Micrognome

Anton Breinl Centre, James Cook University, Townsville, QLD,  11th June, 2010

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1. Introduction to arbovirus infections. Tim Inglis
2. Helminth infections. Richard Bradbury
3. Trypanosomiasis in Australia. Rick Speare
4. Rickettsial Diseases. Steven Graves
5. Travel-related diarrhoeal disease. Sanatu Chatterjee

Introduction to arbovirus infections [full lecture here]

Helminth infections. R Bradbury, University of Tasmania

Helminths infections have been evident since early recorded history.

1. adult male previously resident overseas, with Fascioliasis
2. adult male from Darwin with Paragonimiasis
3. adult refugee ex Africa with Schistosomiasis
4. child in Mauritius with Bartiella
5. elderly adult from Hobart with cutaneous larva migrans
6. adult from Tasmania with Haycocknema myositis

Trypanosomiasis in Australia. R Speare, James Cook University

So far there have been only 4 cases of Trypanosomiasis reported in Australia, but the number is likely to increase due to the arrival of African refugees and increased travel by Australians to African game parks. There are key differences between East and West African Trypanosomiasis in the course of infection, tests used and most effective treatment. However, available laboratory tests are insensitive and all drugs used to treat Trypanosomiasis are toxic. The overlapping geographic distribution of East and West African Trypanosomiasis in Uganda will increase the diagnostic challenge. South African Trypanosomiasis or Chagas’ disease has a different clinical presentation and treatment.

Rickettsial Diseases, S Graves, Hunter Valley, NSW.

There are four groups of diseases caused by the small, obligate Gram negative bacteria that make up the rickettsias. These are Q fever, the spotted fever group, the typhus group and scrub typhus. The key step in arriving at a diagnosis of one of these diseases is to think of rickettsias in the first place.  Epidemiological clues include working in an abattoir, going on safari in Africa, or bush walking. Some but not all patients may have an eschar.  Lab investigations need to be done in a centre with rickettsial expertise and include nucleic acid assays (PCR) or serology. PCR is better during the initial stage of an acute infection, while serology is better after time has passed to develop an antibody response. Micro-immunofluorescence is considered a reference standard serological method.

Traveller’s diarrhoea. S Chatterjee, Kolkota, India

There are an estimated 80,000 cases of traveller’s diarrhoea per day and the condition is top of the travel-associated risks list. However, expatriate residents have almost the same rate of diarrhoeal disease as local people. If a thorough laboratory investigation is conducted, 80% will have a pathogen identified. Almost all international travellers make a food or drink mistake in the first 72 hours of a trip. Common causes are faecal contamination of food, water and drinks, or poorly cooked seafood. In India the attack rate is more than 50%.  Antibiotic use for TD is being re-evaluated. Co-trimoxazole and doxycycline are largely obsolete.  Bismuth and probiotics appear to be ineffective.  Ciprofloxacin works in the majority of cases. Rifamaxin is under active consideration. However 55% cases will resolve spontaneously. On prevention, oral cholera vaccine is useful and has added benefit of prevention of toxogenic E.coli infection.