malaria Archives - TalkAfrique

December 23, 2012January 6, 2013

WHO Says Progress in Malaria Threatened by Funding

Insecticide-treated mosquito net for preventing malaria

Recent gains in the fight against malaria could be reversed because funding has stalled, the World Health Organization (WHO) has said.

Its latest World Malaria Report says 1.1 million lives were saved in the past decade but that the expansion in funding from 2004-09 halted in 2010-12.

Less than half of the $5.1bn (£3.1bn) needed was spent last year.

The WHO’s latest figures – for 2010 – show some 219 million people were infected, with 660,000 people dying. Continue reading “WHO Says Progress in Malaria Threatened by Funding”

April 7, 2012

Fight Against Malaria Compromised by Resistance Spread

Scientists have found new evidence that resistance to the front-line treatments for malaria is increasing.

They have confirmed that resistant strains of the malaria parasite on the border between Thailand and Burma, 500 miles (800km) away from previous sites.

Researchers say that the rise of resistance means the effort to eliminate malaria is “seriously compromised”.

The details have been published in The Lancet medical journal.

For many years now the most effective drugs against malaria have been derived from the Chinese plant, Artemisia annua. It is also known as sweet wormwood.

In 2009 researchers found that the most deadly species of malaria parasites, spread by mosquitoes, were becoming more resistant to these drugs in parts of western Cambodia.

This new data confirms that these Plasmodium falciparum parasites that are infecting patients more than 500 miles away on the border between Thailand and Burma are growing steadily more resistant.

The researchers from the Shoklo Malaria Research Unit measured the time it took the artemisinin drugs to clear parasites from the bloodstreams of more than 3,000 patients. Over the nine years between 2001 and 2010, they found that drugs became less effective and the number of patients showing resistance rose to 20%.

Prof Francois Nosten, who is part of the research team that has carried out the latest work, says the development is very serious.

“It would certainly compromise the idea of eliminating malaria that’s for sure and will probably translate into a resurgence of malaria in many places,” he said.

‘Untreatable malaria’

Another scientist involved with the study is Dr Standwell Nkhoma from the Texas Biomedical Research Institute.

“Spread of drug-resistant malaria parasites within South East Asia and overspill into sub-Saharan Africa, where most malaria deaths occur, would be a public health disaster resulting in millions of deaths.”

The scientists cannot tell if the resistance has moved because mosquitoes carrying the resistant parasites have moved to the Burmese border or if it has arisen spontaneously among the population there. Either way the researchers involved say it raises the spectre of untreatable malaria.

“Either the resistance has moved and it will continue to move and will eventually reach Africa. Or if it has emerged, now that artemisinin is the standard therapy worldwide then it means it could emerge anywhere,” Prof Nosten told the BBC.

“If we were to lose artemisinin then we don’t have any new drugs in the pipeline to replace them. We could be going back 15 years to where cases were very difficult to treat because of the lack of an efficacious drug.”

Artemisinin is rarely used on its own, usually being combined with older drugs to help fight the rise of resistance. These artemisinin based combination therapies are now recommended by the World Health Organization as the first-line treatment and have contributed substantially to the recent decline in malaria cases in many regions.

Prof Nosten says the current spread of resistance could be similar to what happened in the 1970s with chloroquine, a drug that was once a front-line treatment against the disease.

“When chloroquine resistance reached Africa in the middle of the 1970s it translated into a large increase in the number of cases and the number of children who died increased dramatically.”

In a separate paper published in the journal Science researchers have identified a region of the malaria parasite genome that is linked to resistance to artemisinin.

Dr Tim Anderson, from Texas Biomed who led this study, says that while mapping the geographical spread of resistance can be challenging it may be hugely beneficial.

“If we can identify the genetic determinants of artemisinin resistance we should be able to confirm potential cases of resistance more rapidly. This could be critically important for limiting the further spread of resistance.”

According to the World Malaria Report 2011 malaria was responsible for killing an estimated 655,000 people in 2010 – more than one every minute. A majority of these were young children and pregnant women.

The BBC Science Reporter

November 10, 2011

Hope for Malaria Vaccine After Blood Entry Route Discovered

By James Gallagher Health reporter, BBC News

The route all strains of the most deadly malaria parasite use to enter red blood cells has been identified by researchers at the Sanger Institute in Cambridge.

The scientists involved said the finding offered “great hope” for the development of a vaccine, which had the potential to be hugely effective.

Other experts said they were surprised and impressed.

Malaria affects 300 million people each year.

One million die, mostly children in sub-Saharan Africa.

There are many malaria parasites. Plasmodium falciparum is the most deadly and researchers at the Sanger Institute acknowledge it as a “very complex and cunning foe”.

It is exceptionally good at evading and bamboozling the immune system. Within five minutes of being bitten by a malaria-carrying mosquito, the parasite is already hiding inside the liver.

It then emerges from the liver at a different stage in its life cycle and infects red blood cells, where it starts reproducing.

Difficulty

The human immune system struggles to build up resistance to malaria and researchers have struggled in the laboratory.

There is still no approved vaccine against malaria. Large scale trials of the most advanced prototype – RTS,S – showed it halved the risk of getting malaria.

This study, published in Nature, looked at the moment the parasite infected a red blood cell.

They were looking for proteins on the surface of Plasmodium and red blood cells which were necessary for the parasite to identify its target and invade.

Others had been found before, but none were universally used.

The team at the Sanger Institute discovered that “basigin”, a receptor on the surface on red blood cells, and “PfRh5”, a protein on the parasite, were crucial.

In all strains of Plasmodium falciparum tested so far, interrupting the link protected the blood cells from attack.

One of the researchers, Dr Julian Rayner, said: “We were able to completely block invasion using multiple different methods, using antibodies targeting this interaction we could stop all invasion of red blood cells.

“It seems to be essential for invasion.”

The plan is to develop a vaccine which will prime the immune system to attack PfRh5 on the parasite

Fellow researcher Dr Gavin Wright said a vaccine would have great potential as the target was so essential.

“As a starting point for developing a vaccine you couldn’t hope for better,” he said.

Prof Adrian Hill, director of the Jenner Institute at Oxford University, said that after 25 years studying malaria he was “surprised” and “intrigued” by the findings.

He said textbooks and academic research suggested that if you blocked one pathway into the red blood cells, the parasite would choose another.

He added: “It remains to be seen how easy it will be to translate into a vaccine, but [for blood stage vaccines] PfRh5 is now at the top of the list.

“Vaccine candidates will come. If I had to bet, I’d say you’d get some partial efficacy from it.”

October 19, 2011

Malaria Vaccine: Now A Possibility

GlaxoSmithKline research head Moncef Slaoui explains how change of focus to cellular immunity was key to breakthrough

Moncef Slaoui was on holiday with his family when he heard the results of the first small trial, involving African infants, of the malaria vaccine he helped invent. It was a day he would never forget.

“It was 9 August 2004,” he said. “I’m on vacation with my kids, driving between Chicago and Indianapolis and my phone rings and it’s the team calling from Mozambique. I had to stop for at least an hour. I couldn’t drive any more. That was a big, big moment.”

The vaccine had been classed as around 55-60% effective. It was the first sign that Slaoui, now chair of R&D at GlaxoSmithKline, and his colleagues, were going to be successful in cutting the terrible toll of malaria in Africa. Halving the 200m cases a year would save lives and prevent a huge amount of harm.

It had been a long haul. Slaoui had joined the Belgian lab of what was to become GlaxoSmithKline 23 years ago with a background in immunology. “I brought a fresh perspective in what was then modern immunology,” he said. Some of his new colleagues had started work on a malaria vaccine but “it was more or less stalled conceptually”.

No one then had managed to make a vaccine against a parasite infection. Many in the scientific community thought it impossible. “We heard that a lot. There were many controversial discussions on whether we would be able to achieve success,” said Slaoui.

But his ideas drove the effort in a new and successful direction.

Scientists had been attempting to kill off the parasites injected by malarial mosquitoes as soon as they entered the bloodstream. But any vaccine attempting that has only minutes to work because the parasites quickly go to the liver, where the next stage of their life cycle occurs. After five days there is a burst of new parasites in to the blood cells and that is when the child falls ill.

Slaoui suggested using cellular immunity. “Rather than using antibodies that can kill bacteria or a parasite, we used T-cells that recognise [a] cell is not normal because it is infected by a parasite. It opened the opportunity to find the parasite where it [hid] in the liver and kill it there.”

It was easy to say, but hard to do. They needed to find the right adjuvant, a substance that would stimulate the immune system’s T-cells to mount a response against the malaria parasites.

It was in 1996, eight years after Slaoui joined the vaccine effort, that they became sure they were on the right track – during experiments in conjunction with the Walter Reed army medical centre in Washington DC.

Slaoui said: “It was the first demonstration of the proof of concept that we were able to make a vaccine that killed the parasite in the blood and also in the liver.”

The approach used would later be employed in GSK’s pandemic flu and cervical cancer vaccines, which would make money. Slaoui said GSK would not have dropped the malaria vaccine programme, which was solely for the benefit of people too poor to pay, but that the proftable spin-offs undoubtedly helped.

He said: “GSK Biologicals’ leadership was always totally committed to continue the work on the malaria vaccine for two equally good reasons. The malaria vaccine was a great vehicle to advance our platform of adjuvants for many other vaccines, [ones] that were more able to give us a return. But secondly there was truly a commitment to public health in general and our responsibility to society to make vaccines for those who would most benefit, even when they could not afford it.”

This was a stronger motivation in the vaccine community than in the pharmaceutical industry. He added: “Vaccines are associated with public health and the developing world and babies that you save from major infections, and therefore the idealistic motivation is very strong.”

It remained the case, he said. “Yesterday in Seattle [when the results were published] I was with some of the first core-team members – we all started together. It was very emotional.

October 18, 2011

Malaria Deaths Fall over 20% Worldwide in Last Decade

There has been a fall of just over 20% in the number of deaths from malaria worldwide in the past decade, the World Health Organization says.

A new report said that one-third of the 108 countries where malaria was endemic were on course to eradicate the disease within 10 years.

Experts said if targets continued to be met, a further three million lives could be saved by 2015.

Malaria is one of the deadliest global diseases, particularly in Africa.

In 2009, 781,000 people died from malaria. The mosquito-borne disease is most prevalent in sub-Saharan Africa, where 85% of deaths occurred, most of them children under five.

An earlier report here incorrectly referred to a 40% drop in deaths.

It has been eradicated from three countries since 2007 – Morocco, Turkmenistan and Armenia.

The Roll Back Malaria Partnership aims to eliminate malaria in another eight to 10 countries by the end of 2015, including the entire WHO European Region.

Robert Newman, director of the WHO’s Global Malaria Programme, said “remarkable progress” had been made.

“Better diagnostic testing and surveillance has provided a clearer picture of where we are on the ground – and has shown that there are countries eliminating malaria in all endemic regions of the world,” he told an international Malaria Forum conference in Seattle.

“We know that we can save lives with today’s tools.”

Global eradication

A global malaria eradication campaign, launched by WHO in 1955, succeeded in eliminating the disease in 16 countries and territories.

But after less than two decades, the WHO decided to concentrate instead on the less ambitious goal of malaria control.

However, another eight nations were declared malaria-free up until 1987, when certification was abandoned for 20 years.

In recent years, interest in malaria eradication as a long-term goal has re-emerged.

The WHO estimates that malaria causes significant economic losses, and can decrease gross domestic product (GDP) by as much as 1.3% in countries with high levels of transmission.

In the worst-affected countries, the disease accounts for: Up to 40% of public health expenditures; 30% to 50% of inpatient hospital admissions; and up to 60% of outpatient health clinic visits.

September 23, 2011October 7, 2011

Malaria Vaccine Trial Raises Hope

By Matt McGrat, Science reporter

Researchers are to expand a clinical trial of a new malaria vaccine after promising results in a preliminary study in Burkina Faso.

The trial was designed to test safety, but researchers found that vaccinated children had high levels of protection.

Described as a “most encouraging” result, a larger study involving 800 children is now to take place in Mali.

The scientists involved say they are hopeful that the vaccine will ultimately be very cheap to produce.

Around a hundred different malaria vaccine candidates have been developed to date but the MSP3 vaccine tested in Burkina Faso is only the second one to show a substantial level of protection against the illness.

The randomised, double blind study involved 45 children. It set out to test the safety of the vaccine but this follow up study found that children who received it had an incidence of the disease three to four times lower than children who did not.

Initially the children were split into three groups, with two of them receiving the experimental malaria vaccine developed by Dr Pierre Druilhe at the Pasteur Institute in Paris.

“Those two groups had very similar types of immune response, elicited by the vaccine, and the protection is almost identical, so it reinforces the confidence despite the fact that we are still dealing with a small group,” he said.

The vaccine is based on the fact that some adults in Africa acquire immunity because they are constantly exposed to the disease.

Early days

Dr Druilhe and his team discovered a key protein, MSP3, which provokes the body into producing antibodies that kill the parasite.

He said the protein is unique as it does not change much between different strains of the plasmodium parasite that causes malaria. This is believed to be a critical factor in developing an efficient vaccine.

He added: “We performed a large number of epidemiological studies that confirm that there was an association between that vaccine candidate and acquired protection, so when you immunise with this molecule you indeed induce protection.”

Another scientist involved with the Burkina Faso study was Dr Louis Miller, the former head of the Malaria Vaccine Branch of the US National Institutes of Health.

He said: “I was always in favour of this approach as it offered a chance in a field with few successes. I found the results of this preliminary study in Burkina Faso to be most encouraging.”

High transmission

Encouraged by the early results, Dr Druilhe said the trial has now been expanded to 800 children in Mali. But he remains cautious.

“There have been too many claims of effective vaccines so we have to remain very cautious. It has to be confirmed and we have started on work to do that confirmation. Essentially the trial in Mali is about 20 times larger, in extremely high transmission conditions, so it should yield very clear cut results – this will be black and white.”

The other vaccine candidate that has shown success against malaria is called RTS, S. It has been funded by the Bill and Melinda Gates Foundation and is set to go into production with pharmaceutical giant, GlaxoSmithKline.

But there are concerns that it could be expensive, especially for people in Africa and other regions affected by the disease.

Dr Druilhe says his vaccine could be a lot cheaper – perhaps half a dollar or less a bottle.

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The results of the Burkina Faso trial were published in The New England Journal of Medicine.

September 20, 2011October 7, 2011

African Leaders Launch Malaria-Beating Scorecard

A coalition of African leaders on Monday launched a “scorecard for accountability and action” to track their progress in the fight against malaria, following on successes in battling the disease that claims hundreds of thousands of lives in Africa each year.

The 40-member African Leaders Malaria Alliance (Alma), which was launched two years ago, aims to bring malaria deaths to near zero across the continent by 2015 in line with United Nations Millennium Development Goals to improve health, reduce poverty and boost development in Africa.

“The evidence is becoming obvious. Malaria infection in Africa is receding,” Tanzania’s President Jakaya Kikwete told a press conference on Monday in New York for the launch of the scorecard.

He said in recent years 11 malaria-endemic countries in Africa have been able to slash malaria cases by 50 percent.

“The Alma scorecard is a good idea, and in our view it is a powerful monitoring tool because it involves the heads of state at the highest level of leadership and brings a collective focus of governments and partners in the fight against malaria,” said Dr. Luis Gomes Sambo, regional director for Africa of the World Health Organisation (WHO).

Targeted Measures

Kikwete partially attributed the successes to specific measures: distribution of bed nets, residual spraying of insecticide, rapid diagnostic tests and administration of combination drug therapy.

Since 2008, he said, 229 million long-lasting insect-treated bed nets have been distributed in Africa, which he said was sufficient to achieve 84 percent coverage of those at risk of contracting the disease. Homes covered by indoor, residual spraying of insecticide had increased from 20 million to 75 million over the past five years.

The Alma scorecard will be updated quarterly with data on key health metrics across several malaria-endemic countries to help African leaders hold themselves and each other accountable for progress in anti-malaria goals. It aims to spur decisive action among leaders and provide greater transparency in the efforts to fight malaria.

The scorecard will also track indicators for maternal, newborn and child health.

Still a Killer

Kikwete noted that malaria was Africa’s leading killer, affecting 170 million people on the continent each year. A child dies from malaria every 45 seconds, according to the WHO.

Malaria also hurts development, with two percent of Africa’s GDP lost each year because of the illness. Production of goods and services is disrupted and poor families end up spending 25 percent of their incomes for treatment, he said.

Despite successes in combating malaria, Kikwete noted that challenges remain. He said gains must be sustained, access to interventions scaled up and new sources of revenue identified. Also member countries and donor partners need to improve their compliance with commitments to fight malaria.

“We have guided our countries in making great strides in the fight against malaria and we remain committed to do whatever it takes to overcome the remaining challenges and win this war,” Kikwete said.

“Losing is not an option.”

Local Interventions

Among the most successful countries in the malaria battle is Rwanda.

Malaria deaths dropped by 60 percent between 2005 and 2010 through a rapid scale-up of malaria interventions, according to Rwanda’s health ministry.

Rwandan Health Minister Agnes Binagwaho attributed this to an integrated approach with community health workers.

“But more than that we have focused our activities where the people were dying and where people were sick at the community level,” she told Monday’s press conference. “We have a national policy for community health. Our objective is to keep 80 percent of any burden at the community level where people are living.”

She urged other African leaders to come up with homegrown solutions for country ownership in their malaria fight. “You cannot replicate,” she said.

She urged a greater regional approach to fighting malaria, because mosquitoes cross borders, and the creation of public-private partnerships so that bed nets could be produced within Rwanda and on the continent as a whole.

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