It is now over a century since the ins and outs of the mosquito bite and its associated parasites were first elucidated, but malaria still haunts us. Reported numbers range widely, but a safe estimate is given in the latest (2009) figures from the World Health Organization (WHO).1 Some news is good. In Africa, eleven countries showed a greater than 50 per cent malaria reduction ‘in recent years’. This is mainly due to the 290 million insecticide-impregnated bed nets issued to families in sub-Saharan Africa over the last decade. But there are still 106 malaria-endemic countries and areas in the world, and an estimated 225 million malaria sufferers, although this is down on the 244 million recorded in 2005. The financial burden of malaria is still massive, estimated to be 20 per cent of gross domestic product in some countries, not just from deaths, but from chronic and debilitating sickness. And, of course, malaria is still a fatal disease. During 2009, the WHO estimated that 781,000 people died of malaria. Again, this is down from the 985,000 deaths estimated in 2000, but is still the ghastly equivalent of five Boeing 747s crashing every day of the year.
Health charities continue to push for greater awareness and to raise funds. And just as Mr Moore Hogarth found in the 1920s, celebrity endorsement is worth its weight in quinine. Victoria Beckham sported a special mosquito ring designed by Stephen Webster, which was sold to benefit the Malaria No More organization. Actress Sharon Stone made headlines when she spoke out at the World Economic Forum meeting in Switzerland in 2005. She offered Tanzanian president Benjamin Mkapa US$10,000 for bed nets, and according to news reports raised US $1 million from the audience within minutes.2 Save the Children used their ‘celebrity sponsors’ – TV presenter Davina McCall, musician Fran Healey and journalist and broadcaster Mariella Frostrup – to launch World Malaria Day (25 April) in 2008, photographing them posing in swathes of mosquito netting.3 The celebrity glitter is often necessary to get over the fact that malaria is not very newsworthy. It occurs in other countries, affects other people, and the photo opportunities are not exactly glamorous.
One of the problems of trying to get malaria noticed by the international press is that, over a century on from that momentous year, 1897, our means of coping with both fly and parasite have changed little. We keep poisoning the waterholes, and we poison the parasite with quinine, or synthetic substitutes. But there is still a long way to go.
Biodiversity is a powerful buzzword, and the idea of eradicating a species sits ill with notions of conservation. Would it really matter if mosquitoes ceased to exist? In a thoughtful article in Nature examining just this question, Janet Fang was offered the conclusion that there is nothing mosquitoes ‘do’ (pollination, recycling organic matter, food for predators and so on) that other insects could not do instead – apart from transmit malaria.4 Consequently if there were no mosquitoes, there would be no malaria, and there would be more humans.
Thankfully, this total wipeout scenario is not entirely necessary. If enough mosquitoes can be killed and enough malaria-suffering humans treated, there comes a tipping point at which transmission no longer occurs and malaria collapses. But even this ‘second best’ option is a tough target.
The seemingly insurmountable obstacle that we cannot quite overcome is the combination of incomprehensible mosquito numbers and the logistical nightmare of trying to treat a complex and highly mobile human population. Because they breed so quickly, a few surviving mosquitoes can repopulate within weeks, and they are liable to be the insecticide-resistant ones. There is also uneasiness about what this destruction might mean to the wider environment, to non-target organisms, and the spectre of a tropics-wide ‘silent spring’. It is also difficult to administer the intensive medication necessary to rid (or reduce) an entire human population of the malaria blood parasites. All it takes is for one sick person to move from one area to another and the disease is taken into another town or country that may have been previously cleared of the disease, and the cycle starts all over again. We have new insecticides (including mosquito-killing bacteria) and powerful drugs, but this is still the old-fashioned strategy of the mosquito squads. Is there no other way?
Polio, measles and rubella are in terminal decline, and in the case of smallpox, extinction has been achieved. All this has been by immunization. A vaccine against Plasmodium is now the holy grail of malaria research. The problem with malaria is that, although Plasmodium is a simple, single-celled animalcule, it is still vastly more complex than bacteria or viruses; developing a usable vaccine is far from straightforward. Also, Plasmodium constantly changes its surface chemicals, as if evolution has gone into overdrive. A conventional vaccine against one particular strain becomes obsolete before it can be put to use. Nevertheless, work continues.
Bill Gates, chairman of Microsoft and some-time richest man in the world, has been pushing for this vaccine project to be taken very seriously. At a well-publicized conference in Long Beach, California, in 2009, Gates spoke on malaria. He joked that more money was spent on baldness drugs than on a disease that kills roughly a million people a year. Baldness is a terrible and debilitating condition that afflicts rich men, hence the pressing enthusiasm driving this line of research.
To give his audience a taste of mosquito misery, Gates released a container of live mosquitoes into the auditorium: ‘There’s no reason only poor people should have the experience.’ It did what it was intended to do; it caught the media’s attention, even though they rather blew it up into a ‘cloud’ or a ‘swarm’ of mosquitoes. Bill Gates is obviously moved by the world’s malarial malaise and the Bill and Melinda Gates Foundation funds many malaria projects. In November 2010 the foundation gave US$50 million to the Liverpool School of Tropical Medicine. At the moment Bill Gates is known as the man who got a personal computer onto almost every desk in the world. If he can help get a dose of malaria vaccine into everyone living in the malarial tropics, it will be a much more fitting and honourable epitaph.
As I have argued, it is one of the consequences of losing malaria in developed countries that the weighty concern and immediacy of the disease has also been rather lost. And with the concern, all that hard-told and hard-learned knowledge vaporizes, too. All those key facts pressed on an eager world by the likes of Walt Disney and Dr. Seuss, about the Anopheles body position (45-degree angle, tail stuck up in the air), about breeding cycles in gutters and puddles and litter, and about disease transmission through infected saliva (not regurgitated blood), fade, and what is left is a kind of medieval mosquito bestiary, a hodgepodge of mosquito half-truths and folklore. Mosquitoes are far from gone in the world, but the mosquito menace is much reduced in many Western minds.
In 101 Things to Do with a Mosquito (2005), cartoonist Ed Fischer suggests everything from using them as darts to flattening them as bookmarks. Some of his ideas have already been used; ‘smooshed mosquito art’ made an appearance in Atlanta, Georgia. This looks familiar; a man standing behind his lectern holds up a jar of the flies, and demands: ‘If you don’t listen to me – I’ll release these mosquitoes.’ Not one of the cartoons makes reference to malaria or disease.
Larson, again, has a better go at it. Even though there is still no mention of the deadly parasites within, the sinister shadow cast by these flies is used to good effect in his gloomy night-time cartoon showing the husband and wife couple in their bed. ‘Dang it! Doris! Hit the light! . . . I think there’s a mosquito after me.’ There is, it’s hiding in the corner, and it’s as big as an ox. Just as in Walt Disney’s wartime public information film, The Winged Scourge, Larson’s mosquito is magnified to the proportions of a monster. The personal attention of a giant mosquito familiar is funny. The impersonal attention of malaria-infected mosquito hordes is not funny. But this is the image of the killer insect we should try and keep in our minds if we want to keep mosquitoes and malaria in perspective.
Malaria remains the greatest human killer in the world, but even the organizations promoting its understanding and control can still get it wrong. Christian Aid, in a recent series of UK newspaper adverts to encourage readers to sponsor antimalarial bed nets, showed a sad, malaria-infected child; they also pictured a large, but obviously non-malarial, mosquito (without its rear end stuck in the air at a 45-degree angle). Does it matter? As long as they get the £1 text message donation they’re after, perhaps not. But if they can’t get a basic biological fact right at one end of the money tree, it does rather raise questions about whether they know what they’re doing at the other end, where it matters what sort of mosquito bites you. Where it is, quite literally, a matter of life and death.