DIFFUSION DISEASE WHAT IS DIFFUSION The process by

DIFFUSION & DISEASE

WHAT IS DIFFUSION? • : The process by which a characteristic spreads from one place to another over time (people, products, ideas) • Examples: • Architectural styles • Fashion • Language • Technology • Diseases

THE SPREAD OF AGRICULTURE

ANCIENT TECHNOLOGY The spread of iron technology The spread of the chariot

THE DIFFUSION OF PEOPLE

Where does diffusion begin? Hearth: the point of origin or place of innovation Diffusion of Buddhism outward from India

Who is involved with diffusion? * Innovators – risk-takers, educated, have the resources & desire to try new things * Early adopters - social leaders, popular, educated, usually the first one in the group to have the latest gadget * Early majority - deliberate, they like seeing how new technology will fit in their lives * Late majority - skeptical, traditional, lower socio-economic, they react to peer pressure or economic necessity * Laggards – more traditional, fear of debt, may not have the resources to try new things

WHAT ARE BARRIERS TO DIFFUSION? • Time and Distance Decay • The farther from the source and the more time it takes, the less likely innovation is adopted • Cultural Barriers • some ideas are not acceptable in a particular culture e. g. pork, alcohol, contraceptives

DIFFERENT KINDS OF DIFFUSION

1) RELOCATION DIFFUSION • : Ideas and things are spread by the physical movement of people from one place to another • Ex: Amish culture originated in Western Europe, moved to Pennsylvania, is moving westward Amish settlements

2) EXPANSION DIFFUSION • The idea originates in a central place and then expands outwards in all directions • So the idea moves, not necessarily the people • The idea stays strong at the hearth • There are 3 subtypes • A. Hierarchical • B. Stimulus • C. Contagious

HIERARCHICAL DIFFUSION • The spread of an idea or thing from a person of authority/high ranking to other people and places • Ex: the spread of fashion trends start with the upper class, and then spread through society Celebrity trendsetters: Cara Delevinge’s eyebrows, Kylie Kardashian’s lips, Kim Kardashian’s makeup contouring

STIMULUS DIFFUSION • An idea is spread but it is modified so there will be local variations • Ex: Mc. Donalds has spread to India, but they have modified it to fit the local culture. Hindu people do not eat beef, so they have expanded their vegetarian options

CONTAGIOUS DIFFUSION • Rapid, widespread diffusion of a characteristic through a population • Spreads through society equally • Ex: ideas on the Internet spread like this; very quickly since everyone has access to them immediately

PANDEMICS AND INFECTIOUS DISEASES

TRY TO GUESS…WHAT ARE THE TOP 10 CAUSES OF DEATH WORLDWIDE 10. Hypertension (2% of all deaths) 9. Vehicular Accidents (2. 2% of all deaths) 8. Diabetes (2. 7% of all deaths) 7. Diarrhea (2. 7% of all deaths) 6. HIV & AIDS (2. 7% of all deaths) 5. Lung, Tracheal, & Bronchial Cancers (2. 9% of all deaths) 4. Lower Respiratory Infections (5. 5% of all deaths) includes pneumonia, tuberculosis, influenza, bronchitis, etc 3. COPD – Chronic Obstructive Pulmonary Disease (5. 6% of all deaths) 2. Stroke (11. 9% of all deaths) 1. Coronary Heart Disease (13. 2% of all deaths)

CAUSES OF DEATH IN THE DEVELOPED WORLD • Many of the same causes, Heart Disease is still #1 • But there’s no Diarrhea in the Top 10, or HIV/AIDS, • There is Suicide, Alzheimers, Kidney Disease

WHAT IS “MEDICAL GEOGRAPHY”? • Study of the interconnections between population, health and the environment • Cause and diffusion of disease • Provision and consumption of health care • Social construction of health • Effects of environmental change

SOME TERMS TO KNOW • If a disease is epidemic, …. . there are numerous outbreaks and the situation gets more serious. • If a disease is pandemic, …. . this is a serious situation and it means that it has spread globally.

BACTERIAL, PARASITIC, OR VIRAL? • Bacterial: a disease caused by bacteria, it is alive and so can be killed by antibiotics • Viral: a disease caused by a virus, its symptoms can be alleviated but it can’t be cured, it is not “alive” so can’t be killed; some can be treated with antiviral drugs, which fight infection by inhibiting a virus’s ability to reproduce • Parasitic: a disease caused by a parasite (tiny bug or worm)

CAUSE AND SPREAD OF DISEASE • In 1854 London, England there was a Cholera outbreak where 616 people died • At the time they thought it might be spread by inhaling infected air or eating contaminated food

• Dr. John Snow (yes, really) used a dot map to map the addresses of cholera victims and the location of water pumps they used • Discovered that most of the cholera victims lived around one pump that was contaminated • Most famous and earliest case • https: //www. youtube. com/watch? of geography and maps being v=1 jlsyuc. Uwpo utilized to understand the spread of a disease

DISEASE MAPPING

WHERE IS CHOLERA TODAY? Why do we not have cholera in Canada/USA anymore?

CHOLERA DEATHS • Cholera deaths result from severe dehydration caused by diarrhea • This is treatable; in 2004 only 2. 5% of cholera cases were fatal

EPIDEMIOLOGY • : the branch of medicine that deals with the incidence, distribution, and control of disease

EPIDEMIOLOGIC TRANSITION THEORY • Each stage of the demographic transition model has distinctive causes of death • The leading causes of death change from infectious to degenerative types as the demographic transition occurs.

EPIDEMIOLOGIC TRANSITION STAGE 1 Death because of: • High birth rate • Infectious and parasitic diseases (Black Death) • High death rate • Malnutrition • Slow population growth • Happens in very poor, isolated places • Typical life expectancy: 35

PLAGUE • This disease has changed the course of human history • Caused by a bacteria transmitted to humans by fleas from infected rats • There are several types but the most famous is the Bubonic Plague • Named after the hard swollen “buboes” or lumps that develop near the flea bite

MORE PLAGUE • Bubonic plague killed 60%, but some other forms of Plague killed 90% of its victims • When the rats start dying off, the fleas find human hosts • The first incident of this kind of plague was in the years 541 -544 when it spread from Egypt to Europe and killed ¼ of Mediterranean Europe and helped in the downfall of the Roman Empire

PLAGUE AS BIOLOGICAL WEAPON • During various Medieval wars, armies would use plague-infected bodies as biological weapons • They would use them to contaminate enemy’s water supply • Or they would catapult the bodies into the cities during a siege • During WW 2 the Japanese used it on Chinese soldiers

PLAGUE STILL EXISTS • Today there antibiotics and a vaccine but there are still pockets where it survives

RIVER BLINDNESS • Onchocerciasis (River Blindness): a disease caused by infection with the parasitic worm • It is the second most common cause of blindness due to infection • 17 -25 million people are infected • Most infections occur in sub. Saharan Africa, although cases have also been reported in Yemen and isolated areas of Central and South America.

EPIDEMIOLOGIC TRANSITION STAGE 2 • Death caused by receding pandemics – cholera, tuberculosis, typhus, yellow fever • High birth rate • Death rate starts to drop due to advancements in healthcare and sanitation • Rapid population growth; crowded, dirty cities • Late 19 th century Europe and America; or current south Asia, or Latin America • Typical life expectancy: 50

1918 INFLUENZA OUTBREAK • It infected 500 million people • It killed 50 - 100 million of them— 3 -5% of the world's population • One of the deadliest natural disasters in human history • Most flu outbreaks kill young, elderly, or already weakened patients • In contrast this flu killed mostly healthy young adults

HOW DID IT SPREAD • Modern transportation made it easier for soldiers, sailors, and travelers to spread the disease. • In the USA, the disease was first observed in January 1918 • It struck every corner of the globe • In Canada 50, 000 died • http: //www. youtube. com/watc h? v=rb. Yw. NOc. Kqqc

EPIDEMIOLOGIC TRANSITION STAGE 3 • Death caused by degenerative diseases and man-made diseases • Death rates still dropping; people are living longer • Decrease in deaths from infectious diseases (vaccines) • Birth rates also now start to drop • Due to increased tobacco and alcohol use and subsequently fat & caloric intake, deaths due to chronic conditions overtake infectious diseases • Rapid growth (still) • Happens in places like Brazil, Middle East • Typical life expectancy: 60

ANTI-VAX LEADS TO MEASLES OUTBREAKS • Measles was considered eliminated from the USA in 2000 • But now with the antivaccination movement, it’s come back • It’s extremely contagious, airborne, and can be deadly • Preventable through immunization

EPIDEMIOLOGIC TRANSITION STAGE 4 • Death caused by delayed degenerative diseases • Birth rate and death rates stabilize • Cancer and heart disease • Slow population growth • Tobacco, alcohol, poor diet, lack of exercise • Treatment prolongs survival • Increase in aging-related conditions such as Alzheimer's • Happens in richer countries • Typical life expectancy: 70

OBESITY

EPIDEMIOLOGICAL TRANSITION STAGE 5 • Death caused by new diseases, and same reasons as Stage 4 • Some infectious diseases have evolved and returned • New diseases have emerged • New strains of viruses & bacteria are drug resistant • Most people can’t afford new drugs • Populations may be shrinking from low birth rates

MALARIA • Nearly eradicated in 1950 s by spraying DDT in areas infested with the mosquito that carried the parasite. • Returned after 1963 with the evolution of DDTresistant mosquitos

SMALLPOX • An infectious viral disease • Originally known as the "pox” or "red plague” • It killed millions in the 18 th 20 th centuries • It killed 20 -60% of victims (80% of infected children) • After a vaccine was developed, the disease was eradicated in 1979

POLIO • An infectious viral disease • Often causes paralysis of the legs • One of the most dreaded childhood diseases of the 20 th century • A vaccine was developed in the 1950 s • There have been recent outbreaks in Syria and Democratic Republic of Congo

HIV/ AIDS • Infection rates are as high as 25% in southern and eastern Africa. • About 35 million people have died of HIV • 36. 7 million people were living with HIV in 2016

EBOLA • Ebola hemorrhagic fever (EHF): a viral hemorrhagic fever • The largest outbreak to date was the epidemic in West Africa in 2013 -2016 with 11, 310 deaths • It was declared no longer an emergency in March 2016 • The disease kills between 25 -90% of those infected • The virus spreads through bodily fluids

NEW PANDEMICS • SARS (severe acute respiratory syndrome): a viral respiratory disease • In 2002 -2003, an outbreak of SARS in southern China caused an eventual 774 deaths in 37 countries. • No cases of SARS have been reported worldwide since 2004. • H 1 N 1(swine flu): a subtype of the influenza virus • In June 2009, the World Health Organization declared the new strain of swine-origin H 1 N 1 as a pandemic. • This novel virus spread worldwide and had caused about 17, 000 deaths by the start of 2010. In August, the World Health Organization declared the H 1 N 1 influenza pandemic over

ANTIBIOTIC-RESISTANT SUPERBUGS • These are new mutations that are immune to antibiotics • Some of the most concerning strains include CRE, MRSA, and C. difficile • Each of these superbugs are potentially fatal • Most of these strains are acquired in hospital settings