Environmental contamination by Toxocara sp eggs in public areas of Salvador, Bahia State, Brazil

Toxocara prevalence in dogs and cats in Brazil

I herein review published studies reporting the prevalence of Toxocara infection in dogs and cats in Brazil. Based on data gathered from faecal examinations of approximately 38,940 dogs and 5600 cats from different Brazilian studies, the mean prevalence of Toxocara infection is 11.4% (range: 0.7-48.9%) in dogs and 16.7% (0.3-43.1%) in cats. These mean values based on faecal examinations should be interpreted with cautious, considering the obvious differences in terms of sample size, diagnostic tests and animal populations. Accordingly, necropsy investigations reveal higher mean prevalence values (21.9% for Toxocara canis and 27.6% Toxocara cati in dogs and cats, respectively). The contamination with Toxocara eggs in different environments and the significance of these parasites from a public health perspective in Brazil are briefly discussed.

Seroprevalence and risk factors for canine toxocariasis by detection of specific IgG as a marker of infection in dogs from Salvador, Brazil

Toxocara canis is a highly prevalent worldwide canine nematode responsible for enzootic and zoonotic infections. It is considered to be one of the main agents of human visceral and ocular larva migrans. False negative diagnosis may occur because adult infected dogs with "dormant" larvae may have negative fecal test results since they usually do not shed parasite eggs in their stools. During pregnancy, the larvae become active and infect the offspring through the placenta. A serological test can distinguish infected animals, thus increasing the accuracy of the diagnosis for epidemiological studies and prophylactic purposes. In the present work a serological investigation was carried out to study the risk factors for the acquisition of this infection in 301 dogs inhabiting the city of Salvador, northeast Brazil. A validated questionnaire was applied to the donors and caretakers to assess animal management practices. All dogs were submitted to clinical evaluation and blood collection. Serum samples were analyzed for IgG antibodies against excretory-secretory products of T. canis larvae, used as antigens, by indirect ELISA. The overall seroprevalence of anti-T. canis IgG antibodies was 82.7%. Risk factors for T. canis infection included sex, area of origin within the city, homemade leftover food intake, failure to receive regular vaccination against infectious diseases and lack of preventive anti-helminthic treatment. Most of these risk factors suggest a lack of veterinary care and poverty. The high frequency of seropositivity found for toxocariasis in dogs suggests that results based on parasitological fecal examination could underestimate the actual prevalence of the infection.

Human toxocariasis: contribution by Brazilian researchers

In the present paper the main aspects of the natural history of human infection by Toxocara larvae that occasionally result in the occurrence of visceral and/or ocular larva migrans syndrome were reviewed. The contribution by Brazilian researchers was emphasized, especially the staff of the Tropical Medicine Institute of São Paulo (IMT).

Parasitas zoonóticos em fezes de cães em praças públicas do município de Itabuna, Bahia, Brasil

Avaliou-se a contaminação de praças públicas da área urbana do município de Itabuna, BA, Brasil, por parasitos zoonóticos presentes em fezes de cães. Foram coletadas 119 amostras fecais de cães em 10 praças. Logo após, estas fezes foram encaminhadas ao Laboratório de Parasitologia da UESC e analisadas pelo método de Mariano e Carvalho. Do total das amostras analisadas, 56,3% continham alguma forma evolutiva parasitária, sendo o parasita mais freqüente Ancylostoma sp. com 47,9%, seguido por 6,7% de Strongyloides stercortalis, 4,2% tanto para ovos de Toxocara canis quanto de Trichuris vulpis, 2,5% para cistos de Endolimax nana, e 0,8% tanto para cistos de Giardia intestinalis quanto para os de Entamoeba coli.

[Helminthes in sandboxes of day care centers of a city in Southeastern Brazil]

The objective of the study was to test for helminthes in sandboxes in day care centers in the city of Uberlândia, Southeastern Brazil in 2005. Fourteen private and 14 public day care centers with playgrounds were selected. One collection was carried out during the dry season (June and August), and the second one was in the rainy season (September and November). Samples were tested using Willis and Baermann methods. In the first collection, 17 (61%) day care centers were positive for helminthes larvae and 14 (50%) for eggs. In the second collection, 18 (64%) day care centers were positive for larvae and 10 (36%) for eggs. No influence of either season of the year or day care finance condition was seen.

PREVALÊNCIA DE ENDOPARASITAS EM CÃES DA ÁREA URBANA DO MUNICÍPIO DE MONTE NEGRO, RONDÔNIA

RESUMO De julho a agosto de 2001, foram colhidas amostras de fezes de 95 cães (13,8% da população canina) da área urbana do Município de Monte Negro, Rondônia. As amostras de fezes foram examinadas pelos métodos coproparasitológicos de Willis, centrífugo-flutuação em solução de sacarose e centrífugo-sedimentação em água-éter. Das 95 amostras de fezes, somente 15 (15,8%) foram negativas. Foram encontrados helmintos pertencentes a 5 gêneros: Ancylostoma, Toxocara, Trichuris, Spirocerca, Physalopterae 5 protozoários: Sarcocystis, Giardia, Cystoisospora, Cryptosporidium, Hammondia-Neospora. Ovos de Ancylostoma spp. foram os mais prevalentes (73,7% de amostras positivas), seguidos por ovos de Toxocara canis (18,9%) e esporocistos de Sarcocystis spp. (18,9%). Os demais parasitos tiveram prevalências abaixo de 10%. Os resultados encontrados foram comparados com outros trabalhos brasileiros, demonstrando que o gênero Ancylostoma é o mais freqüentemente diagnosticado em cães no Brasil.

Parasitas gastrointestinais em cães institucionalizados no Rio de Janeiro, RJ

Foi estudada a ocorrência de parasitas gastrointestinais em cães recolhidos e mantidos em instituto público de medicina veterinária no Rio de Janeiro, RJ. Amostras de fezes frescas foram coletadas em março de 2004 e analisadas pelos métodos de flutuação de Willis e centrífugo-flutuação em solução de sacarose. De 204 amostras, 45,6% estavam positivas para helmintos gastrointestinais.

Ocorrência de parasitas com potencial zoonótico em fezes de cães coletadas em áreas públicas do município de Ribeirão Preto, SP, Brasil

OBJETIVO: Avaliar a ocorrência de parasitos zoonóticos em fezes de cães colhidas em áreas públicas do município de Ribeirão Preto, enfatizando o risco da ocorrência de infecção humana. MÉTODOS: Entre os meses de maio a dezembro de 2003 foram visitadas 78 praças, localizadas em cinco diferentes áreas do município: sudoeste, noroeste, norte, central e sudeste. Foram recolhidos 331 "pools" de material fecal canino, os quais foram processados pela técnica de sedimentação espontânea. RESULTADOS: Em 56,8% "pools" foram observados os parasitos zoonóticos: Ancylostoma spp. (41,7%), Toxocara canis (24,2%), Trichuris vulpis (15,7%), Giardia spp. (10,2%) e Isospora spp. (3,3%). A prevalência de parasitos foi maior nas praças localizadas na área norte do município (70%). CONCLUSÕES: É necessária a adoção de programas de preservação sanitária destes locais, no sentido de prevenir a contaminação ambiental por parasitos potencialmente patogênicos para o homem.

Environmental contamination by Toxocara sp. eggs in Ribeirão Preto, São Paulo State, Brazil

Toxocariasis is a zoonosis mainly caused by Toxocara canis, an intestinal nematode of dogs. Man acquires the infection through accidental ingestion of viable eggs, and the toxocariasis clinical manifestations may vary from an asymptomatic infection up to the Visceral Larva Migrans syndrome. Seventy eight public squares of Ribeirão Preto, São Paulo, Brazil, including Bonfim Paulista district were visited aiming to evaluate the soil contamination by Toxocara eggs. The squares were divided in five different areas corresponding to the Sanitary Districts of the city. From May to December 2003, soil samples weighting about 250 g each were collected from five distinct sites of each public square. The laboratorial analysis was done by centrifugal-flotation techniques in magnesium sulphate solutions with 5% of potassium iodide (d = 1.33) and zinc sulphate (d = 1.20), and by the sedimentation- flotation in conic chalices with zinc sulphate (d = 1.20). Toxocara sp. eggs were found on 16 (20.5%) squares, with the lowest prevalence (12%) at the central area. From these results, it is expected that the legal authority will adopt protection measures for the city public areas, reducing thus the contamination risk by Toxocara sp. eggs.

[Cutaneous larva migrans: reports of pediatric cases and contamination by Ancylostoma spp larvae in public parks in Taciba, São Paulo State]

Cutaneous larva migrans in children from Taciba, São Paulo, Brazil, was related to contact with sand in public squares, where Ancylostoma spp larvae were detected. The outbreaks were controlled by sanitary education, temporary deactivation and isolation of the squares in order to impede the access of animals and substitution of the sand.

Toxocara spp. eggs in public squares of Sorocaba, São Paulo State, Brazil

The visceral larva migrans (VLM) is a syndrome observed in human infection with helminth larval eggs such as the Toxocara spp. that usually infects dogs and cats. Among the risk factors involved in the occurrence of VLM, particularly important is the size of these animal populations. Sorocaba is a city with a dog population twice as large as that recommended by the World Health Organization. This fact has led to a survey of the presence of Toxocara spp. eggs in public square soils of this city. Thirty squares were selected, fifteen located in the outskirts of the city and fifteen downtown. Soil samples were collected from five distinct sites in the same area. The material was homogenized and drained and 100 g was mixed with a saturated solution of magnesium sulfate and 5% potassium iodine. The floating material was analyzed under the light microscope. Toxocara spp. eggs were found in 16 squares, nine of which were located in the outskirts of the city and seven downtown. It was concluded that Sorocaba squares present a high rate of contamination with Toxocara spp. eggs. The squares in the outskirts of the city presented a higher occurrence of these eggs in comparison with those downtown, although the difference was not statistically significant (p > 0.05).

[Contamination of public squares of Campo Grande, Mato Grosso do Sul, Brazil, with eggs of Toxocara and Ancylostoma in dog feces]

From February to October 1998, the contamination of public squares of Campo Grande, MS, Brazil, by eggs of Toxocara and Ancylostoma was evaluated in dog fecal samples. Out of the 74 public parks examined, 42 (56.8%) were found to be contaminated with Ancylostoma eggs, 8 (10.8%) with Toxocara eggs and 7 (9.5%) with both.

Contaminação, por ovos de Toxocara spp, de parques e praças públicas de Botucatu, São Paulo, Brasil

A freqüência de contaminação de parques e praças públicas de Botucatu, São Paulo, Brasil, por ovos de Toxocara spp foi estudada durante 12 meses, com colheitas mensais de amostras de solo de dez praças, que foram processadas pela técnica de concentração em solução decinormal de hidróxido de sódio. Das 120 amostras analisadas, 21 estavam contaminadas, correspondendo a 17,5%, em um total de seis praças. A maioria desses ovos porém apresentaram características de inviabilidade infectiva. Embora a chance de aquisição dessa zoonose nas praças estudadas seja pequena, existe o risco de infecção da população.

Presença de ovos de Toxocara spp em praças públicas da cidade de Uberlândia, Minas Gerais, Brasil

O objetivo deste trabalho foi verificar a presença de ovos de Toxocara spp nos solos de praças públicas da cidade de Uberlândia, região do Triângulo Mineiro, no período de outubro de 1991 a janeiro de 1992. A cidade possui 89 praças distribuídas em 39 bairros. Para que se tivesse um perfil da ocorrência do parasita, foram colhidas amostras de terra e areia (quando existente) de uma praça, determinada por sorteio, por bairro. As amostras de solo homogeneizadas de 5 pontos distintos das 39 praças foram colhidas em frascos plásticos e analisadas empregando-se os métodos de flutuação em solução saturada de cloreto de sódio e de solução saturada de sulfato de magnésio contendo 5% de iodeto de potássio. Para cada amostra foram realizados os dois métodos em duplicata. Os resultados mostraram estarem contaminados os solos de 9 praças (23,07%), das quais 6 localizavam-se próximas ao centro da cidade. A realização de mais de um método laboratorial permitiu a identificação do agente em maior porcentagem de locais.