Clinical Overview of Campylobacter

Clinical Features

Incubation period is typically 2–5 days.

Infection is characterized by

• Diarrhea (often bloody)
• Abdominal pain
• Fever
• Nausea
• Sometimes vomiting

More severe illness can occur, including bloodstream infection and symptoms mimicking acute appendicitis or ulcerative colitis.

Etiology

Campylobacter is a gram-negative, microaerophilic genus of bacteria of the family Campylobacteraceae. More than 20 species of Campylobacter exist, not all of which cause human illness.

Almost 90% of human Campylobacter illness is caused by Campylobacter jejuni. Less common species – such as C. coli, C. upsaliensis, C. fetus, and C. lari – also infect people.

C. jejuni grows best at 37–42°C and seems to be well-adapted to birds. Birds have an approximate body temperature of 41–42°C and can carry the bacteria without becoming ill.

These bacteria are fragile outside of their hosts. They cannot tolerate drying. Freezing reduces the number of Campylobacter bacteria on raw meat.

At-risk populations

Anyone can become infected with Campylobacter but infection is more common in males, children younger than 5, people 65 and older, people who work with animals (especially birds or poultry), and international travelers.

People at risk for severe disease include people 65 and older, pregnant people, and people with weakened immune systems.

How it spreads

Most infections happen after someone eats raw or undercooked poultry or another food that has been contaminated by raw or undercooked poultry.

People also can get infected from contact with dog or cat feces. Person-to-person spread is uncommon.

Outbreaks of Campylobacter infection are infrequently reported relative to the number of illnesses. Outbreaks have been associated with

• Poultry
• Raw (unpasteurized) milk and dairy products
• Seafood
• Untreated water
• Produce
• Pet store puppies
• Sexual transmission

Disease rates

CDC estimates that 1.5 million people in the United States become ill from Campylobacter infection every year.

Active surveillance indicates that about 20 cases per 100,000 people are diagnosed each year. Many more cases go undiagnosed or unreported.

Diagnosis

Campylobacter can be detected by isolation from a clinical specimen or with a culture-independent diagnostic test (CIDT), such as a polymerase chain reaction test or antigen test.

CIDTs can provide rapid diagnostic testing. However, culture confirmation of CIDT-positive specimens is needed to obtain antimicrobial susceptibility data and a whole genome sequence for molecular subtyping.

Treatment and recovery

Most infections are self-limited. Patients should drink extra fluids as long as diarrhea lasts. Antimicrobial therapy may be used to treat people with, or at risk for, severe illness.

Azithromycin and fluoroquinolones (e.g., ciprofloxacin) are commonly used for treatment, but resistance to fluoroquinolones is common in the United States. Antimicrobial susceptibility testing can help guide appropriate therapy.

Prognosis

Most people with Campylobacter infection recover completely within 1 week.

Campylobacter infection can result in long-term consequences, such as arthritis, irritable bowel syndrome (IBS), and Guillain-Barré syndrome (GBS).

CDC estimates that only 0.2–1.7 in every 1,000 Campylobacter illnesses leads to GBS, but estimates Campylobacter are responsible for 5–41% of GBS illnesses.

Resources

Healthcare professionals can view antimicrobial resistance data for Campylobacter using antibiograms on Sanford Guide's mobile app and website.

The data come from CDC's National Antimicrobial Resistance Monitoring System (NARMS) and are also available through NARMS Now, an interactive web tool containing data on selected enteric bacteria isolated from humans.