Soil-transmitted helminth infections are parasitic infections caused by certain parasitic worms (helminths).
Helminth infections result from soil contamination with helminth eggs present in the feces of infected people in areas with poor sanitary conditions. Some drugs, including this https://pillintrip.com/medicine/iverzine help to solve the problem.
In children, helminth infections lead to disorders of nutritional status and physical development.
Worldwide about 1.5 billion people are infected with soil-borne helminths (geohelminths).
Methods for controlling helminth infections include periodic deworming to eliminate helminths, health education to prevent reinfection, and improved sanitation to eliminate soil contamination with helminth eggs.
A number of safe and effective medications are available to control helminth infections.
Soil-transmitted helminth infections are among the most common infections in the world and affect the poorest and most socially disadvantaged populations. They are transmitted through eggs present in human feces that enter the soil in areas with poor sanitation.
The most common geohelminths include roundworms (Ascaris lumbricoides), lupus (Trichuris trichiura) and ankylostomes (Necator americanus and Ancylostoma duodenale). These geohelminth species are usually grouped together because they require similar diagnostic procedures and respond to the same medications.
The intestinal helminth (Strongyloides stercoralis) is an intestinal helminth that, because of its specific characteristics, requires different diagnostic methods than other geohelminths, and for this reason is often not detected. In addition, this parasite is insensitive to albendazole and mebendazole, so mass prophylactic treatment campaigns for other geohelminthiasis do not affect the morbidity associated with it.
Global distribution and prevalence
Globally, approximately 1.5 billion people, or 24% of the world’s population, are infected with soilborne helminth infections. Such infections are widespread in tropical and subtropical areas, with the highest rates of infection occurring in sub-Saharan Africa, the Americas, China, and East Asia.
More than 267 million preschool children and more than 568 million school-age children live in areas with intense transmission of these parasites and require treatment and prevention.
It is estimated that more than 600 million people worldwide are infected with S. stercoralis. However, because infection with this parasite is concentrated in areas of poor sanitation, its geographical distribution overlaps with that of other geohelminths.
Mechanisms of transmission
Geohelminths are transmitted via eggs excreted with the feces of infected persons. Parasite adults live in th
e intestines, where they lay thousands of eggs daily. In areas with poor sanitation, these eggs enter the soil. Infection by them can occur in different ways:
Consumption of poorly washed, uncleaned, or improperly heat-treated vegetables contaminated with geohelminth eggs;
Consumption of drinking water containing geohelminth eggs from contaminated sources;
ingestion of gehelminth eggs in the digestive tract of children playing on contaminated soil and taking dirty hands into the mouth.
In addition, ankylostoma larvae can hatch from eggs in the soil and develop into forms capable of actively penetrating the body through the skin. Ankylostoma infection occurs mainly by walking barefoot on contaminated soil.
Geohelminth infections are not transmitted directly from person to person or by contact with fresh feces, because parasite eggs excreted with feces only become infectious after about three weeks of maturation in the soil.
A. lumbricoides, T. trichiura and ankylostomas do not reproduce in the human body, so re-infection occurs only through contact with parasites in infectious stages of development in environmental objects. S. stercoralis is able to reproduce in the host, and in immunocompromised individuals uncontrolled reproduction of the parasite can be fatal.
Effects on nutritional status
Geohelminth infections can lead to various disorders of the nutritional status of infected individuals.
The worms feed on the tissues of the host, including blood, which leads to iron and protein deficiency.
In addition, ankylostomiasis causes chronic intestinal bleeding, which can lead to anemia.
Helminth infestation leads to impaired absorption of nutrients. Infection with roundworms can lead to vitamin A deficiency.
Some geohelminths also lead to loss of appetite and, consequently, a decrease in food intake and a deterioration in overall physical tone. Infestation with T. trichiura can lead to diarrhea and dysentery.