ABSTRACT
Resumen Introduction: The diagnosis of intestinal parasitic infections depends on the parasite load, the specific gravity density of the parasite eggs, oocysts or cysts, and the density and viscosity of flotation or sedimentation medium where faeces are processed. Objective: To evaluate the concordance between zinc sulphate flotation and centrifugal sedimentation in the recovery of parasites in faecal samples of children. Materials and methods: Faecal samples of 330 children from day care centers were evaluated by zinc sulphate flotation and centrifugal sedimentation techniques. The frequencies of detection of parasites by each method were determined and the agreement between the diagnostic techniques was evaluated using the kappa index, with 95% confidence intervals. Results: The faecal flotation in zinc sulphate diagnosed significantly more cases of Trichuris trichiura infection when compared to centrifugal sedimentation (39/330; 11.8% vs. 13/330; 3.9%, p<0.001), with low diagnostic concordance between methods (kappa=0.264; 95% CI: 0.102-0.427). Moreover, all positive samples for Enterobius vermicularis eggs (n=5) and Strongyloides stercoralis larvae (n=3) were diagnosed only by zinc sulphate. No statistical differences were observed between methods for protozoa identification. Conclusions: The results showed that centrifugal flotation in zinc sulphate solution was significantly more likely to detect light helminths eggs such as those of T. trichiura and E. vermicularis in faeces than the centrifugal sedimentation process.
Abstract Introducción. El diagnóstico de infecciones parasitarias intestinales depende de la carga de parásitos, la densidad de la gravedad específica de los huevos, ooquistes o quistes de parásitos, y de la densidad y viscosidad de los reactivos de flotación o sedimentación usados para procesar las heces. Objetivo. Evaluar la concordancia entre el método de flotación de sulfato de zinc y la sedimentación por centrifugación en la recuperación de parásitos en muestras fecales de niños. Materiales y métodos. Se evaluaron las muestras fecales de 330 niños de guarderías mediante las técnicas de flotación con sulfato de zinc y de sedimentación por centrifugación. Se determinó la frecuencia de detección de parásitos con cada método y se evaluó la concordancia entre las técnicas de diagnóstico mediante el índice kappa, con intervalos de confianza del 95 %. Resultados. Mediante la flotación fecal con sulfato de zinc, se diagnosticó un número significativamente mayor de casos de infección por Trichuris trichiura que con la sedimentación por centrifugación (39/330; 11,8 % Vs. 13/330; 3,9 %) (p<0,001), con poco acuerdo entre los métodos (kappa=0,264; IC95% 0,102-0,427). Además, todas las muestras positivas para huevos de Enterobius vermicularis (n=5) y larvas de Strongyloides stercoralis (n=3) se diagnosticaron solamente por sulfato de zinc. No se observaron diferencias estadísticamente significativas entre los métodos para la identificación de protozoos. Conclusiones. La flotación centrífuga en una solución de sulfato de zinc presentó una probabilidad significativamente mayor de detectar los huevos livianos de helmintos como T. trichiura y E. vermicularis en heces, que el proceso de sedimentación por centrifugación.
Subject(s)
Animals , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Parasite Egg Count/methods , Parasites/isolation & purification , Parasitology/methods , Feces/parasitology , Intestinal Diseases, Parasitic/diagnosis , Ovum , Protozoan Infections/diagnosis , Protozoan Infections/parasitology , Centrifugation , Child Day Care Centers , Zinc Sulfate , Helminthiasis/diagnosis , Helminthiasis/parasitology , Helminths/isolation & purification , Intestinal Diseases, Parasitic/parasitologyABSTRACT
Poor growth and intestinal parasitic infections are widespread in disadvantaged urban children. This cross-sectional study assessed factors influencing poor growth and intestinal parasites in 376 children aged three to six years in daycare centers in Salvador, in the Northeast Region of Brazil. Data was obtained from seven daycare centers on child weight, height, socio-economic status, health and intestinal parasites in stool samples. Prevalence of moderate underweight (< -1SD > -2SD), wasting and stunting was 12%, 16% and 6% respectively. Socioeconomic status, birth order, and maternal weight were predictors of poor anthropometric status. Almost 30% of children were infected with more than one intestinal parasite. Helminths (17.8%), notably Trichuris trichiura (12%) and Ascaris lumbricoides (10.5%), and protozoan Giardia duodenalis (13%) were the most common types of parasites detected. One percent of children had hookworm and Cryptosporidium sp. and 25% had non-pathogenic protozoan cysts. Boys from families with very low socio-economic status had lower linear growth and presented a greater risk of helminth infection. Deworming is considered an alternative for reducing the prevalence of intestinal parasitic infections in this age group.
Déficit de crescimento e parasitoses são comuns entre crianças residentes em periferias. Em estudo transversal com 376 pré-escolares (3-6 anos) de creches em Salvador, Nordeste do Brasil, avaliamos fatores predisponentes para déficit de crescimento e parasitose. Obtiveram-se dados em sete creches sobre peso da criança, altura, nível socioeconômico, estado de saúde e parasitos em amostras de fezes. Prevalência de baixo peso (-1 < DP > -2), desnutrição e baixa estatura foram 12%, 16%, e 6%, respectivamente; nível socioeconômico, ordem de nascimento e peso materno foram preditores da antropometria. Aproximadamente 30% estavam infectados com ≥ 1 parasita. Helmintos (17.8%), notavelmente Trichuris trichiura (12%) e Ascaris lumbricoides (10.5%) e protozoário Giardia duodenalis (13%) foram os mais comuns; < 1% tinha ancilostomíase e Cryptosporidium sp.; 25% apresentaram protozoários cistos não patogênicos. Meninos de famílias muito pobres tiveram menor crescimento e maior risco de helmintose. A desparasitação pode ser considerada uma alternativa para a redução da prevalência de parasitoses intestinais nesse grupo etário.