Latest news with #LeeHaines
Yahoo
27-03-2025
- Health
- Yahoo
Mosquitoes beware – your next meal could be your last
A drug used to treat rare genetic disorders also makes human blood lethal to mosquitoes, research has shown, raising hopes for a new weapon against malaria. Nitisinone is already used to slow the effects of tyrosinemia type 1, a hereditary condition that can cause severe liver disease and kidney failure, and other diseases. But it also makes any mosquitoes that ingest it unable to digest the blood they feed on, killing them rapidly, research led by the Liverpool School of Tropical Medicine (LSTM) found. The study, published in Science Translational Medicine this week, showed that the drug blocks an essential enzyme mosquitoes need to break down their food. Tests showed a small amount of the drug was even able to kill mosquitoes that have developed the ability to resist conventional insecticides – an increasingly widespread problem that has slowed efforts to combat malaria and other mosquito-borne diseases. 'What makes nitisinone so exciting is its novel mode of action against blood-feeding insects like mosquitoes,' said Dr Lee Haines, an Honorary Fellow at LSTM and one of the authors of the study. 'Unlike conventional insecticides that target the mosquito's nervous system, nitisinone targets an entirely different biological pathway in mosquitoes, which offers a new option for managing the growing problem of insecticide resistance.' The study followed earlier research which first validated the theory that nitisinone could be used to kill insects that feed on blood. It proved highly effective at killing tsetse flies that spread sleeping sickness. While the drug does not prevent a feeding mosquito from infecting someone with a virus, it could provide a new tool to combat the spread of disease by thinning out their populations, the researchers believe. Several insecticides are already widely used in this way, such as ivermectin, a medicine usually used to treat parasitic infections in animals and people and which shortens the lifespan of any insect that ingests it. But ivermectin, while abundant, is toxic in the environment and insects can also develop resistance to it when it is overused. 'Billions of doses have been given to people for the worming campaigns,' said Professor Álvaro Acosta Serrano, another of the study's co-authors. 'Ivermectin is obviously a very popular veterinary drug, so in farms it is polluting the soil and that has some ecological issues.' As well as being much less harmful to other insects or animals in the ecosystem, nitisinone has the added advantage of lasting much longer in the body, he told The Telegraph. 'Nitisinone, because it has a much longer half life in blood – 54 hours compared to Ivermectin which is only 18 hours max – it has much better performance.' As well as helping to suppress mosquito populations by killing those that unwittingly feed on humans carrying nitisinone, the drug could be used against mosquitoes in numerous other applications. It could be used in the sugar-based bait traps currently being tested around the world which lure in mosquitoes and poison them, or it could be sprayed on to bed netting and buildings to get into mosquitoes that way. The researchers are already planning to investigate whether the drug could be given to cows and other livestock animals to turn them into unwitting reservoirs of death for the insects that feed on them. 'This is a very versatile molecule,' Prof Acosta Serrano said. Because it was originally developed to be a herbicide, it has many properties that make it ideal for use in these kinds of applications, including good resistance to UV light, he added. Before all this though the researchers say more work is needed, including safety studies looking at different dosages. They are also yet to study how the drug interacts with antimalarials. Another major challenge is cost. While ivermectin has been produced cheaply by generic drug manufacturers for decades and has been donated in vast quantities to tackle diseases like river blindness, nitisinone – despite being off-patent – remains expensive. 'We need to convince a company to drop the prices because, for vector control use, interventions have to be really cost effective,' said Prof Acosta Serrano. And while nitisinone promises to provide another tool with which to combat mosquito-borne disease, we are still waiting for scientific breakthroughs before we will be able to beat malaria. 'It's important to know that there is not a silver bullet to control any of the vector borne diseases, especially malaria,' he said. 'We still need to come out with better drugs. There is a huge problem with parasites that become drug resistant. We still don't have a completely efficacious vaccine available.' Protect yourself and your family by learning more about Global Health Security Broaden your horizons with award-winning British journalism. Try The Telegraph free for 1 month with unlimited access to our award-winning website, exclusive app, money-saving offers and more.
Telegraph
27-03-2025
- Health
- Telegraph
Mosquitoes beware – your next meal could be your last
A drug used to treat rare genetic disorders also makes human blood lethal to mosquitoes, research has shown, raising hopes for a new weapon against malaria. Nitisinone is already used to slow the effects of tyrosinemia type 1, a hereditary condition that can cause severe liver disease and kidney failure, and other diseases. But it also makes any mosquitoes that ingest it unable to digest the blood they feed on, killing them rapidly, research led by the Liverpool School of Tropical Medicine (LSTM) found. The study, published in Science Translational Medicine this week, showed that the drug blocks an essential enzyme mosquitoes need to break down their food. Tests showed a small amount of the drug was even able to kill mosquitoes that have developed the ability to resist conventional insecticides – an increasingly widespread problem that has slowed efforts to combat malaria and other mosquito-borne diseases. 'What makes nitisinone so exciting is its novel mode of action against blood-feeding insects like mosquitoes,' said Dr Lee Haines, an Honorary Fellow at LSTM and one of the authors of the study. 'Unlike conventional insecticides that target the mosquito's nervous system, nitisinone targets an entirely different biological pathway in mosquitoes, which offers a new option for managing the growing problem of insecticide resistance.' 'A very versatile molecule' The study followed earlier research which first validated the theory that nitisinone could be used to kill insects that feed on blood. It proved highly effective at killing tsetse flies that spread sleeping sickness. While the drug does not prevent a feeding mosquito from infecting someone with a virus, it could provide a new tool to combat the spread of disease by thinning out their populations, the researchers believe. Several insecticides are already widely used in this way, such as ivermectin, a medicine usually used to treat parasitic infections in animals and people and which shortens the lifespan of any insect that ingests it. But ivermectin, while abundant, is toxic in the environment and insects can also develop resistance to it when it is overused. 'Billions of doses have been given to people for the worming campaigns,' said Professor Álvaro Acosta Serrano, another of the study's co-authors. 'Ivermectin is obviously a very popular veterinary drug, so in farms it is polluting the soil and that has some ecological issues.' As well as being much less harmful to other insects or animals in the ecosystem, nitisinone has the added advantage of lasting much longer in the body, he told The Telegraph. 'Nitisinone, because it has a much longer half life in blood – 54 hours compared to Ivermectin which is only 18 hours max – it has much better performance.' As well as helping to suppress mosquito populations by killing those that unwittingly feed on humans carrying nitisinone, the drug could be used against mosquitoes in numerous other applications. It could be used in the sugar-based bait traps currently being tested around the world which lure in mosquitoes and poison them, or it could be sprayed on to bed netting and buildings to get into mosquitoes that way. The researchers are already planning to investigate whether the drug could be given to cows and other livestock animals to turn them into unwitting reservoirs of death for the insects that feed on them. 'This is a very versatile molecule,' Prof Acosta Serrano said. 'Not a silver bullet' Because it was originally developed to be a herbicide, it has many properties that make it ideal for use in these kinds of applications, including good resistance to UV light, he added. Before all this though the researchers say more work is needed, including safety studies looking at different dosages. They are also yet to study how the drug interacts with antimalarials. Another major challenge is cost. While ivermectin has been produced cheaply by generic drug manufacturers for decades and has been donated in vast quantities to tackle diseases like river blindness, nitisinone – despite being off-patent – remains expensive. 'We need to convince a company to drop the prices because, for vector control use, interventions have to be really cost effective,' said Prof Acosta Serrano. And while nitisinone promises to provide another tool with which to combat mosquito-borne disease, we are still waiting for scientific breakthroughs before we will be able to beat malaria. 'It's important to know that there is not a silver bullet to control any of the vector borne diseases, especially malaria,' he said. 'We still need to come out with better drugs. There is a huge problem with parasites that become drug resistant. We still don't have a completely efficacious vaccine available.'
The Independent
26-03-2025
- Health
- The Independent
Malaria breakthrough as scientists find drug makes human blood deadly to mosquitoes
A drug for a rare disease makes human blood deadly to mosquitoes and could help in the fight against malaria, researchers have found. Several methods are currently used to reduce mosquito numbers and, as a result, malaria risk. One is the use of an anti-parasitic medication called ivermectin. When mosquitoes ingest blood containing this medication, it shortens the insect's lifespan. But researchers say this medication is environmentally toxic and when it is overused to treat people and animals with parasite infections, resistance to the drug becomes a concern. Now a study published in the journal Science Translation Medicine has identified another medication, nitisinone, which has the potential to suppress mosquito population and control malaria. 'One way to stop the spread of diseases transmitted by insects is to make the blood of animals and humans toxic to these blood-feeding insects,' said Lee Haines, associate research professor of biological sciences at the University of Notre Dame, honorary fellow at the Liverpool School of Tropical Medicine and co-lead author of the study. 'Our findings suggest that using nitisinone could be a promising new complementary tool for controlling insect-borne diseases like malaria.' This medication is typically used for patients with a rare inherited disease — such as alkaptonuria and tyrosinemia type 1 — whose bodies struggle to break down the protein building block or amino acid tyrosine. The drug works by blocking a type of enzyme called 4-hydroxyphenylpyruvate dioxygenase (HPPD). Blocking this prevents the build-up of harmful disease byproducts in the human body. However, when a mosquito drinks blood containing the drug, it also blocks this HPPD enzyme in their bodies which prevents the insect from digesting the blood, causing them to die quickly. Four people diagnosed with alkaptonuria donated their blood for the study, which was fed to female anopheles gambiae mosquitoes - the primary mosquito species responsible for spreading malaria in many African countries. The researchers explored what concentrations of the drug are needed to kill mosquitoes and compared its effectiveness to the anti-parasitic medication ivermectin. Nitisinone was shown to last longer than ivermectin in the human bloodstream and was able to kill not only mosquitoes of all ages — including the older ones that are most likely to transmit malaria — but also the hardy mosquitoes resistant to traditional insecticides. Mosquitoes which were fed the drug first lost the ability to fly and then rapidly progressed to full paralysis and death, the study authors explain. 'In the future, it could be advantageous to alternate both nitisinone and ivermectin for mosquito control,' Dr Haines said. 'For example, nitisinone could be employed in areas where ivermectin resistance persists or where ivermectin is already heavily used for livestock and humans.' However, more research is needed to determine what dosage of the drug works the best.
