Deworming: How necessary is it and how often should you deworm?

What is deworming?

Deworming is the process of using medicines to rid the body of worms. During deworming, the medicines ingested kill the worms or paralyze them and therefore permit their removal from the body or intestinal tract.  

Many people including children are at risk of worm infection when they eat food or drink water or use utensils that contain the cysts or eggs of worms or their larvae. Eating with unclean hands can also lead to worm infection.  The larvae of some worms also enter the body by penetration through the skin.  

Signs and symptoms of worm infestation

Common worms that infect the body are the roundworm, threadworm (pinworm), whipworm, tapeworm and hookworm. These worms that infect our bodies may cause symptomatic (show symptoms) or asymptomatic (no symptoms observed) disease. 

Symptomatic as well as asymptomatic cases may be detected during stool routine examination when the eggs of worms are detected in the stools. 

Common symptoms and signs of intestinal worm infection are 

• nausea and vomiting 
• diarrhoea
• bloating
• anal itching 
• abdominal distension 
• weight loss
• depressed appetite 
• cough
• anaemia 
• terminal haematuria 
• passage of live worms or their eggs in stools or through the nostrils
• growth retardation
• easy fatigability

These symptoms and signs are largely dependent on the worm load in the intestines or body.

What is a dewormer? 

Dewormer or anthelmintic is a medicine or drug used to kill worms and facilitate their removal from the body. Dewormers usually come in different dosage forms such as tablets and oral suspensions.

Their dosages are calculated usually based on body weight.  However, in mass deworming programs, the height of the individuals is used to determine the doses of some dewormers since the weight can be calculated from the height of the individual using the ideal body weight calculator. 

What are examples of the common dewormers available?

There are various kinds of medicines used for deworming on the market. The commonest ones are;

• Albendazole
• Mebendazole 
• Praziquantel 
• Pyrantel pamoate
• Niclosamide
• Ivermectin
• Others are thiabendazole, diethylcarbamazine, and nitazoxanide.

How do dewormers work?

Dewormers kill worms by interfering with various metabolic processes in the worm which are not present in the host or which are of different characteristics from the host.  

Example; 

• Benzimidazoles (albendazole, mebendazole and thiabendazole) work by inhibiting microtubule aggregation and synthesis in the worm as well as preventing glucose uptake in the worm. 
• Ivermectin causes paralysis of the worm by enhancing chloride influx  through the glutamate-gated chloride channels to cause hyperpolarization. Pyrantel pamoate also paralyzes the worm to permit its elimination from the intestinal tract. 
• Praziquantel also causes contracture paralysis by enhancing  influx of calcium ions through the cell membrane. Niclosamide kills the worm,  specifically tapeworm, by depriving it of energy by inhibiting energy production in the form of ATP. 

After the worms are killed the body would mount an immune attack to eliminate the worms. These dewormers may be used either alone or as a combination to enhance their efficacy against different worms. 

It is however not advised to use three or more dewormers at a time since this would increase adverse effects.  

The use of single dose albendazole (400 mg) or mebendazole (500 mg) annually or biannually for prophylaxis (in deworming) is recommended by the WHO as a public health intervention in young children between the ages of 12 months and 12 years. For children younger than 24 months, half dose of albendazole (200 mg) should be used.

How often should you deworm?

The recommended frequency of deworming is at least twice a year and not frequently than every three months in all persons at risk of worm infestation.  

However, persons with severe worm load such as vomiting worms or worms coming out of the nostrils or abdominal distension due to worms would need to deworm more frequently. 

Deworming children less than 12 months should only be done on the advice of a physician (worm infestation is not common in this age group and the safety of medicines for deworming in this age group is not established).

Should I deworm before or after meals?

The preferred way of administering dewormers especially albendazole, mebendazole is after meals. They are not readily soluble in aqueous solution and therefore not readily absorbed. 

Taking the dewormers after a high fatty meal enhances their absorption.  Praziquantel is also taken with meals. 

However, it is advisable to take your Ivermectin 1 hour before meals or 2 hours after meals. 

The dewormer can be chewed or crushed before swallowing if too big. 

When should you take the dewormer?

It is common to hear that one has to deworm at nighttime because the worms would come out to feed in the intestines.  This claim might probably be because some people hold the opinion that the worms are more active when one is asleep or resting. 

This may hold in the case of threadworms which exit the GIT at night to lay eggs around the anal region and this is usually associated with anal itchiness. However, dewormers can be taken at any convenient time and usually after meals (foods that contain fat). Pregnant women are to deworm in their second and third trimesters and not the first trimester. Safety is not assured in the first trimester. For dewormers such as Mebendazole and Ivermectin, the manufacturer advises pregnant women to avoid throughout pregnancy.

How will I know that I need a dewormer? 

Everyone is at risk of worm infestation. It is advisable to deworm at least twice every year (once every six months). Signs and symptoms associated with worm infection are not usually specific and other diseases should be ruled out. 

Notwithstanding, when one experiences the signs and symptoms such as nausea, vomiting, bloating, diarrhoea, abdominal distension, easy fatigability, itchiness, cough, poor growth in children, wasting, pallor, passage of worms in stools or vomiting worms, worm infection should be suspected and treated accordingly.

How do I get rid of worms naturally from my stomach or without using medicines?

Natural remedies for treating worm infection include; 

• eating carrots
• turmeric
• cloves
• coconut
• garlic 
• drinking a tablespoon full of neem leaf paste
• a tablespoon of the powder of roasted pumpkin seeds dissolved in a glass of water 

What would happen if I do not deworm? 

Failure to deworm can lead to

• anaemia 
• intestinal obstruction 
• cough and wheezes 
• growth retardation especially in children 
• increased rate of transmissibility to other people 
• malnutrition 
• poor cognitive development (in children)
• death. 

Do worms make you hungry? 

Worms can make one hungry as they interfere with digestion and absorption of food. They also utilize the digested nutrients for growth therefore depriving your body of the needed nutrients.

Can worms make you gain weight? 

Worm infestation would not let you gain weight.  It would rather  make you lose weight or become malnourished. The nausea/vomiting and bloating associated with worm infestation rather prevent one from taking in enough food. 

Their competition with the body for nutrients further deprives one of the necessary nutrients for growth. Also since worm infestation triggers an inflammatory response by the immune system there is usually poor appetite hence causing wasting (decrease in body muscle mass) rather than weight gain.

Abdominal distension observed commonly in children following heavy worm infestation might be as a result of obstruction of the gut lumen by the worms which impedes the flow of ingested foods and fluids through the digestive system.  

The obstruction can be relieved by surgery or deworming. The abdominal distension could also be a sign of protein malnutrition. It is just to say that worm infestation does not make one gain weight but if weight gain occurs it is pathological and has to be treated.

How do I protect myself from getting worms into my body?

Sanitation and hygiene are key to preventing worm infestation or their transmissibility. These sanitation and hygiene tips when followed or observed would protect you and your family from getting infected with worms.

• Always use a latrine / toilet when you need to urinate or defecate. Avoid open defecation.
• Keep latrines and the area around the toilets clean.
• Avoid swimming/walking in contaminated rivers, dams or puddles/rice fields. 
• Avoid drinking or cooking with river water.
• Do not stay close to the refuse dump or children should not be permitted to play at the refuse dump.

• Wash hands with soap after going to the latrine or cleaning a child
• Wash hands with soap before and after eating food and when cooking.
• Ensure fingernails are clean and short.
• Always wear shoes when walking outside and wash feet every day.
• Drink clean water or boil the water before drinking.
• Keep food and household water safe and away from flies and dirt
• Always wash fruit and vegetables thoroughly in clean water or salty water and then cook to get rid of eggs or larvae.
• Encourage families and friends to deworm regularly to treat the infection.

Government would play a role by:

• Providing potable water to all
• Building public toilet facilities and ensuring they are properly maintained
• Organizing mass deworming programmes especially in endemic communities
• Educating the public on the need for proper sanitation and improving upon hygienic practices

REFERENCES

Vitamin angels (2019). Reference Manual for Administration of Dewormers to Preschool-Age Children In Vitamin A Distribution Projects. a 501c3 organization. vitaminangels.org

Guideline: Preventive chemotherapy to control soil-transmitted helminth infections in at-risk population groups. Geneva: Word Health Organization (2017). Accessed from: https://www.who.int/elena/titles/deworming/en/

Andrew Hall & Sue Horton (2008). BEST PRACTICE PAPER: DEWORMING NEW, ADVICE FROM CC08, Copenhagen Consensus Center. Frederiksberg, Denmark. Accessed from: www.copenhagenconsensus

Richard A. Harvey,  Pamela C. Champe, Richard D. Howland and Mary J. Mycek (2006). Lippincott’s illustrated reviews: Pharmacology, Indian Edition (3^rd edition), Distributed by B.I  Publications PVT limited, pages 427-432.