Latest news with #P.falciparum
National Geographic
2 days ago
- Health
- National Geographic
Malaria
Anopheles Mosquito Her abdomen full of blood that will nourish her eggs, a femaleAnopheles mosquito takes to the air. Her next landing may be a dangerous one—for the human who receives her bite. The female Anopheles mosquito is the only insect capable of carrying the human malaria parasite. Photograph by Hugh Sturrock Learn about the mosquito-transmitted disease, which kills over one million per year, most of them children. The disease chiefly affects lowland tropical regions, where conditions favor Anopheles mosquitoes, which carry the malaria parasite plasmodium. It's the blood-seeking females that inject these microscopic invaders, each bite acting like an infected hypodermic needle. Of the four kinds of plasmodia, Plasmodium falciparum is by far the most dangerous, responsible for about half of all malaria cases and 95 percent of deaths. Parasite The parasite has a complicated life cycle, which begins in the mosquito's gut before moving to the salivary glands, where it awaits transfer to the next host. Once in a human's bloodstream, the parasite lodges in the liver, burrowing into cells where it feasts and multiplies. After a week or two the plasmodia burst out—around 40,000 replications for each parasite that entered the body. Next they target red blood cells, this time repeatedly, until there are billions of parasites in circulation. If this cycle isn't checked, the body starts to fail, because with so many oxygen-carrying red cells being destroyed there are too few left to sustain vital organs. Meanwhile, all it takes for the parasite to pass on its grim legacy is for another mosquito to stop off for a meal. Almost two-thirds of humans infected live in sub-Saharan Africa, which also bears around 90 percent of the global malaria death toll. A child there dies from the disease about every 30 seconds. Elsewhere, countries worst affected are in southern Asia and Latin America. Those most vulnerable are young children, who have yet to develop any resistance to the disease, and pregnant women who have reduced immunity. Signs of infection include flu-like symptoms such as fever, shivering, headache, and muscle ache. The P. falciparum parasite can lead to life-threatening conditions such as brain damage (cerebral malaria), severe anemia, and kidney failure. Survivors are often left with permanent neurological damage. For centuries the only widely known malaria remedy was quinine, which came from the bark of the cinchona tree of Peru and Ecuador. Then, in the 1940s, a synthetic drug was created using the compound chloroquine. Around the same time, the insecticide known as DDT was developed. These twin weapons led to a worldwide assault on malaria, eradicating the disease in many areas, including the United States and southern Europe. But malaria has made a major comeback since the 1970s, partly because DDT use was severely restricted after it was found to be harmful to certain wildlife, and because the plasmodium parasite started becoming resistant to anti-malaria drugs. With more people now falling sick from malaria than ever before, the need to tackle it has never been so urgent. The top priority, health experts say, is finding a vaccine—seen as the only surefire way of beating the disease. Peekaboo American mosquito nets (left) afforded explorers better vision and ventilation than English ones (right). That's according to the 1926 National Geographic article in which this photo appeared, which chronicled an exploration of the Amazon Valley. Photograph by Albert W. Stevens, Nat Geo Image Collection
The Hindu
25-05-2025
- Health
- The Hindu
Antimalarial agents sidestep insecticide resistance by fighting parasite
Researchers reported in Nature on May 22 that they had identified compounds that could target the deadly malaria-causing parasite Plasmodium falciparum during its developmental stages in Anopheles mosquitoes, potentially enhancing efforts to control malaria in an affordable way in the resource-poor areas where it is often endemic. Per the World Health Organisation (WHO), there were 263 million malaria cases in 2023, up 4.3% from 2022. About 94% of all cases and 95% of all deaths in that year were reported in African countries. Last year, India's Health Ministry said the country had exited the WHO's High Burden to High Impact group in 2024, meaning it longer needs to mount intensive efforts to fight the disease. Even so, the National Vector Borne Diseases Control has estimated that 'about 95%' of India's population 'resides in malaria endemic areas'. While the fight against malaria was boosted by the rollout of the WHO-recommended malaria vaccines RTS,S and R21, an important, cost-effective method to stave off malaria infections is to use nets sprayed with insecticide. But according to the new paper, the nets' impact often levels off when mosquitoes acquire resistance. To this end, the study has thrown up a suite of specific compounds that can be sprayed on the nets and which the researchers have said will confer both long-lasting and resistance-proof protection against P. falciparum. The root of this effort is the idea that rather than killing mosquitoes, killing the parasites could be more effective. The researchers have done this by embedding potent, mosquito-stage antiplasmodial drugs in the same polymer fibres that currently carry insecticide. Because these compounds act on P. falciparum, they 'avoid potential development of resistance by the vector' and can block transmission even when the insecticide on the net no longer works. The researchers screened 81 compounds with known antimalarial properties, targeting the early developmental stages of P. falciparum within mosquitoes. These compounds were applied to the bodies of female Anopheles gambiae mosquitoes before they ingested an infected blood meal. Then the researchers assessed the mosquitoes' parasite burden a week later by counting the number of oocysts, an important phase of the P. falciparum lifecycle when it proliferates into its infectious form. They shortlisted 22 compounds that mitigated parasite infection, including endochin-like quinolones (ELQs) — antimicrobial agents known for their potent action against many human parasites. ELQ-456 in particular completely blocked parasite infections while ELQ-331 tamped down the infection's spread. When mosquitoes landed momentarily on surfaces treated with these compounds, ELQ-456 emerged as the most promising candidate. They also found that when mosquitoes briefly contacted a combination of ELQ-453 and ELQ-613, P. falciparum infections in their bodies were kept to a significant degree from maturing to their infectious forms. Next, the researchers evaluated ELQ compounds by incorporating them into polyethylene films like those used in insecticide-treated nets. Reportedly, the films effectively inhibited parasite development in both standard and insecticide-resistant mosquito strains even after they were stored for a year in the open. Finally, the team assessed the potential for these agents to induce antimicrobial resistance in the parasite. Team members found ELQ compounds with similar mechanisms of action didn't induce resistance across pathways other than their own (a.k.a. cross-resistance). They also raised mutated parasite strains that could resist the agents and reported even their transmissibility was significantly impaired. The team concluded in its paper that the agents' 'straightforward synthesis is a promising indication of cost-effectiveness, and … with additional process chemistry optimisation, manufacturing-scale synthesis, and bulk net production and procurement, these compounds will be an affordable and effective addition to bed nets even in the current highly competitive market.'
Hindustan Times
25-04-2025
- Health
- Hindustan Times
World Malaria Day 2025: Do you know about cerebral malaria; the deadliest form that affects the brain?
World Malaria Day 2025: Every year, World Malaria Day is observed on April 25 to discuss and discover treatment and precautions that can help in preventing malaria from spreading. This day helps in creating awareness about the health complications of the disease and the lifestyle habits that can help in staying safe. Also read | World Malaria Day 2025: Know how malaria can affect your heart We cannot possibly discuss the harmful effects of malaria without bringing up its deadliest form, that affects the brain cells. Known as cerebral malaria, it occurs when infected red blood cells block small blood vessels in the brain, leading to inflammation, swelling, and damage to brain tissue. In an interview with HT Lifestyle, Dr. Praveen Gupta, principal director and chief of neurology, Fortis Memorial Research Institute, Gurugram explained the causes, symptoms and fatality of the disease. Cerebral malaria is caused by the bite of a female Anopheles mosquito carrying P. falciparum. Once in the bloodstream, the parasite multiplies inside red blood cells. In severe cases, these infected cells adhere to the walls of cerebral blood vessels, disrupting blood flow and triggering inflammation. Symptoms typically develop within 7–10 days of infection. Key signs of cerebral malaria include: Diagnosis of cerebral malaria involves blood tests to detect malaria parasites, often through microscopy or rapid diagnostic tests (RDTs). Brain imaging and lumbar puncture may be used to rule out other neurological conditions like meningitis. Cerebral malaria is a medical emergency. Immediate treatment with intravenous antimalarial drugs such as artesunate or quinine is crucial. Supportive care, such as managing seizures, fluids, and oxygen, can also improve survival. Patients typically require intensive care. Also read | World Malaria Day 2024: 10 warning signs of the vector-borne disease you must know Prevention strategies focus on avoiding mosquito bites and controlling the spread of malaria. This includes: Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.
