Could a 30-year-old antiparasitic medication serve as a key in killing pesky mosquitoes and stunting the spread of malaria?
Ivermectin – known for killing roundworms that could cause conditions as severe as elephantiasis and river blindness – had been shown in new research in Burkina Faso to potentially kill or weaken the mosquitoes feeding on people and help prevent malaria transmission.
Medical entomologist Brian Foy of Colorado State University showed in laboratory studies the potential of this research and partnered with researcher Roch Dabiré of the Institute of Health Studies in Bobo-Dioulasso, Burkina Faso, to determine ivermectin’s impact on the disease.
A couple of weeks ago, the developers of ivermectin received the Nobel Prize for their drug breakthrough and its impact on reducing the transmission of parasite-based tropical illnesses.
The researchers ventured into eight villages in one of the country’s southwestern town. In July upon the start of the trial, they administered a dose of ivermectin and another medication, albendazole, to the population, giving the standard combination twice every year for controlling elephantiasis and soil-communicated worms.
In the study, ivermectin tablets were added every three weeks in four villages, excluding pregnant women and those with higher side effect risks, while the remaining four other villages were a control group with no drugs after the initial dose.
In the ongoing trial that will conclude this November, it is suggested that the drug is already showing impact. In the additional ivermectin group, 16 percent fewer cases of malaria were seen among kids under the age of 5, the segment with the highest malaria risk. This meant 94 averted cases so far into the season.
The study would need to be fully analyzed and done on a larger scale. The researchers added that insecticide-treated bed nets along with other measures will not be replaced in the arsenal of anti-malaria treatment.
One possible problem, however, is that mosquitoes have become chemical-resistant, something that could affect ivermectin’s effectiveness.
Medical entomologist Willem Takken from the Netherlands said he is finding it hard “to get enthusiastic” about the research, favoring non-chemical methods such as mosquito traps or bacteria that can stop pathogen transmission in mosquitoes.
But enough ivermectin in the blood, proposed Foy, will make some of the biting female mosquitoes die or too weak to transmit the malaria parasite.
“Any mosquito that ingests your blood that has ivermectin should die or at least be poisoned. It's a prophylactic drug for the community,” Foy explained.
According to the World Health Organization (WHO), antimalarial drug resistance had been detected in three of the five parasites known for causing the disease. This can also result in cross-resistance, where the parasite develops resistance to more than one drug that is part of the same class of chemical compounds.
One option, experts said, is to combine such antimalarials with ivermectin or a similar transmission-interrupting drug.
About 3.2 billion or half of the global population carry a malaria risk. In 2013 alone, there were about 198 million cases and about 584 deaths from it.