The Global Inter-Connections of Health and Disease Copyright Dr. Aran S. MacKinnon We all swim in the same microbial sea “ We all swim in the same microbial sea”

The implications of ill-health and disease The incidence and expansion of disease reveals two significant aspects of global studies: 1. The profoundly intimate connections of humans around the globe 2. Ill-health travels the fault lines of poverty and inequality. Current crises loom large on the horizon: Avian Flu HIV/AIDS, SARS. Others continue to smolder or are re-emerging: malaria, tuberculosis, polio.

Impact Even though we all swim in the same microbial sea, the impact of disease is not experienced equally At greatest risk: The poor, children, women, developing countries/regions

Causes and Factors complex mix of factors can contribute to the outbreak of disease: environment, economics, patterns of global inter- connections, and public health initiatives As the pace and intensity of global connections increases, so too do the risk factors for the spread of disease. Increases potential for severe epidemics Go to this link to see what environmental factors affect malaria BBC - Development and Health – Malaria

Types of Disease Infectious disease [those caused by various microbes [viruses or bacteria- transmitted by people or other vectors such as animals and insects] continues to be a major threat and the dominant one in developing regions of Asia and Africa Chronic disease: such as cardiovascular disease cancer and diabetes [caused by underlying environmental and genetic factors but exacerbated Go to the UN’s World Health Organization (WHO) web site to learn about disease:

History of Disease Humans are biological beings –we have gone through cycles of establishing a balance with pathogens (agents in the environment which cause disease). Infant survival of disease = later tolerance or immunity Population groups who survive infectious disease/epidemics have some tolerance or immunity, but changing conditions such as civil conflict, famine or poverty can undermine this.

Historical Background The Human Genome is a veritable encyclopedia of our genetic past, including experience with infectious diseases. See: The terrifying first horse of the Apocalypse: disease

Historical Background Human interaction with the environment has created risks. Domestication of animals, especially ‘social animals’ such as birds, pigs and cattle have increased possibilities for ‘crowd diseases’ to jump from animals and spread among humans: measles, smallpox etc.

Historical Background: Global trends Urbanization: proximity of humans to each other and animals; sanitation, poverty War and Long Distance Trade drive risk and spread of infections Age of European exploration and discovery sets off Columbian Exchange; introduction of Old World diseases into Americas decimates pop. with no tolerance

History of Global Trends Imperial and colonial encounters create new interactions and forays into potentially disease-rich environments; greater fault lines of conflict and inequality: malaria, yellow fever, sleeping sickness, cholera re-emerge Industrialization accelerates trends toward urban density and inequality increasing risks

Global Trends: Public Health Early efforts at public health aimed at sanitation and water supplies had some good effects Inoculations, Germ theory and Sanitation all aid in decreasing morbidity and mortality Care for soldiers was an early driving force for public health developments; war and armed forces shape and drive many advances Modern efforts: science, vaccines, anti bacterial and viral drugs By 1960s, belief that the developed world had ‘won the war’ against infectious disease

Recent Global Trends Despite major strides, and significant improvements in public health, morbidity/mortality, infectious diseases persist and re-emerge. While drugs remain effective in many cases, some drugs are losing effectiveness with improper use and adaptations by pathogens

Continued disease threats: HIV/AIDS, TB, Avian Flu

Current threats. Influenza: A recurring risk of epidemics The ‘flu has long been a major global threat Increased population growth, congestion, migration and the speed of modern transport combine with human-animal interactions to spark potential threats

Influenza Track Avian Flu at the World Health Organization Site and the Centers for Disease control: Where did it begin? how has it spread? what risks does it pose? what is being done?

HIV/AIDS 40 million people infected, 5 million new infections a year, 3 million deaths a year Probably over 30 million have died, mostly in developing world AIDS is a pandemic, and rates have increased in more developed areas (U.S., Eastern Europe) It is not –as previously thought- just a threat to Gays and Haitians or Africans

HIV/AIDS AIDS travels along pathways of human migration and transportation but it especially travels along fault lines of poverty and inequality. Poor, women, sex workers migrant workers and children are particularly at risk. AIDS pandemic reveals the limits of public health in the modern context

HIV/AIDS

Lifestyles and sexual activities are a factor in transmission, but the poor, powerless and marginalized have little choice in many cases Sex workers, wives of the infected, truckers, soldiers all have high risk Globalization: migrants, displaced people, sex tourism all contribute

AIDS AIDS is treatable; infection rates can be reduced with drugs and condoms Anti-retroviral drugs can allow people to live with AIDS Drug therapies are extremely costly and subject to the politics of the pharmaceuticals

Disease and Drugs There is a political and economic context to the development of new drugs. The developing world does not always benefit from new drugs; many drugs and vaccines needed in the developing world are not developed because the market is too poor.

The new Global threat: Chronic Disease While infectious disease continues to be the biggest killer in poor regions, especially Africa, Chronic diseases are rising and overtaking infections. Expanding industrialization and more open markets combine with rising affluence in some developing regions to create new health risks, especially in S.E. Asia

The Spread of Chronic Disease In newly industrializing countries there is a marked rise in new chronic diseases: Cardiovascular, Cancer, Respiratory illness These are associated with broader social and economic conditions –rising pollution, stress, urbanization, decline in healthy lifestyle, global marketing of foods with fats and sugars.

Chronic disease Leading associated causes: cigarette smoking, automobile pollution, industrial work Increases likely with ageing population (see material on population and consumption)

Causes of Emergence/ Contributing Factor(s) Associated with Infectious Disease Polluted water/water mismanagement: diarrheal disease, malaria, typhoid, cholera, guinea worm disease, cryptosporidiosis Deforestation and land development: malaria, Lyme disease, rabies, plague, yellow fever, Rift Valley fever, schistosomiasis Human demographics, migration and social behavior: dengue/dengue hemorrhagic fever, HIV/AIDS, sexually transmitted diseases, giardiasis Technology and industry: Toxic shock syndrome, nosocomial (hospital ‑ acquired) infections, hemorrhagic colitis/hemolytic uremic syndrome Agriculture, Irrigation and Dams: malaria, hemorrhagic fever, schistosomiasis, influenza Urbanization, International travel and commerce: malaria, cholera, pneumococcal pneumonia, influenza, SARS, BSE and other food-born illnesses Microbial adaptation and change/Drug resistance: Tuberculosis, influenza, HIV/AIDS, malaria, Staphylococcus aureus infections, Staph Climate change Malaria, dengue, cholera, yellow fever, Hanta virus, plague Break down of public health measles, polio, pertussis, tuberculosis, HIV/AIDS Poverty: Risk for all of the above