Helminthic therapy and infectious diseases

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Helminthic therapy and susceptibility to infectious diseases

People enquiring about helminthic therapy are often concerned that the treatment might reduce their ability to fight common infections, but the effect that helminths have on the immune system is complex and not simply a matter of reducing an excessive response. What helminths do is more a case of subtle modulation, i.e., balancing or quieting rather than suppression, of immunity, and they achieve this by deploying an orchestra of molecules with the intension of keeping themselves and their host alive and well for as long as possible. See The effects of helminths on the immune system.

Some investigators worry that helminths could weaken patients' immune systems and leave them more vulnerable to some types of infectious diseases, even under careful medical supervision. But as long as society maintains its current modern hygienic standards, I consider this risk negligible. Given the lack of side effects from helminth therapy, morbidity from immune-mediated diseases, and the toxicities of modern therapies for them, almost certainly exceed the risk from helminthic exposure. [1]

In fact, we can be rather confident in the ability of helminths to modulate the immune system without immunocompromising the host, [2] a view supported by William Parker, whose team at Duke University found enhanced rather than suppressed immune function in animals with increased biodiversity.

Parker says that, far from making the immune system lazy or less effective, helminths actually make it smarter.

People who host helminths can still mount an inflammatory attack on pathogens, but they don't set off self-destructive immune bombs against harmless substances or their own cells.

There is also evidence from elsewhere that intestinal parasites may help the body ward off some infections.

Epidemiological study of the association between malaria and helminth infections in Nigeria -- Full text | PDF (Children with helminths may be less likely to develop malaria.)
Dueling Infections: One Keeps the Other at Bay
Antagonism between two intestinal parasites in humans: the importance of co-infection for infection risk and recovery dynamics
Intestinal worms boost immune system in a surprising way This study found that helminths had stimulated the production of more lymph nodes, which may be what was experienced by the self-treater who posted the following comment online.

After a year or two of starting the therapy, I suddenly noticed that lymph nodes in the neck around my jaw were constantly slightly swollen. This was a new phenomenon for me and HT was the only variable I could point to. I don’t ever remember having reactive lymph nodes to viral or bacterial exposure at any point in my life, but after HT, I now notice it when I have a cold or flu. I got extensive blood work and chest x-ray etc. to rule out any nefarious reasons for the lymphadenopathy, so the only thing I can point to is just a new immune response to my environment. Other than the slight annoyance, it doesn’t seem to cause any problems, and it has seemingly calmed down over time. [3]

The experience of helminth self-treaters

There are reports of both less, and more, infections while hosting worms, but the majority of self-treaters appear to experience a reduced incidence of infection.

I have noticed that since taking on NA (five years now), my winter colds have dramatically shortened. That is, the symptoms (drainage, night coughing) that used to go on for a week now disappear along with the virus -- about two days. [4]

Don't think I've caught a single cold since my infection with hookworm a couple of years ago. [5]

My immunity seems better with HW. I have an immune deficiency that makes me more susceptible to upper respiratory infections. Since starting HW I have successfully fought of infection which is VERY unusual for me. My husband had a cold. Normally that is a disaster for me as a cold in someone else almost always leads to chest infection and bronchitis in me. For the first time in more years than I remember I sniffled for a day and fought it off. (Edited from two posts.) [6] [7]

Anecdotally, I haven't had a single cold or flu since inoculation last March.

It will be 2 years (next month) with helminths. I have around 135 (NA)… I have not had flu or a cold for the last 2 winters even though whole family had severe chest and throat infections. Prior to the worms I would get flu every winter. First holiday last August to Kenya where I did not get ill. [8]

Have been hosting for over 3 years as a reservoir donor. No colds in this time.

I have the flu. I know because my son just tested positive with the nasal swab test. My immune response has been very different from years past, I've always coughed like crazy which ended up as bronchitis, and I've spiked a fever. But this time I have very little coughing and only a low grade fever. 24 hrs later and I'm almost completely over it. I attribute this to having hosted human hookworms for the past nine months. My body is better at handling infection now. [9]

I used to have a cold every 6-8 weeks. My whole life. Since getting NA almost 2 years ago I've only been ill once. [10]

I don't get sinus infections that last for six months any more. I don't get colds that turn into sinus infections. [11]

I just realized that for the first time in my entire life I haven’t (except for 1 day) taken antibiotics in over 2 years. I’ve also successfully been able to fight off multiple illnesses with my buddies. Including sinus infections & UTIs. Coming from someone that was on antibiotics multiple times a year, since early childhood, that’s incredible. [12]

In some cases, the normalisation of immune function by helminths can result in people who previously rarely got infections beginning to get them more frequently.

I got my first cold in years 6 weeks after my first inoculation. (Link expired)

Since I inoculated over 3 years ago, I get sick way way more often. I have Crohn's disease and before my worms I was almost never sick and I was usually the lone person in my house who stayed "healthy" while illnesses ran through everyone else. One of the theories about crohns being due to an overactive immune system seems to be true for me. The worms have dramatically reduced my crohns symptoms but in exchange I catch just about any illness my young kids bring home from school. It's completely worth it, though, as colds, flus, strep, etc on occasion are nothing compared to the pain of crohns! [13]

Prior to HT I didn't get many colds. Now I get colds and flu bugs more often. I think when my immune system was over reactive it killed everything quickly, including attacking my gut. Now that it's less active and colds and flus take hold more often. [14]

Since inoculating less than six months ago I've had my first sinus infection in 43 years, my first lung infection and my first skin infection. None were too serious - but it seems unlikely to be a coincidence. I've always been the person you couldn't give a bacterial infection to if you tried. Having said that, two pesky warts I've had for over a decade have disappeared. I'd say something is shifting! I should point out that I'll take some mild bacterial infections over 4 autoimmune diseases any day. [15]

I never had flu or cold for the last 20 years or what I can remember. Not even once a sneeze or running nose. But after the helminth therapy, I have a flu or cold episode at least twice a year. [16]

(In the 6 months since first inoculating with NA) I’ve had at least 2 nasty bouts of colds/flu - both Covid negative - which I don't normally get. [17]

I caught colds 6x in the first 6 months when I started the therapy with NA. (Very rare the 2 years before). [18]

The duration of colds may be reduced while hosting helminths.

I was accustomed to common cold symptoms enduring for up to two weeks -- drainage causing a nighttime cough that kept me from sleeping. After taking on my (NA) colony, I noticed that my colds only gave me symptoms for ... about 48 hours. No more cough! When my colony died off at three years, I went back to those awful, enduring symptoms. Then when I re-colonized, my next cold's symptoms disappeared in two days. [19]

How infections impact on the benefits of helminthic therapy

When someone who is hosting helminths gets an infection, such as COVID, a cold or the flu, this can cause a brief return of symptoms of whatever disease they are treating.

I had a flu 10 days ago and had a return of crohn’s symptoms. [20]

… any time I get a cold/flu it exacerbates all my allergy-related symptoms by revving up my immune system (especially congestion/headaches, eczema & muscle/joint pain). [21]

I am 7½ months into hw therapy to cope with rhinitis… Last week I caught a minor cold from my kids and have had the worst allergy attack lasting all week. [22]

I have noticed that my old symptoms (systemic reaction to food) that are now much better, flare whenever I get a cold… It does appear to happen each time I get a virus so far…[23]

In one juvenile who is being treated with HDC, a candida flare was suggested as the likely cause of a loss of benefits. [24]

This return of disease symptoms does not occur because the infection has a direct effect on the worms themselves, which may continue to secrete their immune modulating molecules while the infection is active. However, since the effect of these excretory/secretory products is subtle, this may be overwhelmed by the increased activity of the immune system, resulting in the temporary reappearance of symptoms.

If any substance is taken which enhances the immune response, this may also increase the symptoms of autoimmune diseases, making it appear that the substance itself has adversely affected the worms. For example, this can occur with the use of elderberry. [25] [26] (Also see the comments here and here.)

When the immune system settles back to it’s normal level of activity after dealing with an infection and after the use of any immune enhancing substances has ceased, the impact of the worms’ subtle immune modulation will once again become evident, and disease symptoms will gradually subside.

Normal immune balance may be restored within 2-3 weeks after a cold or the flu but, in the case of the latter, it may take a while after the viral infection has been cleared, especially if a secondary bacterial infection develops in its wake.

Helminthic therapy and chronic infections

Some people with chronic infections have noticed an increase in the number and severity of outbreaks after introducing helminths, especially those people who were already suffering frequent outbreaks prior to starting helminthic therapy. Infections such as tuberculosis (TB), Lyme disease, herpes, hepatitis, HIV and CMV, etc., may surge during the early response phase following helminth introduction, because this alters the immune reaction and may reduce the body's ability to suppress active infection. [27] For example, some, but not all, subjects with Herpes may notice more frequent outbreaks after commencing helminthic therapy, and helminth providers may decline to supply someone with a more serous chronic and incurable infection, such as those who are HIV positive.

Anyone with an active chronic, or incurable, infection who does go ahead with helminthic therapy would be advised to consult their physician prior to treatment, and to take steps - for instance increasing prophylactic or suppression therapy - to ameliorate the immunomodulatory effect in the early stages of helminthic therapy.

Helminthic therapy and viral infections

The precise interactions that occur between helminths and viruses are still poorly understood, but it is known that some latent viral infections, such as herpes, can be reactivated temporarily following infection with a parasite such as the one that causes malaria.

One study has revealed how signals from the immune system that help repel a common parasite can inadvertently cause the reactivation of a dormant herpes virus. [28]

However, the temporary reactivation of dormant viral infections does not happen in all cases and there may even be a reduction in viral activity following inoculation, with amelioration of pathology without any increase in susceptibility to, or persistence of, the viral infection. [29] [30] [31]

The rate of progression of HIV disease is no different in populations living in helminth endemic parts of the world compared with the western world, where helminth infections are now almost non-existent. By balancing interactions between inflammatory and regulatory responses, helminths may produce an effect that is at least neutral, and perhaps even protective, for example by reducing the progression of HIV. [32]

Helminthic therapy and herpes

As with other viral infections, herpes may be worsened or reactivated temporarily following the introduction of helminths. [33]

I get cold sores and noticed a small increase shortly after inoculation. [34]

My daughter has herpes. The virus gets activated everytime we inoculate, but only then. We have not seen any increase in activation frequency outside of inoculations (rather the opposite if anything). [35]

Any exacerbation following inoculation should only last up to approximately 6 months, and any doses added while the herpes flare is still active may cause an increase in symptoms, especially within the first 3 or 4 months, i.e., before the first cohort of worms is able to fully exert its suppressive effect on the immune response to itself.

Helminthic therapy should bring about a reduction in outbreaks of herpes once the worms have been hosted for a few months.

I used to get cold sores throughout my adult life frequently and easily ~ the slightest trigger of sunburn, stress, colds, etc. would cause them to appear. Sometimes one would be just healing when another would start. Such a drag! Since HT the incidence of coldsores/HSV outbreaks has drastically dropped to almost none. My HSV1 only appeared once in 3.5 years after a brutal sunburn. (Edited from three posts: [36] [37] [38])

The following year, I have had far less frequent cold sores than I have ever had in my life which i attribute to increased overall health due to the helminths. [39]

Since inoculating, I have not had any cold sores… I'd say my immune system is working well that way! [40]

My cold sores have reduced since taking HWs over a period of 1.5 years. [41]

Occasionally, herpes may improve in the first few weeks following inoculation.

I'm three weeks in and I haven't had a single cold sore which is really rare for me. [42] Week 6 update… I still have not had another cold sore. This is considering I used to get them once to twice a week!! [43]

Supplementary doses may cause a temporary flare of herpes, especially following overly large doses.

I get cold sores and they do get worse (after inoculation) but antivirals pretty much fix it. Plus no outbreak is as bad as when you first get cold sores. [44]

There is also a possibility of a large hookworm dose - even a supplementary one - triggering shingles.

I can't prove this but my shingles began following this bad reaction to 25 hookworms. [45]

Herpes appears to be treatable using high doses of vitamin C, a course of which could be taken prior to, or concurrent with helminthic therapy. [46] [47] (PDF)

Helminthic therapy and Epstein–Barr virus (EBV)

As with other viruses, an existing infection with the Epstein-Barr virus (human herpesvirus 4 (HHV-4)) may theoretically be temporarily worsened or reactivated following an initial inoculation with helminths, or after a large supplementary dose. However, one study found that therapeutic inoculation with NA was not associated with EBV reactivation. [48]

There is no evidence to suggest that helminths might kill the EB virus, but, due to them being effective against inflammation, allergy and autoimmune disease, helminths might help those with EBV by protecting them from the ravages of the inflammation that this infection is known to cause. Helminths might also turn off allergy to EBV and prevent the development of autoimmune diseases which develop more frequently in those infected by this virus. And, since there is evidence that helminths may prevent the development of cancer (see Helminthic therapy and cancer), it is possible they might offer a degree of protection against cancers developing as a sequela of EBV infection.

There is anecdotal evidence that hosting helminths can improve a person's health in spite of them having an EBV infection.

My health turned to crap after EBV in college, turned into lupus-like symptoms and food intolerances, extreme fatigue and depression. 6 month on HW helped immensely and now I am doing very good on HW and L. Reuteri.” (Link expired)

Someone else was able to reap numerous health benefits from hosting hookworms, in spite of having a long-term EBV infection.

The Amazing Dr Wriggly

Helminthic Therapy and COVID-19

See the separate page dedicated to this disease:

Helminthic therapy and COVID-19

Helminthic therapy and bacterial infections

Helminthic therapy and Clostridium difficile (C. diff)

Helminths may have a positive impact on C. difficile infection.

I had several patients who reported about vanishing symptoms from C.diff after starting with TSO. We know that helminths alter the microbiome and it would not surprise me if this alteration also effects the C. diff burden. [49]

The type-2 immune response that is most often associated with helminth infections, allergy and asthma, may be protective during C. difficile infection. [50]

Helminthic therapy and tuberculosis (TB)

Certain helminths may enhance TB infection, whether newly acquired or reactivated [51] and some helminth species may reduce the effect of any anti-TB therapy. [52] However, there is a reduced prevalence of latent TB infection among individuals hosting hookworms.

2018 Human Hookworm Infection Enhances Mycobacterial Growth Inhibition and Associates With Reduced Risk of Tuberculosis Infection — Full text | PDF

And infection with the human whipworm, Trichuris trichiura, may also provide protection against acquiring a TB infection.

2017 Association between parasitic infections and tuberculin skin test results in refugees

In order to combat TB, a certain degree of immune vigilance is required, but a hyper-vigilant immune system will increase the risk of autoimmune disease. The effects of helminthic therapy in TB must be seen in relation to this dynamic.

Below are several further examples of the research into the interactions between helminths and TB. As can be seen, three of these papers addressed the effects of specific helminths that are not used in helminthic therapy. These include Schistosoma mansoni, a blood fluke, the eggs of which penetrate body cavities such as the lungs where, unlike the therapeutic helminths, they actually cause inflammation and promote reinfection and relapse in TB.

2017 Review: Impact of Helminth Infection on Antimycobacterial Immunity - A Focus on the Macrophage -- Full text | PDF

It is now evident that helminth infestations can influence the host response to MTB at multiple levels, from the initial encounter between macrophage and bacilli, to the type of adaptive T cell immunity, and to the development of immunopathology. At the same time, many open questions remain to be answered, both at the clinical–epidemiological level (e.g., regarding the benefit of anthelmintic treatment) and at the fundamental level of immune regulation during coinfection.

2016 Helminth-Tuberculosis Co-Infection: an Immunologic Perspective -- Full text | PDF

It is clear that there is great degree of interaction in the initiation and maintenance of host immune responses to concomitant or co-existing helminth infections and TB. Whether this antigen-specific crosstalk actually alters clinical outcomes remains an important question.

2015 Helminth-induced arginase-1 exacerbates lung inflammation and disease severity in tuberculosis -- Full text | PDF (Schistosoma mansoni)

2014 Coincident helminth infection modulates systemic inflammation and immune activation in active pulmonary tuberculosis -- Full text | PDF (Strongyloides stercoralis)

2005 Low dose chronic Schistosoma mansoni infection increases susceptibility to Mycobacterium bovis BCG infection in mice -- Full text | PDF (Schistosoma mansoni)

2000 Eradication of helminthic infections may be essential for successful vaccination against HIV and tuberculosis PDF