Life in the Fast Lane Medical Blog » Tropical Medicine

Fever, Rash and a Vuvuzela

Chris Nickson — Mon, 27 Sep 2010 00:00:27 +0000

Life in the Fast Lane Medical Blog Fever, Rash and a Vuvuzela

aka Tropical and Travel Troubles 001

A 34 year-old man became unwell soon after arriving in Australia, having recently traveled to South Africa to watch the soccer World Cup. He hasn’t even felt like using the vuvuzela he bought.

Unwell for 4 days, his symptoms include malaise, poor appetite, cough, and fever. He has bilateral conjunctivitis and an erythematous macular rash has started to appear on his neck and face.

Examination of his mouth reveals these lesions:

Image from the Public Health Image Library (PHIL) --- click image for source

Questions

Q1. What is shown and what is the diagnosis?

Answer and interpretation

Koplik spots

These are lesions on the buccal mucosa consisting of pinpoint greyish spots surrounded by bright red inflammation. They are considered pathognomonic of measles (aka rubeola), although they are only seen about 60% of the time, occuring just before the onset of the measles rash.

Measles is a highly infectious ssRNA virus (of the family Paramyxoviridae and the genus Morbilivirus) spread by respiratory secretions via aerosolised droplets.

Worldwide, measles is still the 5th leading cause of death in children aged <5 years-old.

Q2. What is the differential diagnosis?

Answer and interpretation

Australia has been officially measles free since 2009, so the ‘measles clinical syndrome’ of cough, fever, conjunctivitis and rash actually has a low positive predictive value for measles in most settings. However, imported cases may still lead to outbreaks.

The differential diagnosis of the ‘measles clinical syndrome’ includes:

Viruses —
rubella, parvoviruses, HHV6, flaviviruses, adeno-associated viruses, coxsackie, echoviruses
Bacterial infection —
streptococcus, meningococcocus, rickettsiae, spirochaetes (syphilis, Borrelia spp., Spirilium minus)
Fungi —
Coccidioides immitis
Non-infectious or post-infectious causes —
Kawasaki disease and its differentials

Q3. What are the typical clinical manifestations and course of this condition?

Answer and interpretation

Incubation period:

10 days (7-18 days)

Prodrome (2-4 days):

‘measles is misery’
fever, malaise, poor appetite
cough, coryza and bilateral conjunctivitis
Koplik spots (~60%)

Rash:

maculopapular, non-itchy, non-vesicuar rash —
starts behind the ears and hairline, spreads to the face, then the trunk, then the limbs
becomes confluent
fades after about 3 days
patchy areas of desquamation and brown-yellow discolouration my occur

Generalised lymphadenopathy and splenomegaly may occur.

Image from Public Health image Library --- click image for source

The typical time course of symptoms:

Q4. What is the infective period?

Answer and interpretation

Measles is highly infectious and affected patients should be kept in isolation. The infective period is:

from 1 day prior to the appearance of the rash, to 4 days after its onset.

Q5. What are the possible complications of this condition?

Answer and interpretation

Most cases are measles resolve without complication — however fatal complications can occur, especially in young children, the malnourished and the immunocompromised.

Common:

otitis media (9%)
Other ENT and respiratory tract involvement — sinusitis, laryngotracheobronchitis, bronchiolitis, pneumonitis
diarrhoea (8%)
bacterial superinfection (e.g. pneumonia 6%)
exacerbation of Vitamin A deficiency leading to blindness in the malnourished.

Uncommon:

encephalitis (~1/1000, ~15% fatal) — more common in adults
subacute sclerosing panencephalitis (1/100,000)
transverse myelitis
myocarditis
hepatitis

Unlike rubella, measles is not teratogenic in pregnancy but may cause preterm births and stillbirths.

Q6.What is subacute pansclerosing panencephalitits?

Answer and interpretation

A rare degenerative brain disorder that typically follows a case of uncomplicated primary measles, usually in a child younger than average at the time they contracted measles. After 5 to 10 years myoclonus and focal neurological deficits occur, heralding progressive CNS degeneration resulting in death over a period of months to years. The condition is almost unheard of since the widespread adoption of measles vaccination.

Q7. How should a suspected case be managed?

Answer and interpretation

Measles is a notifiable disease.

In the emergency department:

triage to an isolation room and take droplet precautions.

Diagnostic tests to confirm/ exclude measles:

measles IgM serology —
detectable from the first few days of infection (70% at day 3 of illness, about 100% at day 7) until 4-12 weeks. False positives and recent measles vaccination may confound the result.
paired measles IgG serology —
the IgM result can be confirmed by testing for measels IgG within 7 days of rash onset, and repeating the test at 3-4 weeks.
RT-PCR and EIA —
RT-RCP may be used when serology is not diagnostic, to genotype the virus and trace its likely geographical origin.
Can be performed on throat swabs, urine, blood, and nasopharyngeal aspirates.
Tests for other pathogens in the differential diagnosis

Treatment:

supportive care
treat bacterial superinfection with antibiotics
treat complications
vitamin A supplementation if malnourished

Public heath measures (see Q9):

Public health authorities should be contacted as soon as possible to assist in confirming/ excluding the case as soon as possible and so that a potential outbreak can be contained.

Q8. Describe the vaccine used in Australia. When is it given and what are the possible side effects?

Answer and interpretation

The MMR (measles-mumps-rubella) vaccine is a safe and effective vaccine adminstered as 0.5 mL SC/IM.

The MMR vaccine is a live attenuated vaccine that is 99% effective if two doses are administered at ≥12 months of age and at least 4 weeks apart. It is given at age 12 months and 18 months (previously 4 years) in Australia. During an outbreak the vaccine may be given to children as young as 6 months old. Live vaccines should not be given to the imunocompromised or the pregnant, and not within 4 weeks of another live vaccine.

Side effects include:

Malaise, fever (5-15%) and/or a rash (5%) — most commonly 7 to 10 days (range 5–12 days) after vaccination and lasting about 2 to 3 days.
Febrile seizures — 1 case per 3000 doses of MMR vaccine administered
Anaphylaxis — very rare (<1 in 1 million doses), likely due to gelatin or neomycin anaphylactic sensitivity, not egg allergies.
Other rare adverse events attributed to MMR vaccine include transient lymphadenopathy, arthralgia, parotitis and thrombocytopenia (usually self-limiting)
It is uncertain whether encephalopathy occurs after measles vaccination — if so it is very rare.

In the near future, MMR may be replaced by MMRV in Australia, to also provide immunity against varicella (chicken pox).

The MMR vaccine is not causally linked with autism, autistic spectrum disorder or inflammatory bowel disease — most ‘scientific’ proponents of the hypothesis have retracted their claims and there is good evidence to refute it.

Q9. What public health measures are required following the diagnosis of this condition?

Answer and interpretation

Public heath measures:

notify public health authorities
contact tracing
immunisation of susceptible contacts —
MMR vaccine if <72 hours
(the vaccine has shorter incubation period than the wild-type virus)
normal human IgG if >72 hours but less than 7 days
isolation of cases until 4 days after the onset of the rash (14 days for susceptible contacts not vaccinated witihin 72 hours of contact) —
discharged patients should stay at home for this period.

References

Australia Immunisation Hanbook (9th edition) — Measles.
Center for Disease Control and Prevention. Measles.
Durrheim DN, Kelly H, Ferson MJ, Featherstone D. Remaining measles challenges in Australia. Med J Aust. 2007 Aug 6;187(3):181-4. PMID: 17680748.
Immunise Australia Program. National Immunisation Program Schedule
MacIntyre CR, McIntyre PB. MMR, autism and inflammatory bowel disease: responding to patient concerns using an evidence-based framework. Med J Aust. 2001 Aug 6;175(3):127-8. PMID: 11548076.
Marx JA, Hockberger R, Walls RM. Rosen’s Emergency Medicine: Concepts and Clinical Practice (7th edition), Mosby 2009. [mdconsult.com]
Murch SH, Anthony A, Casson DH, Malik M, Berelowitz M, Dhillon AP, Thomson MA, Valentine A, Davies SE, Walker-Smith JA. Retraction of an interpretation. Lancet. 2004 Mar 6;363(9411):750. PMID: 15016483.
World Health Organization (WHO). Guidelines for epidemic preparedness and response to measles outbreaks. WHO/CDS/CSR/ISR/99.1. Geneva: WHO, 1999. Available at: http://whqlibdoc.who.int/hq/1999/WHO_CDS_CSR_ISR_99.1.pdf (accessed Jun 2006).

Life in the Fast Lane Medical Blog - Emergency Medicine education blog

Crazy Bug Hunter 007

Tim Inglis — Thu, 17 Jun 2010 06:27:17 +0000

Life in the Fast Lane Medical Blog Crazy Bug Hunter 007

Anton Breinl (1880-1944)

Anton Breinl - State Library of Queensland.

The Centenary of Australian tropical medicine is as good a time as any to recognize the contribution Anton Breinl made as one of the pioneer crazy bug hunters in our region. Influenced by some of the early giants of medical microbiology, Ehrlich, Virchov and Ross, he took a position running the Runcorn Laboratory at the Liverpool School of Tropical Medicine. He left this position after establishing an international reputation, to set up the Australian Institute of Tropical Medicine in the grounds of the Townsville Hospital. The year was 1910.

From his previous base in Liverpool, UK, he had led expeditions to Brazil and survived yellow fever. He had also survived an accidental infection with trypanosomes, using an experimental medication to treat himself and thus securing a place among that small group of CBHs who have used themselves as laboratory animals. A condition of his appointment was that there should be no recurrence of his trypanosome infection.

Though he made a start on bug hunting in northern Australia and nearby Papua, the intervention of war introduced a major obstacle – there was a severe shortage of clinicians. Breinl had to increase his clinical workload, eventually becoming superintendent of the Townsville Hospital. There he had to endure repeated verbal attacks prompted by wartime anti-German sentiment. He stuck to his post but finally resigned in 1920. When he died in 1944, it was noted that he had been removed from research when he was at the height of his powers.

Breinl’s contribution is recognised in the Anton Breinl Centre at James Cook University, Townsville.

Life in the Fast Lane Medical Blog - Emergency Medicine education blog

Bringing Home the Bacon

Chris Nickson — Thu, 19 Nov 2009 18:42:36 +0000

Life in the Fast Lane Medical Blog Bringing Home the Bacon

In addition to some good suggestions for the removal of tar, there was at least one important food item missing from Food for Emergencies…. A food, that for anyone who needs it, must surely rank as a truly essential emergency remedy.

Bacon is the food.

What is bacon used for? If you need to ask you’ve probably never suffered from furuncular myiasis.

Furuncular myiasis

Myiasis is tissue infestation by fly larvae (Order Diptera). There are different types of cutaneous myiasis, including wound-infestation, migratory and furuncular. Furuncular myiasis results from the fly larvae penetrating the skin where they feed in the subcutaneous tissue. The larvae still need to pop up for air now and then, so seeing a wriggling white thing with black “eyes” (respiratory spiracles) poking out of a skin lump is a dead give away. If the diagnosis is in doubt, bedside ultrasonography may help.

There are two important types of fly that cause furuncular myiasis. The human Bot fly (Dermatobia hominis), found in Central and South America, and the Tumbu or Putsi fly (Cordylobia anthropophagia) from Central and Southern Africa (plus at least one case from Portugal!).

The Bot Fly

The Bot fly is particularly devious. The adult female attaches her eggs to day-flying mosquitoes (sometimes other flies or ticks) who unwittingly carry the eggs to potential hosts (a strategy called “hitch hiking” or phoresy). The eggs hatch in response to body warmth and the larvae (or ‘bots’) burrow through the skin painlessly and develop over about 5 to 10 weeks resulting in painful, and sometimes suppurative, boils. Sometimes antibiotics are needed, and tetanus immunization should be updated as required. The prolonged larval stage means that infested travelers may turn up at Emergency Departments anywhere in the world.

http://www.youtube.com/watch?v=nHHQIQsPvGc

http://www.youtube.com/watch?v=KNDG7WPtVO4

I also recommend watching the Animal Planet Video: “Monsters Inside Me – Invasion of the Botfly“

The Tumbu Fly

The Tumbu fly larvae generally comes into contact with human skin after the adult female fly has laid eggs on clothing (e.g. hanging outside). Again the eggs hatch in response to body warmth. The larvae develop under the skin over 8-12 days forming a boil that is painful and prickles with movement. Ironing clothes is a good idea in endemic areas as it kills eggs and larvae.

http://www.youtube.com/watch?v=P5N-wMGN5L8

Bacon Therapy

Many methods for extracting the larvae have been described for the treatment of furuncular myiasis. I think using bacon fat is a good idea. It doesn’t take too long (about three hours), doesn’t leave dead larvae under the skin (as oil occlusion, lignocaine infiltration or larvacide treatment may), it’s non-invasive (avoids the need for incision and drainage) and is cheap. However, it may not be suitable for extreme cases of Tumbu larva infestation as the female fly lays 100-300 eggs in several batches – that would need a lot of bacon.

Procedure: The furuncles are left covered with bacon fat. This encourages the larvae to exit the skin, either due to suffocation or an attraction to bacon. After about 3 hours the bacon fat is carefully removed with forceps at the ready to help fully extricate the larvae.

What you do with the bacon and the larvae afterward is your business. And if you’ve got myiasis, try to look on the bright side, things could always be worse…

Ocular myiasis - don't use bacon for this, it needs surgery. It is usually caused by a Screwworm rather than Tumbu fly or Bot fly larvae (although the larvum bottom right does look like Dermatobia hominis).

References

Brewer TF, Wilson ME, Gonzalez E, Felsenstein D. Bacon therapy and furuncular myiasis. JAMA. 1993 Nov 3;270(17):2087-8. PMID: 8411575
McGraw TA, Turiansky GW. Cutaneous myiasis. J Am Acad Dermatol. 2008 Jun;58(6):907-26; quiz 927-9. PMID: 18485982

Life in the Fast Lane Medical Blog - Emergency Medicine education blog

You don't know about the stones?

Chris Nickson — Fri, 20 Mar 2009 21:00:16 +0000

Life in the Fast Lane Medical Blog You don't know about the stones?

I really like the tropical tales (“parasites and people”) of the late Dr Robert S. Desowitz, who was Professor of Tropical Medicine at the University of Hawaii and worked with the World Health Organization. His writing often emphasized the role of human factors in the health problems of the world. Human behavior always contributes to the epidemiology of disease, and neglecting it can lead to disaster…

One of my favorite stories is about the stoned toilets of Somalia. It seems that health advisers from a Western nation were appalled by the toilet habits of the Somalis. The entire country seemed to be covered with indiscriminately scattered human feces. Hardly a toilet, flush or any other kind, was to be found in this impoverished nation. Fecally transmitted parasitic, bacterial, and viral diseases were rife. So with all the best intentions, these experts decided to use their government’s aid funds for a pilot project that would provide simple water-seal toilets to a selected village. In due course, several hundred of the cast-concrete devices were placed over soak-away pits that had been laboriously dug to the prescribed dimensions. The advisers then returned to their offices in the capital, satisfied that they had propelled these people onto the road to modern sanitization.
A year later they returned to the village and were met by a community elder, who courteously thanked them for their gift. “They are good sirs, useful as seats, although not too comfortable. However, as toilets they are a mess.” Somewhat surprised by this – what could go wrong with a water-seal toilet that had no moving parts? – they made an inspection tour of the latrines. The elder’s description proved all too accurate. Each toilet was indeed a mess, clogged and rendered useless by a heap of stones and feces. The confused advisers questioned the elder. Why would anyone dump stones into a toilet? The elder looked surprised; everyone, he thought, knew that Somalis distracted themselves while defecating by clicking two stones together. And when they finished they dropped the stones into the most convenient receptacle – the water-seal toilet.
- Robert S. Desowitz, New Guinea Tapeworms and Jewish Grandmothers, 1981.

Elsewhere in the book, Desowitz has a conversation with a governor in Irian Jaya. The governor proposes that improving the health of primitive people is challenging due to the difficulties in changing their customs – that they are “not like you and me”. As Desowitz ponders a response, he notices that both men are smoking cigarettes…

Stones and toilets don't mix...

Professor Desowitz died on the 24th of March 2008, he was 82 years old (obituary-pdf). His fascinating books include: New Guinea Tapeworms and Jewish Grandmothers, The Malaria Capers, Federal Bodysnatchers and the New Guinea Virus, Who Gave Pinta to the Santa Maria?, and The Thorn in the Starfish.

Life in the Fast Lane Medical Blog - Emergency Medicine education blog