Exploring the potential of asparagine restriction in solid cancer treatment: recent discoveries, therapeutic implications, and challenges.

Asparagine is a non-essential amino acid crucial for protein biosynthesis and function, and therefore cell maintenance and growth. Furthermore, this amino acid has an important role in regulating several metabolic pathways, such as tricarboxylic acid cycle and the urea cycle. When compared to normal cells, tumor cells typically present a higher demand for asparagine, making it a compelling target for therapy. In this review article, we investigate different facets of asparagine bioavailability intricate role in malignant tumors raised from solid organs. We take a comprehensive look at asparagine synthetase expression and regulation in cancer, including the impact on tumor growth and metastasis. Moreover, we explore asparagine depletion through L-asparaginase as a potential therapeutic method for aggressive solid tumors, approaching different formulations of the enzyme and combinatory therapies. In summary, here we delve into studies about endogenous and exogenous asparagine availability in solid cancers, analyzing therapeutic implications and future challenges.

Entamoeba gingivalis and Trichomonas tenax: Protozoa parasites living in the mouth.

OBJECTIVE: This review article aims to summarize the existing data on the history, biology and potential pathogenicity of Entamoeba gingivalis and Trichomonas tenax in periodontal disease, as well as the available techniques for laboratory diagnosis. DESIGN: A detailed review of scientific literature available up to October 1, 2022 in three databases (PubMed, Scopus and Web of Science) was performed relevant to biology, biochemistry, epidemiology, and experimental studies on infection by E. gingivalis and T. tenax, as well as laboratory techniques for the diagnosis of both protozoa in periodontal diseases. RESULTS: Accumulated evidence over the decades indicates that the protozoa E. gingivalis and T. tenax are able to interact with host cells and induce inflammation in the periodontal tissue by promoting the expression of pro-inflammatory molecules and the recruitment of neutrophils, contributing to the periodontal disease process. Among the available techniques for the laboratory diagnosis, culture and molecular assays seems to be the best tools for detection of both protozoan parasites. CONCLUSIONS: E. gingivalis and T. tenax are potentially pathogens that colonize the oral cavity of humans and may cause periodontal disease.

Serosurvey of anti-Toxocara canis antibodies in people experiencing homelessness and shelter workers from São Paulo, Brazil.

BACKGROUND: Despite being one of the most prevalent helminth parasitic zoonoses worldwide and particularly in socioeconomically vulnerable populations, toxocariasis remains to be fully investigated in persons experiencing homelessness. Accordingly, the present study has aimed to assess the seroprevalence and associated risk factors of Toxocara spp. exposure in persons experiencing homelessness and shelter workers from a day-shelter in São Paulo city, Brazil. METHODS: Anti-Toxocara IgG antibodies were detected by enzyme-linked immunosorbent assay (ELISA). Univariable and multivariable logistic regression models were performed to assess the risks for toxocariasis. RESULTS: Overall, anti-Toxocara IgG antibodies were detected in 89/194 (45.9%, 95% CI: 39.0-52.9%) persons experiencing homelessness, twice as high (OR = 2.2; 95% CI = 1.245-3.873; P = 0.0089) than the frequency of 22/79 (27.8%, 95% CI: 19.2-38.6) in shelter workers. College education was the only protective factor for Toxocara spp. exposure (OR: 0.23; P = 0.018) revealed by logistic regression. CONCLUSIONS: Although indicating a multifactorial origin of toxocariasis, the present study has assessed a highly vulnerable population with high disease risks and premature death. Thus, the living conditions of the homeless population have influenced the high prevalence of anti-Toxocara antibodies verified here compared with domiciled shelter workers. Despite being less exposed, shelter and other outdoor workers may present an occupational risk to toxocariasis. Future studies should establish whether such environmental exposure might occur in persons experiencing homelessness in other regions worldwide.

Culture isolation and molecular identification of Blastocystis sp. in Brazilian human isolates: preliminary results.

Blastocystis sp. is a protist commonly found in stool samples of humans and animals. Biological and genetic factors of this organism remain controversial. The present study aimed to develop and implement the Blastocystis in vitro culture of Brazilian human isolates for routine use. The fecal isolates (n = 20) were maintained in our laboratory by several passages in Pavlova's medium. Cultures were monitored every 72 h by light microscopy. Genomic DNA was extracted to identify the subtypes (STs). In most isolates, the vacuolar form was prevalent. The amoeboid, granular and cystic forms were observed during in vitro cultivation. STs 1, 2, 3, 4 and 7 were identified. Our preliminary results show the generation time and forms present in the in vitro culture of Blastocystis subtypes isolated from Brazilian human isolates. Therefore, we emphasize the use of in vitro culture as a tool in future studies for the better understanding of the biological aspects of Blastocystis sp.

Evaluation of an enzyme-linked immunoelectrotransfer blot test for the confirmatory serodiagnosis of human toxocariasis.

To improve the serodiagnosis of human toxocariasis, a sensitive and specific enzyme-linked immunoelectrotransfer blot (EITB-IgG) test was developed and evaluated using Toxocara canislarvae excretory-secretory antigens for detecting anti-Toxocara IgG antibodies. The EITB-IgG profile of toxocariasis was characterized by comparing 27 sera from patients with toxocariasis, 110 sera from healthy subjects and 186 sera from patients with other helminth diseases (ascariasis, ancylostomiasis, trichuriasis, enterobiasis, strongyloidiasis, hymenolepiasis, diphyllobothriasis, taeniasis, cysticercosis, hydatidosis and fascioliasis). Antigenic bands of 24, 28, 30, 35, 56, 117, 136 and 152 kDa were predominantly recognized in sera from all patients with toxocariasis. However, only bands of 24-35 kDa were highly specific for Toxocara infection (98.3%), whereas other antigenic bands observed displayed cross-reactivity. Additionally, when the results of the EITB-IgG test were compared to those of the ELISA-IgG test, a 100% concordance was observed for positive results in human toxocariasis cases. The concordance for negative results between the two tests for healthy subjects and patients with other helminth diseases were 96.3% and 53.7%, respectively, showing that the EITB-IgG test has a higher specificity than ELISA. In conclusion, the EITB-IgG test is a very useful tool to confirm the serological diagnosis of human toxocariasis.

Clinical and serological evidence of Toxocara infection in school children from Morrope district, Lambayeque, Peru.

The aim of this study was to estimate the frequency of human toxocariosis in a child population from Morrope district, Lambayeque, Peru. From October to December 2005, 182 school children (96 male and 86 female) were studied. Blood samples were collected for Toxocara ELISA-IgG test and hematological examination. Additionally, stool samples were collected for coproparasitological examination to check cross reactions. We found frequency of positives in 32.4% (59/182) with a significant higher proportion of positivity in male children (p < 0.00001). 71.2% of the children with positive serology (52 male and seven female), were between five and 10 years old, 77.96% had respiratory symptoms, 61.02% had ocular manifestations, 38.98% had hepatic symptoms, 38.98% had mild or moderate eosinophilia, signs statistically associated with seropositivity. 83.5% of studied population had some intestinal parasite, such as: Blastocystis hominis (53.3%), Giardia lamblia (31.3%), Entamoeba coli (29.1%), Entamoeba histolytica/E. dispar (1.1%), Hymenolepis nana (5.49%), and Ascaris lumbricoides (3.3%), but they had not any association with serology results. The ownership of dogs or/and cats were significantly associated with seropositivity to anti-Toxocara antibodies although the presence of such pets within the house was not. In conclusion, clinical and serological evidence of Toxocara infection exists in the studied population.

Kinetics and avidity of anti-Toxocara antibodies (IgG) in rabbits experimentally infected with Toxocara canis.

An evaluation was made of the kinetics and avidity of anti-Toxocara antibodies (IgG) in rabbits experimentally infected with embryonated Toxocara canis eggs. Seventeen four month old New Zealand White rabbits were distributed into two groups. In the experimental group, twelve rabbits were infected orally with 1,000 embryonated T. canis eggs. A second group (n = 5), uninfected, was used as a control. Serum samples were collected for analysis on days 7, 14, 21, 28 and 60 post-infection (DPI). An indirect ELISA test was performed to evaluate the reactivity index (RI) of IgG anti-T. canis antibodies and to calculate the avidity index (AI). The animals showed seroconversion from the 14th DPI, with high AI (over 50%) except for one animal, which presented an intermediate AI. At 60 DPI, all the animals were seropositive and maintained a high AI. The data indicated that specific IgG antibodies formed early (14 DPI) in rabbits infected with T. canis, with a high avidity index that persisted throughout the course of the infection.

Kinetics and avidity of anti-Toxocara antibodies (IgG) in rabbits experimentally infected with Toxocara canis / Cinética e avidez de anticorpos (IgG) anti-Toxocara em coelhos experimentalmente infectados com Toxocara canis

Abstract An evaluation was made of the kinetics and avidity of anti-Toxocara antibodies (IgG) in rabbits experimentally infected with embryonated Toxocara canis eggs. Seventeen four month old New Zealand White rabbits were distributed into two groups. In the experimental group, twelve rabbits were infected orally with 1,000 embryonated T. canis eggs. A second group (n = 5), uninfected, was used as a control. Serum samples were collected for analysis on days 7, 14, 21, 28 and 60 post-infection (DPI). An indirect ELISA test was performed to evaluate the reactivity index (RI) of IgG anti-T. canis antibodies and to calculate the avidity index (AI). The animals showed seroconversion from the 14th DPI, with high AI (over 50%) except for one animal, which presented an intermediate AI. At 60 DPI, all the animals were seropositive and maintained a high AI. The data indicated that specific IgG antibodies formed early (14 DPI) in rabbits infected with T. canis, with a high avidity index that persisted throughout the course of the infection.

Resumo O objetivo deste estudo foi o de avaliar a cinética e a avidez de anticorpos anti-Toxocara canis, em coelhas infectadas experimentalmente com ovos embrionados de Toxocara canis. Foram utilizados 17 coelhos New Zealand de linhagem branca, com quatro meses de idade, distribuídos em dois grupos. No grupo experimental, doze coelhas foram infectadas, oralmente, com 1.000 ovos larvados de T. canis. Um segundo grupo (n=5), não infectado, foi utilizado como controle. Nos dias 7, 14, 21, 28 e 60 pós-infecção (DPI), foram coletadas amostras de soro para análise. O teste de ELISA indireto foi realizado para avaliar o índice de reatividade (IR) de anticorpos IgG anti-T. canis e para cálculo do índice de avidez (IA). A soroconversão nos animais ocorreu a partir do140 DPI, com verificação de alto IA (superior a 50%), com exceção de um animal, que apresentou médio IA. Aos 60 DPI, todos os animais foram soropositivos e mantiveram alto IA. Os dados mostram que em coelhos infectados por T. canis, anticorpos IgG específicos formam-se precocemente (14 DPI), apresentando alto índice de avidez e que se mantém durante o curso da infecção.

[Diagnosis of human toxocarosis]. / Diagnóstico de la toxocarosis humana.

Human toxocarosis is an important parasitic zoonosis caused by larval stages of Toxocara species, the roundworms from dogs and cats. Larval migration through different soft tissues in the human generates several clinical entities in the patient, such as visceral larva migrans, ocular toxocarosis, and neurotoxocarosis. Definitive diagnosis by histopathological methods is very difficult or almost impossible and, nowadays, the diagnosis is usually made by clinical signs/symptoms, epidemiological background of the patient and the use of hematological and immunological tests which finally help to confirm the clinical suspicion of the illness. The purpose of this paper was to update the available knowledge on the use of different tools for both the diagnosis and following up of human toxocarosis.

Human toxocariasis: a seroepidemiological survey in the Amazonian city of Yurimaguas, Peru.

The aim of this study was to determine the seroprevalence of the infection by Toxocara in the general population of the Amazonian city of Yurimaguas, Peru. From March to August 2008, a total of 300 subjects were sampled and tested by means of a Toxocara ELISA-IgG test. A clinical and epidemiological questionnaire was used to assess the symptomatology and risk factors associated with human toxocariasis. The overall rate of seropositivity was 35.66%, with a significant high proportion in children (p < 0.001). The clinical evaluation revealed that 95.33% of the seropositive group had some type of symptomatology: headache (66.36%), respiratory compromise (63.55%), abdominal pain (54.21%), cutaneous signs (40.19%) and ocular manifestations (36.45%), and almost all of them were statistically significant (p < 0.001). Furthermore, 56.07% of the seropositive subjects presented at least one intestinal pathogen parasite with predominance of helminthes, but without significant association (p = 0.334). The analysis of risk factors showed only that the use of public places and geophagia exhibited a significant association with the seropositivity (p < 0.001). Clinical, serological and epidemiological findings associated to infection with Toxocara were observed in the present study and future studies should be done to assess this serious health problem.

Seroprevalence of human toxocariasis in Andean communities from the Northeast of Lima, Peru.

The aim of this study was to assess the seroprevalence of human toxocariasis in three Andean communities from the Northeast of Lima, Peru. A total of 303 subjects including children and adults were studied and blood samples were collected to detect anti-Toxocara antibodies by ELISA-IgG test and by hematological examination; stool samples were collected also for parasitological examination. The overall seroprevalence of toxocariasis observed in the total population was 20.46%, with a significant high proportion in children from one to 10 years old (p = 0.034). Among the subjects with positive serology, 32.26% of them had respiratory disturbances, 22.58% hepatomegaly, 17.74% ocular signs or symptoms, 14.51% abdominal pain, 9.68% neurological involvement, and 4.84% cutaneous signs, but none of these clinical features were associated to a positive serology by multivariate analysis. Furthermore, 79.03% of seropositive subjects also harbored at least one intestinal parasite, which was associated to a positive serology (p < 0.05). The presence of pets within the houses, a previous history of pica or geophagia and the use of public places were also present in this population, but only the latter was associated to the serology (p < 0.05). In conclusion, clinical, serological, and epidemiological evidences for larval Toxocara infection were found in the studied population.

Frequency of human toxocariasis in a rural population from Cajamarca, Peru determined by DOT-ELISA test.

The aim of this study was to estimate the frequency of human toxocariasis in Cauday district, Cajamarca, Peru, using a dot-ELISA test. From June to October 2005, a total of 256 adult subjects were studied. Blood samples were collected for serology by a dot-ELISA test and for hematological examination. Parasitological examination was also carried out in stool samples to check cross-reactions in the dot-ELISA. The frequency observed was 44.92%, with a significant higher proportion of positivity in male subjects. From subjects with positive serology, 45.6% had respiratory symptoms, 40.44% abdominal pain, 32.35% hepatic symptoms, 14.7% cutaneous signs, 13.23% ocular manifestations, 43.38% eosinophilia, and all of these were statistically associated to serology. Among the population evaluated, 90.23% (231/256) were parasitized. From subjects with positive serology, 92.17% had at least one intestinal parasite and the most frequent were: Blastocystis hominis (68.38%), Giardia lamblia (28.68%), Hymenolepis nana (20.0%), Ascaris lumbricoides (15.65%), Entamoeba histolytica/E. dispar (13.24%), Cyclospora cayetanensis (4.41%), Cryptosporidium sp. (1.47%), Enterobius vermicularis (0.87%), Strongyloides stercoralis (0.87%), Taenia sp. (0.87%), and Trichuris trichiura (0.87%). The rate of false positives in the dot-ELISA test was improved by serum absorption each with A. suum antigens, with a decrease of cross-reactions. In conclusion, human toxocariasis is highly frequent in this population and some risk factors like dog/cat ownership, presence of pets within house, and previous history of geophagia were observed in the present study.

Frequency of eosinophilia and risk factors and their association with Toxocara infection in schoolchildren during a health survey in the north of Lima, Peru.

During a health survey in a primary school from the district of Carabayllo (North of Lima, Peru), 200 schoolchildren (96 male and 104 female between five to 12 years old) were randomly selected and divided in two groups (as positive or negative group), according to the serologic result of the Toxocara ELISA test from a total population of 646 schoolchildren. All children were analyzed by hematologic tests to determinate the frequency of eosinophilia and leukocytosis. Additionally, all clinical and epidemiological data were also analyzed to determine their association with toxocariasis. From group of children with positive serology, 40% had some type of eosinophilia in contrast to 19% of children with negative serology, and their association was statistically significant (OR = 2.84, p < 0.001). From all signs and symptoms evaluated, only 'dry cough' was more frequent and statistically significant in the positive serology group (OR = 2.79, p < 0.001). Almost all risk factors evaluated were highly frequent and statistically associated to the positive serology. In conclusion, the presence of eosinophilia and the risk factors evaluated in this population were frequently associated to human toxocariasis.

Estandarización de una prueba de ELISA para detectar anticuerpos IgE en pacientes con equinococosis quistica y su utilidad en el diagnóstico y seguimiento de pacientes tratados con albendazol: reporte preliminar / Standarization of an ELISA test to detect IgE antibodies in patients with cystic echinococcosis and its use in diagnosis and follow-up of patients treated with albendazol: preliminary report

Objetivos: Determinar las diluciones y concentraciones optimas de una prueba de ELISA para detectar anticuerpos IgE, así como su sensibilidad, espécificidad y valor predictivo en pacientes con equinococosis quistica. Analizar si los niveles de anticuerpos IgE especificos se correlacionan con la respuesta al tratamiento médico con albendazol en un periodo mayor a un año de finalizado el tratamiento. Diseño: Estudio cuasiexperimental con grupo control. Institución: Instituto de Medicina Tropical Daniel A. Carrión, Facultad de Medicina, UNMSM, Lima, Perú. Material de estudio: Prueba de ELISA para anticuerpo IgE. Intervenciones: Estandarizacion de la prueba de ELISA para anticuerpo IgE y diseño preexperimento con preprueba y posprueba en un solo grupo, para evaluar su valor en el diagnóstico y seguimiento postratamiento de pacientes con quiste hidatidico hepatico tratados con albendazol. Para la estandarizacion de la prueba de ELISA, se utilizó suero de cinco pacientes con diagnóstico clínico de equinococosis quistica, y la sensibilidad y especificidad de la prueba se usó suero de 30 pacientes aparentemente sanos. Para determinar las reacciones cruzadas, se utilizó 16 muestras de suero de pacientes con otras helmintiasis (ascariasis, strongiloidiasis, toxocariosis, trichuriasis, himenolepiasis, cisticercosis y teniasis). Para el diagnóstico y seguimiento postratamiento de equinocococosis quística, se utilizó el suero de 17 pacientes. Principales medidas de resultados: Sensibilidad y especificidad de prueba estandarizada de ELISA para detectar anticuerpos IgE. Resultados: La prueba estandarizada de ELISA para detectar anticuerpos IgE tuvo una sensibilidad de 95,6 por ciento y una especificidad de 100 por ciento. En los pacientes con quiste hidatídico hepático considerados curados, uniformemente disminuyeron los niveles de anticuerpo tipo IgE hasta la negativización. Se obtuvo elevación de los niveles de IgE en los pacientes que presentaron recurrencia de la enfermedad quística hepática. Conclusiones: En el presente estudio se encontró un excelente nivel de sensibilidad y especificidad de la prueba de ELISA para anticuerpos IgE de equinococosis quística. La curación de los quistes coincidió con una dismuinución progresiva de los niveles de IgE, que pudo llegar a la negativización después de un año postratamiento y fue de gran utilidad para detectar la recurrencia. La persistencia de niveles elevados de IgE en pacientes tratados médicamente fue indicativo de no haber respuesta al tratamiento. Siendo no muy grande el tamaño de la muestra de nuestro estudio, es necesario continuar con la investigación para confirmar estos resultados.

Objectives: To determine best dilutions and concentrations of ELISA test to detect IgE antibody, its sensitivity and specificity and predictive value in patients with cistyc echinococcosis. To analyze the relationship between IgE specific antibody level and albendazole medical treatment response in a period over one year after completion of albendazole therapy. Design: Quasiexperimental study with control group. Setting: Instituto de Medicina Tropical Daniel A. Carrion, Faculty of Medicine, UNMSM, Lima, Peru. Study material: IgE antibody ELISA test. Interventions: IgE antibody ELISA test standardization with preexperimental pretest and post test in one group to assess its value in diagnosis and post-treatment of patients with hepatic hydatid cysts treated with albendazole. For ELISA test standardization we used serum from five patients with clinical and immunological diagnosis of cystic echinococcosis; to test sensitivity and specificity sera of 30 apparently healthy subjects were studied; to determine crossreactions 16 serum samples from patients with other helminth infections (ascariasis, strongiloidiasis, toxocariasis, trichuriasis, hymenolepiasis cysticercosis and taeniasis) were used. For diagnosis and post-treatment evaluation of cystic echinocococosis serum from 17 patients was studied. Main outcome measures: Standarized ELISA test sensitivity and specificity to detect IgE antibodies. Results: Sensitivity and specificity of standardized ELISA test to detect IgE antibody were respectively 95.6 per cent and 100 per cent. Patients with hepatic hydatid cyst considered cured uniformly showed lower levels of IgE antibody even to negativization. There was increase of IgE levels in patients who had recurrence of hepatic cystic disease. Conclusions: This study found excellent sensitivity and specificity of ELISA test for cystic echinococcosis IgE antibodies. Healing of cysts coincided with progressive decrease in IgE levels that could reach negativization after one year post-treatment and was useful to detect recurrence. Persistence of IgE high levels in patients treated medically was indicative of no response to treatment. As sample size was not large, it seems necessary to continue investigation to confirm these results.

Evaluation of immunodiagnostics for toxocarosis in experimental porcine cysticercosis.

We assessed whether immunodiagnostic tests for cysticercosis can cross-react with the currently available immunodiagnostic tests for Toxocara canis in an established animal model for cysticercosis infection in pigs, known host for Toxocara. We examined by TES-enzyme-linked immunosorbent test and immunoblot assay for toxocarosis and cysticercosis the baseline and final follow-up sera of 10 pigs, before and after (3 months) infection with Taenia solium. After successful cysticercosis infection, the nine evaluable pigs became seropositive to T. solium (enzyme-linked immunoelectrotransfer blot assay), but did remain seronegative for Toxocara in both assays, documenting the lack of cross-reactivity with anti-T. solium antibodies in both T. canis assays. These findings should help clinicians better interpret serology for toxocariosis and cysticercosis in endemic areas for both helminth infections.

Evaluation of the dot enzyme-linked immunosorbent assay in comparison with standard ELISA for the immunodiagnosis of human toxocariasis.

A dot enzyme-linked immunosorbent assay (dot-ELISA) was standardized using excretory-secretory antigens of Toxocara canis for the rapid immunodiagnosis of human toxocariasis. Thirty patients with clinical signs of toxocariasis, 20 cases with other parasitic diseases, and 40 healthy subjects were tested. A total of 0.2 ng of antigen per dot, serum dilution of 1:160 and dilution conjugate of 1:1000 were found optimal. The sensitivity and specificity of the assay were 100 and 95%, respectively. Comparable sensitivity of dot-ELISA and the standard ELISA was obtained, but only 3 cross-reactions occurred in the dot-ELISA, compared with 6 in the standard ELISA. Dot-ELISA is simple to perform, rapid, and low cost. Large-scale screening studies should be done to evaluate its usefulness under field conditions.

Diagnóstico de la toxocarosis humana / Diagnosis of human toxocarosis

La toxocarosis humana es una importante zoonosis parasitaria causada por formas larvarias de especies del género Toxocara, un parásito nematodo de los perros y los gatos. La migración de la larva por los diferentes tejidos blandos en el ser humano genera una serie de entidades clínicas en el paciente, tales como el síndrome de larva migrans visceral, la toxocarosis ocular y la neurotoxocarosis. El diagnóstico definitivo es mediante la histopatología en biopsias, pero resulta ser casi imposible de realizar y actualmente su diagnóstico se establece mediante el análisis de la sintomatología clínica, los antecedentes epidemiológicos del paciente y el uso de pruebas hematológicas e inmunológicas de laboratorio que son las que finalmente ayudan a confirmar la sospecha clínica de la enfermedad. El propósito del presente artículo es actualizar los conocimientos que se tienen sobre el uso de las diferentes herramientas para establecer el diagnóstico y el monitoreo de la toxocarosis humana.

Human toxocarosis is an important parasitic zoonosis caused by larval stages of Toxocara species, the roundworms from dogs and cats. Larval migration through different soft tissues in the human generates several clinical entities in the patient, such as visceral larva migrans, ocular toxocarosis, and neurotoxocarosis. Definitive diagnosis by histopathological methods is very difficult or almost impossible and, nowadays, the diagnosis is usually made by clinical signs/symptoms, epidemiological background of the patient and the use of hematological and immunological tests which finally help to confirm the clinical suspicion of the illness. The purpose of this paper was to update the available knowledge on the use of different tools for both the diagnosis and following up of human toxocarosis.

Human toxocariasis: a seroepidemiological survey in the Amazonian city of Yurimaguas, Peru / Toxocaríase humana: inquérito soroepidemiológico na cidade amazônica de Yurimaguas, Peru

The aim of this study was to determine the seroprevalence of the infection by Toxocara in the general population of the Amazonian city of Yurimaguas, Peru. From March to August 2008, a total of 300 subjects were sampled and tested by means of a Toxocara ELISA-IgG test. A clinical and epidemiological questionnaire was used to assess the symptomatology and risk factors associated with human toxocariasis. The overall rate of seropositivity was 35.66 percent, with a significant high proportion in children (p < 0.001). The clinical evaluation revealed that 95.33 percent of the seropositive group had some type of symptomatology: headache (66.36 percent), respiratory compromise (63.55 percent), abdominal pain (54.21 percent), cutaneous signs (40.19 percent) and ocular manifestations (36.45 percent), and almost all of them were statistically significant (p < 0.001). Furthermore, 56.07 percent of the seropositive subjects presented at least one intestinal pathogen parasite with predominance of helminthes, but without significant association (p = 0.334). The analysis of risk factors showed only that the use of public places and geophagia exhibited a significant association with the seropositivity (p < 0.001). Clinical, serological and epidemiological findings associated to infection with Toxocara were observed in the present study and future studies should be done to assess this serious health problem.

O objetivo do presente estudo foi estimar a soroprevalência da infecção por Toxocara em população geral da cidade de Yurimaguas, Peru. Entre os meses de Março e Agosto de 2008, foi estudado um total de 300 pessoas por exame imunológico mediante Toxocara ELISA-IgG teste. Uma ficha clínico-epidemiológica foi utilizada para avaliar a sintomatologia e os fatores de risco associados à toxocaríase. A freqüência geral de anticorpos na população foi de 35,66 por cento com proporção significativamente maior de positividade em meninos de um a 10 anos (p < 0.001). A avaliação clínica revelou que 95.33 por cento do grupo de soropositivos apresentava algum tipo de sintomatologia associada à toxocaríase: 66,36 por cento cefaléia, 63,55 por cento sintomas respiratórios, 54,21 por cento dor abdominal, 40,19 por cento sinais cutâneos e 36,45 por cento manifestações oculares e quase todos estes sinais foram estatisticamente associados ao resultado da sorologia (p < 0.001). Além disso, 56,07 por cento das pessoas com sorologia positiva tinham pelo menos algum parasito intestinal patogênico e com predominância de helmintos, mas sem nenhuma associação significativa (p = 0.334). A análise dos fatores de risco mostrou que o uso de lugares públicos e história de geofagia tiveram significativa associação com a sorologia positiva (p < 0,001). Conclui-se que existem evidências clínicas, sorológicas e epidemiológicas de infecção por Toxocara na população estudada e futuros estudos são necessários para avaliar este sério problema de saúde pública.

Seroprevalence of human toxocariasis in Andean communities from the Northeast of Lima, Peru / Soroprevalência da toxocaríase humana em três comunidades andinas do Nordeste de Lima, Peru

The aim of this study was to assess the seroprevalence of human toxocariasis in three Andean communities from the Northeast of Lima, Peru. A total of 303 subjects including children and adults were studied and blood samples were collected to detect anti-Toxocara antibodies by ELISA-IgG test and by hematological examination; stool samples were collected also for parasitological examination. The overall seroprevalence of toxocariasis observed in the total population was 20.46 percent, with a significant high proportion in children from one to 10 years old (p = 0.034). Among the subjects with positive serology, 32.26 percent of them had respiratory disturbances, 22.58 percent hepatomegaly, 17.74 percent ocular signs or symptoms, 14.51 percent abdominal pain, 9.68 percent neurological involvement, and 4.84 percent cutaneous signs, but none of these clinical features were associated to a positive serology by multivariate analysis. Furthermore, 79.03 percent of seropositive subjects also harbored at least one intestinal parasite, which was associated to a positive serology (p < 0.05). The presence of pets within the houses, a previous history of pica or geophagia and the use of public places were also present in this population, but only the latter was associated to the serology (p < 0.05). In conclusion, clinical, serological, and epidemiological evidences for larval Toxocara infection were found in the studied population.

O propósito do presente trabalho foi estimar a soroprevalência da toxocaríase humana em três comunidades andinas do Nordeste de Lima, Peru. Foi estudado um total de 303 pessoas, entre crianças e adultos. Foram coletadas amostras de sangue para a detecção de anticorpos anti-Toxocara e para a análise hematológica, além de amostras fecais para o exame parasitológico. A soroprevalência geral da população foi de 20,46 por cento com proporção significativamente maior de positividade em crianças de um a 10 anos (p = 0,034). Das pessoas com sorologia positiva, 32,26 por cento apresentavam sintomas respiratórios, 22,58 por cento moléstias hepáticas, 17,74 por cento manifestações oculares, 14,51 por cento dor abdominal, e 4,84 por cento sinais cutâneos. Além disso, 79,03 por cento das pessoas com sorologia positiva tinham pelo menos algum parasito intestinal com associação significativa (p < 0.05). A presença de cachorros dentro das casas, história de pica ou geofagia e o uso dos lugares públicos também estiveram presentes nesta população, mas o ultimo deles só esteve associado com a sorologia positiva (p < 0.05). Conclui-se que existem evidências clínicas, sorológicas e epidemiológicas de infecção por larvas de Toxocara na população estudada.