To date I have spent about 10 years as a consultant in developing countries, and some of my assignments were to place that most people wouldn't chose as a vacation destination. I became concerned with the natural treatment of intestinal parasites and started to recommend a cocktail of wormwood (here is a good NPR article on Wormwood) black walnut and cloves to colleagues who were suffering the effects of an infection (I learned long ago to always boil my water, wash vegies with a few drops of bleach in a sink-full of water, and in restaurants to order mineral water with gas that way you know that it isn't tap water). You know about an ounce of prevention and a pound of cure, right? Wormwood isn't particularly tasty, in fact, most people find it quite bitter.
I got to know Schistosoma mansoni while on the faculty at Oklahoma State University. I use to hang out at the vet school because a good friend, a Ph.D. biologist not a DVM, who taught the parasite courses and had a great lab full of large jars with interesting critters in them. In fact I hung out at the vet school enough that I ended up teaching the practice management course for them. I like hanging out with vets, they are kind people, the love animals and are closer to nature than most people. Anyway my bio-sci prof friend had taught me enough about parasites that I knew what to expect when colleagues in developing countries started to feel the effects.
So here is the good news if you don't like the taste of Wormwood but insist on traveling to high risk countries (and parasite infections happen in first-world countries too). Here is a 2019 paper where live Schistosoma mansoni worms were treated with Nigella sativa or fennel flower aka black cumin. The researchers reported that the mortality rate of worms reached 88.9 percent after they were treated with 100 and 80 micrograms per milliliter (mcg/ml) Chitosan Nanoparticles loaded with Nigella sativa (NSLCN), and 84.6 percent after they were treated with 80 and 60 mcg/ml. After 48 hours, the researchers observed variable effects on the motility and death of the worms. Death rate reached 100 percent in all groups treated with NSCLN. The tea reported in the NPR article cited above was fennel flower tea.
Here is a good review article that summarizes the use of fennel flower in the treatment of a variety of parasitic infections. And here is another recent article that reports on the use of fennel flower oil in the treatment of Schistosoma mansoni with similar positive results. The use of herbs is important in the treatment of intestinal parasites because traditional chemical drugs are not fully effective against schistosomaisis due to the evolving drug resistant worm strains. It appears that worms, like bacteria, evolve and develop resistance to modern drugs.
Hope you never need this information, but store it away in your just-in-case file.
Dr. Dave, ND