Section 1: General review questions 1.1 An outbreak of Staphylococcal food poisoning is traced back to two kitchen staff - one is well but has a positive nasal swab and the other has a septic finger....

Section 1: General review questions 1.1 An outbreak of Staphylococcal food poisoning is traced back to two kitchen staff - one is well but has a positive nasal swab and the other has a septic finger. State which of these two carriers would be described as colonised. Explain your choice. 1.2 Shared syringes among IV drug users is one way HIV is spread. Name the reservoir and the source of infection in this situation. Give a reason for your answer. 1.3 In an endemic area, and with other influences being equal, is immunogenicity directly or inversely related to transmissibility? 1.4 Explain how immunogenicity indirectly affects transmission 1.5 Describe how immunogenicity of an organism is influenced by its antigenic variability Section 2: Disease specific review questions 2.1 Polio is a viral infection that in endemic areas is transmitted largely by the faeco-oral route (that is, passing out of infected hosts via their faeces, contaminating water (or food), and entering an uninfected host through their mouth when they ingest that food or water). It is of low pathogenicity with a clinical to subclinical case ratio of approximately 1 to 20. The pathogenicity does increase with age however. Infection is followed by lifelong, strain specific immunity. In the absence of concurrent immunisation, how will improved environmental hygiene and sanitation influence: a. the age of cases of paralytic polio in an endemic area? Briefly explain why b. the clinical: subclinical ratio of the disease? Briefly explain why 2.2 Hepatitis A is a viral infection transmitted by the faeco-oral route. It is of low pathogenicity for children but of higher pathogenicity for adults. Illness due to hepatitis A is infrequent in children under 8 years of age. In highly endemic areas such as occur in many poorly resourced countries, exposure occurs in early childhood and serum antibodies to Hepatitis A virus (indicating previous infection and current immunity) are present in most people over about 16 years of age, even though few have had clinical hepatitis. Adults in this type of population are not at significant risk of developing hepatitis. However, exposure to hepatitis A is no longer widespread in Australia and Australian adults are often susceptible. You are advising Community Aid Abroad (CAA) on protection against Hepatitis A infection for their overseas aid workers. In order to give sound advice what would you need to know about: a. the overseas working environment and b. the individual CAA workers? (2 Section 3: Case based scenario: Sexually transmitted infections in a central Australian community Suggested resources.