Saturday, 9 January 2016

Mosquitoes Are Spreading a Rare Virus Around the World

BRIAN FOY CAME home from a trip to Senegal to study malaria-carrying mosquitoes with a mysterious illness, and it definitely wasn’t malaria. Both Foy and his graduate student soon recovered from the rash and aching joints—“the flu is worse,” says Foy—but it wasn’t until a chance encounter with another mosquito-disease researcher that they connected the dots. That third researcher’s grandfather had helped identify a little-known African virus in the 1940s called Zika, and that’s what Foy and his student had caught.

As the time, Zika was so rare the Centers of Disease Control and Prevention didn’t even think to test their blood for it. “Hardly anyone had heard of Zika,” says Scott Weaver, who studies arthropod-borne viruses at the University of Texas Medical Branch. But that’s not true anymore. In the past year, Zika has spread from Africa and Asia through the Americas. In Brazil, the number of infants born with shrunken, malformed brains has gone up by a factor of 10 since Zika entered the country, and scientists there are trying to establish a causal link to the virus. This month, Zika turned up in Puerto Rico, which prompted the CDC to issue a travel advisory.

Unfortunately, this kind of story is getting familiar. Zika’s global advance mirrors those of dengue fever and Chikungunya, two other mosquito-borne diseases that went from the Old World to the Americas. It’s also unlikely to be the last virus to spread and take hold in dense, tropical cities full of new humans to infect, especially with modern air travel. In fact, says Foy, “I think you would be foolish if you didn’t think that would happen.” Aedes aegypti, the mosquito species that spreads all three of these diseases, is itself an invasive species from Africa. With climate change, the mosquito’s range is also creeping outward from the equator. Infectious disease researchers used to call things like dengue and Chikungunya “tropical;” it’s an increasingly inapt moniker.

Epidemiologists first started paying attention to Zika in 2007, after an outbreak on the island of Yap in Micronesia. One study found that the virus had infected 73 percent of the island’s population. The virus has since hopped along the Pacific islands. It made its way to South America in May 2015.

Since Zika is so rare, scientists are still figuring out the basics. “There are no really good diagnostics for the virus at the moment,” says Alain Kohl, a mosquito-borne disease researcher at the University of Glasgow. The Zika virus is so closely related to the viruses that cause yellow fever and dengue fever that the classic test for Zika—checking a person’s blood for antibodies that bind to the Zika virus—spikes a false positive when it sees antibodies for those other two diseases, too. This is called cross reactivity, and it makes the test close to useless in Brazil, where most people get dengue, get vaccinated against yellow fever, or both, says Weaver. (It is possible to look directly for viral RNA in patient blood, but this method only works in the first few days of infection.)

Weaver is now working with Brazilian researchers to pin down the link between Zika and brain damage in babies. That means figuring out diagnosis criteria more conclusive than the disease’s vaguely flu-like symptoms. Obstetricians in Brazil will now collect umbilical cord blood from newborns, which they can then test for evidence of Zika infection. Since newborn babies have never been ill with dengue nor had the yellow fever vaccine, the antibody test won’t have the cross reactivity problem.

Another wrinkle to figure out: Zika might spread through sex as well as mosquitoes. That would make it extremely odd among viruses. When Foy returned home with Zika, his wife got sick, too—and she didn’t have any mosquito bites. (In fact, as part of the scientific detective story, they were only able to confirm the Zika diagnosis using her blood, as both Foy and his graduate student had been vaccinated for yellow fever—cross reactivity again.)

Weaver’s team is now gearing up for research into vaccines and treatments for Zika, but the best thing anyone can do now is prevent mosquito bites: long pants, long sleeves, mosquito repellant. And if you’re slogging through a rough winter right now, at least you know the bugs hate the cold.

Sunday, 1 June 2014

Beyond mosquito net hand-outs: the fight against malaria in Nigeria

According to a recent WHO report, Nigeria has one of the highest malaria death rates in the world. To save lives, NGOs must go further than just distributing mosquito nets

Chris Thomas in Washington DC
Guardian Professional, Friday 17 January 2014 16.14 GMT
Jump to comments (3)

In Nigeria the lack of use of mosquito nets is blamed for the spread of malaria, one of the leading causes of child deaths. Photograph: STEPHEN MORRISON/EPA

In Sokoto, Nigeria on a chilly December morning, the state government launched an effort to distribute 2.5 million insecticide treated mosquito nets (ITNs) to households across the north-west corner of the country. This distribution represents the last of nearly 58 million free long-lasting insecticide-treated nets handed out across the nation between 2009 and 2013.

International donors including the Global Fund to Fight Aids, Tuberculosis, and Malaria, World Bank, the UK's Department for International Development and the US's President's Malaria Initiativehave played a significant role in scaling up malaria prevention in Nigeria.

But as Bill Brieger of Johns Hopkins University wrote in his blog Malaria Matters: "Having nets 'in place' and having nets 'used' are two different indicators of success. A major weakness of past public health programming has been providing people with technologically sound and useful interventions without taking into full account the social, cultural and behavioral factors that influence acceptance and use of the interventions."

The proportion of households owning one or more ITNs in Nigeria increased from 8% in the 2008 Demographic and Health Survey (DHS) to 42% in the 2010 Malaria Indicator Survey (MIS) and the proportion of children under five years reported to have slept under an ITN the night before the survey increased from 6% in the 2008 DHS to 29% in the 2010 MIS.

Progress, yes, but certainly not enough. According to the MIS, the most common reason why no one slept under the net was that it was too hot. A smaller percentage of households said the net was too difficult to hang, the net was not needed or there were no mosquitoes. While a review of 59 articles published in Malaria Journal cited inconvenience, comfort, problems with hanging nets, lack of space and low awareness of need as reasons for not using nets.

Demand, however, appears to be on the upswing. We heard that in Sokoto during a recent polio vaccination campaign some mothers refused the vaccination when the stock of mosquito nets ran out. They had been promised free nets with the vaccination. In the end they received vouchers that could be exchanged for nets.

So how do we engage more effectively with communities to increase net usage? Last June at a behaviour change evidence summit organised by the United States Agency for International Development (USaid) and Unicef, partners reviewed evidence in order to better understand how to improve child survival. The evidence reveals progress and opportunity in some areas, and significant gaps in others. It suggests interventions designed to increase the use of health services and community-based messages encourage behaviour change.

Evidence also demonstrates the great potential of new information and communication technologies in strengthening the capacity and skills of health workers, and encouraging treatment. Community participationand knowledge remain main drivers to increase demand and use of ITNs. The culture of malaria prevention must become part of the fabric of life in every community.

"Provision of nets alone will not bring about high coverage in Nigeria. We need to create the demand for insecticide treated nets and for malaria control services, and that has to be done by raising awareness of malaria and community knowledge about the most effective means of preventing and treating it," said Dr Folake Olayinka, director of Support to National Malaria Programme, a partnership between Nigeria's National Malaria Control Programme and other malaria control agencies, led by Malaria Consortium.

Another step is to more effectively mobilise communities and organisations inspired by faith to advance the welfare of children and mothers. In Nigeria, traditional leaders are often on the front lines of changing behaviour. The World Faiths Development Dialogue notes that the Nigerian Interfaith Action Association (Nifaa) is engaging more than 15,000 imams and pastors in communities to speak to their followers about malaria prevention and treatment. The success of NIFAA's work has won support from Nigeria's National Malaria Control Programme and the World Bank.

Another medium of communication on this subject is radio, which is very popular in Nigeria. In three focus group interviews in Sokoto last month, three-quarters reported hearing stories on malaria prevention and treatment on the radio. In a review of Voice of America's broadcasts, malaria prevention messages were clear but often very technical and not very personal and relatable. Analysis of twelve 30-minute episodes of the programme Karamin Sani Kukumi Ne (Little Knowledge is a Danger) over a 12-month period, showed 11 discussions of polio, but only five on malaria. We must become far better at crafting persuasive narratives that trigger an emotional response among listeners, increase frequency and diversify the messenger.

In a paper for the American Journal of Tropical Medicine and Hygiene, Carlos C Campbell and Richard W Steketee wrote that the path to the elimination of malaria must include community involvement and ownership, local and national willingness (including growing domestic funding) to persevere until the task is complete, and unwavering global support.

Back in Sokoto, as families receive nets, we are making progress, but we are still a long way from ensuring that parents take full advantage of simple steps and tools to protect their children.

Harold Tillman, 68, is producing clothes filled with a powerful insect repellent Clothes able to be washed dozens of times before repellent loses the effect Venture comes two years after he lost control of Jaeger and Aquascutum

Put on your mozzyproofs: Jaeger founder gets the fashion bug again - making clothes to help fight malaria

By STEPHEN ADAMS

PUBLISHED: 01:44, 1 June 2014 | UPDATED: 01:44, 1 June 2014

View
comments

He spent almost half a century building up a fashion empire, but lost it over a bank holiday weekend.

Now Jaeger founder Harold Tillman is back in the clothing business but in a very different style – making outfits to combat malaria.

The determined 68-year-old will be producing suits, shirts, trousers and other clothes impregnated with a powerful insect repellent.

Harold Tillman, pictured here with former face of Jaeger Laura Bailey, is taking on the mosquito - by launching a range of clothes which have an inbuilt insect repellent

The revolutionary technology used will allow the clothes to be washed dozens of times before they lose their repellent effect.

The new venture comes two years after he lost control of Jaeger and Aquascutum in a bitter power-struggle with bankers.

He was away in Italy over that Easter when he learned that Lloyds Bank had sold Jaeger’s debt to venture capitalists Better Capital, which put the firm into administration. He says bankers ‘stole’ his company – a charge they deny.

More...

Detractors may see Tillman’s new adventure as a little crazy, but the entrepreneur insisted: ‘I don’t think I’ve gone off my rocker at all. I’m doing things that I want to do, that give benefit back to the world.’

According to the World Health Organisation, half the world’s population is at risk of malaria. In 2012 it claimed an estimated 627,000 lives.

Tillman’s new clothing – and new mosquito nets he is helping produce – will be embedded with SIL2U, tiny porous silica particles with microscopic holes that can be filled with different biological agents.

Mosquitos can bite through thin fabric but the repellant works to stop them coming near

For the anti-malarial garments, the substance will be the repellent IR3535, just as effective as DEET – the most common active ingredient in insect repellents – but far less toxic, oily or smelly.

Mosquitos can bite through thin fabric, so the repellent works by stopping them coming near.

Tillman is also bringing out a spray that temporarily ‘mozzy-proofs’ normal clothes and that can be sprayed on skin, and wet wipes containing repellent and sunscreen.

He is also working with top chemists to create antibacterial hospital bedding – and even paint – by putting peroxide into the particles.

Tillman said the projects were ‘very exciting’, adding: ‘I never realised the market for these sort of products was so big. We are talking billions.’

Jane Kaye-Bailey, founder of UK malaria prevention charity The Butterfly Tree, which works in Zambia, said: ‘I would welcome anything that has the potential to save lives.’

She urged Mr Tillman to make his new products affordable for those in poorer parts of the world, or to give them directly to charities.

Thursday, 29 May 2014

Fast food Blood meals

The Asian Tiger Mosquito

MARK COLVIN: Australian scientists are ramping up their fight against an exotic mosquito that's rapidly spreading around the world and bringing major health problems with it.

The Asian Tiger Mosquito is named for its striped body and aggressive bloodlust. Scientists have begun breeding the mosquito in a Brisbane laboratory to prepare for a possible invasion, which they say is inevitable.

Brad Ryan reports.

BRAD RYAN: It takes a special kind of bravery to put an arm inside a cage that's buzzing with bloodthirsty mosquitoes.

LEON HUGO: There's a stinging sensation.

BRAD RYAN: It's lunchtime for these hungry research subjects, and Leon Hugo's right arm is the meal.

LEON HUGO: It is a painful bite. It is a part of the job that we need to do. Mosquitoes need blood to reproduce, so in order for us to have these mosquito colonies to work with, we need to provide blood.

BRAD RYAN: In recent decades the aedes albopictus, or Asian Tiger Mosquito, has spread from south-east Asia into Africa, Europe and the Americas. But the laboratory-bred colony in Brisbane is the only one in mainland Australia - for now.

GREG DEVINE: Aedes albopictus is the most invasive mosquito in the world. It exists on every single continent apart from Antarctica and Australia at the moment, and of course it's already in the Torres Strait Islands, but it's not on mainland Australia yet.

BRAD RYAN: Associate professor Greg Devine heads the Mosquito Control Laboratory at Brisbane's QIMR Berghofer research centre. He says the Asian Tiger Mosquito is such a persistent biter, it could threaten Australia's outdoor way of life.

It's changed lifestyles in places like Rome, where it's exploded in population since arriving in the nineties.

GREG DEVINE: You think of a traditional Italian lifestyle - there's a lot of public places that people like to go and walk in the evenings, and for a lot of people in Rome that's become very difficult. Public spaces like the central cemetery in Rome, like the botanical gardens, they have such high biting pressures from aedes albopictus that people really don't have the same use of those spaces as they used to.

BRAD RYAN: Of greater concern is the health threat. The mosquito carries diseases such as dengue and Ross River virus and has recently been blamed for infecting tens of thousands of people in Papua New Guinea with a virus called chikungunya, which causes debilitating joint pain and can last for months or years.

GREG DEVINE: It's possible that when aedes albopictus comes in and then we have a very big distribution of a mosquito, which will run all the way from the Torres Strait right down to Hobart, then under certain conditions maybe that's going to be the mosquito that's going to vector or transmit chikungunya particularly well.

BRAD RYAN: Professor Andreas Suhrbier says having access to the mosquitoes will help his research into chikungunya and what Australia should do to prepare for an outbreak.

ANDREAS SUHRBIER : All bets are off, basically. If that mosquito becomes established in Australia, that opens the door for a chikungunya epidemic coming to Australia.

BRAD RYAN: Researchers are also keen to find out how the mosquitoes will interact with native Australian species.

Associate professor Greg Devine:

GREG DEVINE: We want to know whether albopictus is eventually going to displace all those native mosquitoes and then become super-abundant.

BRAD RYAN: Quarantine authorities are still fighting to keep the mosquito out off the mainland and they've successfully dealt with incursions at ports in Cairns, Townsville, and Darwin in recent years. But associate professor Greg Devine says invasion is inevitable.

GREG DEVINE: It is absolutely just a matter of time and of course no-one can predict exactly what that timescale is but we know once it gets into places, it spreads pretty quickly. If you look at the spread throughout the north-east of the United States or throughout Italy and France and the Mediterranean countries then things start happening pretty quickly once it's become established.

MARK COLVIN: Associate professor Greg Devine ending Brad Ryan's report.

Monday, 26 May 2014

Q&A on artemisinin resistance

Artemisinin

In 1971, scientists demonstrated the plant extracts had antimalarial activity in primate models, and in 1972, the active ingredient, artemisinin (formerly referred to as arteannuin), was isolated and its chemical structure described. Artemisinin may be extracted using a low boiling point solvent, such as diethylether, and is found in the glandular trichomes of the leaves, stems, and inflorescences, and it is concentrated in the upper portions of plant within new growth.^[4

The proposed mechanism of action of artemisinin involves cleavage of endoperoxide bridges by iron, producing free radicals (hypervalent iron-oxo species, epoxides, aldehydes, and dicarbonyl compounds) which damage biological macromolecules causing oxidative stress in the cells of the parasite.^[17] Malaria is caused by apicomplexans, primarily Plasmodium falciparum, which largely reside in red blood cells and itself contains iron-richheme-groups (in the form of hemozoin).^[18]

===Cancer drug research===

Artemisinin compounds are being investigated for their potential as anticancer drugs.

^]April 2014

1. What is artemisinin?

Isolated from the plant Artemisia annua, or sweet wormwood, artemisinin and its derivatives are powerful medicines known for their ability to swiftly reduce the number of Plasmodium parasites in the blood of patients with malaria. Artemisinin-based combination therapies (ACTs) are recommended by WHO as the first-line treatment for uncomplicated P. falciparum malaria. Expanding access to ACTs in malaria-endemic countries has been integral to the remarkable recent success in reducing the global malaria burden. In 2012, 331 million ACT treatment courses were delivered by manufacturers to endemic countries – up from 11 million in 2005.

ACTs combine artemisinin derivatives with a partner drug. There are five different ACTs currently recommended by WHO. The role of the artemisinin compound is to reduce the main parasite load during the first three days of treatment, while the role of the partner drug is to eliminate the remaining parasites. In patients who are infected with artemisinin-resistant strains of malaria, the artemisinin compound does not clear all parasites by the third day of treatment. However, patients are still cured as part of a longer treatment regimen, provided that they are treated with an ACT containing a partner drug that is effective in that geographical area.

2. What is the state of artemisinin resistance around the world?

Parasite resistance to artemisinin has so far been detected in five South-East Asian countries: in Cambodia, the Lao People’s Democratic Republic, Myanmar, Thailand and Viet Nam (all in the Greater Mekong subregion). Artemisinin resistance is also suspected is some parts of South America but confirmatory studies are still ongoing. Resistance is occurring as a consequence of several factors, including poor treatment practices, inadequate patient adherence to prescribed antimalarial regimens, and the widespread availability of oral artemisinin-based monotherapies and substandard forms of the drug.

Given the ever-increasing levels of population movement in Asia and the Pacific, the geographic scope of the problem could widen quickly, posing a health security risk for many countries in the region with ongoing malaria transmission. If resistance were to spread to – or emerge in – India or sub-Saharan Africa, the public health consequences could be dire, as no alternative antimalarial medicine is available at present with the same level of efficacy and tolerability as ACTs. There is therefore a limited window of opportunity to avert a regional public health disaster, which could have severe global consequences.

In late 2013, research identified a molecular marker associated with delayed parasite clearance in patients given treatment containing artemisinin. The molecular marker could allow for a more precise mapping and monitoring of the geographical distribution and spread of resistance. It could also enable a retrospective mapping of possible resistance in a large number of settings. WHO is currently working with researchers, national malaria programmes and other partners – within and outside of the Greater Mekong subregion – to map the presence of artemisinin resistance. More details are expected to be available by the end of 2014. Therapeutic efficacy studies will continue to remain a central tool for monitoring the efficacy of nationally recommended antimalarial treatments in all countries.

3. What does WHO recommend to fight the development of artemisinin resistance?

In May 2007, the World Health Assembly called on malaria-endemic countries to progressively cease the provision of artemisinin-based monotherapies (resolution WHA60.18), and in January 2011, WHO released the Global plan for artemisinin resistance containment (GPARC), calling on all stakeholders to maximize efforts to protect the efficacy of ACTs. The GPARC contains a comprehensive set of technical recommendations on how to contain existing resistance and on how to prevent it from emerging elsewhere. Among others, the GPARC urges endemic countries to increase monitoring and surveillance of possible resistance, including through therapeutic efficacy studies, to expand access to diagnostics, and to rationalize the use of ACTs. It also calls on stakeholders to invest in artemisinin resistance-related research, and to mobilize resources.

4. What is being done to contain artemisinin resistance?

Containment efforts are underway in all areas with suspected or confirmed artemisinin resistance in the affected countries. In higher transmission areas, efforts focus on limiting the risk of spread by lowering the malaria burden through intensified malaria control, by increasing access to diagnosis and appropriate treatment, and by scaling up provision of health-care services to migrant and mobile populations. Containment programmes in lower transmission areas seek to achieve an accelerated elimination of P. falciparum parasites.

Overall, these efforts have been effective but need to be further strengthened and expanded. Scaling up basic prevention and control interventions and implementing all of WHO’s recommendations require considerable financial resources, long-term political commitment, and strong cross-border cooperation. Governments of endemic countries also need to take targeted regulatory measures to remove oral artemisinin-based monotherapies from markets, along with antimalarials that do not meet international quality standards. On 25 April 2013, WHO launched an Emergency response to artemisinin resistance in the Greater Mekong subregion to guide an emergency scale-up of containment efforts in affected countries.

Malaria interventions are being scaled up against the backdrop of increasing political momentum in the region. A high-level malaria summit hosted by the Government of Australia on 31 October – 2 November 2012 in Sydney adopted a Consensus on malaria control and elimination in the Asia-Pacific, which also called for the establishment of an Asia-Pacific Leaders Malaria Alliance (APLMA). This was followed by the adoption of the Declaration of the 7th East Asia Summit on Regional Responses to Malaria Control and Addressing Resistance to Antimalarial Medicineson 20 November 2012 in Cambodia. The APLMA was launched at the East Asia Summit in Brunei Darussalam in October 2013.

5. How serious are the consequences of artemisinin resistance?

In the Greater Mekong subregion, patients with resistant parasites still recover after treatment, provided that they are treated with an ACT containing an effective partner drug. However, there is a real risk of parasites developing resistance to all available medicines. For example, in western Cambodia, ACT options have become so limited in the past few years that until recently a non-ACT drug, atovaquone-proguanil, was recommended as first-line treatment. The national malaria programme has now switched back to ACTs but the programme will apply directly observed treatment for all patients, and monitor resistance through molecular markers.

Similarly to the spread of resistance to chloroquine and other antimalarial medicines in the past, there is a possibility that artemisinin resistance will spread or develop independently around the world. However, this is very difficult to predict or compare to previous patterns of resistance, as malaria control interventions have been significantly scaled up during the past decade, leading to substantial changes in the malaria transmission environment.

6. How does this affect the efficacy of ACTs?

National malaria control programmes need to consider the possibility of emerging resistance to both the artemisinin compound and the partner drug. If resistance to the partner drug exists, it is more likely that resistance to artemisinin will also develop, and vice versa. If the treatment failure rate is higher than 10% after treatment with an ACT, WHO recommends that the country changes its treatment policy by switching to an ACT with a different partner drug.

7. What more needs to be done to fight this threat?

Fighting the threat of artemisinin resistance requires an urgent and coordinated international response, as well as robust and predictable financing. The scale-up of containment efforts has major cost implications for the public health budgets of countries in the Greater Mekong subregion, and affected countries cannot fight this challenge alone. Increased international assistance would deliver significant savings in the long run, improving the sustainability and public health impact of malaria interventions around the world. WHO is working with affected countries and partners to ensure a rapid and comprehensive scale up of malaria interventions and containment efforts in the Greater Mekong subregion.

The WHO coordination efforts, based out of a regional hub in Phnom Penh, Cambodia, are being supported by the Bill & Melinda Gates Foundation and the Government of Australia. In addition, the Global Fund to Fight AIDS, Tuberculosis and Malaria has committed US$ 100 million to tackle this threat between 2014 and 2017. While these are significant steps forward, the funding gap remains substantial. In early 2013, WHO estimated that about US$ 300–350 million in additional funding was required for the 2013–2015 period to fully scale up malaria control and containment activities in the affected countries.

Endemic countries outside this region – and in particular on the African continent, where malaria took an estimated 560 000 lives in 2012 – also need to identify additional resources to fully implement the GPARC’s recommendations. One of the most urgent challenges is to strengthen pharmaceutical market regulation, and remove oral artemisinin-based monotherapies from markets around the world once and for all.

This factsheet was originally issued in April 2013 and was updated in April 2014.

Note

To learn more about which countries still allow the marketing of oral artemisinin-based monotherapies, and which companies still produce and market these products, please visit:

Withdrawal of oral artemisinin-based monotherapies