Campylobacter Jejuni PDF

Campylobacter Jejuni ILOs At the end of this session, the student will be able to: § 1.Recognize campylobacter as a cause of infectious diarrhea in all age groups. § 2. Understand the pathogenesis of the infection § 3. Consider the diagnosis of campylobacter in patients with bloody...

Campylobacter Jejuni ILOs At the end of this session, the student will be able to: § 1.Recognize campylobacter as a cause of infectious diarrhea in all age groups. § 2. Understand the pathogenesis of the infection § 3. Consider the diagnosis of campylobacter in patients with bloody diarrhea, fever and abdominal pain. § 4. Differentiate from other causes of bloody diarrhea. § 5. Recognize Guillain Bare syndrome as a possible serious post-complication that may occur post-campylobacter infection. § 6. Understand the role of stool culture in establishing the diagnosis. § 7. Discuss indications of antimicrobial therapy in patients with acute diarrheal illnesses. § 8. Understand the role of mass treatment of animals to prevent the spread of both infections to humans. Causative agent Campylobacter jejuni I and II (most common causes of gastroenteritis) Campylobacter coli Campylobacter larids All the three campylobacters can be normally present in GIT of both domestic and wild animals which act as a reservoir of infection. Mode of Infection 1. Campylobacter can survive for 2-5 weeks in cow’s milk or water kept at 4c but they don’t multiply 2. Ingestion of contaminated food (during preparation of food from animal intestinal contents) 3. Consumption of raw unpasteurized milk 4. Excreta from wild and domestic animals can contaminate surface of water and water borne transmission is important in developing countries 5. Direct and close contact with animal feces as in villages as with poultry, goats, cattle, and dogs 6. Transmission from human to human may occur from infected individuals or from convalescent carriers especially young children. Organisms must be ingested to produce the illness at the infecting dose of 500 organisms. C.jejuni is killed by acid at ph 2.3, indicating that gastric acid is an effective barrier and intake of organisms with milk or other food that neutralize gastric acid enhance infection. Pathogenesis The regions of intestine that are mostly affected jejunum, terminal ileum and the colon. Following ingestion, campylobacter attach to the enterocytes via non fimbrial adhesions. C.jejuni releases enterotoxin and cytotoxin, the enterotoxin is similar in structure and mode of action of E. coli LT or cholera toxin. Non inflammatory diarrhea could occur causing voluminous watery diarrhea. Dysentery like diarrhea occur if there is penetration of terminal ileum and colonic epithelial cells leading to cell death and an inflammatory response. Immunity to infection is acquired following one pr more infective episodes, but the duration of immunity is unknown. Following infection, serum and secretory antibodies to campylobacter enterotoxin, lipopolysaccharides and other surface antigens that are involved in attachment are produced. The presence of secretory IgA against campylobacter is the main determinant of immunity. in a small number of infected people usually the immunocompetent, bacteria translocate from intestinal lumen causing bacteremia. Pathology In the dysentery like illness there are: Inflammatory infiltrates and crypt abscess are seen in lamina propria of terminal ileum, rectal and colonic mucosa. Clinical Presentation IP 2-5 days Duration of excretion of C.jejuni 2-3 weeks after cessation of diarrhea Usually non inflammatory diarrhea, watery, voluminous without blood or fever However, severe bloody diarrhea can occur with blood and fever, abdominal pain. Diarrhea is self-limiting and lasts 2-7 days in general. Complications Malnutrition Hepatic dysfunction Renal failure Malignancy DM Disseminated infection can occur in immunocompromised individuals. Asymptomatic bacteremia. Deep abscesses Meningitis Cholecystitis Reactive arthritis Diagnosis Isolation of C.jejuni from feces culture at 42c at microaerophilic atmosphere Treatment Rehydration in severe watery diarrhea antimicrobial chemotherapy in severe dysentery and disseminated infections. Erythromycin 500mg/6hrs/5 days Azithromycin 500mg/ once daily for 3 days For those with extra intestinal infections (imipenem, 3rd generation cephalosporin, erythromycin for 2-4 weeks)