Sparganosis is a rare zoonotic disease that is spread all over the world.
Sparganum, which finds humans accidentally, is the name of a larval stage of a tapeworm.
Humans get affected by the larval stage of the tapeworm through improper cooking of meat.
The disease can appear as nodules under the skin in different regions of the human body.
Hi everybody let me introduce myself in a different way:
I’ll tell you what problems I cause for humans before I tell you my name and life history.
I cause a disease called “Sparganosis”.
Yes, I’m a rather rare condition in humans and don’t look around... the disease appears as a subcutaneous (under the skin) nodule that can be different sizes or shapes.
Sometimes I form nodules in and around the eye, which is called ocular Sparganosis.
I can also form nodules in the human brain (cerebral Sparganosis) which can lead to seizures.
If you don’t believe me, there’s the story about an East Timorese refugee, who ate raw snakes and frogs, who was the first in Australia to suffer from cerebral Sparganosis way back in 1994. The patient suffered from seizures and partial numbness for months before being diagnosed.
But don’t blame me if you eat raw or undercooked meat because it may then be your turn!
So, who am I?
My name is Sparganum or Pleurocercoid and I am the larval stage of a tapeworm called, Spirometra erinaceii and its relatives.
You could say I’m the offspring of that tapeworm. The parent and the offspring (larvae) have different names, it is indeed confusing.
It was humans who did the classification, not us parasites!
I know the classification was done for your convenience; it doesn’t really matter to me.
Have I scared you so far, talking about worms in your eyes and brain?
Don’t worry, Sparganosis in itself is a mild disease compared to the more deadly diseases caused by other members of my tapeworm family. Quite often, Sparganosis goes undetected, unless I gain entry to your brain, which is a rarity.
Well, anyhow, it is not my job to make friends with you; I’m here for the same reason that you are: we evolved.
Although it may not be an interesting one for you, it is still my story and definitely worth telling.
My parent is a tapeworm known as Spriometra. Yes, I have only one parent because he/she is a hermaphrodite which means that both the sex organs are present in one body.
My parent lives in the small intestine of a variety of carnivores including dogs, foxes and dingoes. After my parent fertilizes its own eggs (freaky!) it lays eggs in the host’s small intestine, which are then passed out in the faeces.
The eggs hatch as a stage called a coracidium (again, you guys named us, don’t blame me!), which is my previous avatar. The carnivores are called definitive hosts because sexual reproduction of my parent occurs in them.
Once the eggs have hatched, the coracidium (my younger avatar) finds an intermediate host, normally a crustacean species (like a crab for example). In the crustacean, the coracidium develops to the next stage called procercoid and then into the larval stage called sparganum or pleurocercoid, which is me by the way (are you confused yet?).
I really don’t know why you humans gave me two names; one was enough of a luxury!
I choose humans rather aberrantly. I (sparganum) wait to be eaten by a second intermediate host which includes many animals including feral pigs, fresh water fish, frogs and snakes.
However, if one of you humans takes me in by eating uncooked feral pig meat or fish or frog meat, I can deceive you by looking very similar to muscle connective tissue, and then I can cause sparganosis.
Well, don’t be surprised by how clever I am: you humans are not the only intelligent creatures on the planet!
By the way, I can also reach you when you eat undercooked or raw crustaceans, albeit in my previous stage called the procercoid (remember?).
My life cycle is completed when a carnivore (dogs etc.) swallows an intermediate host (a bit of a pig or a whole frog, it doesn’t really matter which) and I find my way to attach to the small intestine of my new host and develop into an adult tapeworm.
Isn’t my life cycle interesting?
I have many ways of getting there but my destination in life is clear!
Do you humans have a clear destination in your lives?
When I see someone not cooking meat well enough or undercooking it, I’m over the moon and I say to myself “I will soon be home”.
I wish I could choose a famous human like one of the judges on the cooking shows on television as my next host so that I can be famous too!
Why not? Very recently I affected 9 people in Thailand to emphasise the point that I am spread all over the world including Australia but I am seriously waiting to get even further in life.
I hope you enjoyed my journey and story. By the way, you humans have classified me under “zoonotic diseases”.
Thank you! I am waiting...so feel free to enjoy a nice, rare pork chop today!