Can Eating Raw Salmon Give You Chlamydia?

Salmon is one of the most popular and nutritious fish available However, there have been some concerns about whether eating raw or undercooked salmon can transmit infections like chlamydia This article takes an in-depth look at the risks and provides the information you need to make informed choices about eating salmon.

What is Chlamydia?

Chlamydia is a common sexually transmitted infection caused by the bacteria Chlamydia trachomatis. In humans, chlamydia primarily infects the urethra in males and the cervix in females. It can lead to pelvic inflammatory disease, infertility and chronic pelvic pain if left untreated.

Chlamydia in humans is not zoonotic, meaning it cannot be transmitted from animals to humans. However there are strains of Chlamydia that specifically infect fish and amphibians. These strains are classified under the broader term “Chlamydia-like organisms” (CLOs).

Can You Get Chlamydia from Eating Fish?

The short answer is no – eating fish that carries CLOs does not post a risk for transmitting chlamydia to humans.

CLOs are biologically different from the Chlamydia trachomatis that causes chlamydia in humans CLOs have adapted to infect cold-blooded animals like fish, but cannot survive or reproduce in the warmer body temperatures of humans

So while raw or undercooked salmon may harbor CLOs, consuming it does not put you at direct risk for developing a chlamydial infection. Human chlamydia requires direct sexual contact to be transmitted from one person to another.

CLO Infections in Farmed Salmon

CLOs are emerging pathogens in commercial aquaculture and have been detected in farmed salmon populations globally. One of the most common conditions associated with CLOs in salmon aquaculture is a disease called epitheliocystis.

Epitheliocystis causes lesions on the skin and gills of infected fish. A study published in 2014 found evidence of unique CLO infections in over 90 different fish species, including salmon.

Farmed salmon are particularly prone to epitheliocystis outbreaks due to high stocking densities in ocean pens and nets. Stress, injuries and close contact facilitate the spread of CLOs amongst crowded fish populations.

Signs of CLO Infections in Salmon

Farmed salmon carrying CLOs may display visible cues that they are infected, including:

• White, fluid-filled cysts on the skin, fins, gills or eyes
• Respiratory distress
• Lethargic behavior or loss of appetite
• Discoloration or hemorrhages on the skin

However, CLO infections can also be asymptomatic. Farmers must routinely screen for pathogens to detect and cull infected salmon before they reach markets.

Risks of Consuming Raw Salmon with CLOs

While CLOs are not transmissible to humans, there are some potential risks associated with eating raw salmon carrying these pathogens:

• Gastrointestinal symptoms – CLO cell walls contain LPS endotoxins that may cause nausea, vomiting or diarrhea if fish is consumed raw or undercooked. Thorough cooking neutralizes these compounds.

• Secondary microbial growth – Raw salmon with skin lesions or gill damage provide entry points for spoilage organisms and foodborne pathogens like Listeria, Vibrio and Salmonella. Proper storage and cooking mitigate this risk.

• Parasitic infections – Fish parasites like Anisakis, Diphyllobothrium and Gnathostoma cannot reproduce in humans but may lead to gastric or intestinal distress if consumed alive. Flash freezing or cooking fish to 145°F kills any viable parasites.

• Allergic reactions – Some individuals may experience food hypersensitivity responses to raw fish proteins. Cooking typically denatures these allergenic proteins.

So while CLOs themselves don’t pose a direct infectious threat to human health, raw or poorly handled salmon carries general risks that can be avoided by cooking.

Cooking Salmon to Prevent Infections

Thoroughly cooking salmon to an internal temperature of 145°F destroys any potential CLOs, secondary microbes or fish parasites. The FDA recommends cooking fish to this temperature to control foodborne illnesses.

Some safe cooking methods for salmon include:

• Grilling, broiling or baking until opaque and flakes easily with a fork
• Poaching, steaming or simmering until fish reaches 145°F internally
• Hot smoking salmon to an internal temperature of 150-160°F

Make sure to use a food thermometer to verify salmon reaches a safe final temperature after cooking. Allowing fish to rest for 3 minutes before eating also allows heat to evenly distribute for complete pathogen destruction.

Eating Raw Salmon Safely

While the risks are low, some individuals may still wish to consume raw salmon dishes like sashimi or crudo. Here are some tips to reduce health risks:

• Purchase sushi-grade fish from a trusted retailer or fishmonger
• Make sure raw salmon was previously frozen to required temperatures to kill parasites
• Avoid raw salmon if you are elderly, pregnant, immunocompromised or have certain medical conditions
• Don’t cross-contaminate surfaces and utensils used to prepare raw fish
• Refrigerate leftover raw salmon promptly and consume within 24 hours

Inspect the fish carefully and discard any raw salmon with an unpleasant odor or odd texture or coloring. Use common sense – when in doubt, cook it.

The Takeaway

Can salmon give you chlamydia? No – chlamydia cannot be transmitted through eating fish carrying CLOs. However, raw or undercooked salmon may contain other problematic organisms. Cook salmon thoroughly to at least 145°F and take care when eating high-risk fish like raw sushi or sashimi. While the risks are not excessively high, proper handling and preparation of salmon provides an extra layer of protection against foodborne illnesses.

Chlamydia is primarily spread through unprotected vaginal, anal, or oral sex with an infected individual. It can also be passed from a pregnant woman to her baby during childbirth.