Index
These organisms cause significant morbidity and mortality in endemic countries.
Parasitic infections, caused by intestinal helminths and protozoan parasites , are among the most prevalent infections in humans in developing countries.
In developed countries, protozoan parasites more commonly cause gastrointestinal infections compared to helminths .
Most common and frequent parasites
The most common and frequent parasites are:
- Nematodes (round worms).
- The cestodes (tapeworms).
- The trematodes (flat worms).
Helminths generally cannot multiply in the human body.
Protozoan parasites that have a single cell can multiply within the human body.
There are four species of intestinal helminth parasites, also known as soil-borne helminths and soil-transmitted helminths:
- Ascaris lumbricoides (intestinal worm).
- Trichuris trichiura (whipworm).
- Duodenal ankylostoma.
- Necator americanus (ankylostomas).
These infections are most prevalent in tropical and subtropical regions of the developing world where adequate water and sanitation facilities are lacking.
Recent estimates suggest that Ascaris lumbricoides can infect more than 1 billion people, Trichuris trichiura 795 million and hookworms 740 million.
Other species of intestinal helminths are not widely prevalent. Intestinal helminths rarely cause death.
Instead, the burden of disease is related to lower mortality than to chronic and insidious effects on the health and nutritional status of the host.
In addition to their health effects, intestinal helminth infections also affect children’s physical and mental growth, hamper educational attainment, and hamper economic development.
The most common intestinal protozoan parasites are:
- Giardia intestinalis.
- Entamoeba histolytica.
- Cyclospora cayetanensis.
- Cryptosporidium spp.
The diseases caused by these intestinal parasitic protozoa are known as:
- Giardiasis.
- Amebiasis.
- Cyclosporiasis.
- Cryptosporidiosis.
These diseases are associated with diarrhea. Guard intestinalis is the most common parasitic cause of diarrhea in the developed world, and this infection is also very common in developing countries.
Amoebiasis is the third leading cause of death from parasitic diseases worldwide, with its greatest impact on people in developing countries.
The World Health Organization (WHO) estimates that approximately 50 million people worldwide suffer from invasive amoebic infections each year, resulting in 40-100 thousand deaths a year.
Cryptosporidiosis is becoming more prevalent in both developed and developing countries among AIDS patients and among children under five years of age.
Several outbreaks of diarrheal diseases caused by cyclospora cayetanensis have been reported during the last decade.
The spread of these protozoan parasites in developing countries occurs mainly through faecal contamination as a result of poor sewage and poor water quality.
Outbreaks of these protozoan parasites have occurred in food and water, and the infectious cyst form of the parasites is relatively resistant to chlorine.
Other species of protozoan parasites can also be found in the human intestine, but are not pathogenic, except for microsporidia sp.
Symptoms of intestinal parasites
Common symptoms of intestinal worms are:
- Abdominal pain.
- Diarrhea, nausea, or vomiting
- Gas / bloating.
- Fatigue.
- Unexplained weight loss
- Abdominal pain or tenderness
A person with intestinal worms can also experience dysentery. Dysentery is when an intestinal infection causes diarrhea with blood and mucus in the stool.
Pinworms can also cause a rash or itching around the rectum or vulva. In some cases, you will pass a parasite in your stool during a bowel movement.
Some people can have intestinal worms for years without experiencing any symptoms.
Causes of intestinal parasites
One way to become infected with intestinal worms is to eat undercooked meat from an infected animal, such as a cow, pig, or fish.
Other possible causes that lead to intestinal parasite infection include:
- Consumption of contaminated water.
- Consumption of contaminated soil.
- Contact with contaminated feces.
- Bad sanitation.
- Poor hygiene.
Roundworms are usually spread through contact with contaminated soil and feces.
Once you have consumed the contaminated substance, the parasite travels to your intestine. They then reproduce and grow in the intestine. Once they reproduce and become larger in quantity and size, symptoms can appear.
Risk factors for intestinal parasites
Children are particularly susceptible to intestinal parasites. That’s because they can play in environments with contaminated soil, such as sandboxes and school playgrounds. Older adults are also at higher risk due to weakened immune systems.
Diagnosis of intestinal parasites
If you have any of the above symptoms, and especially if you have recently traveled out of the country, you should make an appointment with your doctor. Your doctor may then perform an exam of your stool. You can take several stool samples to confirm the presence of the parasite.
Another test is the “duct tape” test, which involves taping the anus several times to retrieve the roundworm eggs, which can be identified under a microscope.
If no worms or eggs are detected, your doctor may perform a blood test to look for antibodies that your body produces when it is infected with a parasite.
In addition, your doctor may take an X-ray or use imaging tests such as computed tomography (CT) or magnetic resonance imaging (MRI), depending on the extent or location of the suspected disease.
Treatment
Some types of intestinal worms, such as tapeworms, can go away on their own if you have a strong immune system and a healthy diet and lifestyle.
However, depending on the type of intestinal worm infection, one may require treatment with an antiparasitic medication. Serious symptoms should not be ignored.
Consult your doctor if:
- You have blood or pus in your stool.
- You vomit daily or often.
- You have an elevated body temperature.
- You are extremely fatigued and dehydrated.
Your treatment plan will be determined based on the type of intestinal worm you have and your symptoms. Tapeworm infections are usually treated with oral medications, such as praziquantel (Biltricide), which paralyze the adult tapeworm.
Praziquantel (Biltricide) causes tapeworms to shed from the intestine, dissolve, and then pass out of your body through your stool.
Common treatments for a pinworm infection include mebendazole (Vermox, Emverm) and albendazole (Albenza).
Symptoms generally begin to improve after a few weeks of treatment. Your doctor will most likely take and test another stool sample after completing treatment to see if the worms are gone.
Complications of intestinal parasites
Intestinal worms increase your risk of anemia and intestinal blockages. Complications occur most often in older adults and in people with suppressed immune systems, such as people with HIV infection or AIDS.
Pinworm infections may pose a higher risk if you are pregnant. If you are pregnant and have an intestinal infection, your doctor will determine which deworming treatment is safe to take during pregnancy and will monitor you closely while treating you during pregnancy.
Prevention and control
Intestinal parasitic infections are distributed virtually throughout the world, with high prevalence rates in many regions. Amoebiasis, ascariasis, hookworm infection, and trichuriasis are among the ten most common infections in the world.
Although mortality from these infections is relatively low, complications are not uncommon and many cases require hospital care.
In many countries, malabsorption, diarrhea, blood loss, impaired work capacity, and reduced growth rate due to intestinal parasitic infections are major health and social problems.
In addition, other parasitic infections such as abdominal angiostrongyliasis, intestinal capilariasis, and strongyloidiasis are a local or regional public health problem.
The prevention and control of intestinal parasitic infections is now more feasible than ever due to the discovery of safe and effective drugs, the improvement and simplification of some diagnostic procedures, and advances in the biology of the parasite population.
In recent years, general health care strategies have emphasized preventive medicine and community cooperation in the control of endemic diseases and have created a favorable climate for the design and implementation of control measures against intestinal parasitic infections.
In many countries, endemic intestinal parasitic infections are closely related to economic and social development processes and, therefore, their control can be a sensitive issue, both socially and politically.
In others, the control of intestinal parasitic infections has proven to be a useful entry point for other primary health care activities, for example, in family planning, child care, health education and nutrition.
Some Basic Ways to Prevent Intestinal Parasites
To prevent intestinal parasites, wash your hands regularly with soap and hot water before and after using the bathroom and before preparing or eating food.
You should also practice food safety:
- Avoid raw fish and meat.
- Cook meat thoroughly to temperatures of at least 145 ° F (62.8 ° C) for whole cuts of meat and 160 ° F (71 ° C) for ground beef and poultry.
- Let cooked meat rest for three minutes before carving or consuming.
- Freeze fish or meat at -4 ° F (-20 ° C) for at least 24 hours.
- Wash, peel, or cook all raw fruits and vegetables.
- Wash or reheat any food that falls on the floor.
If you visit developing countries, cook fruits and vegetables with boiled or purified water before eating, and avoid contact with the soil that may be contaminated with human feces.
