New ways to roll back malaria for good - Daily Nation

New ways to roll back malaria for good


Scientists say we need to invest in prevention, diagnosis, treatment and research to eradicate the disease

The biological complexity of malaria, a mosquito-borne infectious disease, presents medical researchers with many potential opportunities to stop the disease in its tracks, malaria experts have said.

According to the scientists, the disease which features a parasite with an elaborate life cycle involving two hosts — mosquitoes and humans — may be eliminated using a multipronged approach.

A clinical trial in Kisumu by Kemri suggests that unlike existing drugs that target the parasite, to reduce the spread of malaria, ivermectin can be used to kill mosquitoes.

Mosquitoes are considered among the world's deadliest animals. They are carriers of viruses that cause Zika, dengue, yellow fever, and chikungunya, diseases that cause millions of deaths per year.

Figures from the 2017 Economic Survey show that malaria caused 16,000 deaths in 2016, making it the second leading cause of death in Kenya after pneumonia.

“We need to sustain the progress made in the fight against the disease, and the only way to do so is to develop new fighting mechanisms,” said Dr Bernhards Ogutu, a chief research officer with the Kenya Medical Research Institute (Kemri).

As the parasite develops resistance to the most effective drugs available, the need for new treatments is becoming urgent, the experts add.

Using genetic and chemical tools, scientists are targeting malaria-causing parasites known as Plasmodium at various stages of development inside insects and humans. They are also looking for new ways of attacking the anopheles mosquitoes that carry the parasites.

Already, new drugs are being tested  to determine their effectiveness and a malaria vaccine is getting ready to be piloted later on this year.

A clinical trial in Kisumu by Kemri suggests that unlike existing drugs that target the parasite, to reduce the spread of malaria, ivermectin can be used to kill mosquitoes.

Traditionally, ivermectin was developed to fight parasites responsible for river blindness and elephantiasis. “We are looking for a new class of drugs that have a different mode of action on malaria. Already, we can tell that one tablet of ivermectin can kill mosquitoes for up to seven days. If we increase the dosage to one-and-a-half tablet or three, the drug’s killing effect can be increased to 28 days,” explained Dr Simon Kariuki, a chief research officer at Kemri’s Centre for Global Health Research in Kisumu.

In a study published in the journal Lancet Infectious Diseases last month, researchers gave 47 participants three tablets (600 milligrams) of ivermectin for three consecutive days and then took blood samples that were then fed to mosquitoes in cages.

The team, working in partnership with the US Centers for Disease Control and Prevention (CDC), and other colleagues from around the world, found that the blood of patients who took three high doses of ivermectin in pill form can be poisonous to mosquitoes for up to 28 days.

According to Dr Kariuki, the drug, tested on 150 adult volunteers, made their blood poisonous to mosquitoes, instantly killing the insects.The team, working in partnership with the US Centers for Disease Control and Prevention (CDC), and other colleagues from around the world, found that the blood of patients who took three high doses of ivermectin.

Drug-resistant parasites

“These results are highly encouraging and if validated in larger-scale trials, ivermectin not only has the potential to play a role in malaria elimination efforts but will also help address the current challenges of targeting mosquitoes that are resistant to the standard insecticides,” noted Kemri Director Dr Yeri Kombe.
In the same county, trials are ongoing on KAF156, a new antimalarial drug developed by Swiss pharmaceutical company Novartis, alongside Medicines for Malaria Venture (MMV).

KAF156 is aimed at dealing with the tough-to-treat drug-resistant malaria. Kenya is among nine countries across Africa and Asia where clinical trials will be conducted.

Initial tests, Dr Ogutu said, suggest that KAF156 has the potential to rapidly clear malaria infection, including resistant strains, as well as block transmission of the mosquito-borne parasite.

“The drug is already showing quite some unique characteristics and has displayed effectiveness in some drug-resistant parasites,” Dr Ogutu said when Daily Nation visited one of the trial sites in Siaya.

KAF156 belongs to a new class of antimalarial compounds called imidazolopiperazines. The drug is designed to be used in combination with an improved formulation of the existing antimalarial drug lumefantrine.

Researchers are also working towards finding new ways of improving the insecticides used in bed nets as well as indoor spraying of homes, as mosquitoes become more resistant to the commonly used insecticides. Pilot implementation of the malaria vaccine known as RTS,S or Mosquirix will also be launched later this year.

However, science alone cannot be used as a silver bullet to fight malaria, said the researchers.

“We need political goodwill to empower people on the basic knowledge of protection, stronger health systems and human resource capacity,” said Dr Kariuki.