Campylobacter spp. are spiral-shaped, Gram-negative bacteria commonly found in animal intestines and sometimes in the human gut. While some strains may live harmlessly, others—especially C. jejuni and C. coli—can cause foodborne illness. Infection usually comes from undercooked poultry, unpasteurised milk, or untreated water (Callahan et al., 2021; Kaakoush et al., 2015).

In the gut, Campylobacter can cause diarrhoea, stomach cramps, and fever, and sometimes more serious issues like reactive arthritis or Guillain-Barré syndrome. Healthy individuals often recover quickly, but those with weaker immunity may face longer or more severe illness. Good food hygiene, safe water, and a balanced gut microbiome reduce the risk. In South Africa, it remains a concern due to food and water safety issues, even in wealthier areas (Bester et al., 2022).

✔ Type of bacteria: Spiral-shaped, Gram-negative bacteria that live in animal intestines and sometimes in humans.

✔ Common species: Campylobacter jejuni and Campylobacter coli are the most frequent causes of human illness.

✔ Main source of infection: Often linked to undercooked poultry, unpasteurised milk, or contaminated water.

✔ Illness caused: Can trigger gastroenteritis, with symptoms like diarrhoea, abdominal pain, fever, and nausea.

✔ Complications: Rarely, it may lead to reactive arthritis or Guillain-Barré syndrome.

✔ Transmission: Mostly foodborne, but can also spread through contact with infected animals or contaminated surfaces.

✔ Risk in South Africa: A concern due to food and water safety issues, even in more affluent areas.

✔ Prevention: Good food hygiene, safe water, and proper cooking of meat.

When Campylobacter spp. enters the body, the immune system quickly recognises it as a threat and activates both the innate and adaptive immune responses. The innate immune system — our body’s first line of defence — responds by sending immune cells like neutrophils and macrophages to the infection site, where they work to engulf and destroy the bacteria (Callahan et al., 2021). This process triggers inflammation in the gut, which can cause common symptoms such as diarrhoea, abdominal pain, and fever. Specialised gut epithelial cells also produce antimicrobial peptides and signalling molecules, such as interleukins, that help recruit more immune cells to fight the infection (Bitew et al., 2022).

The adaptive immune response, which develops more slowly, plays a crucial role in fully clearing the infection and preventing recurrence. Here, B cells produce antibodies — particularly Immunoglobulin A (IgA) — that target Campylobacter in the gut lining, blocking its ability to attach to and invade cells (Callahan et al., 2021; Facciolà et al., 2021). T cells also assist by coordinating the immune attack and destroying infected cells. However, in some people, especially those with certain genetic predispositions, the immune reaction to Campylobacter can trigger autoimmune complications such as Guillain–Barré syndrome (Facciolà et al., 2021). This shows how the immune response to Campylobacter is a double-edged sword — it’s essential for clearing the infection, but if overactivated or misdirected, it can cause long-term health issues.

Unhealthy levels of Campylobacter spp. — usually meaning an active infection or overgrowth — can cause a range of digestive and general symptoms. The most common signs include diarrhoea (often watery or sometimes bloody), stomach cramps, nausea, and vomiting (Bitew et al., 2022). Fever, chills, and a general feeling of weakness or fatigue are also frequent as the body mounts an immune response (Facciolà et al., 2021). These symptoms often appear within 2–5 days after exposure to the bacteria and can last about a week in otherwise healthy individuals.

In some cases, particularly in people with weaker immune systems, symptoms can be more severe and prolonged. These may include persistent diarrhoea leading to dehydration, high fever, and signs of the infection spreading beyond the gut (Callahan et al., 2021). While most infections resolve without long-term effects, Campylobacter overgrowth has been linked to post-infectious complications such as irritable bowel syndrome (IBS) and autoimmune conditions like Guillain–Barré syndrome in a small percentage of people (Facciolà et al., 2021). Because the symptoms can overlap with those of other gut infections, testing is important to confirm whether Campylobacter is the cause.

Campylobacter spp. infections can affect South Africans across different communities, but certain factors in the local context make their impact on gut health more pronounced. In South Africa, Campylobacter is one of the most common causes of bacterial gastroenteritis, with transmission often linked to contaminated food, untreated water, and direct contact with animals. Even in wealthier areas, where sanitation standards are higher, people can still be exposed through undercooked poultry, cross-contamination in kitchens, or travel to areas with higher infection rates (Bitew et al., 2022). Because the bacterium can be present in healthy carriers, outbreaks may also occur in closed or semi-closed communities, such as schools, retirement homes, or workplaces.

When Campylobacter disrupts the gut microbiome, it can trigger short-term illness as well as long-term health consequences. Acute infection can lead to severe diarrhoea, abdominal pain, and dehydration, which are more dangerous for children, the elderly, and those with weaker immune systems. Over time, repeated or severe infections have been linked to post-infectious irritable bowel syndrome (IBS) and autoimmune conditions such as Guillain–Barré syndrome (Facciolà et al., 2021). For South Africans with pre-existing conditions like HIV, which can compromise immune function, Campylobacter can cause more persistent gut dysbiosis and increase vulnerability to other gut pathogens (Callahan et al., 2021). This makes routine gut health testing an important step — even for people who feel healthy — to identify and manage Campylobacter before it leads to more serious complications.

Here’s a simple, layperson-friendly numbered list on how to get and maintain healthy Campylobacter spp. levels:

1. Cook Poultry Thoroughly: Make sure chicken and other poultry reach a safe internal temperature (at least 74°C) to kill Campylobacter bacteria.

2. Prevent Cross-Contamination in the Kitchen: Use separate cutting boards and utensils for raw meat and ready-to-eat foods, and wash them with hot soapy water after use.

3. Wash Hands Often: Clean your hands with soap and warm water before eating, after handling raw meat, and after contact with animals or their environments.

4. Drink Safe Water: Only drink water from trusted, treated sources, and avoid swallowing water from rivers, lakes, or swimming pools.

5. Store Food at Safe Temperatures: Keep perishable foods refrigerated (below 5°C) and do not leave cooked food at room temperature for more than two hours.

6. Maintain a Healthy Gut Microbiome: Eat a diet rich in fibre, fruits, vegetables, and fermented foods (such as yoghurt or sauerkraut) to help beneficial bacteria outcompete harmful ones.

7. Be Cautious When Travelling: In areas with higher infection risk, avoid raw or undercooked meat, unpasteurised dairy, and untreated water.

8. Test Your Gut Health if You Have Symptoms: If you have ongoing diarrhoea, abdominal pain, or changes in gut habits, get tested to detect and address Campylobacter before it causes long-term problems.