Twists and turns in the war with infectious disease.

Abstract

The victors in past wars were often those bearing the deadliest pathogens, rather than the armies with the best weapons and generals,1 and until the battle fields of the Western Front in World War I, deaths from infection exceeded those from artillery. In World War II, more war victims died of microbes introduced by the enemy than of wounds.2However, by 1963, physician and anthropologist T. Aidan Cockburn was suggesting that it was possible to 'look forward with confidence to a considerable degree of freedom from infectious diseases at a time not too far in the future'.3 Within 'some measurable time', it seemed reasonable to anticipate that all the major infections would have disappeared. More than half a century later, it is clear that his optimism was misplaced, although Michael Head of the Infectious Disease Research Network at University College, London, says that Cockburn's speculation was probably 'reasonable enough', given the exciting progress made by developments in the world of antibiotics, adding: 'That said, the evolution of antimicrobial resistance pathogens has been known about for a long time, certainly prior to 1963, so the warning signs have been there'.Dr Katie Jeffrey, Interim Secretary of the British Infection Association (BIA), agrees,His prediction may have been reasonable at the time, but it was also naive. The advent of H1N1, SARS, MERS-CoV and, most significantly, antimicrobial resistant organisms, show that total eradication of infectious diseases is not possible in the foreseeable future.Non-communicable diseases are now the leading cause of morbidity and mortality in most developed nations, but the emergence and spread of new or previously unknown infectious diseases - along with the re-emergence of old diseases - is an increasing global phenomenon and remains a major public health concern around the world.Sharp RemindersA 2014 study4 examined the global changes in the frequency of outbreaks of infectious disease between 1980 and 2013. The data set covered 12,102 outbreaks of 215 diseases, with 44 million individual cases in 219 countries around the world. The researchers examined the relationship between the location and timing of disease outbreaks and the characteristics of outbreak sites, such as the presence of certain animals that transmit disease to humans. The number of outbreaks and the number of kinds of disease had increased significantly since 1980.In the data analysed, 65% of the diseases, making up 56% of all outbreaks, were zoonoses, including HIV, the bubonic plague and Lyme disease and Ebola. Last year's outbreak of the latter was a reminder of the world's continuing extraordinary vulnerability to the threat of infectious diseases. Michael Head commented that although there wereFailures in public health and infection control procedures to contain the outbreak at an early stage, it was the entry and initial spread in big cities that was novel and caught everyone by surprise. We of course now know a lot more about the virus, and also the needs and concerns of local populations - a neglected consideration by many, in my view. We'll be a lot better prepared for any 'next time'.Key DriversThe reasons why the battle against infectious diseases is far from won are well understood. High on the list of 'culprits' is the growth in international travel and trade. Pathogens do not recognise national boundaries and the increasing speed with which individuals now circumnavigate the globe incubating infections makes the control of communicable diseases an enormous challenge for governments and public and primary healthcare systems.Climate change also has some claim to blame. According to the World Health Organization (WHO), some models have shown net increases in malaria over the coming half-century and others little change.5 Latest estimates (December 2014) suggest that there were about 198 million cases of malaria in 2013 and an estimated 584,000 deaths. …