Digestive Diseases

1. Digestive Diseases Shigellosis Campylobacter jejuni Cholera

2. Shigella • Etiology • Family: Enterobacteriaceae • Gram negative • Rod shaped • Non motile • Non spore forming • Very closely related to Escherichia coli

3. Shigella • There are four species of Shigella • S. sonnei • Also known as group D Shigella • Responsible for most cases of shigellosis in the United States • S. dysenteriae • Type 1 • Is rare in the U.S. but can lead to deadly outbreaks in developing countries • S. flexneri • Group B Shigella • Accounts for almost all of the rest • S. boydii • Is the most genetically-divergent of the Shigella genus • S. boydiiis restricted to the Indian subcontinent

4. Shigellosis • Shigellosis is an infectious disease caused by a group of bacteria called Shigella • Endemic in North America, Europe, and the tropics • Every year, approximately 14,000 cases of Shigellosis are reported each year in the United States • Infection is more common in children ages 1-4 years and in the elderly , debilitated and malnourished • The only reservoir for Shigella organism is the human intestinal tract, and infected feces are always the source of the infection • Incubation period is usually 1 to 3 days

5. Transmission • Pass from one infected person to another • Directly by fecal-oral route transmission or indirectly through contact with contaminated objects • Shigella are present in the diarrheal stools of infected persons while they are sick and for up to a week or two afterwards • Widest distribution of the organism is through contaminated water or food • Transmission occurs primarily through individual who fail to wash their hands or clean their fingernails after defecation • Food can also be contaminated by flies that carry enough of the organism for it to multiply to an infectious dose in food • When dogs ingest human feces, the infection can be passed by them to children or other susceptible persons

6. Symptoms • Shigellae invade the intestinal mucosa and cause inflammation • In children: usually produces diarrhea, high fever, nausea, vomiting, abdominal pain with distention, irritability, and drowsiness • Pus, mucus, and blood may appear in stools as a result of the intestinal ulceration (typical of this infection) • In adults: produces many of the same symptoms except that adults generally do not have fever

7. Treatment • Persons with mild infections usually recover quickly without antibiotic treatment • Resistanceto traditional first-line drugs like ampicillin and trimethoprim-sulfamethoxazole is common, and resistance to some other antibiotics is increasing • If an effective one can be found, then the shigellae can be eliminated quickly • When many persons in a community are affected by shigellosis, antibiotics are sometimes used to treat only the most severe cases • Some antidiarrheal drugs can make the illness worse and should be avoided

8. Prevention • No vaccine at present • Control of the human reservoir and sanitary control of environmental sources through: • Adequate treatment of water and sewage, fly control and protection of food, water, and milk from human or mechanical vectors

9. Campylobacter jejuni

10. Campylobacter jejuni • Etiology • Gram negative • S- shaped or spiral rods • Non-spore forming • A polar tail at one or both ends propels the bacteria through liquid • They cannot tolerate drying and can be killed by oxygen • Freezing reduces the number of Campylobacter bacteria on raw meat(They are thermophiles) • Damages the small intestine and the colon

11. Campylobacter jejuni • Epidemiology • Is prevalent in the United States and other developed countries • One of the most common causes of diarrheal illness in the United States • over 2 million cases are reported each year • it is estimated that approximately 100 persons with Campylobacter infections die each year • occurs much more frequently in the summer months than in the winter • isolated from infants and young adults more frequently than from persons in other age groups and from males more frequently than females • As low as 500 organisms can cause infection

12. Transmission • Most cases of campylobacteriosis are associated with eating raw or undercooked poultry meat or from cross-contamination of other foods by these items • Roughly 57% of cases can be traced to chickens and 35% to cattle • to cut poultry meat on a cutting board, and then use the unwashed cutting board or utensil to prepare vegetables or other raw or lightly cooked foods • Unpasteurized milk also transmits Campylobacter through utter infection and contact with milk • some people get infected from contact with the stool of an ill dog or cat

13. Symptoms • characterized by bloody or mucosal diarrhea • The diarrhea is a result of the bacteria's colonization in the intestine and cell death due to the cytolethaltoxin • Other symptoms may include muscle pain, headache, fever, and nausea which are due to dehydration from the diarrhea • most symptoms cease after five days

14. Treatment • Done by managing the symptoms and any complications until the symptoms subside • Antibiotics can be used but are not usually administered unless serious complications arise • Replacement of fluids and electrolytes lost during diarrhea and vomiting are keys to recovery and preventing symptoms from being prolonged • Drinks such as soda and fruit juices contain too much sugar and too few electrolytes to be considered effective treatments for dehydration.

15. Prevention • Proper food handling and hand washing skills are key practices to prevent the spread of Campylobacter jejuni • Make sure that the meat is cooked throughout (no longer pink in the center) • All poultry should be cooked to at least an internal temperature of 165°F • Prevent cross-contamination while preparing foods by using separate cutting boards for raw meats and other foods • Cleaning all cutting boards, kitchen countertops, and silverware with soap and hot water • Do not drink unpasteurized milk or untreated surface water • Be sure that persons with diarrhea wash their hands carefully and frequently with soap to help reduce the risk of spreading the infection

16. Cholera

17. Vibrio cholerae • Etiology • Gram-negative • Curved rod • Non-spore forming • Two serotypes • V. cholera O1 and O139 • These cause outbreaks • O1 causes the majority of causes • O139 confined to South east Asia • Other non O1 and non O139 can cause diarrhea but do not cause epidemics

18. Cholera • It is rare in the United States and other industrialized nations • Global cases of cholera have increased steadily in many places • CDC has an alert of an outbreak of Cholera in several areas of central Mexico beginning in August 2013 • U.S. travelers to areas where it is endemic may be exposed to cholera bacterium • Travelers may also bring contaminated seafood back to the U.S. • It affects both children and adults and can kill within hours

19. Cholera • Acute gastrointestinal infections caused by Vibrio cholerae • Caused by an exotoxin produced by the organism • Most likely to be found and spread in places with inadequate water treatment, poor sanitation, and inadequate. • Humans are the only known reservoir, although there is a possibility of environmental reservoirs

20. Transmission • Person can get cholera by drinking water or eating food contaminated with cholera bacterium • Transmitted through feces or vomitus of carriers or persons with active infections • Epidemic spread usually results from contaminated water supplies • Food is involved more often in sporadic cases in endemic areas • Hands, utensils, clothing, and flies may contaminate food or carry the infection directly to the mouth

21. Symptoms • Infection is often mild or without symptoms, but can sometimes be severe • Incubation period is generally 2-3 days • Communicability lasts as long as the stools are positive, usually only a few days after recovery • Diarrhea will be pale, white flecks appear (“rice water stools”) • Due to massive loss of fluid, other symptoms occur: • Thirst, weakness, sunken eyes, muscle cramps, and cardiovascular problems • Collapse, shock, and death may follow if the patient is not continuously rehydrated until the infection subsides

22. Treatment • Successfully treated by immediate replacement of the fluid and salts lost through diarrhea • Patients can be treated with oral rehydration solution, a prepackaged mixture of sugar and salts to be mixed with water and drunk in large amounts • Severe cases also require: • Intravenous fluid replacement • Antibiotics- to shorten the course and diminish the severity of the illness • Diminish duration of diarrhea, speeds the elimination of the bacteria from the feces

23. Prevention • Proper sanitation and vaccine are the best methods of prevention • Currently, there are two oral cholera vaccines available • People traveling to epidemic areas in other countries may be required to have a vaccination • If possible drink only bottled water • Boil water for 1 minute • Wash your hands often with soap and clean water • Eat foods that are packaged or are freshly cooked and served hot • Do not eat raw and undercooked meats and seafood or unpeeled fruits and vegetables • Dispose of feces in sanitary manner