14 DAY TRIAL // Scientists have recently developed a new method of destroying a class of parasitic worms, which is so hard to kill, that it has spread to a point where it inhabits all the people in several African villages. The tiny invaders are so well adapted to everything one gets to throw at them, that they seem to survive all antibiotic therapies, for example, without suffering any side-effects. Now, experts have determined that adopting an indirect method of destroying the worms may be the most suitable approach.
Therefore, they have devised a course of treatment that is not aimed at destroying the worms themselves, but rather the bacterium cultures these organisms have inside them. The method draws its inspiration from the basic knowledge of our bodies, which holds that we die if all the bacteria inside our gut are removed. We live in symbiosis with them, and neither of us can survive separately. The same holds true for the Mansonella perstans worm, which lives inside people in remote African villages, Wired reports.
A type of bacteria, called wolbachia, has become absolutely necessary to the parasite's survival over the course of its evolution. As such, they have become the primary target for a new therapy, which aims at destroying them. Without the bacteria, the worms soon die too, experts say. This roundabout way proves to be extremely effective at dealing with M perstans, National Institutes of Health (NIH) expert Amy Klion says. She has been the leader of the new study.
“Doxycycline is the first drug that has been shown to be effective in clearing Mansonella perstans parasites from the blood of infected people. The fact that the parasites were not detectable in the blood 3 years after the 6 week treatment suggests that doxycycline also had an effect on the adult worms, which live in the tissues surrounding the lungs, heart and abdomen,” the expert adds.
“The basis of the endosymbiosis between wolbachia endosymbionts and their wormy hosts is currently not understood. Some conclusions can be drawn from the fact that worms lack essential genes for certain metabolic pathways that are present in wolbachia, and vice versa,” Bonn University Clinic doctor Achim Hoerauf adds. The expert made the comment in a letter that appeared in the new study. Both papers were published in the latest issue of the respected New England Journal of Medicine (NEJM).
“Doxycycline is not very easy to administer as a mass drug treatment since it absolutely cannot be given to pregnant women or children under the age of 12 because of effects on developing teeth and bones. Second, courses shorter than 4 weeks have not been very effective in other filarial infections, and this is very impractical for mass administration,” Klion adds.