Don't wash raw chicken — it spreads bacteria around your kitchen

A person washing raw chicken. [Getty Images Bank]

"You're supposed to eat raw chicken without washing it?"

Most people pull a raw chicken out of its packaging and head straight to the sink, rinsing it under running water. The slippery skin and red juices make it feel wrong to cook without washing first.

But that instinct, however natural it may seem, can actually spread foodborne bacteria to surfaces all around the kitchen.

Washing raw chicken. [Getty Images Bank]

The reason: bacteria from a chicken's feces and intestines can scatter onto countertops, utensils and other surfaces during rinsing.

In fact, some countries, including the United States, advise consumers not to wash raw chicken and instead cook it thoroughly right away.

The bacteria can cause dehydration, high fever and even bloody stools in severe cases — and they are far from rare. Some analyses have found the bacteria present in roughly one in three chicken products on the market.

Reported infections in South Korea are also on the rise, and some researchers argue there is an unexpected structural cause behind the growing consumer risk.

That cause, they say, is factory farming — the industrial practice of raising enormous numbers of chickens in confined spaces, which has created conditions that allow the bacteria to spread and adapt more easily.

Bacteria observed in water used to wash raw chicken. [Herald DB]

The bacterium commonly found on raw chicken is Campylobacter, which lives in the intestines of poultry, including chickens. In humans, it causes food poisoning symptoms such as diarrhea, abdominal pain and fever. Chickens, however, carry the bacterium without showing any obvious signs of illness.

The path from a chicken's gut to the dinner table runs through the slaughtering process. When the abdomen is opened and the intestines removed, bacteria from intestinal contents or feces can transfer to the surface of the meat. Sufficient heat can kill the bacteria, but washing alone cannot remove such microscopic organisms.

An AI-generated image of undercooked chicken. [Image produced with ChatGPT]

The US Centers for Disease Control and Prevention advises that raw chicken products are ready to cook and do not need to be washed again. The CDC recommends keeping raw chicken away from vegetables and other foods, using a separate cutting board, and washing hands and utensils thoroughly after handling.

South Korea's Korea Disease Control and Prevention Agency stops short of explicitly telling consumers not to wash raw chicken. However, it advises that if washing is necessary, it should be done last — after all other ingredients have been prepared — and that care should be taken to prevent water from splashing onto surrounding surfaces. The underlying message is that even if chicken is washed, cross-contamination must be prevented.

A chicken farm. [Provided by Animal Liberation Wave]

The bacteria are not an occasional contaminant. A research team from Chungnam National University's Department of Food Science and Technology analyzed domestic studies conducted between 1985 and 2020 and found a combined Campylobacter detection rate of about 36 percent in chicken samples.

In plain terms, three to four out of every 10 samples tested positive. Other studies have found detection rates ranging from the low 20s to as high as the 70s percent, depending on the sample. A substantial share of raw chicken in circulation, the findings suggest, is a significant source of Campylobacter exposure.

Reported infections are also trending upward. According to KDCA infectious disease surveillance data, Campylobacter infections reported in 2025 reached 3,777 cases — an increase of about 400 from the 3,354 cases recorded in 2024, and the highest figure since tracking began in 2015.

Broiler chickens raised on a poultry farm. [Getty Images Bank]

The trend is not limited to South Korea. The European Centre for Disease Prevention and Control and the European Food Safety Authority have both found a statistically significant increase in Campylobacter infections over the past five years. Reported cases in the EU rose from about 140,000 in 2022 to about 168,000 in 2024.

Some researchers attribute the rise partly to higher summer temperatures and humidity driven by climate change. Data from the 29th week of the infectious disease sentinel surveillance report, released Thursday, showed Campylobacter infections had risen about 26.6 percent from the previous week, underscoring the need for continued monitoring.

Beyond weather, however, researchers are pointing to the expansion of factory farming as another driver of infection risk. Scientists at the University of Oxford's Ineos Institute for Antimicrobial Research recently published a study in the Proceedings of the National Academy of Sciences analyzing the relationship between the growth of industrial poultry farming and the evolution of Campylobacter.

The study found that the global chicken population has grown roughly sevenfold since the 1960s, reaching about 31 billion birds. The researchers likened this vast flock to an ecological "pathogen sponge" — a host population that absorbs and amplifies bacteria arriving from multiple sources.

Humans built enormous chicken populations around the world to mass-produce cheap poultry, and from the bacteria's perspective, this created a vast, continuously replenished habitat with an endless supply of new hosts. The way humans produce chicken, the researchers argue, is shaping the ecology and evolution of pathogens themselves.

South Korea is no exception. As of late 2023, about 182 million chickens were being raised in the country, of which about 90 million were broilers raised for meat. The stocking density for broilers is fewer than nine birds per square meter — meaning each chicken spends its entire life in a space barely 30 centimeters across.

The consequences extend beyond infectious disease. High stocking density harms the birds' health, restricting their movement and causing problems such as skin inflammation, feather contamination and elevated stress hormones. Antibiotics used to prevent disease from spreading among densely packed flocks can also make their way into the human body.

A study published in 2018 by the Korean Society for Food Science of Animal Resources collected 58 chicken samples from retail grocery stores nationwide and found that the overall detection rate for antibiotic residues reached 45 percent.

A yellow foreign substance found inside fried chicken. [Screen capture from TikTok channel Morgan Godwin]

Meanwhile, the pus occasionally found in chicken meat is also linked to weakened immunity caused by poor rearing conditions. Pus is particularly common in chickens raised in harsh conditions — cramped enclosures and heavy exposure to antibiotics and pesticides. These are, in effect, sick birds.

Consumers rarely see the yellow pus directly. Most of it is discarded during meat processing, and only the clean portions are packaged for sale. What reaches consumers is the occasional piece where pus buried deep in the flesh was not caught during processing.

Given these conditions, researchers argue that improving the rearing environment for chickens is necessary to reduce the health risks passed on to consumers. Sam Sheppard, a professor at the University of Oxford and the study's lead researcher, said industrial livestock farming "has created one of the largest animal habitats on Earth," calling it "new evidence that human-induced environmental change can increase the spread of infectious diseases."

woo@heraldcorp.com