Campylobacteriosis

Campylobacteriosis refers to infection by the group of bacteria known as Campylobacter. The term comes from the Greek word meaning "curved rod" referring to the bacteria's curved shape. The most common disease caused by these organisms is diarrhea, which most often affects children and younger adults. Campylobacter infections account for a substantial percent of food-borne illness encountered each year.

Description

There are over 15 different subtypes, all of which are curved Gram-negative rods. C. jeuni is the subtype that most often causes gastrointestinal disease. However, some species such as C. fetus produce disease outside the intestine, particularly in those with altered immune systems, such as people with AIDS, cancer, and liver disease.

Campylobacter are often found in the intestine of animals raised for food produce and pets. Infected animals often have no symptoms. Chickens are the most common source of human infection. It is estimated that 1% of the general population is infected each year.

Causes and symptoms

Improper or incomplete food preparation is the most common way the disease is spread, with poultry accounting for over half the cases. Untreated water and raw milk are also potential sources.

The incubation period after exposure is from one to 10 days. A day or two of mild fever, muscle aches, and headache occur before intestinal symptoms begin. Diarrhea with or without blood and severe abdominal cramps are the major intestinal symptoms. The severity of symptoms is variable, ranging from only mild fever to dehydration and rarely death (mainly in the very young or old). The disease usually lasts about one week, but persists longer in about 20% of cases. At least 10% will have a relapse, and some patients will continue to pass the bacteria for several weeks.

Complications

Dehydration is the most common complication. Especially at the extremes of age, this should be watched for and treated with either Oral Rehydration Solution or intravenous fluid replacement.

Infection may also involve areas outside the intestine. This is unusual, except for infections with C. fetus. C. fetus infections tend to occur in those who have diseases of decreased immunity such as AIDS, cancer, etc. This subtype is particularly adapted to protect itself from the body's defenses.

Areas outside the intestine that may be involved are:

• Nervous system involvement either by direct infection of the meninges (outer covering of the spinal and brain) or more commonly by producing the Guillain-Barré syndrome (progressive and reversible paralysis or weakness of many muscles). In fact, Campylobacter may be responsible for 40% of the reported cases of this syndrome.
• Joint inflammation can occur weeks later (leading to an unusual form of arthritis).
• Infection of vessels and heart valves is a special characteristic of C. fetus. Immunocompromised patients may develop repeated episodes of passage of bacteria into the bloodstream from these sites of infection.
• The gallbladder, pancreas, and bone may be affected.

Diagnosis

Campylobacter is only one of many causes of acute diarrhea. Culture (growing the bacteria in the laboratory) of freshly obtained diarrhea fluid is the only way to be certain of the diagnosis.

Treatment

The first aim of treatment is to keep up nutrition and avoid dehydration. Medications used to treat diarrhea by decreasing intestinal motility, such as Loperamide or Diphenoxylate are also useful, but should only be used with the advice of a physician. Antibiotics are of value, if started within three days of onset of symptoms. They are indicated for those with severe or persistent symptoms. Either an erythromycin type drug or one of the fluoroquinolones (such as ciprofloxacin) for five to seven days are the accepted therapies.

Prognosis

Most patients with Campylobacter infection rapidly recover without treatment. For certain groups of patients, infection becomes chronic and requires repeated courses of antibiotics.

Prevention

Good hand washing technique as well as proper preparation and cooking of food is the best way to prevent infection.