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On call no one can hear you scream

30/10/2019

 
The buzzing sound was driving him mad; a nagging at the back of his mind distracting him from the task at hand. All he had to do was change a fuse in the hospital basement in order to get the power back on in the doctors on call room, but it was proving harder than expected. No wonder no one wanted this post, the hospital was in complete disrepair, the managers had privatised the maintenance services and the rota was a shocker.
In the basement the Doctor groped around in the dark feeling for the fuse box. It was only moments ago that his pen torch had failed but at least he would have a reason not to look for pupillary reactions in any more patients tonight.
 
It was getting warmer the further into the basement the Doctor went and the darkness was oppressive. Suddenly his foot clanged against a bucket sending it crashing across the floor, and the Doctor froze waiting to see what would happen.
 
Then he realised, the buzzing had stopped. No wait, there it was. After a few moments the buzzing had definitely started again but this time it sounded loud and angry, and it was getting closer!
 
The Doctor took a sharp breath in and started to worry and he thought to himself “maybe getting some power on in the on call room wasn’t so important after all”. He turned around guessing on the direction which would lead him out. Shuffling carefully but quickly he moved back the way he had come, all the while the buzzing was growing louder.
 
Now the buzzing was almost deafening and sounded close by. Something brushed against the Doctor’s cheek, soft and fluttery. Shuddering the Doctor pressed on just making out the outline of the door leading back to the lit corridor and safety. But would he be quick enough…?
 
No! Just as he reached the door, and stretched forth his hand towards safety, something hard and hairy slammed into his chest throwing him to the ground. Stunned, he was barely aware that there was a weight on his chest before an agonising pain erupted in his sternum. Excruciating waves of pain washed over him, and he started to lose consciousness. The pressure on his chest relaxed and he was barely aware of the buzzing sound again as it slowly faded away and he fell in to darkness…
 
The Doctor first became aware of the voices and then the light.
 
The voices were talking in hushed anxious tones.
 
“We found him outside of the old power room down in the basement. His bleep kept going off so we were able to track him down”, said the gruff voices of security.
 
“He looks dreadful, and there’s some blood on the front of his shirt over a small puncture wound. Do you think he’s been stabbed” said a worried voice which the Doctor recognised as the motherly Ward Sister.
 
“I don’t think so, and who would stab a junior Doctor down in the basement? No, I think this is a case of him blundering around in the dark, probably lost whilst looking for the canteen, and he then walked in to something which jabbed him in the chest and he banged his head when he fell over. All very easy to explain, yes, yes” said the pompous Consultants voice.
 
“Uuuuuurrrrrggghhhhh” said the Doctor.
 
“He’s waking up” said the Ward Sister, stating the obvious.
 
“How do you feel son” patronised the Consultant.
 
“Awful, and my chest really hurts” replied the Doctor groggily.
 
“You take it easy son; you’ve had a bump to your head. Don’t worry about the on call, a few moments of rest and a strong cup of tea and you’ll be back to clerking patients in no time”.
 
Later that same evening, still feeling a bit worse for wear, the Doctor was back seeing patients! The pain in his chest had been getting worse and he was starting to wonder if he ought to pop along to A&E to get checked for concussion.
 
Stopping at the Nurses’ Station for a quick glug of cold coffee he said “hello” to the Staff Nurse of duty but the words stuck in his throat, he quite fancied her but was always a little shy around her. The Nurse looked up but her smile turned to a look of horror as the coffee cup he was drinking from fell from his hands. The Doctor reached up to clutch at his throat and then down to his chest. Then he felt chest pain like he had never experienced before and a dreadful tearing sensation; he fell back on to the floor thinking to himself “maybe I should have gone to the Coronary Care Unit and got an ECG done”.
 
The Nurse screamed and pulled an alarm button calling for a crash team but it was all too late. The Doctor’s head flung back as blood and gore erupted from his chest. The crash team arrived just in time to see a massive larva pushing its way out of the Doctor’s body!!
 
“Quick, give me the defibrillator paddles” said the fast thinking Medical Registrar.
 
“But he’s already gone” sobbed the Nurse, she quite liked this Junior Doctor!
 
Taking the paddles the Medical Registrar gave a firm command, “Charge to 360 and stand clear!”
 
As the whirring of the charging defibrillator reached its high pitched climax the Registrar bravely put a paddle either side of the larva’s pulsating body and pressed the defibrillate button.
 
With a dull thump the larva exploded splattering everyone in icky slime.
 
“Damned botfly”, the Registrar muttered, “and this one showed such promise” he said indicating the fallen Doctor.
 
“Better call the cleaners and get them up here ASAP” he ordered, “I’m off to finish my curry”.
 
Silence settled over the ward once again as the mops and buckets were wheeled out. As the Nurse went back to recording patient observations she wondered what that buzzing sound was… 

Okay, that was gross; but good fun to write :-) although perhaps a bit of a rip off from the amazing and frightening 1979 Sci-Fi horror film “Alien”. But it is Halloween after all and it wouldn’t be the Bug Blog without a Halloween special. So what is really going on here…?
 
The technical term for infestation with fly larvae is myiasis. Most of the time this occurs as a result of flies laying eggs in wounds which then hatch into larvae; but there is one species of fly that has its eggs directly impregnated into their host. Yep while the host is still alive!!
 
Dermatobia hominis, also known as the Botlfy, is a free living fly that requires a live mammalian host to complete its life cycle. The adult flies don’t actually eat, but their larvae require the host to feed and grow before hatching as a fly. They are also sometimes called warble flies, gadflies or heel flies. Apparently a “bott” is a maggot and a “warble” is a skin lump often found on a horse associated with an ill-fitting harness but also found when a botfly larvae is living under the skin.
Botfly larvae
​The botfly doesn’t actually do the impregnating of humans itself; instead it lays its eggs on a different blood feeding insect such as a mosquito, or in the case of D. hominis the vector is a tick. After she has mated, the female botfly captures the vector insect by holding its wings and then lays 15-30 eggs onto the vectors abdomen. The female lives for about 8-9 days and can lay up to 400 eggs on various ticks during her lifetime.
Botfly lifecycle
Click for larger image
When the assaulted tick bites and feeds from a mammal, the eggs “sense” the presence of the warm blooded mammal and the larvae hatch, drop onto the surface and burrow under the skin. Once under the skin the larva matures for 27-128 days until it is ready to drop out into the environment where it pupates before emerging as an adult fly and the cycle repeats. BUT if up to 4 months growing inside you isn’t gross enough then remember that the maturing larvae can be big, up to 2cm long!

The skin lesion of a botfly larva is usually a large swelling with a central punctum which is essentially the breathing hole for the larvae. Yuck!!! They are often intensely itchy. Occasionally patients report feeling larvae move under their skin, especially when the skin gets warm or they have a shower, etc. No stop it!!!

Removing the larvae is not easy. They have evolved a row of inversed spines which face into the host and hence stop the larvae being pulled out. Trying to do pull the larvae out can result in it rupturing or bits breaking off leading to secondary infections.

The best way of removing the larvae (that’s pleural, so not just one beasty in you!) is to apply an occlusive dressing or ointment that obstructs the breathing hole. After 3-24 hours the occlusion dressing is removed and the larvae should poke out seeking air. It can then be grasped with forceps and gently teased and drawn out (at this stage the spines are far enough out of the victim not to get stuck). To be really kind, local anesthetic can be used to make this procedure less painful. If you are not already hiding behind a cushion then you can watch this video which shows larvae being removed!
​

So there you have it. A disgusting Halloween Bug Blog for your entertainment… I mean education… don’t have nightmares…
JASPER ELLIS
31/10/2019 09:25:19 pm

I have seen a Tumbu fly larva, similar to this. I believe these tend to lay eggs on drying washing, so that when the owner of the washing puts their fresh shirt on...

Amna Afzal
7/11/2019 08:12:36 am

it was a scary though informative blog. Thank you David for sharing these stories.


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    Blog Author:

    David Garner
    Consultant Microbiologist
    Surrey, UK

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