“We are at a potential turning point where the first resistance to deworming drugs can be expected. Our model should serve as a timely warning and incentive for the scientific community to make the control of worm infections still possible in the future,” says Luc Coffeng, Assistant Professor in Infectious Disease Control, Department of Public Health at Erasmus MC. With his research group, he has developed a model to predict trends in drug resistance, and expresses concern about the predictions that arise from it.
Parasitic worm infections are common in developing countries, especially those caused by worms transmitted to humans through soil contaminated with human feces (soil-transmitted helminths, STH). Approximately 1 billion people worldwide are infected with STH, suffering from intestinal blood loss, iron deficiency, and malnutrition.
For decades, the infection has been combated through the large-scale distribution of deworming drugs, benzimidazoles, provided for free by pharmaceutical companies. In countries where the parasites are highly prevalent, children in schools receive an annual preventive deworming pill, regardless of whether they are infected or not. This approach has been effective in reducing the number of severe infections, but also has a major drawback: according to Coffeng and colleagues’ model, worms could become resistant to existing therapies within this decade if the approach does not change.
In the model, Coffeng and colleagues have gathered all known knowledge and experience about resistance in worms from both human and veterinary medicine. He explains, “We have built an extensive simulation model of communities of people, with worms in people, and then genes in the worms. With this model, we simulate the expected trends in resistance over a period of 20 years, given the current control strategy against these worm infections.”
According to Coffeng, it is now up to the scientific community to develop alternative strategies against parasitic worm infections and thus prevent resistance to anti-worm medications. This requires better access to clean water, sanitation (such as latrines), and hygiene. If, over time, the number of worm infections is reduced, there may still be a need for new drugs for the treatment of occasional infections.
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