Hot pool Horrors.

Whilst on holiday at Hanmer Springs I couldn’t help but notice the signage.

“Keep head above water!” “No diving or splashing!”

With a 3yo whos idea of not splashing involves a small tsunami each time he hits the water I wondered about the risk and history of these signs.

So what is everyone so worried about?

PAM (Primary amoebic meningitis.)

Caused by Naegleria fowleri a nasty little amoeba which lives in warm soil and can survive for long periods in inadequately chlorinated or filtered warm water. After being “forced” into peoples nasal passages it migrates to their brain and causes an almost always fatal meningitis. (1)

(Hanmer looking lovely below)

The first recorded New Zealand outbreak of amoebic meningitis was in 1968-1978 (8 cases) which lead to the implementation of standards to reduce the risk of infection. (2)

Now pools are classified as naturally occurring pools which are considered high risk and lower risk commercial pools which are required to meet a standard. These pools which usually have a constant flow of water, are filtered and chlorinated. Other important techniques to reduce the incidence of N. Fowleri in the water are foot washes and having no bare soil near the pools themselves. (3)

New Zealand has a large number of geothermal areas and many of these are considered high risk as they are pools which may be dug from the side of a river bank or in some cases out of the earth. (Eg: Welcome Flat hot pools below)


In recent times in 2010 there was another 2 cases in the central north island. (2) Which again lead to improvements in a number of bathing areas.

Quantifying risk is very difficult but some epidemiologists have had a go!

“French epidemiologists estimate that given 10 N. fowleri amoebae per litre of water and a likely inhalation or ingestion of 10 ml of water during swimming, the risk of human infection for a swimmer is 8.5 x 10-8!5” (2)

So clearly pretty low risk but as the diagnosis is often elusive. Eg: unwell male in his 50s with no fever just feeling terrible and no meningeal signs. (4) This often which leads to late treatment which is not very effective with only occasional case reports of survivors (5)

Treatment is usually with IV +/- intrathecal amphotericin  but most patients have had multiple other drugs including standard meningitis therapy (here: ceftriaxone) by the time a diagnosis of PAM is suggested. (2)

Thanks to good public health measures PAM has been reduced to only occasional case reports. It seems that an ounce of prevention really is worth a pound of cure.

Might try keep the lad from dive bombing the sulfur pools next time we are there.



1)The epidemiology of primary amoebic meningoencephalitis in the USA, 1962-2008.       Yoder et al.

2) A case of primary amoebic meningoencephalitis North Island New Zealand.

3) NZ Ministry of health PDF:

4) N Z Med J. 2004 Feb 20;117(1189):U783; author reply U783.
Primary amoebic meningoencephalitis presenting without fever.
Bond B. (GP discussion)

5)A rare case of survival from primary amebic meningoencephalitis Gautam et al

Babies, bilirubin and bullshit?!

Time for a bit of a yarn.

During my Trainee Intern year a few years back I worked at the Sophia Kinderziekenhuis at Erasmus MC in Rotterdam. Whilst there I was told the tale of the invention of ultraviolet therapy for neonatal jaundice. There are a number of different versions but like many stories I like the one I was told first best.

Most midwives will tell you that for many generations people have placed young infants in the sunshine to help them lose their yellow tinge. But it wasn’t until the 1950 and more so the 1970’s that medicine started using phototherapy widely.

Phototherapy baby

The story I was told goes “One day a young paediatrician was walking his dog in the park. Being a beautiful sunny day (when presumably he wasn’t on call) He was enjoying letting his mind wander and the fresh air. Then splat! he stood right in a dog shit and slipped to the ground. Whilst lying on the ground likely in a less stellar mood than he had previously been he noticed something. The dog turd which he had fallen on had been there for sometime and the outer-layer had turned white. He wondered if this was due to the sunshine breaking down the bile and other compounds. This set in motion a further thought about the potential for other compounds to react with sunlight and be broken down perhaps even in the skin?”


Since being told this tale I have chased up the origins of UV phototherapy and sadly no excrement was involved in its discovery. A number of observations including the breakdown of bilirubin in test-tubes exposed to sunlight and improvements in infants treated with natural sunlight lead to Dr. Cremer making the first study and then after the Yanks followed up it was more widely used.

Its interesting the stories which you are told during your medical training and the ones that stick. Anyone got a good yarn they remember from their med school days?



Kicking it.

 Young bloke presents after footy practice last week. Kicking when had sudden pain in his right groin. Did what most do and ignored but still painful and has not improved with rest. He had been reviewed by the team physio and given a diagnosis of a … [Continue reading]