) was significantly lower in stray dogs than in those with an owner (31.9%) and the prevalence of Giardia spp. and Cystoisospora spp. was higher in stray dogs (P < 0.05). No effect of season on the occurrence of the different parasite genera could be observed, except for Ancylostoma spp., for which an increase in the percentage of dogs shedding eggs was observed at the beginning of Summer with a peak occurrence during April and May (Autumn). The prevalence of Ancylostoma spp., T canis, T vulpis, Giardia spp. and Cystoisospora spp. was higher in adult males than in adult females, but significant differences between the two groups occurred only with Giardia spp. Young animals were found to more frequently shed Nematode eggs in feces than adult animals. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Comparison of three concentration methods for the recovery of canine intestinal parasites from stool samples

The aim of present study was to compare the efficiency of a commercial assay and two conventional methods for fecal concentration in detecting canine gastrointestinal parasites. Fecal samples from 254 dogs were processed by centrifugation-sedimentation (CS), centrifugation-flotation (CF) and a commercial assay for fecal concentration (TF-test (R)). The following parasites were detected: Ancylostoma (37.8%), Giardia (16.9%), Toxocara canis (8.7%), Trichuris vulpis (7.1%), Isospora (3.5%), and Sarcocystis (2.7%). The calculated analytical sensitivity indicated that CF was more accurate (P < 0.01) in detecting Ancylostoma, T. canis, T. vulpis and Giardia infections. However, CF showed significantly higher sensitivity only for Ancylostoma, compared to the other two methods. The kappa index value of diagnostic agreement between TF-test and CF was high for T. canis (83%) and moderate for Giardia (72%) and Ancylostoma (63%). The advantages and limitations of each method were assessed for individual diagnosis and epidemiological investigation. (C) 2010 Elsevier B.V. All rights reserved.

Moxidectin-resistant nematodes in cattle in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Prevalence of dog intestinal parasites and risk perception of zoonotic infection by dog owners in São Paulo State, Brazil

Coprological examination was used to estimate the prevalence of gastrointestinal parasites in stray and domiciled dogs from Botucatu, São Paulo State, Brazil. Risk factors for dog infection were assessed in relation to demographic, husbandry and management data. The dog owners completed a questionnaire survey on some aspects of dog parasitism such as parasite species, mechanisms of infection, awareness of zoonotic diseases and history of anthelmintic usage. Parasites were found in the faeces of 138 dogs, with an overall prevalence of 54.3%. Dogs harbouring one parasite were more common (31.4%) than those harbouring two (18.5%), three (3.2%) or four (1.2%). The following parasites and their respective frequencies were detected: Ancylostoma (37.8%), Giardia (16.9%), Toxocara canis (8.7%), Trichuris vulpis (7.1%), Dipylidium caninum (2.4%), Isospora (3.5%), Cryptosporidium (3.1%) and Sarcocystis (2.7%). Stray dogs were found more likely to be poliparasitized (P < 0.01) and presented higher prevalence of Ancylostoma, T. canis and Giardia (P < 0.01) than domiciled ones. Toxocara canis was detected more frequently in dogs with < 6 months of age (P < 0.05) and no effect of sex or breed could be observed (P > 0.05). Except for Ancylostoma, that showed a significantly higher prevalence in dogs living in a multi-dog household (P < 0.01), parasite prevalences were similar in single- and multi-dog household. The answers of dog owners to the questionnaire showed that the majority does not know the species of dog intestinal parasites, the mechanisms of transmission, the risk factors for zoonotic infections, and specific prophylactic measures. The predominance of zoonotic species in dogs in the studied region, associated with the elevated degree of misinformation of the owners, indicates that the risk of zoonotic infection by canine intestinal parasite may be high, even in one of the most developed regions of Brazil.

Reductions in the Prevalence and Incidence of Geohelminth Infections following a City-wide Sanitation Program in a Brazilian Urban Centre

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparação entre técnicas coproparasitológicas no diagnóstico de ovos de helmintos e oocistos de protozoários em cães.

In this study we evaluated the frequency of enteroparasites in pet dogs and their association with age, sex and breed, as well as the efficiency of the Willis-Mollay, Faust, Sedimentation and Direct exam methods. By these methods we processed 401 fecal samples. The samples were positive in the following percentages: Ancylostoma spp. (53.1%), Toxocara canis (20.7%), Cystoisospora ohioensis (15.7%), Trichuris vulpis (3.7%), Dipylidium caninum (2.5%) and Taenia spp. (1.0%). Toxocara canis (67.3%) and C. ohioensis (47.3%) showed higher positivity in the puppies. The Willis-Mollay technique was more efficient in the diagnosis of Ancylostoma spp. and T. canis eggs. The Direct method was the least efficient. It was found that the majority of the cases of D. caninum were diagnosed by the Sedimentation method (8=2.0%), while for T. vulpis Willis-Mollay (12=3.0%) and Sedimentation (13=3.2%) were more efficient. In view of these results, we can recommend the association of Willis-Mollay and Sedimentation methods for the diagnosis of gastrointestinal helminths. Due to the elevated occurrence of Ancylostoma spp. and T. canis, which are involved in zoonotic diseases, it becomes necessary to apply more efficient prophylaxis of canine intestinal parasitosis at the City of Araçatuba, state of São Paulo.

Helmintos parasitos de mocós (Kerodon rupestris Rodentia: Caviidae) de vida livre e de cativeiro, no semi-árido nordestino Brasileiro

This study shows the helminthic fauna of 16 rock cavies (Kerodon rupestris) from the semi-arid region in the State of Rio Grande do Norte, Brazil. Nine animals were captured from the wild and seven from a captive population located at the Centro de Multiplicação de Animais Silvestres, city of Mossoró, were examined in this study. The animals were slaughtered, and post mortem analysis of the digestive tract, trachea, heart, lungs, liver, pancreas, and kidneys were done in search for the presence of parasites. Five species of nematode (Paraspidodera uncinata, Trichostrongylus colubriformis, Trichuris gracilis, Trichuris muris, and Vianella lenti) and one species of cestode (Thysanotaenia congolensis) were identified.

Prevention of soil-transmitted helminth infection

Soil-transmitted helminths (STHs) form one of the most important groups of infectious agents and are the cause of serious global health problems. The most important STHs are roundworms (Ascaris lumbricoides), whipworms (Trichuris trichiura) and hookworms (Necator americanus or Ancylostoma duodenale); on a global level, more than a billion people have been infected by at least one species of this group of pathogens. This review explores the general concepts of transmission dynamics and the environment and intensity of infection and morbidity of STHs. The global strategy for the control of soil-transmitted helminthiasis is based on (i) regular anthelminthic treatment, (ii) health education, (iii) sanitation and personal hygiene and (iv) other means of prevention with vaccines and remote sensoring. The reasons for the development of a control strategy based on population intervention rather than on individual treatment are discussed, as well as the costs of the prevention of STHs, although these cannot always be calculated because interventions in health education are difficult to measure. An efficient sanitation infrastructure can reduce the morbidity of STHs and eliminates the underlying cause of most poverty-related diseases and thus supports the economic development of a country.

Resistance against gastrointestinal nematodes in Crioulo Lageano and crossbred Angus cattle in southern Brazil

Gastrointestinal nematode (GIN) infection is a major cause of production losses in cattle. This study was carried out to evaluate the natural resistance against nematode infection in Crioulo Lageano and crossbred Angus male calves. Crioulo Lageano is a local cattle breed in the state of Santa Catarina, in southern Brazil. Ten weaned calves of each breed were grazed together on pasture and naturally infected with nematodes between July 2009 and December 2010. Once every 28 days, we collected fecal and blood samples for parasitological and immunological tests, as well as recording body weights. After 19 samplings, all animals were slaughtered for quantification and identification of GINs. We found that the animals had been infected with the following nematode species, in decreasing order by the mean number of specimens: Trichostrongylus axei, Cooperia punctata, Ostertagia ostertagi, Haemonchus placei, Oesophagostomum radiatum, and Trichuris spp. There were no significant differences between the Crioulo Lageano and crossbred Angus groups in terms of worm burden or nematode fecal egg count, nor in terms of the mean levels of immunoglobulin (G and A) against C. punctata and H. placei antigens, except in IgA mean level in abomasal mucus against H. placei adult worms that was significantly higher in crossbred Angus cattle (p<0.05). At the end of the study, the crossbred Angus cattle were heavier than were the Crioulo Lageano cattle (mean live weight, 507.35 and 390.3. kg, respectively). Comparative parasitological and immunological evaluation revealed no difference between two breeds in terms of their natural resistance against GINs. © 2012 Elsevier B.V.