Ancylostoma

What is Ancylostoma?

Ancylostoma duodenale, also known as the human hookworm, is a very common type of parasitic infection, particularly in countries where clean water, sanitation, and hygiene facilities are scarce. Along with other similar parasites, known as soil-transmitted helminths (STH), this hookworm is usually transmitted when people come into contact with soil that has been contaminated. Over the past few decades, there have been documented cases where other types of Ancylostoma parasites have been passed from domesticated animals to humans.

What Causes Ancylostoma?

The hookworms A. duodenale, Ancylostoma braziliense, Ancylostoma caninum, and Ancylostoma ceylanicum, are all types of worms that can infect humans. These worms come from infected soil and can also be passed on through contact with domestic pets like dogs and cats, which are the main carriers of these hookworms.

A. duodenale and A. ceylanicum can cause infections in the intestines that leads to symptoms affecting the digestive system, anemia, and can even affect physical strength and mental sharpness. In particular, the A. duodenale worm can also cause symptoms in the lungs if a person is infected.

All these types of hookworms can cause a skin condition known as cutaneous larva migrans (CLM), where the skin shows signs of a red, itchy, snakelike rash that appears to move or creep beneath the skin. It’s also worth noting that in rare cases, a person can experience eosinophilic enteritis, which is an inflammation of the small intestine, due to an A. caninum infection.

Risk Factors and Frequency for Ancylostoma

Over 1.5 billion people around the globe may risk infection from Ancylostoma and other similar infections. Half of these infections are found in Asia and the Pacific, where a mix of tropical climate, overcrowded population, poor hygiene, and sanitation worsens the problem. Ancylostoma, along with other types of hookworms, cause more disabilities than deaths. The resulting malnutrition and anemia from hookworm infections lead to the loss of up to 4.1 million years worth of healthy life each year.

• The most vulnerable groups to contract Ancylostoma infections are preschoolers, school-aged children, and travelers returning from tropical countries.
• People who are often around dogs and cats are also at risk, as they might catch the zoonotic (transmittable from animals to humans) version of the Ancylostoma infection.
• The occurrence of Ancylostoma infection is also linked to seasons, more prevalent during the summer-autumn period.
• It’s not unusual for humans to have infections from multiple Ancylostoma species at the same time.

Signs and Symptoms of Ancylostoma

Ancylostoma infection predominantly affects people who reside in or travel to endemic areas. To diagnose Ancylostoma infection, healthcare professionals need to determine if patients have histories of walking barefoot in endemic regions, interacting with domestic animals, and track the growth and nutritional calibration of children.

Some individuals may not show any symptoms of Ancylostoma infection, while others may experience mild to severe symptoms starting with skin irritation from the invasion of the worm, followed by organ-related symptoms as the worm migrates to the lungs and GI tract, and lastly, the establishment of the worms in the intestine with severe consequences. Here is the journey of Ancylostoma infection summarised:

• Invasion stage: The larvae of the worm penetrate into the skin causing irritation, itchiness, and rashes. The rashes, known as ground itch, could be an indication of zoonotic Ancylostoma, where the larvae only live in the skin causing what is called ‘creeping eruption’ or CLM.
• Migration phase: The larvae move to the lungs and GI tract, triggering symptoms such as cough, sore throat, and discomfort. A rare condition called Loeffler syndrome, marked by a hypersensitive lung response, severe cough, and sore throat, can occur.
• Intestinal phase: This is when the adult worms settle in the human intestine, causing severe symptoms including blood and protein loss, which can result in iron deficiency anemia, appetite loss, abdominal discomfort, and malnutrition. This can potentially lead to physical and cognitive impairment.

Testing for Ancylostoma

The symptoms of an Ancylostoma infection, which is a worm infection, can be quite tricky to pin down because they’re also seen in other infections and health issues related to poor nutrition. Certain common blood test results can point towards this infection, showing things like anemia due to iron deficiency, an unusual number of white blood cells known as eosinophils, and sometimes an increase in a type of antibody called IgE. A chest X-ray might even show irregularities like widespread tiny cloud-like areas in the lungs while the worms are moving through the body. However, this isn’t very helpful once the worms have moved into the gut. These tests need to be looked at very carefully because other worm infections can show the same blood test and X-ray results.

Several traditional tests done on stool samples, like the Kato-Katz and formalin-ether concentration techniques, are the go-to methods for diagnosing an Ancylostoma infection. They do this by spotting any eggs or adult worms. The severity of the infection can be identified by counting the number of eggs in a given amount of stool. But in some cases, the number of eggs might be very low, or the patient might have recently had medication to eliminate the worms. In these situations, testing stool samples isn’t very effective. To solve this issue, some labs have begun using more advanced tests that target specific pieces of the worm’s genetic material. These tests, however, are still being checked to ensure they are as reliable as the traditional methods.

When it comes to diagnosing Cutaneous Larva Migrans, a specific type of this infection where worms affect the skin, stool tests tend to be less useful. Diagnosis can usually be made just by looking at the skin symptoms, as the larvae in this type of infection are limited to the skin. If Eosinophilic Enteritis is suspected, which is an unusual infection of the small intestine caused by A. Caninum, the worm’s eggs won’t be found in stool because humans can’t host A. caninum on a full-term basis. Procedures like colonoscopy and laparotomy, which involve taking tissue samples for examination under the microscope, can be done if needed, but they’re not usually the first choice of tests. Tests to detect A. caninum in your blood are not widely available, though some research labs have developed them.

Treatment Options for Ancylostoma

For the treatment of an Ancylostoma infection, commonly known as hookworm infection, the common medications used are albendazole, mebendazole, or pyrantel pamoate. If Ancylostoma ceylanicum infection specifically is involved, the use of ivermectin and pyrantel pamoate is typically recommended, with benzimidazole drugs also being effective. For pregnant women, deworming treatments may be safely done during the second or third trimester, after weighing the potential risks and benefits.

In addition to medication, addressing nutritional deficiencies and anemia through iron supplements and nutritional support can aid in recovery. A follow-up check, including stool examination and blood tests, should be done after 2 to 3 weeks of treatment to ensure its effectiveness and to detect any possibility of reinfection.

In terms of Cutaneous Larva Migrans (CLM) – a skin infection usually caused by walking barefoot on contaminated soil – the disease usually resolves on its own. However, complications such as secondary bacterial infections can occur if left untreated. A single dose of ivermectin or a three-day course of albendazole can be used to stop the movement of the larvae under the skin. Further, applying a medical cream containing 10% to 15% thiabendazole can be effective. It’s important to also treat pets with deworming drugs like pyrantel pamoate, dichlorvos, febantel, fenbendazole, and mebendazole to prevent the hookworm lifecycle from continuing.

What else can Ancylostoma be?

When it comes to diagnosing chronic blood loss or iron-deficient anemia, it’s essential to rule out diseases that can cause these conditions. These could possibly include:

• Intestinal cancer
• Polyps in the intestine
• Hemolytic anemia (a condition where red blood cells are broken down faster than they can be made)
• Other infections of intestinal parasites

This process is crucial for confirming the presence of an Ancylostoma infection (a type of hookworm).

Similarly, it can be challenging to diagnose Cutaneous Larva Migrans (CLM) due to its similarity with other skin conditions. The conditions that can be easily confused with CLM include:

• Contact dermatitis (a skin rash caused by contact with certain substances)
• Migratory myiasis (a skin condition caused by fly larvae)
• Scabies infection (a skin infestation by a mite)
• Cercarial dermatitis (a skin rash caused by parasitic worms)

These similarly presenting conditions make it difficult to distinguish and correctly diagnose CLM.

What to expect with Ancylostoma

The outlook for people infected with Ancylostoma, a type of parasite, is generally positive if treated correctly. While the chances of death are low, the infection can cause significant illness, particularly if a person gets reinfected.

Using the right medication to kill the parasitic worms (anthelmintic medication), together with iron supplements and a good diet, will usually lead to total recovery. However, some cognitive impairments might still persist.

Possible Complications When Diagnosed with Ancylostoma

Common Issues:

• Anemia due to iron deficiency
• Mental impairment
• Difficulty absorbing nutrients
• Slowed down growth
• Sudden and severe digestive tract bleeding
• Weakness of the heart leading to a build-up of fluid

Preventing Ancylostoma

Health authorities often distribute drugs like albendazole and mebendazole in large amounts in areas where certain diseases are common. This is a control strategy to prevent diseases by using these drugs as preventive treatments. However, apart from taking preventive medication, enhancing cleanliness and good hygiene practices can significantly help prevent infections and repeated infections from certain microorganisms, like Ancylostoma.

Other simple but effective prevention steps include avoiding walking without shoes on beaches or in areas where there’s a high chance of infection. Other measures include cleaning up and preventing animal waste in public places, and improving the way human waste is disposed of in a sanitary manner. These measures can greatly contribute to disease prevention.