Prevalence and intensity of infection of Soil-transmitted Helminths in Latin America and the Caribbean Countries. Mapping at second administrative level 2000-2010
Infections by Ascaris lumbricoides, Trichuris trichiura and hookworm (Necator americanus or Ancylostoma duodenale) occur all over the world, transmitted to humans through soil, vegetation, food and water contaminated by fecal matter that contain the eggs of the parasites.
At the global level it is estimated that intestinal parasite infections affect more than one-third of the world's population with the highest rates in school-age children (SAC). Stunting usually occurs between 6 months and 2 years of age, which overlaps with the period in which the soil-transmitted helminths begin to emerge. STH have been documented as causing impairment of growth and nutrition. The hookworms damage the intestinal mucosa leading to bleeding, loss of iron and anemia. Infections by Trichuris trichiura produce chronic reduction of food intake. During pregnancy, mild or severe infections with hookworms can cause anemia to the mother and damage to the fetus, leading to low birth weight. In areas where helminths are common, deworming activities can be done once or twice per year to the population at risk (without access to improved sanitation facilities), including deworming for pregnant women after the first trimester. Deworming during pregnancy also has been found useful to reduce severe maternal anemia, increase birth weight and reduce infant mortality.
To know the geographical distribution of neglected tropical diseases it is necessary to understand the distribution of each of the diseases, to identify areas with overlapping and to focalize areas for integrated interventions (preventive chemotherapy, health education, water and sanitation, etc.). The epidemiological distribution of some neglected tropical diseases is well known in Latin America and the Caribbean countries (LAC) (e.g. lymphatic filariasis and onchocerciasis); however the distribution of schistosomiasis and soil-transmitted helminths is less well mapped.
The main objective of this study was to map the prevalence and intensity of infection by soil-transmitted helminths for pre-school and school-age children in Latin America and the Caribbean countries (LAC) at the second subnational administrative level for the period 2000-2010, based on bibliographic review of papers published for this time period. Data were restricted to two age groups only: pre-school (1-4 years old) and school-age children (5-14 years old).