Helminths (helmins: worms) are group of parasitic metazoans. Soil transmitted helminths infections or helminthiasis (STH) are caused by these group of parasitic worms namely; roundworm (Ascaris lumbricoides), whipworm (Trichuris trichiura) and hookworms (Ancylostoma duodenale and Necator americanus). They are also called intestinal worms because the adult worms live in the intestine. STH is now the most common parasitic infection of humans worldwide, surpassing even the most common talked about parasitic infection, malaria. “Approximately two billion people are infected and four billion of the world populations are at risk of being infected, as of latest estimate, with highest number of cases occurring in tropical and sub-tropical countries; Sub-Saharan Africa, Latin America, Southeast Asia and China” (source, www.wikipedia.org). STH are usually transmitted by ingestion of eggs which are present in the soil which was contaminated by human feces. Food items such as vegetables and fruits are also contaminated especially in areas where fecal matter is used as manure or fertilizer, the eggs also contaminate the water supply, this happens in areas where there is poor sanitation and poor communities where the people do not have resources to build a toilet or latrine. Transmission can also be through penetration of the skin by the larvae of hookworms or accidental ingestion of the larvae of Ancylostoma duodenale. STH are common among children who play with contaminated sand and put the hand in their mouth or use the same hands to eat without washing them or pick up contaminated food items from the ground. STH is said to be one of the most important cause of intellectual and physical retardation in children, they cause abdominal pain, diarrhea, malnutrition and can be life threatening; the more the number of worms the more severe the disease condition. Effective control measures include; good personal hygiene and sanitation, health education, periodic administration of anthelminth drugs especially for pre-school and school age children as they are the population at highest risk of being infected.
GLOBAL HEALTH PROBLEMS POSED BY HELMINTHS INFECTIONS
According to the World Health Organization, estimates taken worldwide show that approximately;
• 807-1121 million people are affected by Ascaris lumbricoides
• 576-740 million are affected by hookworms
• 604-794 million are affected by whip worm
• 880 million children need treatments from any one of these infections and that 135,000 die per year from these infections (cause of death is usually due to the high amount of worms in the individual because the more the worms, the more the severity of the infection).
Ascaris is the most widespread STH; children are more commonly affected by Ascaris lumbricoides. Mild infections show little or no symptom, heavy infections can result in physical weakness, severe intestinal block and retard growth in children. Severe ascariasis can also cause pneumonia and...