Campylobacteriosis

Overview
Campylobacteriosis is among the most common bacterial infections of humans. It produces an inflammatory, sometimes bloody, diarrhea or dysentery syndrome. It is responsible for proctocolitis in participants of anoreceptive intercourse, bacteremia in AIDS patients and other immunocompromised patients, and travelers' diarrhea. Helicobacter pylori is closely related to Campylobacter and causes peptic ulcer disease.

Epidemiology
An estimated 2 million cases of Campylobacter enteritis occur annually in the U.S., accounting for 5-7% of cases of gastroenteritis. A large animal reservoir is present, with up to 100% of poultry, including chickens, turkeys, and waterfowl, having asymptomatic infections in their intestinal tracts. An infected chicken may contain up to 109 bacteria per 25 grams, and due to the installations, the bacteria is rapidly spread to other chicken. Ten to five hundred bacteria are enough to infect humans.

Pathophysiology
Campylobacter organisms are curved or spiral, motile, non–spore-forming, gram-negative rods. The known routes of transmission are fecal-oral, person-to-person sexual contact, raw milk and poultry ingestion, and waterborne (ie, through contaminated water supplies). Exposure to sick pets, especially puppies, has also been associated with outbreaks. The infectious dose is 1000-10,000 bacteria. Campylobacter species are sensitive to hydrochloric acid in the stomach, and acid reduction treatment can reduce the amount of inoculum needed to cause disease. Symptoms begin after an incubation period of one to seven days. The sites of tissue injury include the jejunum, the ileum, and the colon. C jejuni appears to invade and destroy epithelial cells. Some strains of C jejuni produce a cholera-like enterotoxin, which is important in the watery diarrhea observed in infections. The organism produces diffuse, bloody, edematous, and exudative enteritis. In a small number of cases, the infection may be associated with hemolytic uremic syndrome and thrombotic thrombocytopenic purpura through a poorly understood mechanism. In patients with HIV, infections may be more frequent, may cause prolonged or recurrent diarrhea, and may be more commonly associated with bacteremia and antibiotic resistance. The severity and persistence of infection in patients with AIDS and hypogammaglobulinemia indicates that both cell-mediated and humoral immunity are important in preventing and terminating infection.

Features
Patients usually have a history of ingestion of inadequately cooked or contaminated meat (poultry in particular), unpasteurized milk, or untreated water. The actual latent period is 1-6 days (typically 1-2 days). A brief prodrome of fever, headache, and myalgias lasting as long as 24 hours is followed by crampy abdominal pain, fever as high as 40°C, and as many as 10 watery, frequently bloody, bowel movements per day. Abdominal pain and tenderness may be very localized, mimicking acute appendicitis. Complications include toxic megacolon, dehydration and sepsis. Generalized form of the infection can occur in little children ( < 1 year of age) and immunocompromised people. Chronic course of the disease is possible; such form of the process  is  likely to develop without a distinct acute phase. Chronic campylobacteriosis features long period of sub-febrile temperature, asthenia and depletion; eye damage, arthritis, endocarditis  may develop if  infection is untreated.

Diagnosis
Campylobacter organisms can be detected on gram stain of stool with high specificity and a sensitivity of ~60%, but are most often diagnosed by stool culture. Fecal leukocytes are present and indicate an inflammatory diarrhea.

Treatment
In most cases, reposition of liquid and electrolytes is enough.

The use of antibiotics is controversial. Some studies show that erythromycin rapidly eliminates Campylobacter from the stool without affecting the duration of illness. Studies in children with dysentery due to C jejuni have shown benefit from early treatment with erythromycin. Treatment with antibiotics, therefore, depends on the severity of symptoms. Antimotility agents, such as loperamide, can lead to prolonged illness or intestinal perforation in any invasive diarrhea, and should be avoided.

Prognosis
It is usually self-limited without any mortality. Occasional deaths occur in young, previously healthy individuals because of volume depletion and in persons who are elderly or immunocompromised.

Prevention

 * Pasteurization of milk and chlorination of drinking water destroy the organism.
 * Treatment with antibiotics can reduce fecal excretion.
 * Infected health care workers should not provide direct patient care
 * Separate cutting boards should be used for foods of animal origin and other foods. After preparing raw food of animal origin, all cutting boards and countertops should be carefully cleaned with soap and hot water.