2nd AIF deployment in 1942

It is the 70th anniversary of the bombing of Darwin during the Second World War. More bombs rained down on Darwin Harbour that during the infamous attack on Pearl Harbour. But the attack on Darwin was only one of a series of coordinated raids on Australian targets. Singapore had just fallen to the advancing Japanese. Contrary to belief at the time, this was not a prelude to invasion. It was a preparation for the invasion of Timor. Three groups were dispatched to halt the enemy advance before they reached Australia. These were Sparrow, Gull and Lark Forces. Two of these were swiftly overrun, but a few hundred survivors of Sparrow Force and the commando-trained 2/2nd Independent Company consolidated in East Timor and sustained a guerrilla campaign for a year against vastly superior enemy forces.

The story of this heroic and largely forgotten struggle is told in a new exhibition launched this weekend by the Museum of Western Australia, entitled Debt of Honour. Artefacts, pictures, rare footage and interviews with surviving veterans of the 2/2nd Independent Company, 2nd AIF draw back the curtains on this action and its aftermath. The story is as much about the Timorese who helped the men of the 2nd/2nd survive and strike back at the enemy, and the tragic loss of life when Sparrow Force finally withdrew.

CAPT Dunkley, RAMC

The tropical medicine story in Debt of Honour is not difficult to winkle out. The small Army Medical Corps unit deployed with Sparrow Force was led by a CAPT Roger Dunkley, their only medical officer. He had to deal with malaria, other tropical infectious diseases and battle casualties in a makeshift field hospital under constant threat of enemy attack. It is said that he didn’t lose a single patient, yet very little is known about him beyond his service in both World Wars. His official portrait photo shows him as a quietly confident younger man. Other photos in the exhibit show him at ease with his comrades-in-arms, if a little war-weary.

There is much in this exhibition for those with an interest in the origins of our current friendship with Timor Leste, going back to the post-war ties between diggers and the families of their Timorese helpers (known as criados).

Debt of Honour runs until 20th May, before touring the rest of the country and going to Timor Leste. Entry is free.

Repaying the debt:

• 2/2nd Commando Association of Australia
• Bairo Pite Clinic, Dili, Timor Leste
• Melville Friends of Hatolia and Lete Foho
• Lab Without Walls, Timor Leste Project

Digger's slouch hat showing double diamond insignia of 2nd/2nd

When the wind blows

.. the cradle will rock. So the rhyme goes, reminding us that the elements are indiscriminate in their destructive actions. At the time of writing Tropical Cyclone Iggy lingers off our shore, still a little undecided on if and where to make landfall.

TC Iggy

The Australian Bureau of Meteorology website provides a useful introduction to cyclone climatology. The northwest WA coast is the most cyclone-affected coastline in Australia. The annual averages are:

• 5 tropical cyclones form off the northwest coast
• 2 cyclones come ashore
• 1 of these will be severe, most often in March or April

Making tracks

Cyclone tracks vary considerably, some making U-turns or even loops. However, BOM notes that there is a preferred route starting in a south westerly direction, then turning more southerly and eventually south easterly when they travel as far south as the Pilbara.

The link with melioidosis

The path cyclones follow has been a matter of interest to the Micrognome for some time because of the link between melioidosis and severe weather in northern Australia. His team noticed there was a correlation between the direction cyclones took in a given year and the number of cases of severe disease.

Cyclone dynamics

Cyclone physics is complex and reflected in the variability of their destructive effect, wind speed, rainfall and duration. In general, BOM notes four main stages in the life-cycle of a tropical cyclone: formative, immature, mature and decay. We noted that the years when more cases occurred were years in which cyclones made landfall over the Northern Territory then followed a south westerly track. Years with cyclones approaching exclusively from the West and making landfall over the Kimberley or Pilbara coast were not bad years for severe melioidosis.

The fluid dynamics of interaction between a cyclone and the land it passes over  are most definitely complex. An added level of complexity is the rainfall that occurs in the cyclone’s decay stage. This looks like it may explain some of the excess cases observed in the NT.

At least we can predict cyclones like TC Iggy are unlikely to cause extra cases of melioidosis, while the likes of TC Carlos (see moving image) are a different kettle of fish.

Melioidosis info sources

• melioidosis clinical guideline
• the treatment of melioidosis
• melioidosis, a disease of surprises

It’s that time of year when gnomes engage in their annual migration. This year the Micrognome followed the mercury downhill and ended up on the apple isle for a few cool days off grid.

Ah, the epicurean delights of Launceston and its hinterland. But if the food, wine and excellent service aren’t reason enough, here are some other excuses to visit Tasmania:

• beaches on the Freycinet Peninsula
• glimpses of history
• morning cloud lifting off mountainsides (picture above)
• the Cradle Mountain National Park (below)
• rare flora and fauna
• bountiful harvests
• serious off grid activities: bush walks, sea kayaking, fishing
• unlimited Oxygen
• limited Net access

Why wouldn’t you?

There’s no doubt about it. Recent shark attacks in WA have attracted comment from leading politicians. But how about this for a new angle on the shark thing: according to a Sydney researcher, the term “shark attack” is sensationalist and misrepresents their intentions.

These comments followed an ‘incident’ in New South Wales last week involving an encounter between a swimmer and a shark.

The MicroGnome wonders how many sharks were interviewed and whether the opinion of any (human) victims has been sought. Shark advocacy could be a very lonely crusade, given the frequency of shark sightings, attacks and near-misses (map).

If we have to be  PC should we not speak of shark-assisted bacterial attack, or inoculation with extreme prejudice?

Followers of this blog will be familiar with our digressions into slow food, epicurean travel and even the culinary delights of good food closer to home. But in the white heat of clinical science, we have to make do with coffee fumes and the occasional thought of home cooking.

The holiday season has provided the Micrognome and colleagues ample opportunity to get back into the kitchen and rediscover the pleasure of serving up good food to family and friends. Sometime, just sometimes, the watched pot hasn’t done its stuff quickly enough to stop the mind racing back to the lab. On one such occasion the MicroGnome paused to consider how much cooking technology we use in the molecular biology lab.

Here’s a short list of lab gear and kitchen equivalents:

The big difference, obviously is the scale of operation. So why do we sweat the small stuff in the lab, then need so much cold storage space? The average sized -20′C freezer in a domestic kitchen is dwarfed by the -80′C freezers we use to store stuff. Maybe we make up for the small scale by hoarding more, longer.

Given this re-connection with the MicroGnome’s inner chef, readers will not be surprised to learn that cutlery tidies make excellent containers for automatic pipettes, colour-coded cutting boards are suitable for molecular contamination control, and stacking food boxes are good eyeline tidies for the likes of tips, 1.5mL tubes and 96 well trays.

Not all of this works well in a lab without walls, but maybe we should think about taking over the camp kitchen when we need to hitch up a bunsen.

What’s your lab cooking today?

Followers of this blog will know how much a good cup of coffee matters to the MicroGnome. Regulars will know how to ask for their preferred cup in several languages. Australian coffee taxonomy is typically descriptive, direct and Anglo-Saxon; as you would expect from a nation with a high consumption: production index. Some will be surprised to know that Australia produces coffee. Not a lot, to be sure, but about as much as you’d expect from an island with relatively little suitable coffee-growing territory. However, that may have to change if we’re to keep up with our daily coffee needs.

• Coffee alert 1: scientists are beginning to warn that a series of coffee pests are already reducing output of the majority Arabica bean. Coffee borer and a fungal infection called coffee rust have reduced yields so much that well-known brands have had to put up their prices. The coffee berry borer, Hypothenemus hampei, is native to Africa. It is a small beetle recognised as the world’s most harmful coffee pest.  Interestingly, there is some evidence that commensal Wolbachia bacteria may help determine the sex of coffee borer beetles: proof that bacteriology is far from boring.
• Coffee alert 2: climate change monitors warn that even small changes in local temperature will significantly increase the reach of these threats to the global coffee crop, making coffee a sensitive indicator of global warming. We might whinge about the increasing price of a cappuccino, but spare a thought for the producers. Coffee is grown around the world in the tropical zone, where warmth, persistent moist air and good rainfall combine to support a viable crop. Coffee is therefore an important cash crop for many poorer parts of the world, and a loss of production translates directly to a loss of income for already disadvantaged communities.
• Coffee alert 3: If you take a look at the coffee growing map of the world, you can see considerable overlap with a range of tropical infectious diseases. Diseases such as tuberculosis, malaria, leishmaniasis, dengue and leprosy feature in many of the coffee growing areas. Neglected tropical diseases such as onchocerciasis, filariasis, other arbovirus infections, rickettsial diseases and nutritional disorders are also part of the epidemiological coffee-growing map. Then there are the food and water-borne diseases of these places: acute gastrointestinal infections, enteric fever, cholera and dysentery, giardiasis, amoebiasis, strongyloidiasis and other helminth infections.

Maybe we ought to look more closely at the links between growing coffee and tropical diseases. At very least, we ought to ask how the coffee industry could improve health benefits of the coffee producers. Something to consider the next time you enjoy your favourite wake-up drink.

MicroGnome, 2-JAN-12.

This is the time of year when we reflect on the event of the past year and prepare for what might be coming over the horizon. 2011 was a year of steady progress in the field of infectious diseases, with notable milestones in all of the big three and some game-changing developments for other infections.

The MicroGnome has picked a handful of achievements for this 2011 MicroGnome review that should inspire anyone with an interest in infection. If you have been living under a stone all year, maybe you should try the coffee zone for a less demanding read.

• Malaria: progress made on a malaria vaccine that works

Reporting the preliminary results of a phase three trials of the RTS,S vaccine candidate in neonates and infant groups from seven African countries over 14 months, the authors of a November paper in the New England Journal of Medicine reported a halving of malaria, and a 45% reduction in severe malaria cases. While these effects are far less than routinely used childhood vaccines, they raise hopes for development of a mortality-reducing malaria vaccine.

• Tuberculosis: working out rapid molecular tests for TB in low income countries

Promising early performance studies prompted the World Health Organisation and other donor agencies to equip clinical laboratories in resource-poor countries with rapid molecular screening tests for pulmonary tuberculosis. In a useful review of this application of molecular microbiology, Carlton Evans explains the need for caution in the introduction of this technology to low and middle income countries.

• HIV/AIDS: antiretroviral therapy has a primary preventive effect

There is a growing awareness of the potential for antiretroviral agents in a preventive role. In a mathematical model of the cost effectiveness and impact of different strategies, an international group showed that effective preventive pre-exposure prophylaxis of the uninfected partner could be more effective than commencing ART earlier in the infected partner.

• Septicaemia: MALDI-TOF speeds up bacterial identification in septicaemia

The application of mass spec-based methods for identifying the contents of blood cultures has been gathering pace in Europe for several years, and has started to spread to other parts of the world. While some clinical laboratory directors might have their heads stuck in the sand, there are plenty of pathologists who would give an arm and a leg for equipment that can trim around 24hr or more off the time to identification of bacterial causes of septicaemia. Klein and colleagues are one of many groups working out how to implement this emerging technology in a busy clinical laboratory service.

Influenza: working out why the vaccine had adverse effects

the adverse effects of Australian produced vaccine are thought to have been due to suboptimal virus splitting by a deoxycholate-based procedure. Benefits of vaccination still outweigh the risk of adverse effect.

• Dengue fever: vaccine trials promise improvements in dengue control

A phase three trial of a tetravalent live attenuated vaccine against dengue virus is now under way. Once industrial production of this promising candidate has been established, its efficacy confirmed and administration optimised, it will be of considerable interest to many parts of the tropics where dengue is a substantial burden on the public health.

So what’s in store for 2012, apart from more of the same?

At a guess, it looks like we’re going to drill deeper into severe sepsis, see an expanding series of field studies and continue our peripatetic investigation of tropical infectious diseases. The language of infection series is set for significant expansion in support of teaching and training activities. One outcome of our 2011 MicroGnome Review was to recognise the need for an expanded writing team. The group sends you their best for 2012, and will now pause briefly to welcome in the New Year.

Trouble in paradise

Once again, Bali has been in the news for the wrong reasons. A favoured holiday destination for so many Australians, Bali has now added a sinister new hazard to its growing list of health risks with notification of HIV infection contracted as a result of a holiday visit to a tattoo artist. Australian public health physicians have urged anyone who has recently got a tattoo while on holiday in Bali to have their HIV status checked: trouble in paradise.

The list of recently documented infection risks associated with travel to Bali and neighbouring Indonesian islands includes:

• Dengue, a common and potentially serious viral infection transmitted by mosquito bites. Cases here have almost doubled every year for five years and are mostly associated with international travel, particularly to Bali. There is currently no vaccine and no effective treatment. Control relies on avoiding mosquito bites where the disease is present.
• Gastrointestinal infections due to Salmonella, Campylobacter and E.coli. Around one third of Salmonella cases originate overseas, mostly in Bali where Salmonella Enteritidis is common.
• HIV/AIDS, and other blood borne viruses from contaminated tattoos, but can also arise from unprotected intercourse, recreational injecting drug use and other exposure to contaminated blood or body fluids. Evidence in recent case may point to tattoo but other routes of infection are possible. In recent case causal contribution of tattoo is debatable.
• Legionnaires’ disease connected with hotel air conditioning, spa baths and warm water systems. Recent cases in people staying in Kuta hotel.
• Rabies, from dog and monkey bites. More than 130 local rabies deaths in recent years. Most districts affected. A control programme has caused a fall in numbers of cases, but has not eliminated the disease. Regular reports of tourists unable to obtain or complete post-exposure vaccination in Bali due to inadequate supply. [Read Geographical Magazine's article on the Bali rabies eradication programme]
• Other infections: Japanese encephalitis can occur following mosquito bites in rural areas. Chikungunya is another mosquito-borne viral infection with an unpronounceable name. Leptospirosis can arise following exposure to contaminated inland water. Sexually transmitted infections are common when holiday-makers let their guard down, throw caution to the wind and engage in behaviour they may come to regret soon afterwards.

The current (as of 26-DEC-11) official recommendation is to reconsider travel to Indonesia, but this doesn’t seem to stop large numbers of Australian holiday makers travelling without taking professional advice or specific health precautions. General practitioners and travel medicine specialists have to pick up the pieces when holiday-makers fail to respect the hazards of mass tourism in a developing country. The risks are not the same as those of holiday travel at home. A naive she’ll-be-right approach to international travel in our region is irresponsibly dangerous.

As some readers already know, the Micrognome has been out of action, suffering the kinetic effects of a vehicle accident. For the second time in a year, our gnome experienced the skills of colleagues in a nearby emergency department. This time, though, he went to work in an ambulance, kinetic effects having already transformed the gnomobile into an untidy sculpture. Entering the ED via a trauma bay is not a highly recommended way to start work. Being on the receiving end of EMST standard procedure was quite surreal, knowing what was going to come next at every step of the way including when and how the nurse will slice through your nice cotton shirt (this hospital will have the shirt off your back!).

kinetic effects

Happily, the kinetic effects were significantly reduced by the swift deployment of every airbag imaginable. The oncoming vehicle hit the gnomobile’s forward nearside, spinning it round. So the Micrognome was rocked but not rolled. His ribs brushed the edge of the steering wheel. It could have been much, much worse. And it gave the gnome a good excuse to visit his hospital as a mystery shopper, as one helpful friend pointed out.

The specifics of this particular MVA aside, the down time has given our gnome an opportunity for reflection on the connection between infection and vehicle collisions, lateral or otherwise. The literature inevitably concentrates on the immediate catastrophic kinetic effects and their consequences. Until recently there has been a paucity of good data on infection as a consequence of vehicle accidents. These non-kinetic effects are now starting to feature in larger population studies.

• Fraser DR et al. Infective complications after vehicle trauma in the United States. Surg Infect 2011; 12: 291-6.  Nearly 800,000 vehicle trauma patients were surveyed in the US National Inpatient Sample (drivers 59%, passenger 18%, motorcyclists 13%, pedestrians 9%). 5.7% (44331 patients) had a post-traumatic infective complication. Those with spinal cord injury had the highest rate of infection complications, and the risk increased with prolonged hospital stay, particularly including intensive care admission for more than 7 days.

• Kourbeti IS et al. Infections in traumatic brain injury patients. Clin Microbiol Infect 2011. In this study from a neurosurgical centre, 760 patients between 1999 and 2005 with a median age of 41yr were surveyed. 214 developed infection. Multivariate analysis indicated that 2 or more surgical procedures, additional infections, lumbar or ventricular drains and CSF leaks were all associated with increased infection risk. It has been suggested use of probiotics could reduce the infective complications of traumatic brain injury.

• So why don’t we worry more about infection as a late complication of vehicle trauma? Perhaps the answer can be found in the thinking around the early management of vehicle trauma. One influential consensus conference working on definitions of systemic inflammatory response syndrome in the critically injured patient found that while there was an increased risk of sepsis, severe sepsis and septic shock following penetrating trauma, the only significant difference in mortality was between shock and other categories of physiological deterioration and organ dysfunction (Muckart DJ et al. Crit Care Med 1997; 25: 1765-6).

• Prevention of infection is therefore best effected by primary and secondary prevention i.e. stop the accidents from occurring in the first place, and minimise their effects through safety features in the vehicles. In view of WA’s recent history of road accident deaths, it was good to hear a sober reminder of the need for caution on the roads over the summer holiday period. Having survived a high impact collision and experienced the cocooning effect of front and side airbags, the Micrognome agrees that younger drivers must be encouraged to focus on safety and not high performance.

• Worryingly, the data suggest that these is a small percentage of young adults who persistently take silly risks with their lives. A large study in Florida (Eaton DK et al. MMWR Surv Summ 2010; 59:1-142) showed that almost 1 in 10 high school students rarely or never wear a seat belt and over a quarter are willing to ride in a vehicle driven by someone under the influence of alcohol. It’s tempting to think “only in America”, but the recent antics of some high school students closer to home suggest that an ill-founded belief of immortality is alive and well in Australia.

• For insight into risk-taking behaviour and how it affects vehicle trauma casualties, an interesting study of the ecology of fatal traffic accidents provides some useful insight (Moller AP et al. 2011). This group looked at the species of birds killed by collision with motor vehicles in one location in Europe. They found that the risk of fatality was a function of species abundance, rather than whether they either sat on the road or swooped low towards vehicles. Controlling for species abundance, they noted that higher risk of collision was present in species with short flight range (therefore increased risk taking), solitary species, a large bursa of Fabricius, or with Plasmodium infection.

This last observation brings us full circle, and raises the obvious question: does pre-collision infection increase the probability of collision by affecting risk-taking behaviour in humans? Common sense suggests it would. There may be more to infection and trauma than is currently acknowledged.

Micrognome, 11-DEC-11

What is a bacterial full stop?

These and other insights into how the language of infection is punctuated can be found in a new chapter in LoI: punctuation (highlighted paragraph at the top of Micrognome’s home page).

The comma, full stop, quotation, question and exclamation marks all get a mention. Apostrophies only get a passing nod, though a future post may give this grammatical problem child a special mention.

Micrognome, November, 2011.

Cultural diversity

The Commonwealth Heads of Government Meeting (CHOGM) was over in a few action-packed days. During the week surrounding all those high level meetings, Perth-dwellers welcomed a host of visitors from all over the planet.

partying on after sunset

Naturally, there were plenty of events to celebrate and showcase cultural diversity. Flags flew to mark the culmination of the Commonwealth Arts Festival, the best chanteuse sang, and the band played on into the night. The week long party ended with a spectacular display of fireworks on the banks of the Swan River, with the City of Perth as a backdrop.

The Micrognome couldn’t help notice this exhibition of Western Australia’s unique biodiversity, packaged in a cluster of boxes. Not the lab-in-a-box this time, but at least his beloved Kimberley got a generous mention. Sadly missing from this window on cultural diversity was any mention of the diversity of culture; specifically bacterial culture, we know inhabits this State. So much work to so, such large distances and so few already working on it. The Micrognome suspects there may be an opportunity there for an enterprising environmental bacteriologist.

Lab-in-a-box?

Clinical Parasitology

This list captures a typical top ten common enteric parasites of medical importance, though the order of importance will vary around Australia. Information on Entamoeba histolytica is given, as this species is a common reason for a test request even if a positive result is relatively uncommon. The pathogenic role of several of the other parasite species is debatable, and detection may be more useful as an indication of poor hygiene, recent international travel or immune compromise. Further details at the CDC.

Hebridean coast

See the superb SBS doco on the Outer Hebrides (the End of the Earth) here.

For one week only.

Shark map WA

Western Australia’s most recent fatal shark attack has given sandgropers something to take their minds off the current international event in town. Plenty of newsprint, news footage and comment has agonised over how to respond to another grisly death by jaws. Shark experts point out that the global death toll from shark attacks is around one tenth the deaths caused by coconuts. But that doesn’t help the debate much. We prefer to let the data speak for itself. Here is a summary of the geography and timeline of shark attacks in WA since 2000: the WA shark map.

Fatal shark attacks off the WA coast since 2000.

fatal attacks

Non-fatal attacks with serious injuries since 2000:

serious injuries

WA shark attack time line, 2000-2011

Encephalitis outbreak

Gorakhpur, Uttar Pradesh (arrow)

Reports of an encephalitis outbreak centred on the northern Indian town of Gorakhpur are starting to filter through. Those most severely affected are mainly children. The area experiences periodic outbreaks of Japanese encephalitis, especially when rain promotes mosquito breeding, but local health authorities say this appears to be different from Japanese encephalitis and are blaming it on contaminated water.

The Micrognome wonders what public health lab assistance is available in this part of India, knowing from recent Lab Without Walls experience that truly portable virology investigation tools are not often in evidence. If the world can muster the technology to put a tablet computer in the hands of children in far flung villages, surely it can spare the time and effort to bolster their defences against a rogue arbovirus or variant enterovirus?

It is encouraging to hear that authorities strengthened the investigating team based at the local BRD Medical College, and the the Centers for Disease Control are assisting with sample analysis (BBC report). Time (and lab results) will tell if this is an emerging infectious disease or not.

Meanwhile, it would be good to hear that public health capability has been permanently strengthened in order to sustain disease control measures arising from preliminary investigations. History suggests that once an outbreak dies down, the issue slips out of the public eye and key disease control measures ease off.

Further information:

• BBC: encephalitis
• BBC report, encephalitis in India, October 2011

Jobs well done

Much has been said already about Steve Jobs’ achievements since his all-too-early passing. There is no need to repeat a detailed assessment of his contribution to consumer communications or applied information technology. But the Micrognome cannot avoid a brief appreciation of a life dedicated to improving information design.

• MacBook air, on which much of this blog & most of our papers are written
• iPod, on which Micrognome’s language learning media are stored
• iPad, which delivers assorted medical apps, lab results & stores scientific papers into the hospital or clinical lab
• iPhone that provides the mobile link with the Web

All jobs well done, establishing the links between the problems and the problem-solvers in a global professional network.

So it’s over to us now. The technology is no longer the obstacle. It’s up to us to work out how to best use iT to benefit others, whether it’s a matter of bridging the health gap in our own remote communities, neighbouring countries, delivering distanced education or just working out how to order a better cup of coffee.

Calculated risk?

Shark bitten?  2 fatalities in as many weeks is not the best publicity for WA tourism as the CHOGM circus comes to town.

[The disappearance of a morning bather off Cottesloe in Western Australia has set off another salvo of rounds in the long-running debate over how best to avoid shark attacks.] That was the comment on 13-OCT-11. Now, with a second shark-attributed fatality in two weeks off the Western Australian coast, we wonder if paddlers, surfers and other beach goers might give the beckoning brine a miss for a while.

As soon as the beach was declared fit for use after the first attack, intrepid sandgropers were back in the water demonstrating their ownership of the shark-contested zone. Bathers strayed beyond the flags, but few ventured past the beacon. Examination of the stats suggests that the roads are a riskier environment than Australian coastal waters, but a second attack in such a short time has upped he ante.

For those who like to be well-informed, the Australian Shark Attack File has been maintained by Taronga Zoo since 1984. Three fatal shark attacks have occurred off WA this year.

• Australian shark attacks
• map of Australian shark zones with timeline of recent fatal shark attacks (Australian Geographic)
• global shark attack map
• infections in non-fatal attacks

snowflake?

Fractal geometry, anyone?

Here’s one for those who appreciate the beauty of cellular organisation in the microbial world. No need to tell you what microbe this is – if you need to know, you’ll have recognised it already. If you don’t know its name, never mind. Just appreciate the fractal geometry.

Micrognome, October, 2011.

Flu vaccine conversation

After all the huffing and puffing over whether or not to vaccinate against epidemic influenza at the start of the winter respiratory virus season, we appear to have got away almost unscathed. Critics of vaccination will, no doubt, rub their hands with glee and claim that it all goes to show that we don’t need the vaccine. Those of us who’ve had to deal with the severe end of the disease spectrum are left wondering how such a small piece of microbial real estate can still cause fatalities when the bulk of the population gets off scot free. Maybe we needed to get the controversy out of our system, air our natural leanings to skepticism or whatever other camouflage we need to use for not liking the annual flu shot.

Cause of vaccine reaction?

• The discussion previously known as a controversy has morphed into a more considered conversation on attitudes to flu vaccination and the specific reasons for the high level of adverse reactions seen in children. Kelly and colleagues highlight the importance of public confidence in population vaccination programmes, and how that trust is more quickly lost than earned (1). In their analysis of last year’s adverse flu vaccine events, they propose that the vaccine reactions may have been due to use of deoxycholate as a virus splitting agent in the brand of flu vaccine associated with many of last year’s adverse events.

Low vaccine uptake by hospital workers

• Reducing the risk of these reactions is obviously a priority if public confidence in flu vaccination is to be rebuilt. Reliance on personal attitudes towards a public vaccine programme is obviously a flimsy basis for progress when the general public have a low opinion of vaccination in the first place. Withdrawal of the offending vaccine was an important start, but a much deeper understanding of the connection between vaccination and claimed adverse effects is needed if health professionals are to be relied upon to support future vaccination programmes. This rather grim conclusion is the logical consequence of the low rates of flu vaccination reported in another study in the same edition of the Medical Journal of Australia (2). Health care workers generally don’t like getting their annual flu shots. The Micrognome suspects that some hospital doctors suffer from delusions of immortality, but recognises that others harbour concerns about Guillain-Barre syndrome following flu vaccination. This study concludes that vaccination may need to be mandatory or a matter of policy in order to increase health care worker uptake.

While the Micrognome dislikes the annual inconvenience and discomfort of flu vaccination, he recognises a need as a responsible citizen to man the hospital barricades against the advancing hordes of influenza virus each winter. In that respect, each shot is another brick in the wall.

Let the conversation continue.

References

1. Kelly HA, Skowronski DM, de Serres G, Effler PV. Adverse events associated with 2010 CSL and other inactivated influenza vaccines. Med J Austral 2011; 195: 318-320.
2. Seale H, MacIntyre CA. Seasonal influenza vaccination in Australian hospital health care workers: a review. Med J Austral 2011; 195: 336-338.

Myiasis

Dermatobia larva, ca. 1cm long

Infestation of skin by fly larvae, which feed on living or dead tissue

There are three main variants of this condition: cutaneous, body cavity and accidental myiasis

1   Cutaneous myiasis

• bloodsucking, in which larvae attach to the skin and either bite or suck blood: Auchmeromyia, Tabanidae, Therevidae
• furuncular, in which larvae penetrate skin to make boil-like lesions: Cordylobia, Dermatobia, Wohlfartia
• creeping, in which larvae tunnel in the epidermis without completing their life cycle: Hypodermatinae, Gasterophilinae
• wound/traumatic, in which larvae develop in wounds: Calliphoridae, Fanniidae, Muscidae, Phoridae, Sarcophagidae

2   Body cavity myiasis

• nasopharyngeal, lung, auricular & ophthalmomyiasis in which eggs or larvae deposited in cavities: Calliphoridae, Oestridae, Phoridae, Sarcophagidae

3   Accidental myiasis

• intestinal, in which larvae ingested or enter via rectum: Anisopodidae, Calliphoridae, Drosophilidae, Fanniidae, Muscidae & others
• urogenital in which adults attracted to infected tissue or clothing: Anisopodidae, Calliporidae, Fanniidae, Muscidae and others

Larva of Dermatobia hominis, the cause of furuncular cutaneous myiasis in man, cattle, dogs, other mammals and some birds in Central and South America.

D. hominis is occasionally seen in international travellers from outside the region. Dermatobia belongs to the Cuterebrinae sub-family of the Oestridae family of Diptera. Their larvae have bodies with strong, evenly distributed spines and posterior spiracles with a lot of small, serpentine slits.

A small nodule with a central breathing pore develops around the larva at the site of penetration. These swelling usually last for a few weeks, before the mature larva emerges and drops to the ground to pupate.

Reference:

Hall MJR, Smith KGV. Diptera causing myiasis in man. Ch 12. ed Lane RP, Crosskey RW. Medical Insects & Arachnids. Chapman & Hall, London, 1993. ISBN 0 412 40000 6.

Micrognome, October, 2011