Improvement in cyst recovery and molecular detection of Giardia duodenalis from stool samples.

Molecular detection of Giardia duodenalis by polymerase chain reaction (PCR) is difficult in faecal samples due to inhibitors that contaminate DNA preparations, or due to low cyst concentrations. In order to eliminate inhibitors, improve cyst recovery and molecular detection of G. duodenalis, different types of water, distillates (MDs), deionized (MDz), injection (MI) or Milli-Q® (MM) were used instead of formaldehyde (F) in the laboratory routine method (Ritchie). Cysts were isolated from faecal samples with low cyst concentrations (< 1 cyst/field), medium (1-2 cysts/field) or high (> 2 cysts/field). Cyst recovery was improved using all water types (MDs, MDz, MI, MM) compared to formaldehyde. At all cyst concentrations, the use of MM consistently showed the greatest recovery of G. duodenalis cysts . DNA samples from recovered cysts were tested for the glutamate dehydrogenase (GDH) and ß-giardin (ßg) genes. The use of Milli-Q® water allowed to detect both genes in all cyst concentrations, including low. The method processed with the other types of water amplified these genes at high and medium cyst concentrations. GDH and ßg genes were not detected when the sample was processed with formaldehyde. These experimental results were confirmed in clinical samples. The results suggest that Milli-Q® water provides the highest cyst recovery from stool samples and, correspondingly, the highest sensitivity for detecting G. duodenalis by microscopy or PCR for GDH and ßg genes, even at low concentration of cysts.

Identification of public areas with potential toxocariasis transmission risk using geographical information systems.

UNLABELLED: Geographic information system (GIS) or Health geography is a geographical identification of the spatial variation of contagion disease and zoonosis risk in certain conditions. OBJECTIVE: Comparing the variation of environmental contamination of Toxocara spp. sands of lawns and public areas through the Geographic Information System. MATERIALS AND METHODS: Were investigated 98% of Parana recreational urban areas such as, schools, public parks and squares filled with sand and/or lawn. Samples were analyzed using zinc sulphate solution centrifuge-flotation, density 1.420, and water sedimentation. Maps were developed by ESRI Arc GIS 9.2. RESULTS: Total 77/98 (78,6%) of public spaces shown Toxocara spp. eggs presence. No significant difference was observed (p = 0,9999) between eggs prevalence in sand 44/56 (78,6%), and lawn 33/42 (78,6%), at school (p = 0,6898) and squares (p = 0,0616). Egg contamination prevailed in periphery areas in the sand 20/27 (74%) and lawn 18/21 (86%). However, no significant difference was observed between sand and lawn contamination from schools and parks to central and peripheral areas. Although schools 62/66 (93,9%) presented a higher number of enclosed spaces, did not provide a lower frequency of pollution (p = 0,3327). CONCLUSION: GIS observed a scattered pattern of zoonosis among schools and public squares sand and lawns, with predominance of contamination in the peripheral areas with presence of dogs/cats.

Avaliação eosinofílica e soropositividade para anticorpos IgG anti-toxocara em crianças atendidas pelo sistema único de saúde / Eosinophilic count and seropositivity for IgG antibodies to toxocara spp. in children assisted at the public health service / Evaluación eosinófila y suero-positividad para anticuerpos igG anti-toxocara en niños atendidos por el sistema único de salud

OBJETIVO: Verificar a associação entre a presença de eosinofilia e a soropositividade para anticorpos IgG anti-Toxocara spp. em crianças atendidas pelo Sistema Único de Saúde no Noroeste do Paraná, Brasil. MÉTODOS: Estudo retrospectivo com crianças de sete meses a 12 anos, atendidas pelo Sistema Único de Saúde do Noroeste do Paraná, com teste ELISA para a pesquisa de anticorpos IgG anti-Toxocara spp. e contagem de eosinófilos (eosinofilia >600 células/mm³). RESULTADOS: Entre as 1.199 crianças, 386 (32,2 por cento) apresentaram anticorpos IgG anti-Toxocara spp. A soroprevalência e a eosinofilia foram mais frequentes em crianças de sete meses a cinco anos. A eosinofilia foi observada em 7,8 por cento dos pacientes soro-reagentes ao Toxocara spp.. CONCLUSÕES: Foi observada elevada prevalência de anticorpos anti-Toxocara spp., principalmente nos menores de cinco anos. Com exceção de algumas crianças que apresentaram sintomas respiratórios e presença de eosinofilia, a maioria foi assintomática e não mostrava eosinofilia. A pesquisa de eosinófilos é ferramenta secundária para o diagnóstico de toxocaríase.

OBJECTIVE: To study the association between the presence of eosinophilia and IgG antibodies to Toxocara spp. in children assisted by the public health service, in the northwestern region of Parana State, in southern Brazil. METHODS: A retrospective study of children aged seven months to 12 years old assisted by the Public Health Service in northwest state of Paraná, Brazil. ELISA test was performed in all children in order to detect IgG antibodies to Toxocara spp. and eosinophil amounts (eosinophilia > 600 cells/mm3). RESULTS: Among 1,199 screened children, 386 (32.2 percent) had IgG antibodies to Toxocara spp. The seroprevalence of Toxocara spp. and the eosinophilia were more common among children of seven months to five years old. Eosinophilia was observed in 7.8 percent of seropositive patients to Toxocara spp. CONCLUSIONS: There was a high prevalence of anti-Toxocara spp., mainly in children under five years old. With the exception of some children who had respiratory symptoms and eosinophilia, most of them were asymptomatic and did not present eosinophilia. Eosinophilic count is a secondary laboratory finding in the diagnosis of toxocariasis.

OBJETIVO: Verificar la asociación entre la presencia de eosinofilia y una suero-positividad para anticuerpos IgG anti-Toxocara spp. en niños atendidos por el Sistema Único de Salud en el noroeste de Paraná, Brasil. MÉTODOS: Estudio retrospectivo en niños de siete meses a 12 años de edad, atendidos por el Sistema Único de Salud en el noroeste de Paraná, con prueba de ELISA para la investigación de anticuerpos IgG anti-Toxocara spp. y recuento de eosinófilos (eosinofilia > 600 células/mm³). RESULTADOS: Entre los 1.199 niños, 386 (32,2 por ciento) presentaron anticuerpos IgG anti-Toxocara spp. La suero-prevalencia y la eosinofilia fueron más frecuentes en niños de siete meses a cinco años. La eosinofilia fue observada en 7,8 por ciento de los pacientes suero-reactivos al Toxocara spp. CONCLUSIÓN: Se observó elevada prevalencia de anticuerpos anti-Toxocara spp., principalmente en niños menores de cinco años. Excepto por algunos niños que presentaron síntomas respiratorios y presencia de eosinofilia, la mayoría de ellas fue asintomática y mostraban eosinofilia. La investigación de eosinófilos es herramienta adicional a los casos con indicios clínicos de toxocariase.

Serological, clinical and epidemiological evaluation of toxocariasis in urban areas of south Brazil.

Toxocariasis is a worldwide public-health problem that poses major risks to children who may accidentally ingest embryonated eggs of Toxocara. The objectives of this study were to investigate the occurrence of anti-Toxocara spp. antibodies in children and adolescents and the variables that may be involved, as well as environmental contamination by Toxocara spp. eggs, in urban recreation areas of north central mesoregion, Paraná State, Brazil. From June 2005 to March 2007. a total of 376 blood samples were collected by the Public Health Service from children and adolescents one to 12 years old, of both genders. Samples were analyzed by the indirect ELISA method for detection of anti-Toxocara antibodies. Serum samples were previously absorbed with Ascaris suum antigens, and considered positive with a reagent reactivity index >1. Soil samples from all of the public squares and schools located in the four evaluated municipalities that had sand surfaces (n = 19) or lawns (n = 15) were analyzed. Of the 376 serum samples, 194 (51.6%) were positive. The seroprevalence rate was substantially higher among children aging one to five years (p = 0.001) and six to eight years (p = 0.022). The clinical signs and symptoms investigated did not show a statistical difference between seropositive and seronegative individuals (p > 0.05). In 76.5% of the investigated recreation places, eggs of Toxocara were detected in at least one of the five collected samples. Recreation areas from public schools were 2.8 times more contaminated than from public squares. It is important to institute educational programs to inform families and educators, as well as to improve sanitary control of animals and cleaning of the areas intended for recreation in order to prevent toxocariasis.

Serological, clinical and epidemiological evaluation of toxocariasis in urban areas of south Brazil / Avaliação sorológica, clínica e epidemiológica da toxocaríase em áreas urbanas do sul do Brasil

Toxocariasis is a worldwide public-health problem that poses major risks to children who may accidentally ingest embryonated eggs of Toxocara. The objectives of this study were to investigate the occurrence of anti-Toxocara spp. antibodies in children and adolescents and the variables that may be involved, as well as environmental contamination by Toxocara spp. eggs, in urban recreation areas of north central mesoregion, Paraná State, Brazil. From June 2005 to March 2007. a total of 376 blood samples were collected by the Public Health Service from children and adolescents one to 12 years old, of both genders. Samples were analyzed by the indirect ELISA method for detection of anti-Toxocara antibodies. Serum samples were previously absorbed with Ascaris suum antigens, and considered positive with a reagent reactivity index >1. Soil samples from all of the public squares and schools located in the four evaluated municipalities that had sand surfaces (n = 19) or lawns (n = 15) were analyzed. Of the 376 serum samples, 194 (51.6 percent) were positive. The seroprevalence rate was substantially higher among children aging one to five years (p = 0.001) and six to eight years (p = 0.022). The clinical signs and symptoms investigated did not show a statistical difference between seropositive and seronegative individuals (p > 0.05). In 76.5 percent of the investigated recreation places, eggs of Toxocara were detected in at least one of the five collected samples. Recreation areas from public schools were 2.8 times more contaminated than from public squares. It is important to institute educational programs to inform families and educators, as well as to improve sanitary control of animals and cleaning of the areas intended for recreation in order to prevent toxocariasis.

A toxocaríase é um problema de saúde pública mundial, com maior risco para crianças que podem, acidentalmente, ingerir ovos embrionados de Toxocara spp.. Os objetivos deste estudo foram avaliar a ocorrência de anticorpos anti-Toxocara spp. em crianças e adolecentes e as variáveis que podem estar envolvidas, bem como a contaminação ambiental por ovos de Toxocara spp., em locais de recreação, em áreas urbanas da mesorregião norte central, Paraná, Brasil. De junho de 2005 a março de 2007 foram coletadas 376 amostras de sangue de crianças e adolescentes de um a doze anos, de ambos os sexos, atendidas pelo Sistema Único de Saúde. As amostras foram analisadas pelo método de ELISA indireto para detecção de IgG anti-Toxocara e previamente absorvidas com antígeno de Ascaris suum. Foram consideradas reagentes as amostras com índice de reatividade > 1. A análise das amostras de areias (n = 19) e gramados (n = 15) de cada município foi realizada em todas as praças e escolas públicas. Das 376 amostras de soro, 194 (51,6 por cento) foram positivas. A taxa de soroprevalência foi substancialmente mais elevada entre as crianças na faixa etária de até um a cinco (p = 0.001) e de seis a oito anos de idade (p = 0,022). Os sinais e sintomas clínicos investigados não mostraram diferenças estatísticas entre soropositivos e soronegativos (p > 0,05). Em 76,5 por cento dos locais de recreação investigados, ovos de Toxocara foram detectados em pelo menos uma das cinco amostras. Os locais de recreação das escolas públicas estavam 2,8 vezes mais contaminados do que as praças. É importante a realização de programas educativos junto às famílias e educadores, o controle sanitário de animais e a higienização dos locais destinados à recreação para prevenção da toxocaríase.