It’s not that often the MicroGnome gets to see Leishmania promastigotes wiggling their little tails, but this week was the exception. Here they are, tiring a little after a couple of hours’ exertion in NNN media:

You can find more information on the group of diseases known as leishmaniasis via a previous post on Leishmaniasis and the parasites that cause it.

Now that the MicroGnome can reliably get lecture notes onto this Blog, here is the Malaria series for students of tropical medicine:

The subject of expedition stress was covered during the ACTM-WA/PathWest/Rural Clinical School day conference on Wilderness & Expedition Medicine last month.

Here’s a copy of the presentation for those who were too stessed to get there on the day.

STOP PRESS

When: March, 2011. Exact date to be announced in New Year.

• Paper 1 at 09:45-12:15pm
• Paper 2 at 13:45-16:15hrs
• including 15” instruction & reading time, 2hr writing time and 15” administration window

Where:

In Townsville and Perth, plus any other major Australian centre, in accordance with demand and availability of exam supervisors/venue.

Who:

• A   FACTM (Clinical) Medical graduates qualified and registered to practice in Australia or New Zealand. Overseas qualified medical practitioners currently licensed to practice in either Australia or New Zealand (e.g. as trainees or on conditional registration) will be eligible to enter for the FACTM examination. At least two years of medical practice and some experience in tropical or travel medicine are advisable. Those with less clinical experience will be expected to make a case for early entry in order to avoid disappointment.
• B   FACTM (Paraclinical). The Paraclinical Fellowship exam is designed for other health care professionals qualified and licensed to practice in Australia or New Zealand with an interest in tropical or travel health e.g. paramedics, remote area nurses, travel health clinic staff, medical laboratory scientists, epidemiologists, veterinary medical and scientific officers, pharmacists and other professions allied to medicine

How:

1. Register your expression of interest with the College Secretariat and apply for the Affiliate category of membership (the application form can be found on the ACTM website) before 30th September, 2010. If you have recently completed a Diploma in Tropical Medicine recognised by the College, you may apply for recognition in lieu and exemption from the part 1 exam (Clinical).
2. Indicate your preferred exam centre, your 2 referees and the names of any senior ACTM members who are willing to act as local exam supervisors.
3. The College will contact you with detailed exam instructions including an invoice for exam fees ($500)
4. Complete your exam revision
5. Attend examination centre and complete papers 1 and 2
6. Results will be communicated to candidates via the College Secretariat after completion of marking, audit by the external examiner and review by the College Examination Board.
7. Candidates must achieve an overall mark of 50% in both papers to be granted a pass and MUST achieve an aggregate score of at least 60% in their preferred topic. For FACTM (Clinical) candidates, the preferred topic is automatically Clinical Tropical Medicine.
8. No grades other than PASS or FAIL will be given, however the highest scoring successful candidates in each of the Clinical and Paraclinical streams will be recognised with a College award.

What:

• Paper 1 will comprise different multiple choice question formats, including 30 x 5 subquestion T/F from a bank of 45 arranged by topic area (i.e. 150 x T/F) with negative marking, and 20 x 5 objective structured questions from a bank of 25 without negative marking. Total marks will be expressed as a final mark out of 50 plus a subtotal for the preferred topic.
• Paper 2 will comprise 10 data interpretation questions arranged by topic of which 8 must be attempted, and 10 short notes questions of which 8 must be attempted. Short notes questions will be designed to be answered succinctly in table, dot point, annotated list, graph or sketch diagram form. Total marks will be expressed as a final mark out of 50 plus a subtotal for the preferred topic.

Recommended revision plan:

• A    Clinical: use the Oxford Handbook of Tropical Medicine as a baseline, supplemented by the respective chapters in 22^nd edition of Manson’s Tropical Diseases, and the core text books for your chosen three other topics. Aim for a DTM&H standard of knowledge and use the sample questions with worked answers on the College website to assess your knowledge. Supplementary revision material can also be found on the MicroGnome website. When using other study materials, seek an Australasian perspective on the subject matter.
• B      Paraclinical: use the core textbooks in the recommended list to master each of the four topics. Priority should be given to health issues of direct relevance to the Australasian region, as applied by health practitioners in Australia and New Zealand. Ensure a good grasp of the common, the serious and life threatening. The part 1 exam will emphasise breadth of knowledge with practical use in our region. Sample questions with worked answers can be found on the College website. These examples are not exhaustive, nor are revision materials.

If in doubt about the scope of knowledge required, use the recommended textbook for that topic as a guide.

TJJI for the IEB, 13-AUG-10

What could be more difficult than trying to work out the cause of a serious pneumonia in time to guarantee successful treatment? Here are the ACTM primer of tropical medicine notes on the topic:

• ACTM Primer of Tropical Medicine
• Pulmonary Eosinophilias

So you missed this morning’s Tropical Medicine Breakfast and left the usual culprits to clear up the remains of breakfast. You missed a treat in more ways than one. With apologies to our out-of-town brethren who really do it tough, here are the electronic versions of the two Leishmaniasis units you missed.

1. Leishmaniasis 1: clinical tropical medicine
2. Leishmaniasis 2: clinical parasitology & entomology

For those working towards the ACTM Fellowship exam there are some useful on-line learning resources:

• eMedicine
• WHO
• Centers for Disease Control & Prevention
• Medical Journal of Australia

Clinical case of upper abdominal pain in overseas resident

A 54 year old businessman presents with right upper quadrant pain after spending the last six months living in Java.

An ultrasound scan revealed gallstones. A laparoscopic cholecystectomy was then performed. At this point a lesion was observed on the surface of the liver, but not biopsied.

Four months later, on another return visit to Australia, the patient re-presented with fever, a cough and pain radiating to his shoulder tip. He was admitted to a district hospital and a chest X-ray performed. Changes consistent with right lower lobe consolidation were observed and intravenous antibiotics (i.v. Ticarcillin/Clavulanic acid) commenced. The patient did not improve and was transferred to a larger hospital.

After 7 days of intravenous antibiotics he coughed up a large quantity of viscous, brown phlegm with a paste-like consistency. These CT scan views were obtained at this point:

CT thorax after coughing up 'anchovy paste'

CT upper abdomen showing hepatic lesion

The patient’s serum was sent to the Microbiology laboratory with the following result:

Entamoeba histolytica titre > 1:4096

This was seen under the microscope in the paste-like sample of phlegm:

Microscope view of patient's sputum, showing microbe with internalised red cells

Q1   What do the CT scans show?

Show answer

Q2   What object was seen under the microscope?

Show answer

Q3   What pathological process explains these observations?

Show answer

Q4   What treatment would you recommend?

Show answer

• Additional clinical questions
• Amoebiasis in Australia
• Travel related infections, case series from SCGH

So here it is; MicroGnome’s FACTM teaching unit on rabies.

You can find supplementary materials on the Priobe Net.

Download (PDF, 183.43KB)

ABC News, video clip on rabies outbreak in Bali, 29-DEC-10

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

Menu

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.

The MicroGnome recommends the following reading on the topics of Rabies and Schistosomiasis for those preparing for the part 1 FACTM exam.

Rabies

• Oxford Handbook of Tropical Medicine, 3rd edition pp 414-7.
• Manson’s Tropical Diseases, 22nd edition pp 799-814.

Schistosomiasis

• Oxford Handbook of Tropical Medicine, 3rd edition pp 314-7, and 370-1.
• Manson’s Tropical Diseases, 22nd edition pp 1425-60.
• Practical Guide to Clinical Parasitology, 2nd edition, pp 372-3.

These sources will be summarised in the mini-lectures next Tuesday.

Another nasty mosquito-borne disease brought by the Indo-Papuan conveyor. S Richie, Cairns, QLD

[notes on a lecture at the Centenary of tropical medicine meeting, Townsville, QLD, 12-13th June, 2010]

In 1995 cases of fatal encephalitis appeared for the first time in the Torres Strait. These were initially thought to be Murray Valley Encephalitis, but on further investigation turned out to be Japanese encephalitis. Conditions in the Torres Strait Islands (TSI) were suitable for JE transmission due to the presence of wading birds, pigs and receptive mosquito vectors, notably Culex annulirostris. There was concern that the combination of herons, egrets and feral pigs might lead to the spread of JE south through much of the Eastern Australia.

By April 2005 Aedes albopictus was present in the TSI and both Dengue and Chikungunya viruses could be detected. Some of the movement of this mosquito vector was blamed on the movement of heavy mining equipment around the region. Expansion of its geographic distribution now included areas as far afield as SE USA, S Europe and the W Pacific. As a potential Dengue virus vector there was concern that it might spread into Eastern Australia. Its ability to breed easily in small quantities of still water included in the TSI beached boats and discarded coconut shells.

Much of the fauna of the regional has been divided into distinct biogeographic regions separated by the Wallace line (named after the naturalist and co-discoverer of natural selection, Alfred Russell Wallace). This neat separation of fauna and flora has been blurred recently by anthropogenic factors such as transmigration. There have also been climate-mediated effects such as the Indo-Pacific region drought caused by a pronounced El niño effect in 1997/8. Modelling of the movement of an air packet during Cyclone Sid showed the plausibility of propulsion of Cu annulirostris from Papua New Guinea to the northern Cape York Peninsula during a cyclone.

Further mosquito breeding opportunities have been created by the well-intentioned installation of rain water tanks in the TSI by aid agencies. The legal entitlement to permit traditional owners’ family visits adds another means of assisting arbovirus migration. So a cordon sanitaire was established against Aedes albopictus. Other Culicine species have been observed on the Australian mainland, including Culex gelidus close to Brisbane airport. This species is a potential vector of JE in SE Asia.

The mechanism of arbovirus movement from SE Asia to Australia is less a conduit and more a conveyor belt. The question is which arbovirus will be next? Could it be Chikungunya virus? And what impact will the global movement of the human population have on this process?

Our next Tropical Medicine Breakfast is coming up fast. We’re going to be taking a look at two very different infections associated with travel in tropical places: rabies and schistosomiasis. For those studying for the part 1 FACTM exam, a short reading list will appear on this site before the weekend. Event calendar.

TMB notice

Snake bite. Prof D Warrell, University of Oxford

[notes on a plenary talk given at the Centenary of Tropical Medicine conference in Townsville, QLD, on 12-13th June, 2010)

Snake bite is one of the most neglected of tropical diseases. Its victims often die before admission to hospital and are thus lost from statistical analyses. A study from Bangladesh reported an estimate 700,000 bites per year causing 6000 fatalities. In India where the offical figure is 14,000 deaths from snake bite over many years, the estimated annual fatality figure has been estimated at over 45,000. Recent methods of analysis have applied a verbal autopsy to obtain more accurate data. Current figures are therefore likely to underestimate the global impact.

The burden of disease caused by snake bite is being reduced by a combination of approaches:

1. minimising contact with snakes through behaviour modification & appropriate clothing
2. improved first aid measures
3. better medical management

There has been a substantial  Australian contribution in several areas:

1        description of the Australian herpetofauna. Some are amongst the most venomous known. A new species of Taipan was recently discovered and named Oxyuranus frontalis, distinguished by a subtle difference in the arrangement of head scales, requiring examination at close quarters.

2        antivenom development. First use of antivenom was by Albert Calmette of the Institut Pasteur in Saigon, in 1894. He successfully used a specific antivenom raised against the monacled cobra venom to treat a laboratory worker who had been accidentally exposed. However, subsequent experience showed that this antivenom was too specific to use for all snake bites. In 1902 Tidswell described a tiger snake antivenom. Tiger snake bite has a fatality rate of up to 85%.

3        understanding the action & evolution of snake venom. Snake venoms are highly specialised in their action and have considerable specificity. They include a muscle damaging phospholipase, group C and D prothombin activators and naturietic peptides. The ACE inhibitor captopril was developed from the venom of the Brazilian jararaca snake.

4        development of effective first aid methods. Hamilton-Fairley recognised that snake venoms were rapidly absorbed via the lymphatics and that ligatures worked only as long as they were applied. However, some venoms are partly inactivated during this period. The pressure immobilisation method was described by Sutherland in 1979 and is now widely used. There are anecdotal descriptions of deterioration after release of the pressure bandage, but there has been no prospective RCT or other formal trials of clinical efficacy. The PIM approach is difficult to teach well, apply consistently and maintain, especially during transport to hospital. Alterntive methods e.g. the Monash foam rubber pad, may be more widely applicable at lower cost and with less prior expertise.

Before the colonial era Australia’s indigenous peoples had learned to live with some of the most dangerous snakes in the world. Data are hard to come by and suggest a currently variable experience of snake bite in indigenous communities from never recorded to a leading cause of death. Locally, the Banjan people introduce their children to the issue through dramatic instruction by wise people, or gubi murrays. They are taught to respect snakes, to walk in single file, to know places and times where snakes will be, and to burn off the area around a campsite. Snake bite is seen as a punishment for breaking the adult code. There have been no cases of snake bite or subsequent death in recent times (oral account, Russell Butler).

Clinical Case of the Febrile Returned Traveller

Ms A, a 23 year old aid worker who has just returned after half a year overseas. She spent six months on aid work in the Amazon region and had a two week holiday in Mozambique on her way home. She took no travel health precautions before or during her travel.

She developed fever and profuse diarrhoea on her last day in Mozambique, and went straight from the airport to the Emergency Department.

On initial examination she was alert and oriented, but unwell and dehydrated with a pulse of 120 and a blood pressure of 90/60. She had diffuse abdominal tenderness and a mildly enlarged spleen. Her chest was clear.

Q1. What is your differential diagnosis?

Show answer

The initial investigations were:

• Hb  100
• WCC  8.6
• Plts  25
• Na  135
• K  4.8
• Ur  13.7
• Cr 149
• Stool microscopy – no parasites seen

These blood investigations produced this result.

Q2. What are these investigations ?

Show answer

Q3. What is the result?

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Q4. What other widely available investigation would give a rapid confirmatory result?

Show answer

Q5. What treatment would you commence?

Show answer

The patient had a very stormy course.

• she was given 8L iv crystalloid in the first 24h, iv artesunate (SAS Category A, requiring informed consent), and exchange transfusion (6 units packed cells)
• despite this, she deteriorated and went into multiple organ systems failure and DIC, requiring 29 days in intensive care
• she was discharged from hospital, having lost 8/10 toes to necrosis

Additional resources

• other clinical problems
• malaria revision
• malaria files
• seafood poisoning & toxins

By popular demand, the Stafinator has provided a series of clinical problem-solving cases in tropical medicine.

Download (PDF, 5.63MB)

Some of these will appear on the MicroGnome site shortly as self-assessment exercises with the usual range of on-line features. In the meantime, click and enjoy. For other cases from the Stafinator, go to the Clinical Questions tab.

The next Tropical Medicine Breakfast at SCGH will see a change of form and content. Be prepared for some challenging clinical cases from the head of Infectious Diseases & Tropical Medicine, Dr Ronan Murray.

As the cases will be presented as unseen clinical problems, no material will appear in advance, other than the units that can already be found here at the Micrognome and on the Priobe Net site (see below). We recommend reading these notes if you want to earn your breakfast next Tuesday. The session is at 07:30 and will run until 08:30hr, on Tuesday 8th June in the ED Seminar Room, Sir Charles Gairdner Hospital.

Tropical medicine learning support at MicroGnome:

• malaria 1
• malaria 2
• malaria 3
• malaria 4
• arbovirus infections 1
• arbovirus infections 2
• neglected bacterial diseases 1
• neglected bacterial diseases 2

Tropical medicine resources at the Priobe Net:

• Plasmodium (malaria)
• Arboviruses
• Melioidosis

Oxford Handbook of Expedition and Wilderness Medicine. Johnson C et al. 2008, Oxford University Press. ISBN 978-0-19-929661-3

This title has been recommended as supplementary reading for the Fellowship of the Australasian College of Tropical Medicine part 1 exam (FACTM pt 1), and provides useful background reading for key modules (e.g. Malaria 3).

You know you’ve come to depend on a textbook when you feel lost without it. That was my fate recently when I had to go off on a field trip without my copy. It was a bad case of separation anxiety. This book is a strong addition to the Oxford Handbooks series and comes as a result of a collaboration between travel and medicine experts and the Royal Geographical Society’s Geography Outdoors centre. Hardly surprising, then, that this is a very practical book packed with advice for the intrepid traveller. This is more than a handy guide to doctors, nurses and paramedics. It has well laid-out advice . So what does this guide provide you? The contents follow a logical continuum, with emphasis on leading priorities:

1. Expedition medicine
2. Preparations
3. Food, water and hygiene
4. Crisis management
5. Emergencies – diagnosis
6. Emergencies – trauma
7. Emergencies – serious illness and collapse
8. Skin
9. Head and neck
10. Remote emergency dentistry for doctors
11. Chest
12. Abdomen
13. Limbs and back
14. Infectious diseases
15. Psychological and psychiatric problems
16. Risk from animals
17. Plants and fungi
18. Anaesthesia in remote locations
19. Cold climates
20. Mountains and high altitudes
21. Rivers, lakes and oceans
22. Caving expeditions
23. Hot environments – deserts and tropical forests

Three snapshots should give you an idea of how useful this book can be:  detailed instructions on how to purify water in the field, an overview of how to diagnose and treat gastrointestinal complaints during an expedition, an entire chapter on coping with risk from land and marine animals, and a guide to set up a medical evacuation by helicopter. This is an extremely practical book for people who need to know how to do things in remote places. It is necessarily short on explanation, discussion and speculation – not things you’re likely to have time or space for until you’ve made it back home in one piece.

The μGnome got out his set of paintbrushes today to refresh a set of disease maps for the forthcoming tropical medicine breakfast session at Sir Charles Gairdner Hospital.

Gone are the neat little red outlines carefully added to world map outlines. This is the genuine graffiti version in block colour – world distribution of scrub typhus and melioidosis, as of May, 2010.

The stand-alone maps will appear on the Priobe Net shortly.

Download (PDF, 618.35KB)

Manson’s Tropical Diseases. 22nd edn. Ed GC Cook, AI Zumla. Elsevier, 2009. ISBN 978-1-4160-4470-0

When a medical textbook reaches its 22nd edition, it has clearly become an institution. Manson’s Tropical Diseases has become one of the leading sources of authoritative opinion on tropical medicine in the English-speaking world. The most recent edition goes well beyond the standard fare of tropical infectious diseases to cover the challenges of other medical specialties in the tropics and a collection of non-infective conditions. This diverse range of topics has been presented to a consistently high standard; a notable editorial achievement for a topic with such breadth. 89 chapters are divided into 12 sections and supplemented by on-line material in a series of 5 appendices. It adds up to 1783 pages of carefully crafted professional writing.

From recent use [FACTM on-line modules; Malaria & Arbovirus Infections] I have been particularly impressed by Nick White’s magisterial chapter on malaria and David Smith’s group’s review of arbovirus infections. Both chapters are examples of lucid prose that is a pleasure to read for reading’s sake. They are also one of reasons Manson’s Tropical Diseases has sustained its success over so many editions, through making the familiar read as new while making the genuinely novel accessible to a wider audience. The editors have achieved this difficult balancing act by retaining many of their chapter authors from the 21st edition.

Manson’s Tropical Diseases is recommended further reading for the FACTM pt 1 exam.

Sections: underlying factors in tropical medicine, symptoms and signs, system-oriented disease, related specialties in the tropics, environmental/genetic disorders, viral infection, rickettsial infections, bacterial infections, mycotic infections, protozoan infections, helminthic infections, ectoparasites.

It’s time for a bit of variety. Sadly, we need to move on from malaria to deal with other arthropod-borne diseases. Next, it’s the turn of the arbovirus infections, with particular emphasis on the ones that we encounter more often in our own region. Next Tuesday (11th May, 2010) we’re running the arbovirus infection unit in our Clinical Tropical Medicine series. There will be two mini-lectures, the first of which is reproduced here for wider educational use. The second will be  a Medical Entomology module on the arthropod vectors of arbovirus infection.

Download (PDF, 233.68KB)