Common causes of diarrhoea: Understanding aeromonas infection

What is an aeromonas infection?

Aeromonas are a type of bacteria that can cause an acute diarrhoeal illness. It is a fairly common cause of gastroenteritis, which occurs most often throughout the warm summer months in most countries. 

The infection usually resolves without the need for treatment, but infections are also associated with wounds, and they can cause opportunistic systemic disease in immunocompromised patients. 

Aeromonas infection may be associated with pneumonia in patients who have survived near drowning, as it is a bacterium commonly found in freshwater). Aeromonas infections are in the same family as Vibrio cholerae, the pathogen that causes cholera following the ingestion of faecally contaminated water or shellfish.

Where are aeromonas found?

Aeromonas are found in water and infection may occur from swallowing contaminated water, handling contaminated fish or water, and not washing hands thoroughly. Proper hand washing may reduce the risk of transferring infection from one person to another.

Symptoms of aeromonas infection

The time between swallowing the bacteria and symptoms starting (the incubation time) can be between 1-7 days but is most frequently between 24 and 48 hours

Many patients who carry aeromonas will display no symptoms at all and the infection may only be identified when faecal matter is being tested for other reasons. In individuals who do have some symptoms as a result of the infection, they are often experienced mildly – a typical set of symptoms would include:

• Watery diarrhoea
• Generalised pain in the abdomen and stomach area
• Some vomiting
• A mild fever.

More severe aeromonas gastroenteritis resembles the symptoms of shigellosis (a diarrhoeal disease caused by food poisoning), with blood and leukocytes found frequently in the stool.

Treatment for aeromonas infection

Many illnesses that result from aeromonas infection will clear without treatment and an individual’s immune system response will often deal with it adequately.

Sensible measures such as eating well, maintaining good levels of personal hygiene and staying well hydrated will be sufficient for most patients who contract an illness caused by aeromonas.

More serious gastroenteritis may require further treatment. Always speak to a healthcare professional if you have any concerns.

Preventing further illness

To prevent further illness caused by aeromonas:

• Wash hands thoroughly after visiting the toilet, changing a nappy, handling animals, fish or reptiles, and engaging in leisure activities in or on water.
• Wash hands before cooking, handling food, eating, or feeding food to the young and/or elderly can also help reduce the risk of disease spreading.
• Use separate knives and chopping boards for raw meat or other foodstuffs

Carefully wash all fruits and vegetables before eating.

Related Reads:

• How should we wash our vegetables?
• What are probiotics and how do they work?
• 4 factors that may affect your immune system

References

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9195132/ 
2. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/diarrhoea#treatment-for-diarrhoea 
3. Jinendiran, S., Archana, R., Sathishkumar, R. et al. Dietary Administration of Probiotic Aeromonas veronii V03 on the Modulation of Innate Immunity, Expression of Immune-Related Genes and Disease Resistance Against Aeromonas hydrophila Infection in Common Carp (Cyprinus carpio). Probiotics & Antimicro. Prot. 13, 1709–1722 (2021). https://doi.org/10.1007/s12602-021-09784-6 
4. https://www.tga.gov.au/products/biologicals-blood-and-tissues-and-advanced-therapies/biologicals/faecal-microbiota-transplant-products-regulation#:~:text=FMT%20products%20are%20manufactured%20from,and%20nasogastric%20or%20nasoduodenal%20tube