Ascariasis

What is Ascariasis?

About one billion people globally are affected by Ascaris lumbricoides, causing over 60,000 deaths each year. It’s mostly found in tropical and subtropical countries, with high instances in Sub-Saharan Africa, Latin America, China, and East Asia. Unluckily, this disease is often overlooked, despite causing an estimated loss of 1.2 to 1.5 years of healthy life due to disability.

What Causes Ascariasis?

Ascariasis is a disease caused by a type of large, soil-borne roundworm called Ascaris lumbricoides. Adult female roundworms can grow to be between 20 and 30 cm long, while male roundworms can reach between 15 and 20 cm in length. These worms have a pink, yellow, or white color. Female worms are generally thicker with a straight rear end, whereas male worms are a bit thinner with a curved rear end and two retractable mating organs.

These roundworms have a life span of about one year. After a year, the adult worms die and are naturally expelled from the body through the digestive tract. This process can actually result in the person being cured of the disease, as long as they don’t get reinfected. It’s important to note that these worms don’t reproduce while in the human body.

Risk Factors and Frequency for Ascariasis

Ascariasis is a common type of parasitic infection that affects humans globally. Traces of it have been found throughout history; from ancient Egyptian writings to mummified remains dating back to 800 B.C. Even famous figures like Hippocrates and Aristotle mentioned this infection. Ascariasis predominantly infects individuals in tropical and subtropical areas, particularly where sanitation standards and personal hygiene are poor. Additionally, areas where human waste is used as fertilizer are at elevated risk. With increased travel and migration rates, even regions that typically experience lower infection rates are seeing more cases.

Signs and Symptoms of Ascariasis

Ascariasis is an infection that can have varying symptoms. Some people do not show any symptoms but may experience stunted growth and malnutrition over time. However, when symptoms exist, they can include:

• Abdominal pain
• Bloating
• Nausea and vomiting
• Loss of appetite
• Intermittent diarrhea

If a large number of the infecting larvae travel through the lungs, they can cause a condition known as Loeffler syndrome. The symptoms of this syndrome include:

• Wheezing
• Shortness of breath
• Cough
• Coughing up blood
• Fever

In more severe cases of Ascariasis, the adult worms can travel to tube-like structures in the body like those found in the biliary and pancreatic system. This can result in various complications such as inflammation of the gallbladder, bile duct, or pancreas, blockage of the small intestine, twisted intestine and other serious conditions. It is important to note that children are more vulnerable to these complications than adults.

Testing for Ascariasis

A female worm can lay a staggering 200,000 eggs daily. This makes it easier to detect the presence of the worm from a stool test. The most effective diagnostic measure is still the stool exam where they look for large, brown oval-shaped eggs that have a layered shell. It’s worth noting that there might be times when no eggs are found in the stool. This usually happens when the worm is moving to different parts of the body and growing, which typically lasts around a month. Only mature worms start laying eggs. Occasionally, an adult worm might be spotted in the stool or coming out from back passage. In rare cases, the worms can be coughed up or can even be present in urine.

Apart from stool tests, a blood test can show an increased count of a type of white blood cell called eosinophils during the active movement of the worm from the intestines to the lungs. There is also a chance of finding worm larvae, or young forms of the worm, in sputum, which is a mix of saliva and mucus coughed up from the respiratory tract. If abdominal X-rays are taken, they might show specific patterns that indicate the presence of worms; however, it isn’t a foolproof method of diagnosis. Imaging techniques like Ultrasound or CT scans can help pinpoint worms in the bile duct and gallbladder. An investigative procedure known as an endoscopic retrograde cholangiopancreatography (ERCP) can also aid in both diagnosing and treating these infestations.

Treatment Options for Ascariasis

Even the milder cases of Ascaris infection (a type of parasitic worm infection) should receive treatment to avoid problems that may arise when the parasites move around in the body. However, during the time the parasites are migrating through the lungs, medical treatment isn’t recommended due to the potential for increasing the risk of pneumonia.

The commonly recommended treatment for Ascaris infection is a single dose of a medication called albendazole, at a dose of 400 mg. Alternatively, the medication mebendazole can be used, either as 100 mg two times a day for three days or as a single dose of 500 mg. Another option is ivermectin, given once at a dose between 100 and 200 micrograms per kilogram of body weight.

For pregnant women, the treatment options include piperazine (either 50 mg per kilogram a day for five days or a single dose of 75 mg per kilogram), or pyrantel pamoate (11mg per kilogram, up to a maximum of 1 g). Pyrantel pamoate is the preferred treatment in this case. It’s important to note that these treatments focus on the adult parasites. That’s why re-treatment is usually advised one to three months later, as it allows any immature parasites time to grow into adulthood, at which point they can be killed by the medication. There are also alternative treatments available, such as nitazoxanide and levamisole.

If the infection has caused a partial blockage in the intestines, a nasogastric tube (a tube inserted through the nose and down into the stomach) may be used. Along with this, the patient is typically told not to eat or drink, receives fluids through a drip, and is given piperazine. If the blockage in the intestines is complete, surgery may be needed to make a cut into the intestines and remove the worms. If parts of the intestines have died off, these may also need to be removed and the healthy parts joined back together. After the surgery and once normal bowel movement is restored, anti-parasitic medication should be given to kill any remaining parasite eggs.

What else can Ascariasis be?

When experiencing certain symptoms, doctors will explore a range of potential health conditions to identify the right diagnosis. These conditions might include:

• Acute cholangitis (an infection in the bile duct)
• Acute pancreatitis (inflammation of the pancreas)
• Appendicitis (an inflamed or infected appendix)
• Ascending cholangitis (a serious infection of the bile duct)
• Asthma (a chronic condition affecting the airways)
• Cholecystitis and biliary colic (gallbladder problems)
• Hookworm (a type of intestinal parasite)
• Intussusception (when a part of the intestine folds into another part)
• Large bowel obstruction (when the large bowel or colon gets blocked)
• Small bowel obstruction (when the small intestine gets blocked)

A thorough examination and appropriate tests will help the doctor reach an accurate diagnosis.

What to expect with Ascariasis

Research conducted in Asia and Africa shows that a single dose of a medicine called albendazole can cure over 95% of cases. This medication gradually reduces the number of disease-causing eggs over the next few weeks in almost all the cases.

However, for preventing the disease from coming back, it’s critical for the patient to move locations. Improved sanitation and access to clean drinking water are also crucial needs in these areas.

There’s an ongoing effort to target many communities for socio-economic growth, which can help lessen the impact of ascariasis, a parasitic disease.

Preventing ascariasis involves avoiding contact with manure, wearing suitable footwear, and importantly, education about the disease.

Possible Complications When Diagnosed with Ascariasis

• Bleeding from the rectum
• Blockage in the bowel
• Appendicitis (inflammation of the appendix)
• Disorders of the liver and bile ducts
• False cyst in the pancreas

Recovery from Ascariasis

In order to prevent children from experiencing developmental setbacks, it’s necessary to give them Vitamin A supplements. For people living in areas where the disease is common, if there are still disease-causing eggs present in the stool, treatment should be repeated within three to six months. Following the prescribed medication treatment is crucial to completely get rid of the disease.

Preventing Ascariasis

Teaching people, ensuring access to clean drinking water, and enhancing cleanliness procedures are essential steps that need to be taken.