- March 13, 2016
- Posted by: emobile
- Category: Trending Topic
Emobileclinic Trending Topic
This disease is said to be common among poor and most deprived communities. We would add that since everyone eat farm resources, you cannot but be careful when it comes to helminth infections as they are transmitted by eggs present in human feaces and contaminate the soils most especially in the rural area where proper hygiene is not in place.
According to WHO, more than 1.5 billion people, or 24% of the world’s population, are infected with soil-transmitted helminth infections worldwide. Infections are widely distributed in tropical and subtropical areas, with the greatest numbers occurring in sub-Saharan Africa, the Americas, China and East Asia. Over 270 million preschool-age children and over 600 million school-age children live in areas where these parasites are intensively transmitted, and are in need of treatment and preventive interventions.The main species that infect people are the roundworm (Ascaris lumbricoides), the whipworm (Trichuris trichiura) and hookworms (Necator americanus and Ancylostoma duodenale).
Soil-transmitted helminths are transmitted by eggs that are passed in the faeces of infected people. Adult worms live in the intestine where they produce thousands of eggs each day. In areas that lack adequate sanitation, these eggs contaminate the soil. This can happen in several ways:
eggs that are attached to vegetables are ingested when the vegetables are not carefully cooked, washed or peeled;
eggs are ingested from contaminated water sources;
eggs are ingested by children who play in the contaminated soil and then put their hands in their mouths without washing them.
In addition, hookworm eggs hatch in the soil, releasing larvae that mature into a form that can actively penetrate the skin. People become infected with hookworm primarily by walking barefoot on the contaminated soil.
There is no direct person-to-person transmission, or infection from fresh faeces, because eggs passed in faeces need about 3 weeks to mature in the soil before they become infective. Since these worms do not multiply in the human host, re-infection occurs only as a result of contact with infective stages in the environment.
Morbidity and symptoms
Morbidity is related to the number of worms harboured. People with light infections usually have no symptoms. Heavier infections can cause a range of symptoms including intestinal manifestations (diarrhoea and abdominal pain), general malaise and weakness, and impaired cognitive and physical development. Hookworms cause chronic intestinal blood loss that can result in anaemia.
Soil-transmitted helminths impair the nutritional status of the people they infect in multiple ways.
The worms feed on host tissues, including blood, which leads to a loss of iron and protein.
The worms increase malabsorption of nutrients. In addition, roundworm may possibly compete for vitamin A in the intestine.
Some soil-transmitted helminths also cause loss of appetite and, therefore, a reduction of nutritional intake and physical fitness. In particular, T. trichiura can cause diarrhoea and dysentery.
The nutritional impairment caused by soil-transmitted helminths is recognized to have a significant impact on growth and physical development.