Diagnosis and drug resistance of human soil-transmitted helminth infections: A public health perspective.

Soil-transmitted helminth (STH) infections represent a major public health problem globally, particularly among socio-economically disadvantaged populations. Detection of STH infections is often challenging, requiring a combination of diagnostic techniques to achieve acceptable sensitivity and specificity, particularly in low infection-intensity situations. The microscopy-based Kato-Katz remains the most widely used method but has low sensitivity in the detection of, for instance, Strongyloides spp. infections, among others. Antigen/antibody assays can be more sensitive but are parasite species-specific. Highly sensitive PCR methods have been developed to be multiplexed to allow multi-species detection. Novel diagnostic tests for all STH species are needed for effective monitoring, evaluation of chemotherapy programmes, and to assess the potential emergence of parasite resistance. This review discusses available diagnostic methods for the different stages of STH control programmes, which vary in sensitivity and spectrum of detection requirements, and tools to evaluate drug efficacy and resistance.

Importancia de la referencia médica en el diagnóstico de parasitosis intestinales por métodos coproparasitológicos / Medical reference importance in the intestinal parasitic diagnosis for coproparasitologic method

La Sección de Geohelmintiasis del Instituto de Medicina Tropical estudia las muestras de heces por examen seriado que incluyen examen directo, Formol-Tritón-Éter y Baermann. Otras técnicas coproparasitológicas como: Graham, Kinyoun y Kato-Katz, se realizan por solicitud del médico tratante. Los objetivos del presente estudio fueron: valorar la calidad de la referencia médica, el impacto en el diagnóstico al aplicarse las técnicas coproparasitológicas y la ocurrencia de óarasitosis intestinales de los pacientes que asiste a esta Sección. A cada referencia médica se le colocó una puntuación entre 0 y 12 puntos según la presencia o no de determinados parámetros de calidad. Para un total de 392 referencias: 170 procedentes de hospitales públicos, 157 del Instituto de Medicina Tropical, 38 de instituciones privadas y 27 sin información, el promedio de puntuación fue de 4 puntos. La baja calidad de las referencia médica impidió valorar el impacto de las mismas en el diagnóstico parasitario por técnicas coproparasitológicas. Los parásitos de mayor ocurrencia (n = 460) fueron Blastocystis hominis (8,7 por ciento), Entamoeba coli (3,5 por ciento), Ascaris lumbricoides (2,9 por ciento) y Giardia intestinalis (2,3 por ciento). De los pacientes virus de inmunodeficiencia humana +, a 5 se indicó Kinyoun en la referencia médica (10/173), uno fue positivo para Cryptosporidium sp. Dos pacientes referidos por prurito anal e indicación de Graham, ambos negativos para Enterobius vermicularis. Cuatro pacientes fueron referidos por esquistosomosis sin indicación de Kato-Katz. Una referencia médica completa contribuye en la aplicación de las técnicas coproparasitológicas de elección, favoreciendo un diagnóstico certero y oportuno. A partir de estos resultados se estructuró una referencia médica piloto para iniciar una labor educativa al personal de salud sobre las técnicas coproparasitológicas.

Soil transmitted helminthes laboratory of the Tropical Medicine Institute studies feces by simple method, Formol-Triton-Eter and Baermann. Other coproparasitologic techniques like: Graham, Kinyoun and Kato-Katz are process if they are asked by physicians. The objectives of the current study were: evaluate the reference quality of the medical record, the impact in the final diagnosis applying coproparasitologic techniques and the occurrence of parasitic intestinal disease. Each reference was evaluated between 0 and 12 points, depending on the presence of quality parameters. For a total of 392 reference: 170 patients from public hospital, 157 from Tropical Medicine Institute, 38 from private hospital and 27 without information, the mean reference evaluation was 4 points. The poor quality of the reference did not permit to measure the impact in the final parasitologic diagnosis. The most frequent parasites were Blastocystis hominis (8,9 percent), Entamoeba coli (3,5 percent), Ascaris lumbricoides and Giardia intestinalis (both with 2,54 percent). For the total HIV positive (10/173), only for 5, Kinyoun technique was solicited by the reference, Cryptosporidium sp. was positive for one. Two patients were referred because of pruritus ani and indication of Graham, both were negative for Enterobius vermicularis. Four patients referred with suspect of schistosomiasis without a Kato-Katz indication by the doctor. A complete reference of the medical record contributes to the application of the first choice of coproparasitologic techniques, to favor real diagnosis towards the benefit of the patients. We structured a new model of reference of the medical record to initiate an education labor of the health personal about the coproparasitologic techniques.