AN ENCYCLOPEDIA OF SUSTAINABILITY
Heading: Society Topic: Epidemics
Globalization has linked the entire human population of the planet, making the Earth physically into one country. One of the effects of this new unity is an increased vulnerability to epidemic diseases, which can spread more easily from person to person and country to country. The problem is aggravated by extreme differences beween countries in the extent and quality of their health and medical services. Epidemics can build momentum among the poor, and then overwhelm everyone. The present extremes of wealth and poverty put everyone at risk, providing a further incentive (as if one were needed) to to work for a more just and equitable world.
The rapid spread of bird flu around the world has raised major concerns about a possible human epidemic if the virus mutates to be transmissible between humans. Those in wealthy countries who thought that their expensive health systems protected them from epidemics, and that mass mortalities were only a problem of the poor in developing countries, may be mistaken. Given the speed at which influenza viruses mutate and spread, it is not at all certain that an effective vaccine can be developed in time to protect more than a fraction of the population, and the supply of antiviral medications that can at least reduce the severity and thus mortality of the flu will certainly be inadequate. The worst case scenario taken seriously by health officials suggests that a human variant of the H5N1 bird flu, if it retains its present virulence, could kill up to 70% of those catching it, and a flu epidemic usually affects about 30% of the population, suggesting that nearly a quarter of the population could die as the epidemic sweeps around the world. The economy and society would be extremely disrupted as transportation and commerce would be interrupted, so secondary effects in a globalized world economy would also be significant. How the world responds to such a challenge will depend much on the spirit of unity and solidarity within and among communities and nations.
This is not the only threat from epidemics. Infectious diseases are on the rise and now kill 17 million people a year, particularly young people in the developing world. Rising levels of drug resistance are making them more difficult to treat (WHO, 1996a). The concern over new viruses, started with HIV causing AIDS, has been reinforced as other emergent viral diseases have been reported, including Ebola, Hantavirus and Rift Valley Fever. Growing drug resistance, new virulent strains, continuing poverty, the breakdown of public health measures, and increased human contact are leading to renewed outbreaks of other epidemic diseases (WRI/UNEP/UNDP/WB, 1996). Travel and urbanization are increasing human vulnerability to epidemics of both old and emerging diseases (Maurice, 1993; Day, 1996). There is also concern that climate change may have significant effects on health (WHO, 1996b).
Tuberculosis is now the world's single largest cause of death from a single agent, with one third of the population latently infected and 3.1 million deaths in 1995, up 13 percent from the previous year (WHO, 1996a). At the rate TB is spreading, it could claim over 100 million lives over the next 50 years. The association of TB with the AIDS epidemic is one of the main reasons for the increase (Kochi, 1996).
There are presently about 300-500 million clinical cases of malaria a year, 90 percent in Africa, and malaria deaths rose 5 percent in 1995, killing 2.1 million people, mostly children (WHO, 1996a). Global warming could cause another 50-80 million cases as disease-bearing mosquitoes move into new areas (Martin and Lefebvre, 1995; Pearce, 1995a; IPCC, 1995).
Food poisoning and food-borne diseases are also rising rapidly, even in the most developed countries. The incidence in Europe tripled over the last decade, and in the US there may be 24-82 million cases and 10,000 needless deaths from food poisoning annually. Increased environmental contamination, wider exchange of pathogens, and large-scale food processing and preparation are some causes implicated (Maurice, 1994).
Recent increases in solar ultraviolet (UV-B) radiation at ground level, related to stratospheric ozone depletion, are expected to augment adverse health effects such as skin cancer, eye cataracts and suppression of immune response.
While life expectancy has generally been increasing for decades, there has been a sharp reversal in recent years in some countries of Central and Eastern Europe and sub-Saharan Africa. In Russia, life expectancy among men decreased from 65 years in 1987 to 57 in 1994. Causes may include the stresses of economic transition, deteriorating health care, and possibly the toxic burden of decades of environmental contamination. In Africa, the AIDS epidemic is expected to reduce average life expectancy by almost 8 years (WRI/UNEP/UNDP/WB, 1996).
REFERENCES AND SOURCES
Based partly on materials originally prepared for UN System-wide Earthwatch