Fungus Knocks Out Malaria In Mosquitoes

Scientists have come up with a new approach to controlling malaria. Instead of killing the mosquito that transmits the malaria parasite, the researchers have found a way to let the mosquito live, while killing the parasite inside it.
Scientists hope to use a fungus to keep malaria-carrying mosquitoes like the Anopheles gambiae species from growing resistant to insecticides.
Enlarge Courtesy of James Gathany/CDC

Scientists hope to use a fungus to keep malaria-carrying mosquitoes like the Anopheles gambiae species from growing resistant to insecticides.
Scientists hope to use a fungus to keep malaria-carrying mosquitoes like the Anopheles gambiae species from growing resistant to insecticides.
Courtesy of James Gathany/CDC

Scientists hope to use a fungus to keep malaria-carrying mosquitoes like the Anopheles gambiae species from growing resistant to insecticides.

The technique involves a fungus called Metarhizium anisopliae. It's a fungus that can penetrate directly into a mosquito.

"The insect literally fills up with fungus," says Raymond St. Leger of the University of Maryland. Ultimately, filling up with a fungus is a bad thing for the mosquito. With time, the fungus will kill the mosquito, but at first, it's just an annoyance to the insect.

Curing Mosquitoes Of Malaria

St. Leger realized that he could use the fungus to do things inside the mosquito. "The trick we did was to engineer the fungus so that it produces a protein which is anti-malarial, anti the parasite itself," he says.

You don't get malaria by being bitten by any old mosquito, or even one of the 30 to 40 species within the Anopheles genus that can transmit malaria. You have to be bitten by a mosquito that is actually carrying the malaria parasite.

The fungus acts like a little hypodermic syringe, and when it's in the blood of the insect, the fungus then produces the anti-malarial protein, and within a couple of days it basically cures the mosquito of malaria.

- Raymond St. Leger, University of Maryland

What St. Leger's genetically engineered fungus does is rid the mosquito of the parasite. "So the fungus acts like a little hypodermic syringe, and when it's in the blood of the insect, the fungus then produces the anti-malarial protein, and within a couple of days it basically cures the mosquito of malaria," he says.

If the mosquito isn't carrying the malaria parasite, it can't spread the disease. These findings appear in the latest issue of the journal Science.

St. Leger says it's also possible to genetically engineer the fungus to kill the mosquito quickly. And he and his colleagues have done that.

Staying An Evolutionary Step Ahead

But finding ways to reliably and permanently defend people from mosquitoes is tricky. Insecticides have been used, natural plant toxins have been used, even fungi have been used.

"One by one, these defenses have fallen, as the mosquitoes have managed to outflank every attempt we've made to control them by some evolutionary trick or other," says St. Leger.


"Of course, it does open up the prospect that the malaria could become resistant to whatever you put in the fungus," says Andrew Read, a senior scholar at the Center for Infectious Disease Dynamics at Penn State University.

Clearly, the malaria parasite can develop resistance to drugs used to treat it. But Read says it should be possible to modify the anti-malarial proteins in the fungus to keep one step ahead of the parasite.

Although this new approach has only been tried in the lab, Read says it should be ready for field testing before too long.

"It's already approved for agricultural use for locust control," says Read, although that's for a version of the fungus that hasn't been engineered to produce anti-malarial proteins.

Getting approval to release a genetically modified fungus into the environment will probably take longer. But Read thinks it will be worth the effort. "One of the great things about this paper is it does raise the scientific interest a lot in the fungi as injection systems into the mosquito," he says.

It's an approach that might be useful for other diseases carried by mosquitoes, as well.

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Mosquito-Attacking Fungus Engineered to Block Malaria

Although public health efforts have eradicated some diseases and helped limit the impact of many others, malaria continues to present a massive public health issue. A large fraction of the world’s population lives in areas where the parasite poses a risk, and it kills a million people annually, most of them in the developing world.

The malarial parasite, Plasmodium, has proven tough to tackle for a variety of reasons. Once in a human, it manages to change the proteins that cover its surface often enough that our immune systems have trouble mounting a successful response. Unlike a bacteria or virus, the parasite is a eukaryote, just like humans, which means that it’s harder to find unique biochemical properties that would let us target it with drugs. Plasmodium has also been able to evolve resistance to the few drugs that we’ve been using to treat it. That evolution of resistance extends to its vectors, a few species of mosquitoes, which have also evolved resistance to many of the pesticides we have used to keep them in check.

All of that might seem to be enough to make tackling malaria seem like an intractable problem. But some researchers are reporting some success with a new approach to limiting its spread: engineering a mosquito parasite to attack it before it can reach humans.

The species of mosquitoes that transmit malaria are themselves vulnerable to parasites, including some forms of fungus. This has led to interest in using these fungi as a form of biological insecticide. But the fungus doesn’t always kill quickly enough, and if it did, it might end up facing the same sorts of problems that chemical insecticides do: the mosquitoes would simply evolve resistance to the fungus as well.

The solution the researchers arrived at is to use a form of fungus that doesn’t kill the mosquitoes until late in their lives, after they’ve had a chance to reproduce. This keeps them from evolving resistance, but wouldn’t keep them from spreading Plasmodium. To do that, they turned to a bit of genetic engineering, creating fungi that produce various proteins that attack the parasite.

The authors tried a variety of approaches. These parasites exit the mosquito through its salivary gland, so the authors created a modified protein that coated the glands, blocking Plasmodium’s attempts to latch on to them. They also used a fragment of an antibody that binds directly to Plasmodium’s, as well as a toxin present in scorpion venom that kills it.  They merged two of the approaches, fusing the venom protein to the one that coats the salivary gland.

To a degree, all of them worked. The fungus alone had a weak effect on the invasion of the salivary glands by Plasmodium, dropping it by 15 percent. But the engineered fungi dropped it by anywhere from 75 to 90 percent. Two of the combined approaches dropped it by 97 and 98 percent. Thus, in the presence of these modified parasites, Plasmodium had a hard time getting to where it could infect humans.

Depending on the precise timing of fungal infection, the authors estimate that it could reduce transmission by 75-90 percent if it reaches the mosquitoes within 11 days of their picking up the Plasmodium. And that’s a conservative estimate, given that this estimate was based simply on the presence or absence of the malarial parasite in the salivary glands. The levels in the fungus-infected animals were greatly reduced, which should limit transmission even further.

Although this shouldn’t select for resistant mosquitoes, it still has the potential to drive the evolution of Plasmodium that can resist the scorpion toxin. There are two reasons the authors think this might not be a huge problem. For one, the fungus can obviously express a number of toxins at the same time, which makes it much more difficult for Plasmodium to evolve a way around it. The other thing is that there are many proteins that could potentially be used to target it; this is especially appealing, given that an antibody fragment was one of the proteins used in this experiment, suggesting that it should be possible to create a large panel of interfering molecules.

The other nice thing about this approach is that this fungus (or its relatives) can attack other mosquito species, including the ones that spread Dengue fever. This is a very promising fungus.

The general approach holds promise as well, since we reported on another use of an engineered, disease-fighting pathogen already this month. There have been millions of years of evolution that help pathogens target specific species and tissues, something that we’re rarely able to do with drugs. If it’s possible to take advantage of that specificity, it can be a powerful tool.

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U.S. Ambassador Concerned Malaria in Papua

U.S. Ambassador  to Indonesia Scot Marciel visited the  Academy of  Midwifery  at the Polytechnic  of Health  Jayapura  and meet the students studying there through a program supported by  the U.S.  Agency for  International Development (USAID) and UNICEF. The students were educated in order to improve maternal and child health.

"Ambassador Marciel discuss innovative ways to incorporate antenatal care with the treatment of malaria, in a program that has been funded by USAID since 2006," said a spokesman for the United States Embassy, Roman Woronowycz,

According Marciel, malaria has become a major health challenge in Papua. Pregnant mothers and their babies at risk of malaria sar be, because the disease can cause anemia, placental infection, lower birth weight infants, causing premature birth, miscarriage, and even death.

"Few midwives in Papua, which has expertise treating pregnant women who are suffering from malaria,

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Tripped India Malaria Data

India is still diharu-blue by malaria. According to the records media journal The Lancet malaria killed more than 200,000 people in India every year. This amount is 13 times more than the estimate of World Health Organization, WHO.
However, new research shows that the number of people who had died from malaria in India has been estimated much lower than the real state.
The research team claimed the WHO figures only include deaths due to malaria in clinics and hospitals. In fact, many people died from the disease at home.
Doubt
One of the authors of the report Professor Prabhat Jha said malaria is a common cause of death in the country with the most dense population in the world. "Malaria not only kills children, but also many adults," said Professor Jha, Director of the Center for Global Health Research in Toronto, Canada.
The researchers requested that number be corrected and treatment of malaria victims were given more adequate funding.
However, the WHO rejected the Lancet reported figures, because the number was obtained through a survey from house to house.
Director of WHO's global malaria program in Dr. Robert Newman acknowledged that the evaluation method used by the organization currently does have a weakness, but doubt the results of research that appeared in The Lancet about the number of deaths from malaria in India.
However, he welcomed the new effort to estimate the number of deaths from malaria. "It is important to evaluate the exact cause of death due to any disease requires a different strategic management," he said.
WHO estimates that malaria causes approximately 10,000 to 21,000 deaths in India in 2006.

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Carrier Mosquitoes Malaria Evolve

Two strains of mosquitoes spreading malaria in Africa are genetically evolved to become the new species is different from previous. It is known from international research that led scientists from Imperial College London (ICL) of the strain M and S strains of Anopheles gambiae that exist in Sub-Saharan Africa.

Physically, the strain M and S were identical. However, genetically, they have different kinds of mosquitoes that were supposed to be distinguished. Genetic differences that make the effort to control the mosquito Anopheles gambiae populations ascertained only effective for one strain and not effective for other strains. Therefore, if the will is made of insecticides to eradicate mosquitoes, the insecticide should be effective for both types of strain.

Lead researcher, George Christophides of the Division of Cell and Molecular Biology at the ICL, as quoted by ScienceDaily, mentioned, malaria is a deadly disease. One in five deaths occurring in Africa are caused by malaria. "A good way to eradicate malaria is to control mosquitoes as carriers of disease," he said.

Based on data from the World Health Organization (WHO), 200 million people stricken with malaria worldwide, mostly in Africa. Malaria kills one child every 30 seconds.

Other researchers from the ICL, Mara Lawniczak, said the study shows, the evolution of malarial mosquitoes spreading much faster than previously thought. Therefore, genetic monitoring is hidden in the mosquito to do if they want to succeed in dealing with malaria since
strategies to cope with a different mosquito strains with strategies to deal with the other strains.

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Beware of malaria in the Mentawai Kemenkes

What to look out for is diarrhea, a common disease occurs due to poor environmental sanitation, and malaria because of the area include malaria-prone areas, "said Health Minister Endang Rahayu Sedyaningsih when met after inaugurating echelon I officials within Kemenkes in Jakarta.

Various measures, according to Minister of Health, has done Kemenkes an effort to reduce the risk of outbreak, which started with spraying disinfectant in the refugee camps.

Director General of Disease Control and Environmental Health (P2PL) Kemenkes, Tjandra Yoga Aditama said, spraying disinfectants have been carried out in cooperation Kemenkes with the local Health Department to control the population of flies and mosquitoes.

In addition, Tjandra said that malaria prophylaxis was given to 231 volunteers working in the area. "Anti-malarial drugs are also increasingly available and every team that went to remote areas and mosquito nets supplied OAM. Stock netting is available from the center and there are plans for help from UNICEF," he said.

Kemenkes P2PL Directorate has also sent to the Mentawai drugs in anticipation of malaria. For environmental sanitation, Kemenkes also been talking with the local Public Works Department and will be acted upon immediately.

Meanwhile, to catastrophic eruption of Mount Merapi in Yogyakarta, Minister of Health expressed anticipation among others done to prevent outbreaks of respiratory disease as a result of continuous rain of ash occurred.

"Merapi has been handled well by the medical team in Yogyakarta and Central Java. The watch was respiratory infection, can irritate the throat and lungs as well, eyes and skin," said Minister of Health.

Kemenkes has distributed at least 50 thousand masks to the public so as not to inhale dust eruption of Mount Merapi, despite the Minister of Health recommends that people remain at home until the eruption ends. "If you do not need to be true, do not have to leave the house, even if have to leave the house, use a mask,

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Malaria Still Threatens Refugees Wasior

Thousands of refugees flood disaster in Wasior, Wondama Bay, West Papua, October 4 and, increasingly  vulnerable  to malaria. Cause, weakening the body's resistance of refugees  plus poor environmental hygiene in the vicinity of the location of shelters.

In refugee camps in the area of ​​the Forestry Training Centre in the region Fasharkan, Manokwari.tercatat there were at least 82 refugees had malaria since the first day of their refuge there last October 10. There are as many as 1148 flood victims seeking refuge at this location.

While in the refugee camps in the field Kodim, Manokwari is the total number of refugee as many as 758 people, there are at least 60 refugees who got malaria since 12 October.

Coordinator at the Health Post of Forestry Training Center Dr. Laura Agustina and officers in the field Kodim health posts, Manokwari Hendrik Marisan who met separately on Monday, hoping to do fumigation (fogging) again in the areas surrounding refugee camps.

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Beware of Malaria in Rainy Season

Malaria is an infectious disease that can cause death, if patients are not given treatment immediately.

During this time, he said, the malaria endemic areas around the southern coast of Lebak, because in these areas if the rainy season becomes a breeding ground for anopheles mosquitoes that live in the lagoon-lagoon coast.

Some districts that have become endemic malaria coast, namely Sub Cihara, Binuangen, Bayah, Cilograng, Malingping, and Panggarangan.

"I ask people who live around the coast guard requested that the disease attacks," he said.

To prevent the spread of malaria illness prompted more people to the movement to eradicate the mosquitoes nest (PSN) and environmental hygiene.

"Movement is more effective to turn off PSN chain of malaria compared with fumigation or fogging," he said.

During this time, Public Health Service has conducted larvaciding spraying to kill mosquito larva of Anopheles breeding in the lagoon-lagoon on the coast.

In addition, also spread the fish's head to lead it to kill mosquito larvae in lagoons around the coast.

Malaria is usually attacked in the high rainfall so that coastal communities were asked to be aware of the disease.

PHC Officers Bayah Lebak Anwar admitted, during these malaria cases are often attacked.

But throughout 2010 did not result in casualties because they quickly get treatment.

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