By: Chioma Umeha
Last Tuesday’s news about the discovery of a substance which will eliminate malaria, one of the world’s most deadly diseases, is no doubt cheery to many across the world, especially Nigerians. This is not surprising as Nigeria is one of the world’s endemic malaria countries.
This report is coming on the heels of a recent report published in Science – a scientific journal, which announced the success of a phase 1 trial of the early-stage clinical evaluation of an investigational malaria vaccine known as the PfSPZ Vaccine, conducted by researchers at the National Institute of Allergy and Infectious Diseases, NIAID, part of the National Institutes of Health. In reaction, global researchers had observed that preliminary studies have confirmed that the vaccine is safe to generate an immune system response, and to offer protection against malaria infection in healthy adults. Experts in Nigeria also described this as a welcome development. However, it is believed that the latest discovery which was announced Tuesday could be used to help stamp out deadly diseases such as malaria, which kills approximately one million people yearly.
Also, the Daily Newswatch investigations has shown that if this latest discovery is fast-tracked, Nigeria will save N160 billion between now and next year. The World Health Organisation (WHO) just before the dawn of this year announced that 80 per cent of malaria deaths occur in 14 endemic countries, with Nigeria, Democratic Republic of the Congo and India among the worst hit. In its last year’s annual assessment report on malaria, which was released at the United Nation (UN) Headquarters in New York, WHO further said that to stave off backsliding and resurgences in 2013 and 2014, 2.4 billion U.S. dollars was urgently required, of which one billion dollars was needed in Nigeria alone. The report noted that the initial funding scale-up saved 1.1 million lives, stressing that 58 per cent of them were in countries where the disease was widespread. It explained that the international funding for malaria appeared to have reached a plateau “well below the level required to reach the targets set by world governments and institutions in 2,000 with the adoption of the MDGs, which have a target deadline of 2015’’.
The WHO report stated that an estimated 5.1 billion U.S. dollars was needed yearly between 2011 and 2020 to achieve universal access to malaria interventions in the 99 countries with ongoing malaria transmission. It added that the slowdown in funding threatened roll-back impressive gains made against the preventable mosquito-borne disease over the last decade. However, the agency report yesterday said that U.S. scientists are working on an ‘invisibility cloak’ for mosquito-plagued people, pets and livestock. According to the report, the ‘invisibility cloak’ will replace traditional repellents The researchers noted that some compounds found in human sweat attract mosquitoes while chemical compounds, including 1-methylpiperzine, block mosquitoes’ sense of smell. They explained that the substances which they discovered occur naturally on human skin and block mosquitoes’ ability to smell and target their victims. Scientists believe the research could be another step in the fight to stamp out deadly diseases such as malaria. Speaking at the National Meeting & Exposition of the American Chemical Society, research chemist Ulrich Bernier said that far from being a nuisance, mosquitoes are more deadly to humans than any other animal. In the U.S. alone, mosquitoes spread rare types of encephalitis, an inflammation of the brain as well as transmitting heart worms to pet dogs and cats.
Dr Bernier said: “Repellents have been the mainstay for preventing mosquito bites.” In Nigeria, there are several popular repellent and are hardly effective. Though they have been in use for a long time, many do not like the feel or the smell of the repellant. In US, the most widely used repellant, DEET, is quite effective and has been in use for a long time but some people don’t like the feel or the smell of the repellant, Bernier said. “We are exploring a different approach, with substances that impair the mosquito’s sense of smell. If a mosquito can’t sense that dinner is ready, there will be no buzzing, no landing and no bite,” he explained. Female mosquitoes, which suck blood to obtain a protein needed to produce fertile eggs, can smell people from over 100 feet away. A person’s scent, Dr Bernier explained, comes from hundreds of compounds on the skin, many emitted through sweat and others produced by bacteria. To identify which of these attract mosquitoes, Bernier and colleagues at the Mosquito and Fly Unit at the U.S. Department of Agriculture’s Agricultural Research Service Centre for Medical, Agricultural, and Veterinary Entomology in Florida, used a special mosquito cage divided by a screen. They sprayed various substances into one side of the cage and documented the effects in attracting mosquitoes.
Some compounds, like lactic acid – a common component of human sweat – were definite mosquito lures, drawing 90 per cent of the mosquitoes to the screen. With other compounds, however, many of the mosquitoes did not even take flight or seemed confused. Dr Bernier said: ‘If you put your hand in a cage of mosquitoes where we have released some of these inhibitors, almost all just sit on the back wall and don’t even recognise that the hand is in there. We call that anosmia or hyposmia; the inability to sense smells or a reduced ability to sense smells.’ He said that a group of chemical compounds, including 1-methylpiperzine, block mosquitoes’ sense of smell. This may help explain why mosquitoes fly toward some people but not others.
The substances have a molecular architecture found in ingredients in dozens of medicines and other products and they appear suitable for use in cosmetics, lotions, clothing and other products that currently incorporate mosquito repellants, he said. The Mosquito and Fly Unit has been doing research on mosquito repellents since the 1940s. In the 1990s, it accumulated information on substances secreted through the human skin or formed by bacteria on the skin that make some people more attractive to mosquitoes than others.
This story was published in Newswatch Times on September 12, 2013.