Class Notes (837,484)
Canada (510,274)
Geography (296)
GG231 (53)
Rob Milne (25)

Lesson 9 Notes.docx

5 Pages
Unlock Document

Rob Milne

Lesson 9: Diseases 9.1 - Epidemics • Affect human populations most directly. Impact only on people, not on structures of society. • Most similar to droughts of any natural hazard. • Relevant Key Terms: o Outbreak: simultaneous, related occurrence of several cases o Epidemic: uncontrolled outbreak of communicable (infectious or contagious) disease o Pandemic: international or wide-travelling simultaneous epidemics of the same condition o Epidemiology: study of distribution and determinants of health-related events in human population o The Agent: the disaster o The Environment: that which it affects o The Host: affected people • Communicable (contagious) diseases are the leading cause of mortality in developing countries. Mostly due to socio-economic conditions, limited prevention, and water contamination. • Spread of disease will occur: o if the population is not immune and includes carriers o if susceptibility to disease increases through conditions such as malnutrition • Transmission rates increase because of: o Water contamination o Lack of routine prevention programs o Overcrowding in refugee camps leading to increased contact with carriers 9.2 - Case Study: Bubonic Plague (Black Death) • Disease spread by rodents – fleas to rats to humans. Swelling of lymph nodes, infection, pneumonia leading to high fever, delirium, vomiting, bleeding and finally death. (Standard). • First pandemic – Justinian’s Plague in Asia, Africa and Europe – 100 000 victims. • Second pandemic – Black Death – 50 000 000 deaths. Half in Asia and Africa, other half in Europe. • Third pandemic – Hong Kong – carried by rats aboard steamships. Spread worldwide however preventative measures limited the deaths and outbreak. Vulnerability • No noticeable groups had greater vulnerability. Gathering in groups spread more easily. E.g. Religious gatherings. • Use of historic documents to understand local populations and impact of diseases. 9.3 – Cholera • A water-borne disease that comes from sewage and contaminated water supply • ‘Mapping’ used to find source of disease. Geographic information systems used for locating the source and tracking spread of epidemics. 9.4 – Aids/HIV • Transferred through exchange of infected body fluids including blood and semen (giggity). • Originally believed vulnerability was limited to homosexual activity, IV drug use and hemophiliacs. • Today, vulnerability linked to poverty. 95% of cases in poorer countries. No cure – drugs to extend life – chronic disease now. Claimed 30 000 000 lives in two decades. 40 000 000 infected estimated. Vulnerability • Current Trend – Increasing at a decreasing rate • Region Trend – Highest in Africa (specifically southern) with Asia next highest • Age/Domestic Trend – Higher in Urban Areas. Higher in Women. • Treatment levels are increasing in Africa. 9.5 – Bird Flu (Avian Influenza) • Became evident in 1997 due to large poultry death • Focus on the virus strain H5N1 because of its; o Ability to transfer from birds to humans o High mortality in humans o Potential for a severe pandemic • Caused by infection from avian influenza viruses – Occur naturally among birds. Extremely contagious among birds but not human-to-human. Essentially eating infected poultry, contact with fecal matter of poultry or other liquid secretions can get you sick. • Mortality rate is 70% in humans. Flu Pandemics • Occur on average once every 10 to 50 years – typically spreading globally within a year and highly contagious. • Come with little warning, peak rapidly and then subside. • Spread usually in waves with 2 and 3 waves stronger than the first. Spanish Flu • 1918-1919 – killed 40 million people. Spread by soldiers travelling through Europe to N.A. • Unique characteristics – mainly targeted the young adult age group. • Ability to spread throughout the atmosphere. Asian and Hong Kong Flu • Vulnerability greater in infants and elderly. • Not as deadly due to the preventative measures taken to prevent outbreak. Prediction and Warnings • Disease is unpredictable in its severity, mortality, and pattern of spread • Rapid exponential surge that overcomes a population's capacity to cope • Disease occurs in waves with increasing severity and different targets • Virological surveillance is critical in reducing the level of impact • Many pandemics originate in Asia with close contact between humans, ducks and pigs • While quarantine and restricted travel has little
More Less

Related notes for GG231

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.