Dramatic Decrease in Prevalence of Soil-Transmitted Helminths and New Insights Into Intestinal Protozoa in Children Living in the Chaco Region, Bolivia

Abstract

We assessed the prevalence of intestinal parasites among 268 2–12-year-old children living in rural areas, small villages, and semi-urban areas of the Chaco region, south-eastern Bolivia. The overall parasitism was 69%. Only protozoa, helminths, or co-infections were observed in 89.2%, 5.9%, or 4.9% of the positive children, respectively. A significant progressive increase in overall parasite prevalence was found when passing from rural areas to small villages and semi-urban areas. The most commonly found species were Entamoeba coli (38.4%), Giardia intestinalis (37.7%), and Blastocystis spp. (16%). Hymenolepis nana was the most prevalent helminth (5.6%), followed by Ascaris lumbricoides and hookworms (1.5% and 0.4%) evidenced only in rural areas and in villages. Molecular diagnostics identified Blastocystis subtypes 9 and 2, and 5 infections by Entamoeba histolytica and 4 by Entamoeba dispar. The dramatic decrease in prevalence of soil-transmitted helminths with respect to that observed about 20 years ago (> 40%) evidences the success of the preventive chemotherapy intervention implemented in 1986. Health education and improved sanitation should be intensified to control protozoan infections.

Desigualdad en la prevalencia de parasitosis intestinal en escolares de una escuela urbana y dos rurales de la comuna de Puerto Montt

“…Las prevalencias encontradas en este estudio en el sector rural se acercan a otros estudios realizados en Chile en territorios similares 9,11,12 y en América Latina y el Caribe (ALC) [27][28][29] , diferenciándose de otros que declaran prevalencias sobre 90% 30 , donde incide la condición étnica además de pobreza e insalubridad. En el sector urbano, la prevalencia encontrada en este estudio es más baja que en el sector rural y menor que la reportada por Araya et al , no encontrándose otros estudios en sectores urbanos con los que comparar, por lo menos en esta última década.…”

Giardia intestinalis infection associated with malnutrition in children living in northeastern Brazil

“…G. intestinalis infection was observed in all age groups, mainly in children 7-14 years of age. This downward trend in the prevalence of STHs associated with persistent protozoan infections has been observed in other countries and may represent a challenge for the control of parasitic intestinal infections [17].…”

“…Policies for controlling intestinal parasites focus on soil-transmitted helminths (STHs) and schistosomiasis, and do not take into account the burden of protozoan parasites, which require different drugs/dosages and treatment durations [16][17][18]. The aims of the present study were to assess the prevalence and factors associated with G. intestinalis infection and to determine its impact on the nutritional status of children in rural northeastern Brazil.…”

FREQUÊNCIA DE PARASITOSES INTESTINAIS: um estudo com crianças de uma creche de Santa Cruz do Sul - RS

“…Já, Macchioni et al, 24 em estudo realizado na área rural de Chaco, na Bolívia, relatam ter encontrado maior prevalência do parasita Giadia intestinalis. Saeed et al 25 realizaram uma pesquisa com crianças menores de 5 anos em Cartum, Sudão, encontrando 11% de crianças infectadas por Giardia intestinalis (25,9%).…”