Eideard

Mosquito landing boxes in Tanzania

Researchers in Tanzania have chemically reproduced the stench of smelly feet in an innovative new approach to combat the spread of malaria in the country.

The scientific team at Tanzania’s Ifakara Health Institute has developed a potent serum — similar to that of human foot odor — to lure and kill mosquitoes, which can carry malaria and other diseases.

Four times more powerful in attracting mosquitoes than natural human odor, the synthetic smell is now being used in a pioneering research program aimed at killing mosquitoes outdoors using a “mosquito landing box…”

Mosquitoes are lured inside the boxes by the synthetic odor, which is dispersed by a solar-powered fan. Once inside, the insects are either trapped or poisoned and left to die.

“Substances we omit when we sweat, such as lactic acid, act as a signal to mosquitoes … The aim here was to produce a mixture that would mimic a human being.” The result, said Fredros Okumu, was a chemical blend that “smelt just like dirty socks…”

“This is a great example of an African innovator, with an African innovation, tackling an African problem,” said Dr Peter Singer, CEO of Grand Challenges Canada.

“Malaria kills about 800,000 people a year, mostly children, in Africa. At the moment existing technologies, such as bed nets and sprays, tend to repel mosquitoes inside the home.

“This technology attracts mosquitoes outside the home to kill them, and could be complimentary to what is there now,” Singer continued…

For Okumu, this is a personal as well as a scientific venture. Born in western Kenya, malaria has been apart of Okumu’s life for as long as he can remember.

“All the places I have lived have been malaria zones. When I was growing up I had malaria at least twice every year,” he said.

Most American and Europeans have little knowledge of this terrible disease. So many people die, so many children especially, it really is one of the grim reapers of African history.

The first clinical trial for a vaccine against the most widespread strain of malaria, Plasmodium vivax, is now under way at the Walter Reed Army Institute for Research, near Washington DC. The BBC’s Jane O’Brien speaks with those heading the trial and individuals who are being bitten by infected mosquitoes to help further the research.

US army medic Joseph Civitello admits that becoming deliberately infected with malaria – one of the world’s deadliest diseases – is “definitely nuts”. But without such volunteers, it would be almost impossible to test a new vaccine aimed at protecting the military overseas and preventing some of the estimated 300 million cases of malaria that occur every year.

First Sgt Civitello is part of the world’s first clinical trial of a vaccine against Plasmodium vivax – the most widespread strain of malaria…

“It was weird because I did this knowing I was going to get sick,” says Sgt Civitello. “Fortunately I’m in a hotel room with doctors and nurses nearby and not out in the woods somewhere.”

Unlike most of the other volunteers in this unique trial, Sgt Civitello wasn’t given the test vaccine.

He’s part of a small control group – a human yardstick – needed by doctors to confirm that all the study participants have been infected. And as predicted, about 10 days after being bitten by mosquitoes in a laboratory, he displayed all the symptoms of malaria…

Twenty-seven other volunteers in the study had been given varying doses of the vaccine for several months prior to infection…

Then, at the beginning of November, they were bitten by mosquitoes imported from Thailand and infected with Plasmodium vivax malaria…

He adds: “What we do here plays a critical, pivotal role in the fight against malaria. Without this model of challenging the human body with malaria, we would be unable to effectively develop and figure out whether a vaccine works or not…”

RTFA for the details, the methodology, the human story of the volunteers for this first trial.

Regardless of assurances, knowledge of the history of precedent testing, you never feel quite confident of the outcome especially when – as in this study – you’re assured you are part of the control group. The last human trial I volunteered for was a double blind; so, none of us knew who was part of the control and who was getting the vaccine for the disease under test.

In the arid Southwest, the backyard pool was the equivalent of the white picket fence: a sign the homeowners had achieved middle-class status. But as the foreclosure crisis emptied neighborhoods, the once-gleaming pools — caked with algae and infested with mosquitoes — became fetid reminders of all that was lost.

One afternoon in Las Vegas, Robert Cole approached a 3,215-square-foot house on Bracken Cliff Court, armed with his chief weapon against the mosquito scourge: a container of silvery fish. A “For Sale” sign advertised the pool and spa out back. You could smell them from the frontyard.

The deck area near the small pool was decorated with red rocks and outfitted with a blue basketball hoop. On the water’s surface, a slick of green algae inched toward a rubber duck.

Cole tossed four fish into the spa and six into the pool, and a few drops of water splashed him. “Ugh,” he grimaced. “I got that nasty stuff on me.”

Cole, 36, is an environmental health specialist with the Southern Nevada Health District. He and six others are charged with stopping the pools from becoming disease incubators. In recent years, as Sin City turned into Foreclosure City, the team has been swamped…

“As the economy went south, the number of green pools went north,” said Chris Conlan, supervising vector ecologist in San Diego County’s Department of Environmental Health, which stages weekly helicopter flyovers to spot rancid pools.

California, Arizona and Florida also rely on Gambusia affinis, or mosquitofish. The inches-long creatures can survive for months in stagnant water, and to them a batch of larvae is a prime-rib buffet.

RTFA. My guess is folks who really didn’t qualify for the mortgages they eventually defaulted on – are also the same who leave the property damaged deliberately or at least conditions like these – a disaster waiting to happen over time.

Am I being too cynical?