Human bites - how do we stack up?

Listening to the World War Z audiobook, a Chinese doctor states that the human mouth is teeming with bacteria, more than the most unhygienic dog - he was surprised that a human bite mark had no infection accompanying it (because it was a zombie bite).

This made me wonder - in terms of animals that bite and the resulting infection, how bad is it comparatively to get bitten by a human? I’m assuming something like a Komodo Dragon’s bite would be an order of magnitude worse. Assume that our human is biting another human, and has a reasonable oral hygiene routine.

Human bite infection suggests 10-15% likelyhood of infection. The associated injury of Fight Bite (knuckles ripped open when striking a face) is more serious problem, due to force, skin tautness, tendon injury and broken tooth edges.

Family Practice Notebook suggests 50% likelyhood of infection for both Dog bite and cat bite. The major factor is deep penetrating canines that deposit bacteria in a hard to clean wound. Human bites are less penetrating. Lion and tiger bites get infected, but I suspect the severity of the initial bite is somewhat more concerning. Smaller canids and felids are similar to their domestic cousins.

Sea Mammal bites commonly get infected in a nasty way.

Si

Considering that Komodo Dragons have venom glands and humans don’t – yes, it would be a lot worse.

This is an old urban myth.

Not literally true; a dog or cat mouth has more bacteria.

But effectively somewhat true, in that the bacteria in a human mouth is all bacteria that can live & grow within a human body (obviously). Thus an increased chance that some bacteria in there would cause an infection in the bitee.

About 2 years ago, when I was in the hospital with a badly infected arm from a cat bite in the thumb, my doctor said that the closer the species was to humans, the more likely to pass on an infection that would thrive in a human. Thus bites from mammals like dogs or cats are more likely to cause serious infections. Monkey bites are even worse. And human bites, in his opinion, were the worst of all.

Of course, si_blakely’s point is also important – the deepness of the bite & difficulty of cleaning it greatly affect the chances of it causing an infection.

Human bite wounds have a roughly 10-15% chance of becoming infected according to this link. I’ve certainly heard about the “fight bite” phenomenon before - someone punches someone else in the mouth, cuts their hand on the teeth, and later contracts a fairly serious infection.

Human bites can potentially (albeit rarely) transmit viruses like hepatitis B and C and HIV, which are much more worrying than bacterial infections.

Slight hijack, but I love these stories: Doing a project on zoonoses years ago, I read a lot of fascinating case reports. One woman lost an arm to necrotising fasciitis after being bitten by her pet rabbit. A slaughterhouse worker punctured his finger with a chicken bone and ended up with a chronically infected arm. Two years on, despite treatment, the smell was still so bad his doctors found it difficult to be in the same room as the poor guy.

Anecdotal and FWIW:

One of my kids happened to accidentally sink his teeth into his brothers head at a playground. Off to the hospital for some stitches.

The doctor that treated him said that human bites can be particularly dangerous. He said he worked in a prison and bites were not uncommon and there were a lot of serious infections as a result.

Again, anecdotal, but it supports some of the earlier posts.

Thanks for the replies and links; the dog claim did make me raise an eyebrow.

I dunno, but even if there is an increased infection risk I think I’d rather be bitten by a human than a tiger!

But dogs and cats are more likely transmit rabies. I’d rather get HIV than rabies.

Also, infection with Capnocytophaga canimorsus can kill you.

I can tell you from experience, both parts of the sentence are true.

Thanks Malleus - I had partially forgotten that you have had experience of this - this comment from LSL Guy about the 'Dope in another thread has never been so true

Add been bitten by a lion to that list. Although you may not be planning to make a career out of it. :wink:

Si