Is there added value from using three serial samples when surveying the occurrence of intestinal parasites in children?

BACKGROUND: Surveys for intestinal parasitic infections (IPIs) often involve samples from three sampling dates analysed by various microscopy techniques. However, analysis of three samples per individual is a huge burden on time and resources. We compared the value from analysing three or fewer samples. METHODS: In this cross-sectional study, three faecal samples were collected every other day from 332 children from two locations in Guantanamo province, Cuba. Samples were analysed by wet mount with Lugol stain, Willis flotation method and Kato-Katz thick smear. RESULTS: Most parasites were detected by wet mount, although helminth eggs not found by wet smear were detected by the Willis flotation method (in particular) and Kato-Katz smear. Blastocystis spp. was the most commonly detected parasite (about 65%), then Giardia duodenalis and then Entamoeba spp. Although analysis of two stool samples significantly increased occurrence data for Blastocystis, this was not so for the other parasites. For none of the protozoan parasites were results from analysing three samples significantly higher than results from analysing just two samples. CONCLUSIONS: Analysing two faecal samples by wet mount and the Willis flotation method provides useful data for estimating the prevalence of IPIs in relatively high prevalence settings. Analysing further samples provides limited additional information and adds an extra burden in terms of time and resources.

Primoinfección por Toxoplasma gondii en gestantes de Atención Primaria de Salud en La Habana / Primoinfection by Toxoplasma gondii in pregnant women in Primary Health Care in Havana

Introducción: La primoinfección por Toxoplasma gondii adquirida durante el embarazo puede causar manifestaciones clínicas graves en el producto de la gestación, hecho tratable y prevenible. Objetivo: Describir evidencias serológicas de primoinfección por T. gondii en gestantes de Atención Primaria de Salud (APS) en La Habana. Metodología: Se realizó una descripción retrospectiva de resultados serológicos de embarazadas pesquisadas en APS, La Habana, desde 2005 a 2011. Se procesaron 1820 sueros en el Laboratorio Nacional de Referencia de Parasitología del Instituto Pedro Kourí (LNRP-IPK) a través de inmunofluorescencia indirecta (IFI), VIDAS TOXO IgM y Toxo IgG Avidity. A las muestras con títulos de anticuerpos ≥ 1/128 por IFI, se les determinó IgM; si eran positivas, se precisó la avidez de IgG. Resultados: Hubo 1151 (63,2 por ciento) sueros negativos. La mayoría eran gestantes entre 16 y 35 años con un promedio de positividad de 34,1 por ciento, sin diferencias significativas entre los municipios de procedencia. Prevalecieron los títulos de IgG anti-Toxoplasma 1/16-1/64, en gestantes de más de 35 años hubo 120/209 (57,4 por ciento), resultado significativo al compararlo con el grupo menor de 16 años (4/14; 28,5 por ciento). En 58 mujeres aparecieron títulos de IgG ≥ 1/128 (3,1 por ciento), y predominaron las menores de 16 años (2/14; 14,2 por ciento). El 17,2 por ciento de las embarazadas resultó IgG e IgM positivas, aspecto relevante en La Habana Vieja (6,8 por ciento). Se encontraron cifras bajas de avidez en 5/10 (índice < 0,200 IgG), que representó el 0,2 por ciento del total de las gestantes estudiadas. Conclusión: En embarazadas de algunas áreas de salud en La Habana, hubo evidencias de primoinfección por T. gondii(AU)

Introduction: Primoinfection by Toxoplasma gondii acquired during pregnancy can cause severe clinical manifestations in the newborn parameters; it is a treatable and preventable event, though. Objective: To describe serological evidence of primoinfection by T. gondii in pregnant women in Primary Health Care (PHC) in Havana. Methods: A retrospective descriptive study of serological results of pregnant women screened in the PHC, Havana, from 2005 to 2011 was conducted. A total of 1820 sera were processed at the National Reference Laboratory of Parasitology of Pedro Kourí Institute (LNRP-IPK) through indirect immunofluorescence assay (IFA), VIDAS TOXO IgM and Toxo IgG Avidity. Samples with antibody titers ≥ 1/128 by IFA were tested for IgM; if positive, IgG avidity was determined. Results: 1151 sera (63.2%) yielded negative results. Most were pregnant women between 16 and 35 years of age with an average positivity of 34.1 percent, without significant distinction between municipalities of origin. Anti-Toxoplasma IgG titers prevailed 1/16-1/64. In pregnant women over 35 years of age, titers were 120/209 (57.4 percent), a significant result when compared with the group under 16 years of age (4/14; 28.5 percent). IgG titers ≥ 1/128 (3.1 percent) appeared in 5858 women, and those under 16 years of age predominated (2/14; 14.2 percent). IgG and IgM were positive in 17.2 percent of pregnant women, a relevant aspect in Old Havana (6.8 percent). Low levels of avidity were found in 5/10 (index < 0.200 IgG), which represented 0.2 percent of the total number of pregnant women studied. Conclusion: In pregnant women in some health areas in Havana, primoinfection by T. gondii was confirmed(AU)

Identification of two potential aetiological agents of chronic diarrhoea in an immunocompromised patient in Cuba using conventional and molecular diagnostic techniques.

The aetiology of diarrhoea in a patient in Cuba with HIV was investigated. Although molecular diagnostics are still not used in many under-resourced settings, here traditional methods were supported by use of PCR. This approach enabled detection of a dual infection (Cystoisospora belli and Enterocytozoon bieneusi), the latter of which was not identified by microscopy with Didier's trichromic staining.

A retrospective study of Taenia spp. in Cuban patients: what does molecular analysis tell us?

Taeniosis is a neglected disease, particularly in developing countries, and is caused by infection with the adult tapeworm of either Taenia solium, Taenia saginata, and Taenia asiatica. Of these, T. solium is of primary concern due to the potential for cysticercosis should T. solium eggs be ingested. In Cuba, all cases of taeniosis are assumed to be caused by T. saginata, although some cases of cysticercosis have been documented. It is therefore important to gain further insights regarding the species causing taeniosis in Cuba, especially as diagnostic records indicate an increasing incidence, with the highest number of cases reported in 2020. In this study, we analysed 37 Taenia-positive faecal samples (or proglottids isolated from faecal samples) from the period 2001 until 2020 from all regions of the country. Genomic DNA was extracted from the samples, which had been stored in 10% formalin, using the QIAamp Tissue Kit. Species identification was carried out by duplex real-time PCR targeting the mitochondrial DNA. All cases were found to be T. saginata, and sequence analysis of three isolates confirmed the identification of this species. Our data do not provide any evidence that T. solium currently occurs in Cuba. However, given the relatively low number of samples analysed here, that the parasite may be imported with visitors or travellers who have been in endemic countries, and that taeniosis has relatively mild symptoms and thus infected patients may not seek medical attention, we recommend species determination for all taeniosis cases reported in Cuba.

Diagnosis of intestinal protozoan infections in patients in Cuba by microscopy and molecular methods: advantages and disadvantages.

Microscopy is the gold standard for diagnosis of intestinal parasitic diseases in many countries, including Cuba, although molecular approaches often have higher sensitivity as well as other advantages. Fecal samples from 133 patients were analyzed by light microscopy and also real-time multiplex qPCR targeting Giardia duodenalis, Cryptosporidium spp., and Entamoeba histolytica, and, separately, Dientamoeba fragilis. Microscopy revealed G. duodenalis occurred most commonly (17 patients), followed by Blastocystis spp. (12 patients). In a few patients, Entamoeba histolytica/E. dispar, Cryptosporidium spp., and Cyclospora cayetanensis were identified. Molecular analysis identified 4 more G. duodenalis infections and 2 more Cryptosporidium spp. infections; concordance between microscopy and PCR showed almost perfect agreement for G. duodenalis (κ = 0.88) and substantial agreement for Cryptosporidium (κ = 0.74). PCR indicated that E. dispar, rather than E. histolytica, had been identified by microscopy. Additionally, 16 D. fragilis infections were detected using molecular methods. Although both microscopy and molecular techniques have a place in parasitology diagnostics, for parasites such as D. fragilis, where microscopy can underestimate occurrence, molecular techniques may be preferable, and also essential for distinguishing between morphologically similar microorganisms such as E. histolytica and E. dispar. Although in resource-constrained countries such as Cuba, microscopy is extremely important as a diagnostic tool for intestinal parasites, inclusion of molecular techniques could be invaluable for selected protozoa.

Sporadic cyclosporiasis in symptomatic Cuban patients: Confirmation of positive results from conventional diagnostic methods by molecular assay.

In Cuba, there are few studies on cyclosporiasis. Here, we report results from 1247 stool samples from symptomatic patients that were examined by microscopy methods and positive cases confirmed by nested PCR targeting the 18S rRNA gene, followed by sequencing. Seven positive samples, all diagnosed during May-June, were confirmed by the molecular method, indicating an occurrence in this patient cohort of 0.56%.

Concordance of Giardia duodenalis assemblages determined by different PCR methodologies in three observational studies in Cuba.

Giardia duodenalis is one of the most important intestinal parasites globally, especially in children, and in Cuba is the leading cause of chronic paediatric diarrhoea in this population. G. duodenalis is composed of eight genetic groups (or assemblages), two of which (A and B) are apparently zoonotic, occurring in both humans and other animals. However, consensus on the most appropriate genotyping scheme for optimal characterization of G. duodenalis isolates is lacking. In this article we present the results of three descriptive observational studies conducted in Havana, Cuba between 2010 and 2013, with the aim of comparing the results from molecular (PCR) approaches targeting different genes in order to assign with confidence 224 isolates of G. duodenalis to the correct assemblages. In each sub-study, following DNA isolation by the phenol/chloroform/isoamyl alcohol extraction method, PCR targeting the triose phosphate isomerase (tpi) gene was used for molecular characterization, as well as one additional PCR-method targeting another gene or pair of genes. DNA amplification was obtained in 87%, 83%, and 80% in the three sub-studies. Although excellent agreement (kappa index = 1) was recorded between results from some pairs of genes, for other combinations only moderate or substantial agreement was achieved. These results highlight the importance of interpretation of genotyping data, especially when single genetic markers are used. From the results of our studies, PCR targeting a combination of the tpi gene and the intergenic spacer region of rDNA may be a useful approach for the molecular characterization of G. duodenalis isolates.

Meningoencefalitis Eeosinofílica por Angiostrongylus Cantonensis: a un cuarto de siglo de una enfermedad emergente en las Américas

Hace 25 años se reportó por primera vez en Cuba y en el hemisferio occidental la aparición de una enfermedad emergente: la meningoencefalitis eosinofílica producida por larvas del helminto Angiostrongylus cantonensis; Recopilar de forma resumida la experiencia acumulada y los aportes al estudio de esta zoonosis realizados a lo largo de estos años; Se recogen las evidencias iniciales, los aportes a la parasitología y la malacología, los estudios experimentales y moleculares en la esfera de la inmunología y la neuroinmunología, los hallazgos clínico-patológicos en niños y adultos enfermos con las particularidades de la enfermedad en nuestro medio con especial acento en los aportes científicos nunca antes reportados, Se documenta el testimonio, los principales aportes y hallazgos entre los cuales se encuentran los estudios malacológicos, el papel de la IgE y los mecanismos involucrados en el sistema nervioso central, los patrones de síntesis intratecal de inmnoglobulinas y los elementos clínicos que brinda en niños y adultos(AU)

Prevalence and risk factors of intestinal parasites in Cuban children.

OBJECTIVES: To determine the prevalence of intestinal parasite infections and their risk factors in children in urban and rural settings in two Cuban municipalities. METHODS: A total of 1320 Cuban schoolchildren aged 4-14 were tested by stool examination for intestinal parasite infections and evaluated by parental questionnaire for a number of common environmental, sanitary, socioeconomic and behavioural risk factors. Multivariate regression was applied to examine the relationship between the respective parasite infections and the risk factors. RESULTS: Prevalences of intestinal parasite infections were 58% in Fomento and 45% in San Juan y Martínez; for helminth infections, these were 18% and 24% and for protozoa infections, 50% and 29%, respectively. Helminth infections were associated with high parental education (maternal: OR 0.68, CI 0.50-0.93; paternal: OR 0.71, CI 0.52-0.96), absence of toilet (OR 1.57, CI 1.12-2.19), consumption of water from a well or river (OR 0.56, CI 0.41-0.77) and eating unpeeled/unwashed fruit (OR 1.37, CI 1.01-1.87); protozoa infections were only associated with high maternal education (OR 0.72, CI 0.57-0.91). CONCLUSIONS: Paediatric intestinal parasite infections are still prevalent in certain areas in Cuba and associated with a number of common environmental, socioeconomic and sanitary risk factors.

Pesquisaje de giardia lamblia por los métodos de heces fecales directo e intubación duodenal / Giardia lamblia screening by the methods of direct stool and duodenal intubation

Se estudian 40 pacientes procedentes de la consulta de gastroenterología del Hospital Pediátrico Docente "William Soler" con el diganóstico positivo de Giardia lamblia por el método de heces fecales directo o por la intubación duodenal. Se encontró que el método de investigación en heces fecales fue eficaz en correlación con los casos positivos por intubación duodenal en el 92

, no así la correlación del líquido duodenal con respecto a las heces fecales positivas de entrada que fue del 56

. Otros datos relacionados con la procedencia, cuadro clínico y edad se expresan sucintamente. nuestros resultados indican que, el método de estudio en heces fecales, es de alta efectividad, por lo cual recomendamos indicar un seriado de 3 heces fecales directo, como mínimo, antes de acudir a la intubación duodenal

Pesquisaje de giardia lamblia por los métodos de heces fecales directo e intubación duodenal / Giardia lamblia screening by the methods of direct stool and duodenal intubation

Se estudian 40 pacientes procedentes de la consulta de gastroenterología del Hospital Pediátrico Docente "William Soler" con el diganóstico positivo de Giardia lamblia por el método de heces fecales directo o por la intubación duodenal. Se encontró que el método de investigación en heces fecales fue eficaz en correlación con los casos positivos por intubación duodenal en el 92 %, no así la correlación del líquido duodenal con respecto a las heces fecales positivas de entrada que fue del 56 %. Otros datos relacionados con la procedencia, cuadro clínico y edad se expresan sucintamente. nuestros resultados indican que, el método de estudio en heces fecales, es de alta efectividad, por lo cual recomendamos indicar un seriado de 3 heces fecales directo, como mínimo, antes de acudir a la intubación duodenal

Enterobiasis en niños asistentes a circulos infantiles del municipio Artermisa en 1988 / m

Mediante la técnica de la cinta adhesiva (Graham) se estudian 506 niños de los circulos infantiles de Artemisa y 201 niños de la localidad, no asistentes a los mismos y captados a través de consultorios del médico de la familia, ambos grupos en las edades comprendidas de 0 a 5 años. El 26 por ciento de los niños estudiados en los círculos infantiles fueron positivos así como el 20 por ciento de los que permanecían en sus casas. Posteriormente al diagnóstico, los positivos se dividieron en 3 grupos a los que se les aplicaron 3 esquemas de tratamiento diferente, se les controló a los 16; 19 y 21 días y se obtuvieron los mejores resultados con el esquema normado (AU)