Wednesday, 14 April, 2021

Reducing Worm Infestations

Dr. Shyam P Lohani


A worm infestation still is one of the most common diseases affecting children from low and middle-income countries. Ascariasis, Trichuriasis, Hookworm, and Enterobiasis, which are transmitted through contaminated soil, are the major worm infestations of public health importance.
Intestinal worm infestations are widely prevalent in tropical and subtropical countries and often occur in places where there are economic hardships and poor sanitations. More than five billion people are at risk of infection with soil-transmitted helminths and over one billion people are infected, particularly in developing economies. Possible causes leading to intestinal worm infection are usually consumption of contaminated water, contaminated soil, contacts with contaminated feces, poor sanitation, and poor hygiene.

Globally, 1221–1472 million cases of Ascariasis, 750–1050 million cases of Trichuriasis, and 740–1300 million cases of hookworm infestation have been reported (WHO, 2012). It has been estimated that almost 25 per cent of the world population has been infected with one or more species of soil-transmitted helminthes alone (WHO, 2002). Intestinal parasites are endemic in most tropical and subtropical countries, particularly in developing countries due to poor living conditions with inadequate hygiene and sanitation, illiteracy, overcrowding, and low economic, educational, and poor hygienic behaviour of people.
The highest prevalence and intensity of infection with soil-transmitted helminths (STH) is usually observed among school-going children. Chronic helminths infections are manifested among young children in terms of delayed physical and mental development, anemia, and protein-energy malnutrition. Intestinal parasite infections are often linked to poverty and inadequate access to water, sanitation, and hygiene (WASH). The influence of unsafe hygiene on morbidity is particularly severe in malnourished children.
Intestinal worm infestation is a preventable global health problem and is a matter of serious concern for the stakeholders particularly in developing economies. Overcrowding, contamination of water, poor sanitation, and migration of people to cities greatly favour transmission of parasitic infection resulting in high endemicity. Soil-transmitted helminth infections form the most important group of intestinal worms and account for 27 per cent of the entire school-age and preschool-age children population in the world, who are in need of anthelminthic treatment.
The most common symptoms of intestinal worms are abdominal pain, diarrhea, nausea, or vomiting. Gas/bloating abdominal pain or tenderness, fatigue, and weight loss are other common manifestations. Dysentery may be seen in a person with intestinal worms and intestinal worms can also cause a rash or itching around the rectum or vulva. In some cases, infected individuals pass a worm in the stool during a bowel movement. There have been reports that some people may have intestinal worms for years without experiencing any symptoms.
Children are particularly susceptible to intestinal worms. The reason for high risk in children is due to their habit of playing in environments with contaminated soil, such as sandboxes and school playgrounds. Older adults are at increased risk when their immune system is weakened such as in the case of HIV/AIDS or to those with transplanted organs.
It has been estimated that about 10 per cent of people in the developing world are infected with intestinal worms. People residing in developing countries are at the highest risk owing to drinking water from contaminated sources and because of inadequate sanitation levels. Intestinal worms increase our risk for anemia and intestinal blockages. Complications may also occur more frequently in older adults and in people who have suppressed immune systems, such as people with HIV or AIDS infection and those with organ transplantation.
Intestinal worm infections can pose a higher risk in pregnant women. For pregnant with an intestinal worm infection, it is particularly to choose antiparasitic medication therapy that is safe to take during pregnancy and should be monitored closely during the entire period of pregnancy.
WHO (2006) recommends preventive chemotherapy (PC) to all at-risk people living in endemic areas once a year where the prevalence of STH in the community is over 20 per cent, and twice a year where it is over 50 per cent. However, administration of albendazole and mebendazole is not recommended in pregnancy during its first trimester for safety reasons; but is permissible in the 2nd and 3rd trimesters.

Role of FCHVs
Morbidity due to intestinal worm infestation, particularly STH, thus, is a global health problem affecting nearly two billion people in more than 100 countries. The high prevalence of intestinal worm infestation is considered as an indicator of poor living conditions and inadequate sanitation in a community.
A large number of children in developing countries are infected with common intestinal worms. The parasites can cause malnutrition and hinder a child's ability to grow, thrive, and learn. The basic provision for hand washing and regular deworming can overcome or prevent the morbidities caused by intestinal parasite infections. There is a significant reduction in the rate of intestinal infestations over the last few decades in Nepal. Female Community Health Volunteer (FCHV)’s role in decreasing STH has highly been acknowledged throughout the world. Thus, in this endeavour, their role cannot be undermined and should be scaled up to all over Nepal.

(A Professor, Lohani is the founder and academic director at Nobel College.