Eradicating disease

TO EXTERMINATE a living species by accident is normally frowned on. To do so deliberately might thus seem an extraordinary sin. But if that species is , the sin may be excused. This parasitic organism causes the most deadly form of malaria. Together with four cousins, it is responsible for about 450,000 deaths a year, and the ruination of the lives of millions more people who survive the initial crisis of disease. Besides the direct suffering this causes, the lost human potential is enormous. The Gates Foundation, an American charity, reckons that eradicating malaria would bring the world $2 trillion of benefits by 2040. Malaria is one of the worst examples of the damage that transmissible diseases can wreak. But it is not alone. AIDS carries off fit, young adults by the millions and tuberculosis by the hundreds of thousands. Measles, whooping cough and diarrhoea together kill over 1m children a year. Parasitic worms and mosquito-borne viruses like dengue, though they take relatively few lives, debilitate many.