5 key points on fever in international travellers (clinical problem)

• a travel history should be obtained from anyone with a febrile illness
• malaria should be excluded in anyone with a fever who has been in a malaria-endemic area recently
• then consider dengue & other arbovirus infections if there has been mosquito exposure
• do not forget the neglected bacterial tropical infections: enteric fever, leptospirosis, scrub typhus & melioidosis
• do not forget to ask about potential risk for sexually-transmitted infections & HIV/AIDS

5 key points on enteric fever (lecture notes)

• potentially fatal infection caused by bacteria in the Salmonella Typhi group
• diarrhoea is uncommon in its early stages
• a rare infection where personal & community hygiene is of a high standard
• diagnosis is best confirmed in early infection by blood culture
• resistance to commonly used antibiotics is common

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

Registration is now open for the forthcoming day conference on Wilderness & Expedition Medicine in Bunbury, on Saturday 2nd October.

Download (PDF, 89.45KB)

• As interest in the conference is running high, we recommend early registration to ensure your place.
• Preliminary programme information can be found here. All speakers have been secured for the day.
• Programme details will be posted on this site as they become available.

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

And here is the other FACTM pt 1 teaching unit you may have missed last Tuesday. It deals with Schistosoma species; the group of blood flukes that cause a range of clinical syndromes including swimmer’s itch, Katayama fever and urinary schistosomiasis. You can find additional information on the Priobe Net.

Download (PDF, 398.96KB)

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

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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.

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?

Show answer

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.

11th to 14th June 2010.

• ACTM 19th Annual Scientific Meeting
• 25th AIMS Annual North Queensland Conference, Queensland Tropical Division
• James Cook University 40th Anniversary

There is still time to jump on the bandwagon: pre-conference workshops are not all fully booked. There is also room for a few more delegates during the weekend conference, which is packed with good tropical medicine, pathology, medical science and tropical public health [programme].

James Cook University Anton Brienl Centre; Friday 11th June, 2010

Conference highlights

• Keynote Address: Emeritus Professor David Warrell – Snake bite envenoming: 100 years of Australian contributions to combating the world’s most neglected tropical disease
• Robert Steffen: Risk and prevention of neurological infections in travellers
• Rod Campbell AM: The Robert Hirst Memorial Lecture: Modern microbiology in the tropics
• Santanu Chatterjee: Destination India

[conference or workshop registration]

]]> http://micrognome.priobe.net/2010/06/celebrating-100-years-of-tropical-medicine-in-townsville/feed/ 1 http://micrognome.priobe.net/2010/06/clinical-challenges-in-tropical-medicine/ http://micrognome.priobe.net/2010/06/clinical-challenges-in-tropical-medicine/#comments Fri, 04 Jun 2010 00:06:47 +0000 micrognome http://micrognome.priobe.net/?p=1125

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)

What’s the connection between Ena Sharples; the hairnet helmeted doyenne of Coronation St and tropical medicine? Coronation St afficionados would be hard pressed to place the sullen rows of back-to-back brick terraces with the humid tropics.

The explanation will be unveiled during next Tuesday’s tropical medicine breakfast in the Emergency Department seminar room at Sir Charles Gairdner Hospital.

You may glean a shrew idea if you take a look at the lecture notes before Tuesday.

Download (PDF, 830.79KB)

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)

Medical Entomology for Students. 4th edn. M Service. Cambridge University Press, 2008. ISBN 978-0-521-70928-6

Medical Entomology for Students

Mike Service brings his trademark clarity to this fourth edition of his highly regarded introductory textbook of medical entomology. It contains core subject material that has been tought to generations of DTM&H candidates.

Entomology is a very visual branch of the natural sciences and benefits from illustration. One of the strengths of this text is the careful choice of line diagrams that reinforce key differentiating features of disease vectors. In the 4th edition, colour figures have been added to support insect recognition skills.

Other modifications have been made for the fourth edition, particularly in recognition of recent changes in vector control. New transmission cycles for West Nile and Japanese encephalitis viruses have also been included.

The author’s emphasis on clinical and public health relevance runs from cover to cover and has led him, for example, to simplify the nomenclature used for Aedes mosquitoes. He is at pains to remind readers that this is a necessarily selective approach more suited to a subject matter primer, than to an exhaustive reference text. However, the enduring relevance of this book throughout the tropics is a measure of its continuing success.

This book has been recommended as core reading for the FACTM pt 1 exam.

Chapters:  introduction to mosquitoes, Anopheline mosquitoes, Culicine mosquitoes, black-flies, phlebotomine sand-flies, biting midges, horse-flies, tsetse-flies, house-flies and stable-flies, flies and myiasis, fleas, sucking lice, bedbus, triatomine bugs, cockroaches, soft ticks, hard ticks, scabies mites, scrub typhus mites, miscellaneous mites.