Can a person get sick from aquarium water

One hardly thinks twice about plunging a hand into an aquarium or handling aquatic equipment and filtration media.  After all it’s only water and the source of the water was probably the tap in the house.  That’s the same water that is used to water plants, cook dinner, and fill a drinking glass.  It must be clean.

On the day the aquarium was filled, the water was clean.  However, the moment water came into contact with anything in the aquarium, the water became tainted with whatever was in the aquarium.  From that point forward the water became it’s own biome, capable of supporting any number of disease pathogens.

Pathogens can be introduced to water in any number of ways.  Common sources of pathogens in aquariums are:

1. livestock (fish, invertebrates)
2. water from aquarium stores
3. plants from stores or friends
4. rocks
5. corals
6. insects
7. aquarists hands

Even the air in the house can carry cysts with dormant protozoans.  It is almost impossible to keep pathogens away from an aquarium.

When a pathogen finds aquarium water it has found an oxygenated moist environment which typically has nutrients and warmth.  This is the very definition of a growth environment for the pathogenesis of any number of opportunistic pathogens.

Typically people have robust immune systems well able to defend against the occasional introduction of a foreign body.   Our bodies have the ability to identify, target, and neutralize most contagions.

However, as we have learned from the recent pandemic, not everyone is equal in their ability to defend against an infection.

When it comes to contagion with a pathogen it is a numbers game.  If the number of contagious components are few, our immune systems can probably ward off infections.  This is providing our health is good and we have enough biochemical resources with which to mount a defense against the contagion.

When our bodies are ‘run down’ or suffer from an immunodeficiency, the available resources to fight contagions are few.  What would typically be an inconsequential infection suddenly becomes quite serious requiring medical intervention.

The human body is teeming with bacteria.  We are discovering the great benefits of having a healthy series of bacterial colonies living inside and out of our bodies.  There is a natural balance to the numbers  and types of bacteria that infest us.

Our health depends on a bacteria pushing back at other bacteria, keeping their numbers  in check.  When the balance changes and there is an overabundance of one type of bacteria over another, we become ill and develop symptoms until the correct numbers of bacteria are restored.

This balancing process of one organism affecting and offsetting another is essential for the human body biome to function correctly.  The same principles at work in the human body are at work in the aquarium biome.

There are any number of different bacteria, fungi, virus’, and protozoans.  All living in balance with one another keeping each other in check so as to not allow one to become dominant over the others.

Many of the aquatic bacteria, fungi, virus, and protozoans are benign to us and our immune systems have great success fighting and eliminating them.  However, some aquatic pathogens found in aquatic creatures and in the aquarium are not either not known to our immune systems, or are presented to our immune systems in such great numbers that we have difficulty eliminating them.

When this happens we develop an infection and it often requires medical intervention to assist our natural ability to eliminate the foreign pathogen.  The ability of a normally occuring pathogen in an aquarium to attack our bodies and cause an infection is called a zoonotic infection.

Several aquarium pathogens have zoonotic potential, meaning they can infect both animals (including fish) and humans. While zoonotic infections from aquariums are relatively rare, it is essential to take precautions to minimize the risk. Here are some common zoonotic aquarium pathogens:

1. Mycobacterium marinum: This bacterium can cause fish to develop fish tuberculosis, and it can also infect humans, causing a skin condition known as fish tank granuloma or “fish handler’s disease.” People with compromised immune systems are particularly susceptible.
2. Aeromonas and Pseudomonas: These bacteria are common in aquatic environments and can cause bacterial infections in fish. While zoonotic transmission is rare, people with weakened immune systems or open wounds can be at risk of infections if they come into contact with contaminated water.
3. Edwardsiella tarda: Another bacterium found in aquariums that can cause infections in both fish and humans. It may lead to gastrointestinal issues in humans, particularly those with compromised immune systems.
4. Cryptosporidium and Giardia: These are parasitic protozoa that can infect both fish and humans. While they primarily affect the gastrointestinal tract in humans, they can cause problems for fish as well.
5. Anisakis spp.: These parasitic nematodes can infect fish and humans. Humans can contract anisakiasis by consuming raw or undercooked infected fish.
6. Streptococcus iniae: This bacterium can cause streptococcal infections in fish, and there have been reports of infections in humans after handling infected fish or water.
7. Vibrio spp.: Certain species of Vibrio can cause infections in both fish and humans. People with weakened immune systems or underlying health conditions are more at risk.

It’s important to note that the risk of zoonotic infections from aquariums is generally low, especially if proper hygiene practices are followed, and the aquarium is well-maintained.

To minimize the risk of zoonotic infections:

• Wash hands thoroughly with soap and water after handling aquarium water or fish.
• Avoid contact with aquarium water if you have any open wounds or compromised immune function.
• Wear gloves when cleaning the aquarium or handling fish if you have any skin abrasions.
• Avoid consuming raw or undercooked fish from aquariums.

If you have concerns about zoonotic infections or experience any symptoms after handling aquarium fish or water, seek advice from a healthcare professional or a qualified fish veterinarian.