اسم ورقم المقرر – Course Name and No. 4/16/2019

Define and recognize the various types of acute diarrheal illness Objective Define and recognize the various types of acute diarrheal illness Describe the epidemiology the host defenses in preventing the gastrointestinal infection   Explain pathogenesis by which Escherichia coli ,Campylobacter and Yersinia and their management Discuss the microbiological methods used for diagnosis of each of the bacterial agents including microscopy, selective media for maximal recovery Describe the pathogens, risk factors, clinical presentation and prevention of food poisoning travelers and antibiotic associated diarrhea. Name the etiological agents causing food poisoning and their clinical presentation 4/16/2019

introduction Diarrhea is a condition in which there is : - Unusual frequency of bowel movements (more than 3 times a day) - Changes in the amount ( more than 200g a day). Change in consistency( liquid stool). It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. WHO defines : Having 3 or more loose or liquid stools per day, or as having 3 or more loose stool. 4/16/2019

Three types of diarrhea Acute diarrhea is an attack of loose motion with sudden onset which usually lasts 3 to 7days . The most important causes of acute watery diarrhoea in young children. rotavirus, enterotoxigenic Escherichia coli, Shigella, Campylobacter jejuni Chronic diarrhea is termed when the loose motion is occurring for 3 weeks or more Dysentery . The term dysentery refers to diarrhoea with visible blood mucus in the faeces. The most important cause of acute dysentery is Shigella. Campylobacter jejuni. Entamoeba histolytica 4/16/2019

EPIDEMIOLOGY Approximately 111 million episodes of gastroenteritis in Children, which result in 25 million visits to clinics, 2 Million hospitalizations, and 352,000 to 592,000 deaths. About 1/3 of total hospitalized children are due to Diarrheal diseases and 17%of all deaths in indoor Pediatric patients are related to this condition. 4/16/2019

AGENT FACTORS Diarrhea is mostly infectious. A large numbers of organism are responsible for acute diarrhea Viruses: Rota virus, adenovirus,enterovirus,Norwalk Bacteria: Campylobacter E.coli,Shigella,Salmonella,cholera vibrio parahemolyticus Parasites. G.lambia, Cryptosporidium,H.nana (Hymenolepis nana) malaria e Fungi: Candida albicans 4/16/2019

MODE OF TRANSMISSION It is mainly feco-oral route MODE OF TRANSMISSION It is mainly feco-oral route.It is water- borne,foodborne disease or may transmit via fingers,fomites,flies or dirt. The disease is most common specially between 6months to 2 years.The incidence is higher during weaning period It occurs due to combined effects of reduced maternal antibodies, lack of active immunity and introduction of contaminated food or direct spread through child’s hands. 4/16/2019

pathogenesis by which Escherichia coli Campylobacter and Yersinia and their management E. coli is a gram-negative, rod-shaped bacterium that is commonly found in the lower intestine . E. coli strains are harmless, but some serotypes are pathogenic and can cause serious food poisoning fecal–oral transmission is the major route through which pathogenic strains of the bacterium cause disease. which makes them ideal indicator organisms to test environmental samples for fecal contamination اسم ورقم المقرر – Course Name and No. 4/16/2019

Pathogenesis of E coli Escherichia coli are normal inhabitants of the human gastrointestinal tract and are among the bacterial species most frequently isolated from stool cultures. When E. coli strains acquire certain additional genetic material, they can become pathogenic; Diarrheagenic E. coli are among the most frequent bacterial causes of gastroenteritis worldwide Enterotoxigenic . E coli (ETEC) type of Escherichia coli and one of the leading bacterial causes of diarrhea in the developing world, as well as the most common cause of travelers' diarrhea. Enteropathogenic E. coli (EPEC) causative agent of diarrhea in humans, rabbits, dogs, cats and horses اسم ورقم المقرر – Course Name and No. 4/16/2019

Con. Enteroinvasive . E. coli (EIEC) type of pathogenic bacteria whose infection causes a syndrome that is identical to shigellosis Enterohemorrhagic E. coli (EHEC) The most infamous member of this pathotype is strain O157:H7, which causes bloody diarrhea and no fever. EHEC can cause(HUS) hemolytic-uremic syndrome and sudden kidney failure. It uses bacterial fimbriae for attachment (UTI ) اسم ورقم المقرر – Course Name and No. 4/16/2019

Lab diagnosis Microscopy: Gram’s staining Gram negative bacilli Culture: MacConkey’s agar Lactose fermenting, mucoid pink colored colonies Eosin methylene blue (EMB is the selective and differential medium for coliforms اسم ورقم المقرر – Course Name and No. 4/16/2019

Campylobacter (meaning "curved bacteria") is a genus of Gram-negative bacteria. Campylobacter typically appear comma or s-shaped and motile. Most Campylobacter species can cause disease and can infect humans and other animals. Campylobacter enteritis is a common cause of intestinal infection. These bacteria are also one of the many causes of traveler's diarrhea or food poisoning. People most often get infected by eating or drinking food or water that contains the bacteria . اسم ورقم المقرر – Course Name and No. 4/16/2019

Pathogenesis Produces a toxin called Cytolethal Distending Toxin (CDT). There is evidence that C. jejuni infections commonly precede Guillain Barré Syndrome (GBS) which results from a case of molecular mimicry whereby host produced anti-Campylobacter antibodies recognize and cross react with self gangliosides and damage peripheral nerve tissue اسم ورقم المقرر – Course Name and No. 4/16/2019

What Are the Symptoms The onset of disease symptoms usually occurs 2 to 5 days after infection with the bacteria, but can range from 1 to 10 days. The most common clinical symptoms of Campylobacter infections include diarrhoea (frequently bloody), abdominal pain, fever, headache, nausea, and/or vomiting. The symptoms typically last 3 to 6 days. Complications such as bacteraemia (presence of bacteria in the blood), hepatitis, pancreatitis (infections of liver and pancreas, respectively), اسم ورقم المقرر – Course Name and No. 4/16/2019

Lab diagnosis Skirrow's medium is effective for isolating Campylobacters from human faeces . In microaerophilic condition PCR Serum test Campy Agar 4/16/2019

Yersinia is a Gram-negative bacillus-shaped bacterium, belonging to the family Enterobacteriaceae. It is Motile at temperatures of 22–29°C, but becomes non motile at normal human body temperature The portal of entry is the gastrointestinal tract. usually lead to mild self-limiting enterocolitis or terminal ileitis and adenitis in humans. Symptoms may include watery or bloody diarrhea and fever, Yersiniosis is usually self-limiting and does not require treatment. For sepsis or severe focal infections, especially if associated with immunosuppression, the recommended regimen includes doxycycline in combination with an aminoglycoside. اسم ورقم المقرر – Course Name and No. 4/16/2019

Viral Causes Viral infection is probably the most common cause of infectious diarrhoea Rotavirus is a common cause of diarrhoea in infants and young children. 10 trillion particle per ml don't destroy by acid or digestive enzymes .The virus infects only the mature villus epithelial cells at the apices of small intestinal villi. Management should focus on rehydration status. Fecal testing is not routinely indicated. . اسم ورقم المقرر – Course Name and No. 4/16/2019

Con. Large amounts of rotavirus are shed in the stool of infected people and the virus can be easily spread via contaminated hands and objects, such as toys. Children can spread rotavirus both before and after they become sick with diarrhea. Norovirus is frequently implicated in outbreak situations. اسم ورقم المقرر – Course Name and No. 4/16/2019

Clostridium difficile toxin C. difficile is the major identifiable cause of antibiotic- associated diarrhoea. The prevalence of asymptomatic colonisation of the bowel ranges from <5% in the community to over 20% in hospitalised patients. It is more prevalnt in the elderly. C. difficile toxin testing is indicated for patients who develop diarrhoea while in hospital, on antibiotics or receiving chemotherapy. اسم ورقم المقرر – Course Name and No. 4/16/2019

Prevention Safe consumption of food and water Travelers should eat only in restaurants with a reputation for safety and should not consume any food or beverages from street vendors. Cooked foods that are still hot when served are generally safe. Salads containing uncooked vegetables or fruit and food left on the table in open containers should be avoided. Even ice cubes should be made with water that has been boiled. اسم ورقم المقرر – Course Name and No. 4/16/2019

Prevention Preventive antibiotics are recommended only for people who are particularly susceptible to the consequences of traveler’s diarrhea, such as those whose immune system is impaired. The antibiotics most commonly recommended are ciprofloxacin and azithromycin. 4/16/2019

Treatment Fluids Antidiarrheal drugs Sometimes antibiotics or antiparasitic drugs When symptoms occur, treatment includes drinking plenty of fluids and taking drugs that stop diarrhea such as loperamide. These drugs cannot be given to people who have a fever or bloody stools or to children under 2 years of age. 4/16/2019