1. Epidemiology L.O – To discuss the meaning of ‘epidemiology’ and relate it to relevant examples.

2. What is epidemiology? Epidemiology is the study of the incidence (number of cases) of disease and pattern of a disease with a view to finding the means of preventing or controlling it. Epidemiology is concerned with: Morbidity of a disease – the number of people currently living in the diseased state. Mortality of a disease – the number of people who die from a specific disease (within a time frame).

3. What is Epidemiology? Incidence – the number of new cases of a specific illness diagnosed or reported during a period of time. Incidence Rate – as incidence and then divided by the number of people at risk for the disease. Prevalence – the number of current cases of a condition or illness at one time, no matter when it started. Prevalence rate – as prevalence and then divided by the total number of people who may be at risk for the illness or condition.

4. Notifiable Diseases If a doctor suspects a case of a certain infectious disease then they have a statutory duty to notify the Local Authority. The LA must then inform the HPA Centre for Infections with details of each case. The Information Management and Technology Department who have responsibility for collating these weekly returns and analysing the data before making the information public.

5. Which diseases must be notified? Poliomyelitis Anthrax Cholera Food Poisioning Malaria Measles Meningitis Mumps Rabies Rubella Tetanus TB Viral Hepatitis Whooping Cough

6. Discuss the key points associated with this diagram…

8. Question What similarities can you see between the two diagrams?

9. Influenza Influenza can cause regular epidemics and can lead to death. Avian Influenza virus occurs naturally in birds and usually does not cause illness. However, there are times when it can spread and kill domestic birds. There are times when Avian Influenza can spread to humans, usually those working closely with affected birds. Humans can be affected by many different strains of influenza. These different strains have slightly different antigens on their surface and these antigens are constantly changing.

10. Task 1)Use your knowledge of antigens and the immune system to explain why people can be infected by influenza on many occasions. 2)If the prevalence of a disease is high, but its incidence rate is low, what does this tell you about the disease? 3)Suggest why a) mumps b) food poisoning and c) TB are notifiable diseases 4)Suggest reasons why the official figures for incidence of some diseases may not be the same as the true incidence of these diseases.

11. Task 5) Use your knowledge of TB and HIV/AIDS to suggest ways of controlling and preventing both. 6) Explain why the incidence of these diseases is much higher in some countries than in others.