Saccharomyces boulardii reduces the vertical transmission of Toxocara canis larvae in mice.

Probiotics have been shown to reduce the intensity of Toxocara canis infection in mice. However, larval transmission of this nematode also occurs via transplacental and transmammary routes. Thus, the aim of this study was to evaluate the effect of the Saccharomyces boulardii probiotic on the vertical transmission of T. canis in Swiss mice. The mice received 107S. boulardii colony-forming units per gram of food. The supplementation began 15 days before mating and was maintained throughout pregnancy and lactation. The animals were inoculated with 300 T. canis embryonated eggs on the 14th day of pregnancy. The presence of larvae was examined in the organs of the females and their offspring. The examined organs included the following: brain, liver, lungs, heart, kidneys, spleen, eye, skeletal muscle (carcass) and mammary glands of lactating females. There was a 42% (P = 0.041) reduction in the number of larvae transmitted to offspring in the group that received probiotic-supplemented food (GI). Additionally, there was a 50% reduction (P = 0.023) in the number of larvae found in the brains of lactating offspring in the GI group. These results reveal the potential of S. boulardii probiotic use as an auxiliary method of controlling visceral toxocariasis.

A prospective seroepidemiological study of toxocariasis during early childhood in coastal Ecuador: potential for congenital transmission and risk factors for infection.

BACKGROUND: Although Toxocara spp. infection has a worldwide distribution, to our knowledge, no data from birth cohorts have been reported in published studies on the potential for congenital transmission and determinants of infection in early childhood. METHODS: We followed 290 mother-infant pairs from birth to 5 years of age through periodic collection of data and samples at birth, 7 and 13 months and 2, 3 and 5 years of age. Data on potential risk factors and confounders were collected by maternal questionnaire. Blood for plasma was collected from the mother at time of birth and periodically from the child for detection of anti-Toxocara spp. immunoglobulin G (IgG) antibodies using a Toxocara canis larval excretory-secretory antigen-based enzyme-linked immunosorbent assay. Stool samples were collected from the mother around the time of birth and periodically from the child for microscopic detection of soil-transmitted helminths (STH). Associations between potential risk factors and Toxocara spp. seroprevalence and seroconversion were estimated using multivariable logistic regression and generalized estimating equations. RESULTS: Toxocara spp. seroprevalence was 80.7% in mothers and in children was 0%, 9.3%, 48.4%, 64.9%, and 80.9% at 7 months, 13 months, 2, 3 and 5 years, respectively. Risk factors significantly associated with increases in seroprevalence over the first 5 years of life in multivariable analyses were age [Odds ratio (OR) 2.06, 95% confidence interval (CI) 1.39-2.27, P < 0001], male sex (female vs. male: OR 0.66, 95% CI 0.48-0.89, P = 0.006), maternal ethnicity (non-Afro vs. Afro-Ecuadorian: OR 0.65, 95% CI 0.47-0.91, P = 0.011), lower maternal educational and socioeconomic level, and childhood STH (OR 2.29, 95% CI 1.51-3.47, P < 0.001). Seroconversion rates for infection were greatest at 2 years of age (3.8%/month). Factors associated significantly with seroconversion at 2, 3 or 5 years were childhood STH infection, male sex, and more frequent domestic cat exposure. CONCLUSIONS: Our data, from an area of high Toxocara spp. endemicity, indicate no congenital transmission but high rates of seroconversion after 13 months of age reaching maternal levels of seroprevalence by 5 years of age. Factors associated with seroprevalence and seroconversion included STH infections, domestic cats, maternal ethnicity, male sex, STH infections, and markers of greater poverty.

Parasitos zoonóticos em solos de praças públicas no município de Sousa, Paraíba / Zoonotic parasites in soils of public squares in the municipality of Sousa, Paraíba

Os espaços coletivos com grande circulação de pessoas e animais tutelados ou errantes, como as praças públicas, podem gerar um problema para a saúde pública, uma vez que os animais podem eliminar fezes contaminadas por parasitos nesses locais, desempenhando um importante papel epidemiológico na transmissão de zoonoses parasitárias. Portanto, este trabalho teve como objetivo avaliar a contaminação por parasitos zoonóticos em dez praças públicas da cidade de Sousa, Paraíba, bem como avaliar o melhor método de diagnóstico de infestação ambiental por estes parasitas. Foram feitas coletas de solo em cinco pontos diferentes de cada praça, por raspagem superficial em quadrantes delimitados por 15 cm, sendo coletados 200g da parte central de cada ponto. Os métodos de diagnósticos utilizados foram Flutuação Simples, Sedimentação Simples, Faust e Centrífugo-Flutuação em Solução de Sacarose. Das praças avaliadas, 90% (9/10) obtiveram pelo menos uma amostra positiva. O gênero de parasito mais frequente foi Ancylostoma spp., presente em 70% (7/ 10) das praças analisadas; seguido por Strongyloides spp., coccídeos e Taenia spp., em 40% (4/10); Toxocara spp.,em 30% (3/10); eCystoisospora spp. e Trichuris spp., em 10% (1/10). O método de Sedimentação Simples foi o mais eficaz, resultando em 44% (22/50) de amostras positivas. Os demais métodos não atingiram 15% de positividade. Concluiu-se que as praças públicas analisadas encontram-se altamente infestadas por parasitos zoonóticos, representando um risco a saúde pública no município de Sousa-PB.

Collective spaces with large circulation of people and animals domiciled or wandering, such as public squares, can generate a public health problem, since the animals can eliminate feces contaminated by parasites in these places, playing an important epidemiological role for zoonose transmission. Therefore, the objective of this work was to evaluate the contamination by zoonotic parasites in ten public squares of the city of Sousa, Paraíba, as well as to evaluate the best method for the diagnosis of environmental infestation by these parasites. Soil samples were collected at five different points of each square, by surface scraping in quadrants delimited by 15 cm, with 200g of the central part of each point being collected. The diagnostic methods used were Simple Flotation, Simple Sedimentation, Faust and Centrifugal-Fluctuation in Sucrose Solution. At least one positive sample in 90% (9/10) of the evaluated squares. The most frequent parasite genus was Ancylostoma spp., present in 70% (7/10) of the analyzed squares; followed by Strongyloides spp., coccidia and Taenia spp., in 40% (4/10); Toxocara spp., in 30% (3/10); and Cystoisospora spp. and Trichurisspp., in 10% (1/10). The Simple Sedimentation method was the most effective, resulting in 44% (22/50) of positive samples. The other methods did not reach 15% positivity. It was concluded that the analyzed public squares are highly infested by zoonotic parasites, representing a public health risk in the municipality of Sousa-PB.

[Epistemological analysis of the scientific knowledge about Toxocara sp. with the emphasis on human infection]. / Análise epistemológica dos conhecimentos científicos sobre Toxocara sp. com ênfase na infecção humana.

The scope of this article was to analyze the evolution of knowledge about Toxocara sp. from a zoonotic point of view by means of scientific data published between the years 1996 and 2015 using epistemology as a tool. The epistemological analysis of the evolution of knowledge on the zoonotic aspect of Toxocara sp. in Brazil revealed that, in general, little new information was added which had, over the period studied, slow and discontinuous absorption, and was not incorporated in the social reality from the standpoint of public health.

Este artigo objetivou analisar a evolução do conhecimento sobre Toxocara sp. em seu aspecto zoonótico por meio de dados científicos entre os anos de 1996 a 2015 utilizando a epistemologia como ferramenta. A análise epistemológica da evolução do conhecimento sobre o aspecto zoonótico de Toxocara sp. no Brasil demonstrou que, de uma maneira geral, foram agregadas poucas novas informações as quais tiveram, ao longo do período estudado, absorção lenta, descontínua, e não foram inseridas na realidade social do ponto de vista de Saúde Pública.

Análise epistemológica dos conhecimentos científicos sobre Toxocara sp. com ênfase na infecção humana / Epistemological analysis of the scientific knowledge about Toxocara sp. with the emphasis on human infection

Resumo Este artigo objetivou analisar a evolução do conhecimento sobre Toxocara sp. em seu aspecto zoonótico por meio de dados científicos entre os anos de 1996 a 2015 utilizando a epistemologia como ferramenta. A análise epistemológica da evolução do conhecimento sobre o aspecto zoonótico de Toxocara sp. no Brasil demonstrou que, de uma maneira geral, foram agregadas poucas novas informações as quais tiveram, ao longo do período estudado, absorção lenta, descontínua, e não foram inseridas na realidade social do ponto de vista de Saúde Pública.

Abstract The scope of this article was to analyze the evolution of knowledge about Toxocara sp. from a zoonotic point of view by means of scientific data published between the years 1996 and 2015 using epistemology as a tool. The epistemological analysis of the evolution of knowledge on the zoonotic aspect of Toxocara sp. in Brazil revealed that, in general, little new information was added which had, over the period studied, slow and discontinuous absorption, and was not incorporated in the social reality from the standpoint of public health.

Experimental transmission of Toxocara canis from Blattella germanica and Periplaneta americana cockroaches to a paratenic host.

The present study assessed the capacity of Blattella germanica and Periplaneta americana to disseminate and transmit infective phases of T. canis to rats, which were used as a model paratenic host. P. americana and B. germanica inoculated orally with T. canis larvated eggs shed eggs and larvae in their fecal matter during the first 6days post-inoculation. Larvae were recovered from the brain, lungs, kidneys and liver of rats that had been inoculated with either infected cockroaches or their feces. ELISAs of serum detected an increase of antibodies anti-T. canis excretion-secretion antigens, whereas Western Blot (WB) showed 4 bands (120, 50, 35 and 28kDa) that were similar to those found in positive control rats. Macroscopically, the liver and kidneys of infected rats had hemorrhagic areas with milk-spot-like lesions. The lungs showed diffuse grey protuberances. Histologically, hemorrhagic areas with leucocytic infiltrate were observed in the liver, lungs and kidneys. Some larvae were found within a granuloma that was surrounded by eosinophils and other leucocytic infiltrates. Larvae were found in the brain, but without inflammatory infiltrate. Both cockroach species that ingested larvated eggs of T. canis may shed viable larvae or eggs in their fecal matter. The induction of specific serum antibodies, presence of larvae in tissues and characteristic lesions associated with larval migration in the organs of rats that had ingested either whole adults or feces of B. germanica or P. americana demonstrate the capacity of these cockroaches to transmit toxocariosis to paratenic hosts.

Toxocara spp. seroprevalence in pregnant women in Brasília, Brazil.

INTRODUCTION:: The impact of gestational toxocariasis is an understudied topic on female reproductive health. We estimated anti-Toxocara IgG prevalence among pregnant women in Brasília, Brazil, and investigated the association of the infection with history of abortion and contact with pets. METHODS:: Infection was diagnosed using ELISA with excretory/secretory antigens. Participant information was obtained via questionnaires. RESULTS:: Of 311 pregnant women, 23 were anti-Toxocara IgG positive. Twenty-two percent of anti-Toxocara IgG-positive participants and 26% had previously miscarried. Previous contact with pets was associated with higher toxocariasis prevalence. CONCLUSIONS:: A direct relationship between toxocariasis and contact with pets was observed, but there was no relationship with the miscarriage prevalence.

First report of Toxocara cati in the domestic land snail Rumina decollata.

The prospective role of the land snail Rumina decollata as a potential paratenic host of Toxocara cati for domestic cats was studied. R. decollata specimens and cats' feces were collected from the open spaces of a Buenos Aires city hospital. Cats' feces were analyzed and snails were digested to identify T. cati stages, by morphological and molecular analyses. T. cati larval eggs were recovered from 23.5% (4/17) of the sampled feces. Twenty percent of snail pools (5/25) were confirmed to be positive for Toxocara spp. third larval stage (L3) by PCR. The mean value of total larvae recovered per gram of snail in all positive pools was 5.1, with a maximum 33 L3/pool. This is the first report of T. cati infective larvae in R. decollata domestic snail as a paratenic host, since the relationship between infection in snails and in cats' feces could be demonstrated in a common environment.

Chronic polyarthritis as isolated manifestation of toxocariasis.

Human toxocariasis is a parasitic zoonosis mainly caused by Toxocara canis or Toxocara cati and is acquired by ingestion of the parasite's embryonated eggs. Arthralgia and/or arthritis were reported in up to 17% of the cases, generally with acute duration (less than 6 weeks). However, to our knowledge, chronic polyarthritis, as the isolated presentation of Toxocara infection, was not reported. One of the 5809 patients that was followed up at our service (0.017%) had chronic polyarthritis as the single manifestation of toxocariasis and was described herein. A 3-year-old girl was referred to our service with severe painful chronic polyarthritis for a period longer than 10 weeks and morning stiffness of 30min. Dog contact exposure history in the recreational areas of neighborhood was reported. Her exams showed high levels of eosinophils in peripheral blood (29%), bone marrow aspirate revealed marked eosinophilia (32%) and Toxocara enzyme-linked immunosorbent assay (Elisa) was positive (1:1280). She was treated with paracetamol (40mg/kg/day) and thiabendazole (25mg/kg/day) for 10 days, and all manifestations reduced. After eight months of follow-up, she was on clinical and laboratorial remission. In conclusion, we described a case of chronic polyarthritis, as isolated manifestation of toxocariasis, mimicking juvenile idiopathic arthritis and leukemia. Importantly, this zoonosis should be considered in patients with arthritis and eosinophilia.

Toxocariasis and childhood asthma: A case-control study.

OBJECTIVE: The objective of this study is to investigate the association between anti-Toxocara IgG seropositivity and asthma in children. METHODS: This was a case-control study conducted in a university hospital in south Brazil between May 2012 and June 2013. Were recruited 208 children up to 12 years old of whom 156 had asthma (cases) and 52 did not have asthma (controls), with a case-control ratio of 3:1 matched by age. Children's parents or guardians were interviewed using a structured questionnaire with closed questions. Serology was performed using enzyme-linked immunosorbent assay (ELISA) with excretory-secretory antigen of Toxocara canis (TES). RESULTS: The seroprevalence of IgG anti-T. canis antibodies was 12.8% in the cases and 7.7% in the controls. There was no significant association between seropositivity to T. canis and risk of asthma (adjusted odds ratio [OR]: 1.89, 95% CI: 0.52 to 6.89, p = 0.33). Household income < 2 minimum salaries, paternal school years < 9, allergic rhinitis in children, a positive family history of asthma and rhinitis and contact with cats were significantly associated with asthma, with adjusted ORs (95% CIs) of 3.05 (1.21 to 7.73), 2.83 (1.11 to 7.18), 10.5 (4.32 to 25.6), 2.65 (1.14 to 6.17), 2.49 (1.07 to 5.78) and 2.73 (1.03 to 7.27), respectively. CONCLUSIONS: This study did not find a statistically significant association between seropositivity to Toxocara sp. and risk of asthma in children. Low family income, low paternal education level, concomitant allergic rhinitis, family history of asthma and allergic rhinitis and contact with cats were independent factors associated with childhood asthma.

Chronic polyarthritis as isolated manifestation of toxocariasis / Poliartrite crônica como manifestação isolada da toxocaríase

ABSTRACT Human toxocariasis is a parasitic zoonosis mainly caused by Toxocara canis or Toxocara catiand is acquired by ingestion of the parasite’s embryonated eggs. Arthralgia and/or arthri-tis were reported in up to 17% of the cases, generally with acute duration (less than 6weeks). However, to our knowledge, chronic polyarthritis, as the isolated presentation ofToxocara infection, was not reported. One of the 5809 patients that was followed up at ourservice (0.017%) had chronic polyarthritis as the single manifestation of toxocariasis and wasdescribed herein. A 3-year-old girl was referred to our service with severe painful chronicpolyarthritis for a period longer than 10 weeks and morning stiffness of 30 min. Dog contactexposure history in the recreational areas of neighborhood was reported. Her exams showedhigh levels of eosinophils in peripheral blood (29%), bone marrow aspirate revealed markedeosinophilia (32%) and Toxocara enzyme-linked immunosorbent assay (Elisa) was positive(1:1280). She was treated with paracetamol (40 mg/kg/day) and thiabendazole (25 mg/kg/day)for 10 days, and all manifestations reduced. After eight months of follow-up, she was onclinical and laboratorial remission. In conclusion, we described a case of chronic polyarthri-tis, as isolated manifestation of toxocariasis, mimicking juvenile idiopathic arthritis andleukemia. Importantly, this zoonosis should be considered in patients with arthritis andeosinophilia.

RESUMO A toxocaríase é uma zoonose parasitária causada principalmente pelo Toxocara canis ou peloT. cati. É adquirida pela ingestão de ovos embrionados do parasita. A artralgia e/ou artriteforam relatadas em até 17% dos casos, geralmente com duração aguda (menos de seis sema-nas). No entanto, que se tem conhecimento, a poliartrite crônica como manifestação isoladada infecção por Toxocara ainda não foi descrita na literatura. Um dos 5.809 pacientes acom-panhados em nosso serviço (0,017%) exibiu poliartrite crônica como manifestação únicada toxocaríase e foi descrito neste estudo. Uma menina de três anos foi encaminhada aonosso serviço com poliartrite crônica dolorosa grave por um período superior a 10 semanase rigidez matinal diária de 30 minutos. Foi relatada história de exposição a contato comcão nas áreas de lazer do bairro. Seus exames revelaram níveis elevados de eosinófilos nosangue periférico (29%), o aspirado de medula óssea revelou eosinofilia acentuada (32%)e o ensaio imunoenzimático ligado a enzima (ELISA) para Toxocara foi positivo (1:1.280). Acriança foi tratada com paracetamol (40 mg/kg/dia) e tiabendazol (25 mg/kg/dia) durante10 dias e houve regressão de todas as manifestações. Depois de oito meses de seguimento,a pequena paciente estava em remissão clínica e laboratorial. Em conclusão, descreve-seum caso de poliartrite crônica como manifestação isolada da toxocaríase, que mimetizouuma artrite idiopática juvenil e leucemia. É importante ressaltar que essa zoonose deve serconsiderada em pacientes com artrite e eosinofilia.

elevated trans-mammary transmission of Toxocara canis larvae in BALB/c mice.

Toxocariasis is a widespread zoonosis and is considered an important worldwide public health problem. The aim of this study was to investigate the frequency of trans-mammary Toxocara canis infection in newborn BALB/c mice nursed by females experimentally infected with 1,200 eggs after delivery. After 50 days of age, the presence of larvae in different organs of the offspring was investigated. Trans-mammary infection was confirmed in 73.9% of the mice that had been nursed by infected females. These data show a high trans-mammary transmission of T. canis and confirm the significance of this transmission route in paratenic hosts.

Elevated trans-mammary transmission of Toxocara canis larvae in balb/c mice / Elevada transmissão transmamária de larvas de Toxocara canis em camundongos BALB/c

Toxocariasis is a widespread zoonosis and is considered an important worldwide public health problem. The aim of this study was to investigate the frequency of trans-mammary Toxocara canis infection in newborn BALB/c mice nursed by females experimentally infected with 1,200 eggs after delivery. After 50 days of age, the presence of larvae in different organs of the offspring was investigated. Trans-mammary infection was confirmed in 73.9% of the mice that had been nursed by infected females. These data show a high trans-mammary transmission of T. canis and confirm the significance of this transmission route in paratenic hosts.

A toxocaríase é zoonose amplamente difundida e considerada importante problema de saúde pública. O objetivo deste estudo foi avaliar a frequência da transmissão transmamária de Toxocara canis em camundongos BALB/c neonatos amamentados por fêmeas experimentalmente infectadas com 1.200 ovos logo após o parto. Após 50 dias de idade, foi avaliada a presença de larvas em diferentes órgãos dos neonatos. A infecção por via transmamária foi confirmada em 73,9% dos camundongos amamentados por fêmeas infectadas. Estes dados demonstram elevada transmissão transmamária de T. canis e confirmam a importância desta via de transmissão em hospedeiros paratênicos.

Transmammary infection in BALB/c mice with chronic toxocariasis.

Human toxocariasis is a neglected public health problem. Infection of humans generally results from the accidental ingestion of embryonated Toxocara canis eggs, but it is important to broaden knowledge about other forms of transmission. This study aimed to demonstrate the prevalence of transmammary transmission in mice with chronic toxocariasis. BALB/c mice in groups 1 (G1) and 3 (G3) were inoculated with 1200 T. canis eggs 60days before mating, whereas those of group 2 (G2) were not infected. After delivery, the G1 neonates were transferred to G2 females to be nursed, and vice versa. Thus, the mice generated by G2 females and breastfed by G1 females could be infected only during lactation. In the G3 group, offspring were not exchanged. The search for T. canis larvae in the bodies of the lactating females and their offspring was performed after weaning and at 60days old, respectively. The frequency of transmammary infection in the mice generated by G2 uninfected females and breastfed by G1 infected females was 19.8%, which was similar to that observed (19.6%) in the mice bred and fed by G3 females. The frequency of infection in the mice generated by G1 females and breastfed by G2 females was only 4.2%, which was lower than that of G1 (p=0.0064) and G3 (p=0.0062) groups. Transmammary infection by mice with chronic toxocariasis was found to be more prevalent than congenital infection.

Human toxocariasis: current advances in diagnostics, treatment, and interventions.

Toxocariasis is a neglected zoonosis caused by the nematodes Toxocara canis and Toxocara cati. This disease is widespread in many countries, reaching high prevalence independently of the economic conditions. However, the true number of cases of toxocariasis is likely to be underestimated owing to the lack of adequate surveillance programs. Although some diagnostic tests are available, their sensitivity and specificity need to be improved. In addition, treatment options for toxocariasis are limited and are non-specific. Toxocariasis is listed as one of the five most important neglected diseases by the CDC. This review presents recent advances related to the control of toxocariasis, including new immunodiagnostics, therapies, and drug formulations, as well as novel interventions using DNA vaccines, immunomodulators, and probiotics.

Toxocariasis: seroprevalence in abandoned-institutionalized children and infants.

Toxocariasis is an infection that has worldwide distribution. Toxocara canis is the most relevant agent due to its frequent occurrence in humans. Soil contamination with embryonated eggs is the primary source of T. canis. This study aimed to determine the seroprevalence of toxocariasis in 10-month to 3 year-old abandoned infants, considered to be at high risk because of their orphanhood status and early age. Blood samples were collected from 120 children institutionalized in an orphanage in the city of La Plata. In this study, we observed 38.33% of seropositive cases for T. canis by ELISA and 45% by Western blot techniques; significant differences among groups A (<1 year), B (1-2 years) and C (>2 years) were also found. In research group A, children presented a seropositivity rate of 23.91%, in group B of 42.85% and in group C of 56%, which indicates an increase in frequency as age advances, probably because of greater chances of contact with infective forms of the parasite since canines and soil are frequently infected with T. canis eggs. Abandoned children come from poor households, under highly unsanitary conditions resulting from inadequate or lack of water supply and sewer networks, and frequent promiscuity with canines, which promotes the occurrence of parasitic diseases. These children are highly vulnerable due to their orphanhood status and age.

Toxocariasis: seroprevalence in abandoned-institutionalized children and infants / Toxocariosis: seroprevalencia en infantes expósitos, abandonados e institucionalizados

Toxocariasis is an infection that has worldwide distribution. Toxocara canis is the most relevant agent due to its frequent occurrence in humans. Soil contamination with embryonated eggs is the primary source of T. canis. This study aimed to determine the seroprevalence of toxocariasis in 10-month to 3 year-old abandoned infants, considered to be at high risk because of their orphanhood status and early age. Blood samples were collected from 120 children institutionalized in an orphanage in the city of La Plata. In this study, we observed 38.33% of seropositive cases for T. canis by ELISA and 45% by Western blot techniques; significant differences among groups A (<1 year), B (1-2 years) and C (>2 years) were also found. In research group A, children presented a seropositivity rate of 23.91%, in group B of 42.85% and in group C of 56%, which indicates an increase in frequency as age advances, probably because of greater chances of contact with infective forms of the parasite since canines and soil are frequently infected with T. canis eggs. Abandoned children come from poor households, under highly unsanitary conditions resulting from inadequate or lack of water supply and sewer networks, and frequent promiscuity with canines, which promotes the occurrence of parasitic diseases. These children are highly vulnerable due to their orphanhood status and age.

La toxocariosis es una enfermedad presente en todo el mundo. Como causa primaria de infección se cita la contaminación de los suelos con huevos embrionados de Toxocara canis. Nuestro objetivo fue determinar la seroprevalencia de toxocariosis en niños expósitos (abandonados) de 10 meses hasta 3 años, los que se consideran de alto riesgo por su condición de orfandad y escasa edad. Las muestras de sangre fueron recolectadas de 120 niños institucionalizados en un orfelinato de la ciudad de La Plata. En este estudio, se observó un porcentaje de seropositivos para T. canis de 38,33 % por la técnica de ELISA y de 45 % por la técnica de Western blot, con diferencias significativas entre los grupos etarios estudiados (A: < 1 año, B: 1-2 años, C: > 2 años). Los niños del grupo A presentaron una frecuencia de seropositividad de 23,91 %; los del grupo B, de 42,85 % y en los niños del grupo C fue del 56 %. Esto indica un incremento de la frecuencia de presentación a medida que aumentó la edad, debido probablemente a las mayores posibilidades de contactar con estados infectantes del parásito, ya que los caninos y el suelo se hallan frecuentemente infectados por huevos de T. canis. Los niños abandonados provienen de hogares carenciados, donde a las malas condiciones de higiene resultantes de la ausencia de red de agua y cloacal se le agrega la frecuente promiscuidad con caninos, lo cual propicia la presencia de parasitosis. Sumado a la condición de desamparo, esto produce un estado de máxima vulnerabilidad.

Toxocariasis: seroprevalence in abandoned-institutionalized children and infants / Toxocariosis: seroprevalencia en infantes expósitos, abandonados e institucionalizados

Toxocariasis is an infection that has worldwide distribution. Toxocara canis is the most relevant agent due to its frequent occurrence in humans. Soil contamination with embryonated eggs is the primary source of T. canis. This study aimed to determine the seroprevalence of toxocariasis in 10-month to 3 year-old abandoned infants, considered to be at high risk because of their orphanhood status and early age. Blood samples were collected from 120 children institutionalized in an orphanage in the city of La Plata. In this study, we observed 38.33% of seropositive cases for T. canis by ELISA and 45% by Western blot techniques; significant differences among groups A (<1 year), B (1-2 years) and C (>2 years) were also found. In research group A, children presented a seropositivity rate of 23.91%, in group B of 42.85% and in group C of 56%, which indicates an increase in frequency as age advances, probably because of greater chances of contact with infective forms of the parasite since canines and soil are frequently infected with T. canis eggs. Abandoned children come from poor households, under highly unsanitary conditions resulting from inadequate or lack of water supply and sewer networks, and frequent promiscuity with canines, which promotes the occurrence of parasitic diseases. These children are highly vulnerable due to their orphanhood status and age.(AU)

La toxocariosis es una enfermedad presente en todo el mundo. Como causa primaria de infección se cita la contaminación de los suelos con huevos embrionados de Toxocara canis. Nuestro objetivo fue determinar la seroprevalencia de toxocariosis en niños expósitos (abandonados) de 10 meses hasta 3 años, los que se consideran de alto riesgo por su condición de orfandad y escasa edad. Las muestras de sangre fueron recolectadas de 120 niños institucionalizados en un orfelinato de la ciudad de La Plata. En este estudio, se observó un porcentaje de seropositivos para T. canis de 38,33 % por la técnica de ELISA y de 45 % por la técnica de Western blot, con diferencias significativas entre los grupos etarios estudiados (A: < 1 año, B: 1-2 años, C: > 2 años). Los niños del grupo A presentaron una frecuencia de seropositividad de 23,91 %; los del grupo B, de 42,85 % y en los niños del grupo C fue del 56 %. Esto indica un incremento de la frecuencia de presentación a medida que aumentó la edad, debido probablemente a las mayores posibilidades de contactar con estados infectantes del parásito, ya que los caninos y el suelo se hallan frecuentemente infectados por huevos de T. canis. Los niños abandonados provienen de hogares carenciados, donde a las malas condiciones de higiene resultantes de la ausencia de red de agua y cloacal se le agrega la frecuente promiscuidad con caninos, lo cual propicia la presencia de parasitosis. Sumado a la condición de desamparo, esto produce un estado de máxima vulnerabilidad.(AU)

Toxocariasis: seroprevalence in abandoned-institutionalized children and infants. / Toxocariasis: seroprevalence in abandoned-institutionalized children and infants.

Toxocariasis is an infection that has worldwide distribution. Toxocara canis is the most relevant agent due to its frequent occurrence in humans. Soil contamination with embryonated eggs is the primary source of T. canis. This study aimed to determine the seroprevalence of toxocariasis in 10-month to 3 year-old abandoned infants, considered to be at high risk because of their orphanhood status and early age. Blood samples were collected from 120 children institutionalized in an orphanage in the city of La Plata. In this study, we observed 38.33

of seropositive cases for T. canis by ELISA and 45

by Western blot techniques; significant differences among groups A (<1 year), B (1-2 years) and C (>2 years) were also found. In research group A, children presented a seropositivity rate of 23.91

, in group B of 42.85

and in group C of 56

, which indicates an increase in frequency as age advances, probably because of greater chances of contact with infective forms of the parasite since canines and soil are frequently infected with T. canis eggs. Abandoned children come from poor households, under highly unsanitary conditions resulting from inadequate or lack of water supply and sewer networks, and frequent promiscuity with canines, which promotes the occurrence of parasitic diseases. These children are highly vulnerable due to their orphanhood status and age.

Vertical transmission of Toxocara canis in successive generations of mice / Transmissão vertical de Toxocara canis em gerações sucessivas de camundongos

Visceral toxocariasis is a neglected zoonosis caused by Toxocara canis larvae in unusual hosts. In dogs, the definitive host, the infection occurs mainly through transplacental and transcolostral transmission. Studies on experimental models have shown that vertical transmission may result from acute infections. Considering that toxocariasis is characterized as a chronic infection, with possible reactivation of larvae present in the brain, this study evaluated the presence of larvae in the brain of female BALB/c mice and their offspring with chronic infection during three successive pregnancies. ELISA-TES was used to evaluate the antibody levels. T. canis larvae were detected in the brain tissue of the mice during the three successive generations evaluated. The offspring's IgG level gradually decreased, and mean absorbance (ABS) above the cutoff point (0.070) was observed only at 30 (0.229) and 50 (0.096) days of age, while IgM was not detected. The infections in the offspring confirmed that vertical transmission of T. canis larvae occurred during chronic toxocariasis in three successive generations of mice.

A toxocaríase visceral é uma zoonose negligenciada causada por larvas de Toxocara canis em hospedeiros não usuais. Em cães, os hospedeiros definitivos, a infecção ocorre normalmente por transmissão transplacentária e através do colostro. Estudos com modelos experimentais têm demonstrado a ocorrência de transmissão vertical durante a infecção aguda. Considerando que a toxocaríase é caracterizada como uma infecção crônica, com uma possível reativação das larvas presentes no cérebro, este estudo avaliou a presença de larvas no cérebro de camundongos Balb/C fêmeas e suas proles com infecção crônica durante três gestações sucessivas. Para avaliar os níveis de anticorpos foi utilizado ELISA-TES. Larvas de T. canis foram detectadas no encéfalo dos animais durante as três gerações sucessivas avaliadas. O nível de IgG das proles foi diminuindo gradualmente e as médias de absorbâncias (ABS) acima do ponto de corte (0,070) foram evidenciadas somente aos 30 (0,229) e 50 dias (0,096) de vida, enquanto que não foi detectada IgM. Infecções das proles confirmam a transmissão vertical de larvas de T. canis durante a toxocaríase crônica em três gerações sucessivas de camundongos.