Terminating a helminth infection

This page addresses the termination of the four species of helminth used in helminthic therapy. The eradication of other organisms requires different species-specific drugs and dosing regimens. [1]

Alternatives to termination

If hosting therapeutic helminths causes intolerable side effects, it may be possible to reduce and manage those adverse effects without sacrificing all the helminths, either by treating the side effects or, in the case of NA of TT, by reducing the size of the colony.

Since TS and HD only survive in a host for 2-3 weeks at most, and side effects from these species are typically short-lived anyway, there is usually no need to consider termination of these non-human helminths.

Treating the side effects

Many of the side effects that can follow helminth inoculation manifest in a similar way whichever species is being hosted and can mostly be treated using the same strategies, many of which are detailed on the following page.

• Treating the side effects

Reducing the colony size

If treatment of the side effects doesn't provide sufficient relief, it may still not be necessary to terminate the entire colony. Carrying out a partial cull can reduce the severity of side effects while leaving some worms to continue the therapy.

A partial cull can be achieved by using any of the substances categorised in the Human helminth care manual as being potentially harmful to human helminths (marked with an ❌), although the effects of these substances are not as predictable as those of an anthelmintic drug.

For example, a single 500mg dose of mebendazole may kill approximately 30% of a colony of NA and, if this doesn't provide sufficient relief from the side effects, further doses of the drug can be taken as required.

Availability of anthelmintic drugs

The availability of anthelmintic drugs varies between countries. For example, albendazole is available with a prescription in Europe [2] but not available on prescription in the US or UK. Also, where this drug is prescribed "off-label", the cost can be astronomical, e.g., as much as US$ 700 per tablet. [3][4]

However, mebendazole, albendazole and pyrantel pamoate are all used to treat both hookworm infection and Enterobius vermicularis (EV) infection (pinworm' in the US, and 'threadworm' in the UK and Australia), and at least one of these drugs is generally available over the counter (OTC) in Western countries to treat EV, which is very common in children. For example, mebendazole is available OTC in the UK, and pyrantel in the US. If a pharmacist is asked for medication to treat a family whose members have all contracted EV, the medication they supply will be more than enough to eradicate a hookworm infection in a single individual. See the current dosage guidelines on the US Centers for Disease Control website, here:

• Clinical Care of Soil-transmitted Helminths

Alternatively, albendazole and other anthelmintics can be obtained online from a number of suppliers including the following.

• Mark Cuban Cost Plus Drug Company (US-based) Everything is sold at cost plus 15%.

• United Pharmacies (US-based)

• AllDayChemist (Japan-based) 12 x 400mg albendazole was US$ 13.50 in March 2023, but delivery can be slow.

The service (of AllDayChemist) is good. The main downside is that shipping time--to me in the US--seems extremely long. One month is not unusual. [5]

• Medsmex (Mexico-based) 2 x 200mg albendazole were $16.73 in March 2023.) Shipments may take a month to reach some US addresses. [6]

However, customs departments in some European countries may block shipments from outside the EU. [7]

Another source of anthelmintics is veterinary medications, which are often available without a prescription. [8] Care must obviously be taken with dosing when using veterinary products in humans because of the much larger body weight of many farm animals, but dosing recommendations for products that are tailored for sheep can arguably provide a reasonable guide due to the similarity of body weight between sheep and humans. [9] For example, see the dosage for sheep for this product.

Factors that influence the effectiveness of anthelmintic drugs

The efficacy of anthelmintic treatment depends on the drug used, the dosing regimen and the timing of doses in relation to food as well as potentially the product brand and the form of the tablets used. It may also depend on the host's microbiome profile. [10]

• The timing of treatment in relation to meals can make a significant difference to treatment efficacy.

For example, the effectiveness of albendazole (and possibly other anthelmintics) against hookworms can be enhanced by taking the drug on an empty stomach.

When a systemic pharmacological effect of albendazole is required, e.g. in echinococcosis, maximal systemic availability is desirable and may be achieved by giving albendazole together with a fatty meal. However, in conditions where low systemic availability and a high intraluminal content of the drug is desirable, as in the treatment of intestinal helminthiasis, the drug should be taken on an empty stomach in order to reduce its absorption. [11]

When a single dose of 400 mg of albendazole was given to subjects who had not had any food for 6 hours or more prior to treatment, the cure rate for hookworm was raised from 59% to 90%. [12]

• Different brands of an anthelmintic drug may have different efficacy rates. [13]

• Different forms of tablet containing an anthelmintic drug may have different success rates. For example, chewable tablets may be more effective if they are crushed. [14]

Terminating a human hookworm (NA) infection

Current CDC recommendations

Here is the current advice from the United States Centers for Disease Control and Prevention for treating hookworm infections.

• Clinical Care of Soil-transmitted Helminths.

Note. Ivermectin is not recommended for use against hookworms. In fact, this drug has shown limited effectiveness in the case of hookworms, with low cure rates often reported around 3.8% in clinical observations. [15]

Praziquantel’s effectiveness against human hookworms is modest at best and inconsistent. However, it may still harm hookworms to an extent consistent with the strength of the host’s immune response. So hookworms hosted by individuals with more aggressive immune systems are likely to be more adversely affected than those hosted by more hookworm-permissive hosts.

Patient experiences

1x400 mg (albendazole) tablet per day for 3 days worked for me. A previous attempt using only 1 dose of 400 mg. 'stunned' the HW, but they recovered in 3 or 4 days. [16]

An NA host who is helminth-permissive (her genetic endowment gives any helminths she hosts a much easier time than they would get in most other people) was able to terminate her hookworm colony by taking 400 mg albendazole each day for four days. Even though the drug was 2 years past its expiration date, she stopped passing hookworm eggs and was unable to incubate more larvae until 12 weeks after reinoculating with 5 larvae from another source.

Alternative anthelmintics

Anything marked with an ❌ on the following page will or may kill, or cause the loss of, human helminths, including hookworms.

• Human helminth care manual

An interesting study of plant extracts seems to indicate several of them are more effective than albendazole. [17]

Ethanolic Pomegranate peel extract at 0,25ml/kg is relatively safe for the gut microbiome and coming close to the efficacy of albendazole. I would repeat after a week. [18]

The timing of re-dosing with hookworms

There may be some advantage in allowing a period of time for the host’s immune system to resettle after the termination of a hookworm colony, but no specific reason to do this has been suggested and, since the biological half-life of albendazole and mebendazole is only 8-12 hours and 3-6 hours respectively, it should be safe to reinoculate 48 hours after completing the course of anthelmintic treatment.

Terminating a human whipworm (TT) infection

Current CDC recommendations

Here is the current advice from the United States Centers for Disease Control and Prevention for treating TT infections.

• Clinical Care of Soil-transmitted Helminths.

Note. Praziquantel has proved to have little effect on whipworms.

Further information

Single drug doses are ineffective

Single doses of anthelmintics are not very effective against Trichuris trichiura. For example, in one study, a single 500 mg dose of mebendazole only achieved a cure rate of 25.5%. [19] In another trial, a single dose of ivermectin (at 600 mcg/kg) had a cure rate of only 12.2%. [20]

Three-day courses are more effective

The US Centers for Disease Control and Prevention (CDC) state that whipworm is effectively treated using albendazole, mebendazole or ivermectin, but that each drug needs to be taken for 3 days. [21]

Five-day courses are the most effective

100 mg mebendazole, given twice daily for 5 consecutive days, can effectively terminate a T. trichuria infection. [22]

Terminating a rat tapeworm (HD) infection

Hymenolepis diminuta (HD) is only likely to mature in adult humans who are immunocompromised. Otherwise, the worms will die naturally after approximately 2-3 weeks, so there is rarely any need to deliberately terminate an HD infection in adults.

There is a possibility of HD maturing and persisting in approximately 1% of children, potentially causing gastric pain and/or worsening of behavioural symptoms. In these cases, termination of the infection using an anthelmintic drug will bring about a cessation of symptoms within 1-3 weeks of the drug being administered.

The drugs used to terminate a Hymenolepis infection are described on the following webpage.

• Centers for Disease Control and Prevention: Clinical Care of Hymenolepiasis (Dwarf Tapeworm)

Terminating a pig whipworm (TS) infection

Since the porcine whipworm, trichuris suis, only survives in humans for approximately 2-3 weeks, there is little need to deliberately terminate a TS infection. If it were necessary, Wikipedia suggests that this species can be terminated with medicines such as doramectin, ivermectin and febantel.

Terminating suspected pathogenic helminths

If an individual believes that their health is being adversely affected by a pathogenic helminth, they should determine exactly which organism this is by having a DNA polymerase chain reaction (PCR) stool analysis carried out. This can be ordered internationally online from Diagnostic Solutions in Atlanta Georgia, US.

If this test proves positive, the individual should seek treatment using whatever specific drug has been found to be most likely to successfully eradicate that particular organism. This can be checked on the US Centers for Disease Control (CDC) website. This course of action is preferable to using a "parasite cleanse", which can do more harm than good by causing indiscriminate damage to the biome and upsetting the microbiological equilibrium. See Why a parasite cleanse can make you worse.

An intestinal worm which grows large enough to be seen with the naked eye when mature but which is microscopic when administered in helminthic therapy. Wikipedia:Helminths

The reintroduction to the digestive tract of a controlled number of specially domesticated, mutualistic helminths (intestinal worms) in the form of microscopic eggs or larvae to reconstitute a depleted biome to treat or prevent chronic inflammation, autoimmune disease and other immune-related disorders, including allergy.

An intestinal worm which grows large enough to be seen with the naked eye when mature but which is microscopic when administered in helminthic therapy. Wikipedia:Helminths

the human hookworm, Necator americanus

the human whipworm, Trichuris trichiura

the porcine (pig) whipworm, Trichuris suis

Hymenolepis diminuta, a murine (rat) tapeworm.

The introduction of an infectious agent into an organism. Helminth inoculation

A substance capable of eliminating or destroying intestinal worms.

A helminth that lives in the small intestine. Necator americanus (NA) is the only hookworm species used in helminthic therapy. Its microscopic larvae are applied periodically to the skin.

A human helminth known as 'pinworm' in the US, and 'threadworm' in the UK.

Enterobius vermicularis. Enterobius vermicularis

Refers to Enterobius vermicularis in the US, and to Strongyloides stercoralis in the UK.

Refers to Strongyloides stercoralis in the US, and to Enterobius vermicularis in the UK.

A substance capable of eliminating or destroying intestinal worms.

the degree to which something is successful in producing a desired result; success.

the ability to produce a desired or intended result.

All the microorganisms living in and on the body, or the genome of these microorganisms. "Microbiota" refers to the specific population of microorganisms living in a certain part of the body, such as the gut. These two terms are often used interchangeably.

A helminth that lives in the small intestine. Necator americanus (NA) is the only hookworm species used in helminthic therapy. Its microscopic larvae are applied periodically to the skin.

a change which is a result or consequence of an action or other cause.

hookworm, usually referring to the human hookworm, Necator americanus

The active immature form of an insect, or an animal such as a helminth, which develops from an egg and eventually transforms again into its adult state.

A helminth with a tapering whiplike body that lives in the colon. In helminthic therapy, the microscopic eggs of either the human Trichuris trichiura (TTO) or pig Trichuris suis (TSO) are taken in a drink.

A helminth with a tapering whiplike body that lives in the colon. In helminthic therapy, the microscopic eggs of either the human Trichuris trichiura (TTO) or pig Trichuris suis (TSO) are taken in a drink.

The human whipworm used in helminthic therapy and taken periodically as microscopic eggs (TTO) in a drink.

A helminth with a flat, ribbon-like, segmented body. Only the murine (rat) tapeworm, Hymenolepis diminuta, is used in helminthic therapy and this generally does not reach adulthood in humans so requires regular dosing of HDC.

A murine (rat) tapeworm used in helminthic therapy that generally does not mature in humans and is taken as cysticerci (HDC) in a drink every 2 or 3 weeks.

An organism that lives in or on another organism (its host) and benefits at the host’s expense. (The organisms used in helminthic therapy are, strictly speaking, not parasites, but mutualists, because they have a mutually beneficial symbiotic relationship with their hosts.)