There are few diseases within the DTM&H that cause confusion like schistosomiasis, or should it be ‘Bilharzia’ or even ‘snail-fever’, or all of these depending on what aspects you wish to explain. Correct definitions aside, this disease is certainly complex and a testimony to what millions of years of parasite evolution can achieve. In short, schistosomiasis is caused by an unusual parasitic flatworm, unusual in that unlike other related parasitic worms, the schistosomes are dioecious and not hermaphrodites. Moreover, as part of their lifecycle, infectious larvae of these worms are exclusively associated with aquatic habitats. Collectively, this makes them a unique lifeform on our planet, and combined with an ability to invade our bodies directly by crossing unbroken skin, incredibly successful.
If you think washing, bathing or swimming in freshwater lakes, ponds or streams in Africa is safe, think again! Schistosomes are highly evolved to exploit our daily habits of cleanliness or recreation and have several other intriguing physiological tricks and complex life-history strategies. This makes them expert exploiters, for example, they can happily live for decades within your blood-system, exchanging mates with competitive copulations between ‘aggressive’ male and ‘submissive’ female populations. Even today with an effective orally administered drug, praziquantel, schistosomiasis still causes much mischief and suffering. Did you know that across the world, over 200 million people live with this disease or that millions of mothers inadvertently infect their babies each day upon unsafe cleaning?
So how can the story of tens of millions of years of parasite evolution and suffering of mankind immemorial be condensed into 3 hours of lecture content? To do so we have taken an enticing blend of videos, anecdotes and animations which are eventually brought together in a humorous song (Pass the praziquantel see below). This song was originally created and performed by students at a DTM&H International Night. As it was considered so good and popular it was donated to Prof. Bertie Squire, who then passed onto us. We have found it very useful in a variety of teaching settings.
PASS THE PRAZIQUANTEL (to the tune of “Mine eyes have seen the glory”)
When you’ve swum in Lake Malawi, got ashore without a hitch
But you’re reaching for your towel when your skin begins to itch,
You’ve been sharing with the water snails their ecological niche,
Schistosoma’s come to stay
Chorus Pass the, pass the praziquantel
Pass the, pass the praziquantel
Pass the, pass the praziquantel,
Schistosoma’s come to stay
On returning from your holidays canoeing in the river
You start to cough and wheeze and soon you’re feeling all a quiver
See Bertie at the Trop Shop who can feel your spleen and liver.
Schistosoma’s come to stay.
Chorus – Pass the, etc.
When you go to use the bathroom you will get a nasty shock,
For your urine looks like Beaujolais and not at all like Hock,
If you’ve listened to the lectures then you’ll know just what you’ve got,
Schistosoma’s come to stay.
Chorus – Pass the etc.
You might think that Mrs Mansoni’s as happy as can be,
Enveloped by her husband in your rectal mesentery
In fact she is a feminist crying “sisters set me free!”
Schistosoma’s come to stay
Chorus – Pass the etc.
Foremost, this song adds a little humour to what is a serious affliction and disease of the forlorn. It creates an atmosphere of participation, hope and realism that this disease can be eventually conquered. We have seen that after the song, which we sing at the end after giving several prior prompts, always gets a strong round of applause and cheers. It typically ends with much happiness and laughter. How often do students join together and experience the simple pleasure of song?
The song does its job admirably, in that it sites the issue/problem to a specific-setting where many of the class have already visited. Did you know that the greatest number of patients with schistosomiasis in the UK have returned from Lake Malawi? It also highlights the cardinal sign of urogenital schistosomiasis in that the patient’s urine becomes red, like an aged Beaujolais, owing to blood being passed in it. A particular species of schistosome, Schistosoma mansoni, was named in honour of Sir Patrick Manson and it is delightful to continue to recognise this legacy as many students are unfamiliar with the enormous contribution of this medical giant of clinical tropical medicine and parasitology.
Only the more erudite students will realise that urogenital schistosomiasis is caused by Schistosoma haematobium, such are the subtleties of schistosomiasis! Nevertheless, after the song is it obvious that ‘pass the, pass the praziquantel’ is crucial part in the solution towards its lasting control. In our lectures we highlight how the disease is linked to poverty and how other strategies can be used to synergise with regular treatment. The key purpose of the song, like outreach of praziquantel treatment, is to take part and participate!
Russell Stothard Chair in Medical Parasitology Faculty of Biological Sciences +44 (0)151 705 3724 russell.stothard@lstmed.ac.uk
Amaya Bustinduy (LSHTM)Associate Professor in Tropical Paediatrics Faculty of Infectious and Tropical Diseases (LSTMH) +44-020-79272220 Amaya.Bustinduy@lshtm.ac.uk