Fish Tuberculosis (fish tb)
i’ve been posting about fish TB the last few days because i suspect two of my fish had gotten it. I’m going to try to make a coherent post for anyone else who may need information about it because i had searched all over and there’s not very much about it and the things i learned were from several different sources. i’ll cite everything at the end but please remember that i am by no means a professional and some of the stuff i include could be incorrect! it’s always smart to do your own research as well. (i’m not going to include pictures bc GROSS and i’m not going to include a lot of the science-y stuff bc i barely understand it and have 6 brain cells)
To begin, fish tuberculosis is a bacterium closely related to Mycobacterium tuberculosis (human TB) called Mycobacterium marinum. It is commonly referred to as fish tb, but it isn’t actually tuberculosis at all! Which is good news since this is a zoonotic disease, meaning it can be transferred from an animal to a human. In humans, fish tb would present itself as a skin infection. It can be passed onto a human who has an open cut or scrape on their hand and then puts their hand inside the infected fish’s water. It is also more likely to infect someone with a compromised immune system. It is very, very rare for a human to catch this as the bacteria cannot survive at temperatures above 98.6 degrees fahrenheit (or 37 degrees celsius) and that’s why it stays in the colder extremities like the hands and feet. While it is very rare, it’s still possible so if you believe you’ve come in contact with it, it is best to go the the doctors and get tested.
Symptoms of this in fish are:
- Wasting away. your fish becomes emaciated looking in just days. this is why fish tb is sometimes referred to as ‘wasting away disease’
- lesions on the body
- scale loss
- lethargy
- curved spine
- some fish develop popeye
Symptoms of this in humans are:
- lesions on the skin. it begins as small purple or red bumps on the skin, usually more prominent on your dominant hand and can go up to your elbows. normally it doesn’t pass that point.
- Usually these bumps can become painful and irritated.
- in more severe cases, it can spread to the soft tissue and cause arthritis.
- in absolutely worst case scenarios, it can get so bad where amputation is necessary.
What makes this disease especially scary is it can be present in a fish OR human and not show any symptoms for months. You could believe you have a perfectly healthy fish and then a month later, you find your fish on the brink of death. While there are treatments for this disease in fish, they are very harsh and almost never work. Many people suggest putting down your fish when the signs of it finally show because there’s no reason to allow your fish to suffer. As for treatments in humans, all you need is some antibiotics to treat and combat it. so far, the disease is not known to be resistant to any antibiotics! most people who get infected are on antibiotics for about 2 months. it’s important to note that it is not deadly to humans!
Luckily, this bacteria is not capable of human to human transfer. meaning, no need to worry about infecting anyone else. But fish are able to spread it to one another through a few ways:
- A fish eats an infected fish OR an infected fish’s dead body.
- A fish eats the infected fish’s waste.
- A fish is living with an infected fish and has an open wound.
it’s very easy to get panicky over a situation like this. your fish is dead and now you think you’re infected. but the likelihood of you catching this is very, very low. in the usa, the rate (for all cases, not just aquaria) is around 0.27 infections per 100,000 population. it is important to just be aware of this disease and use it as a reason to be especially careful when handling your tank.
luckily, there are ways to avoid something like this from happening!
- never, ever put your hands in the tank without protective gear if you have any sort of cut or open wound! gloves are a great way to keep your hands nice and safe. i picked up disposable ones and a nice pair of reusable, heavy duty ones that go up to my elbows.
- always wash your hands after messing around with your tanks! this includes washing your hands (and gloves) in between tanks if you have multiple ones.
- (this one seems like common sense but) keep your things aquarium specific! if you use a bucket for your water changes, make sure it’s only used and only ever been used for this specific purpose.
so if you believe your fish got infected with TB, the best course of action is to euthanize the fish, throw the fish’s entire tank setup away and get yourself tested. it is possible to clean your tank after a tb outbreak, but this disease is VERY resistant to cleaners. most people would use bleach because it’s aquarium safe and seemingly kills everything, but people have reported the disease coming back once they’ve put new fish in. personally, i am just going to throw everything away (tank, decor, gravel, filter, heater, all of it!) and even go so far as smashing my tank so someone else can’t use it (and disposing it in a trash bag triple bagged.) it is also important to properly dispose of your fish’s body. it’s never good to flush a fish but especially not good in this situation. the best way is to soak your fish’s corpse in bleach after they have been euthanized and throw them away. i know it seems cruel, but it’s the best way to keep yourself and others safe. i let my fish sit in a cup of bleach for an hour then wrapped his body (being careful NOT to touch him!!!) in paper towels and put that inside a ziploc bag. i even splashed some bleach into the bag just to be extra sure. also, be sure to NEVER dump infected water outside. pour it down the drain and then bleach your sink or bath. it isn’t possible to become infected by sitting in a bath that had infected water poured down it, but it’s best to be safe! also, you can just clean your cleaning equipment well and still use it after but personally, i just felt better repurchasing my gravel vacuum, buckets and nets.
as always, please let me know if any of this information is incorrect in anyway. the very last thing i want to do is misinform people!
sources: (warning! there are a few graphic pictures of wounds on a person in the 3rd source. view at your own discretion)
https://www.practicalfishkeeping.co.uk/blog/articles/should-you-be-worried-about-fish-tb
https://microbewiki.kenyon.edu/index.php/Mycobacteriosis_(Fish_Tuberculosis)
http://mobile.dudasite.com/site/fishtanksandponds?url=http%3A%2F%2Fwww.fishtanksandponds.co.uk%2Ffish-health%2Fmycobacterium-marinum.html&utm_referrer=https%3A%2F%2Fwww.google.com%2F#2908
http://www.aquaticcommunity.com/disease/tbc.php