Zagworm (or Xagworm), although relatively unknown in the west, is becoming increasingly common in mainland Africa and is now the third leading cause of death in the Republic of Liberia after lung cancer and malaria.

Despite its name, Zagworm, like Ringworm, is actually a fungal parasite rather than an actual worm; the name comes from the track marks left by the fungus when breaking down tissue which resemble the pathways of burrowing worms.  These distinctive features, but the absence of worms themselves, coupled with the ‘possessed’ appearance of sufferers led the Motuans of Papua New Guinea to believe that the disease was caused by a demonic parasite; they therefore named it after the Motu word for Satan – ‘Xag’.

Transmission of the parasite is frighteningly easy and fairly unique.  Since the spores are so small, they can essentially hitch a ride on some larger strains of bacteria, making catching Zagworm as easy as catching the common cold, although far more dangerous without treatment.

Zagworm spores: Among the smallest fungal spores in the world

Once ingested the spores hatch into gametophytes and burrow into the body, generally settling on tendons or large areas of sinew, where they grow and break down the tissue.  This erosion of tendons and sinew causes the first noticeable symptom of a Zagworm infection: involuntary reflex reactions.  This rapid tensing and relaxing of the muscles (especially in the limbs) can cause involuntary jumping or, more commonly, falling over; at other times the affected person can be expected to lash out or upwards with the arms and can often result in the patient punching themselves repeatedly in the face.

The next stage of the illness usually sees the fungus spread to the brain, causing memory loss, paranoia and delusions; if treatment isn’t administered early at this stage then recovery is very unlikely.  In some rare cases, where tendons are completely broken down before the destruction of brain tissue has proved fatal, Zagworm can cause Detached Bone Syndrome (DBS), a particularly horrific condition that can see the body contort into painful and unnatural positions, such as joints bending backwards or bones sliding out of position.  The trauma of witnessing this condition in a person who is already highly mentally unstable has been the inspiration for many posession myths, including much of the content of the 1973 film ‘The Exorcist’.

Despite how common the parasite is, and the fact that it is almost always fatal if left undiagnosed, Zagworm can be easily and cheaply treated with voriconazole; it is therefore only prevalent in communities without easy access to medical treatment or areas of extreme poverty.


A diagram detailing the medullic lobe of various species of swan

In 1590, 3 years before his death, the English playwright and notorious drinker, Christopher Marlowe, was challenged in a drunken bet to fight a swan caught in Hyde Park by Ingram Frizer, the man who would later be responsible for stabbing him to death.

Christopher Marlowe

Although the details of the bet are unclear it seems that Marlowe, using a shovel, dealt an almost fatal blow to the swan and in doing so severed its medullic lobe (the black lump above it’s beak).  The bird eventually recovered and was kept for the next year in captivity by Dr Rodrigo López, the physician of Queen Elizabeth I, during which time he noted that the swan had:

“tempered it’s manner to that of a goose; Her tongue will not obey her heart, nor can Her heart inform her tongue of that passion we all recognise of Juno’s beloved bird”

The swan had become calm, docile and unaggressive to such an extent that it was taken as a pet by the Queen during her last years.  As a direct result of this all swans are still today the property of the monarch and it is illegal to kill a swan in the UK, all stemming from Elizabeth’s love for the animals.

Dr López, interested in animal as well as human physiology became fascinated by this change in demeanor and noted that, unlike most water fowl, swans have a hole in the front of their skull through which a part of the brain (the medullic lobe) protrudes.  He developed the process of tying string around a swan’s beak and medullic lobe in order to calm the animals, a process that was still being used by swan keepers up to 50 years ago.

Queen Elizabeth I

With the advancement in brain mapping technologies in the first half of the 20th century, the famous psychiatrist, Bernard Hollander, identified the medullic lobe as the centre for negative emotional states such as anger and depression.  Taking the anecdotal evidence of Dr López’s work with swans he set about trying to somehow suppress the lobe in a human brain, a task that proved far more difficult due to the fact that it is located far closer to the brain’s centre. 

During a highly controversial series of experiments on some of his more severely depressed or violent patients he, along with Portuguese physician and neurologist António Egas Moniz, developed a surgery he called prefrontal leukotomy (better known now as lobotomy) which sought to isolate and sever the medullic lobe.  The results were mixed as it proved almost impossible to isolate the desired areas without first damaging other parts of the brain, leading to mild to severe brain damage in almost all cases.  

Despite the unpleasant side effects, however, almost all patients treated were alleviated of their original symptoms and for a few years it became an acceptable last resort surgery for patients suffering from chronic depression.

In 1951, during unrelated tests on the newly developed anti-tuberculosis agents isoniazid and iproniazid, Dr Irving Selikoff and Dr Edward Robitzek, identified that, while innefective aginst the onset of TB, the drugs acted as suppressants for the medullic lobe and that while treatment continued they managed to achieve chemically what Hollander and Moniz had attempted surgically.  The anti-depressant drug had been born. 

In initial clinical trials of the drug it proved less effective on women than men, this has since been attributed to hormonal differences in the brain but at the time, and in the wake of the then recent identification of Postpartum (or postnatal) depression, it led to some more left-field commenters putting forward the notion that depression was the natural state for women.  However in 1957, the Swiss Psychiatrist Roland Kuhn discovered that compound “G 22355” (later imipramine) was not only equally effective on men and women, but that it was in fact almost twice as effective on both.

Today many variants on imipramine are used by doctors all over the world (in fact the compound Paroxetine is compulsory for all citizens of Burma over the age of 18) and recent developments have led to stronger and more effective versions with less side effects.