„Approved” on methodical conference department of infectious diseases and epidemiology „____” ____________ 200 р. Protocol № _____ Chief of Dept., professor __________ V.D. Moskaliuk METHODOLOGICAL INSTRUCTIONS to a fifth year student of the Faculty of Medicine on independent preparation for practical training Topic: TOXIC FOOD-BORNE INFECTIONS. ESCHERICHIOSIS. CAMPYLOBACTERIOSIS. Subject: Major: Educational degree and qualification degree: Year of study: Hours: Prepared by assistant professor Infectious Diseases Medicine Specialist 5 2 Sydorchuk A.S. Topic: Toxic food-borne infections. Escherichiosis. Campylobacteriosis. 1. Lesson duration: 2 hours 2. Aims of the lesson: 3.1. Students are to know: • etiology of toxic food-borne diseases, escherichiosis, campylobacteriosis, types of pathogens, their principal properties; • epidemiology of toxic food-borne diseases, escherichiosis, campylobacteriosis; • pathogenesis of toxic food-borne diseases, escherichiosis, campylobacteriosis and morphology of organs afflicted by these pathogens; • symptoms and development of typical and atypical toxic food-borne diseases, escherichiosis, campylobacteriosis; • clinical characteristic of toxic food-borne diseases, escherichiosis, campylobacteriosis; • complications of toxic food-borne diseases, escherichiosis, campylobacteriosis; • diagnosis of toxic food-borne diseases, escherichiosis, campylobacteriosis; • laboratory methods of examination at toxic food-borne diseases, escherichiosis, campylobacteriosis; • differential diagnosis of toxic food-borne diseases, escherichiosis, campylobacteriosis including distinguishing between similar diseases; • treatment of toxic food-borne diseases, escherichiosis, campylobacteriosis with taking into account of course severity; • prophylactic and antiepidemic measures at toxic food-borne diseases, escherichiosis, campylobacteriosis. 3.2. Students are to be able: • to question a patient in order for obtaining of information on disease history and epidemiologic anamnesis; • to perform clinical examination of a patient; • to formulate and to substantiate the diagnosis of toxic food-borne diseases, escherichiosis, campylobacteriosis; • to prepare a plan of additional patient examination; • to evaluate results of laboratory examination; • to determinate a course severity; • to make differential diagnosis to distinguish between similar diseases (salmonellosis, cholera, food borne diseases, typhoid fever etc); • to prescribe adequate pathogen and etiotropic treatment; • to prepare a plan and organize prophylactic and antiepidemic measures. 3.3. Students are to acquire the following skills: • to conduct clinical examination of a salmonellosis patient and other acute intestinal diseases; • to formulate and substantiate a clinical diagnosis; • to prepare a plan of paraclinic patient examination; • to take samples of material (stool, vomitory masses, suspicious food-stuffs, water after irrigation of the stomach) for bacterioscopy and other quick analysis methods and bacteriological examination for revealing of causative agents; and to take samples of material (blood) for PCR (polimerase chain reaction) and other quick analysis methods (ELISA) and serological examination for revealing of the agent or antibodies against their; • to evaluate results of paraclinic patient examination; • to organize hospitalization and treatment of a toxic food-borne diseases, escherichiosis, campylobacteriosis patient ; • to provide emergency aid at severe toxic food-borne diseases, escherichiosis, campylobacteriosis; • to plan and organize prophylactic measures against toxic food-borne diseases, escherichiosis, campylobacteriosis; • to plan and organize antiepidemic measures to localize and liquidate a toxic food-borne diseases, escherichiosis, campylobacteriosis source. 4. Advice to students. Toxic food-borne infections is an acute transitory disease, caused by conditionally pathogenic bacteria. These bacteria are capable to produce exotoxin (in food-stuffs). The disease is accompanied with symptoms of the damage of the upper parts of the gastrointestinal tract (gastritis, gastroenteritis) and by violation of the water-electrolyte balance. Etiology. Many types of the conditionally pathogenic bacteria may be agents of the toxic food-borne infections and produce exotoxin out of the human organism on the different food-stuffs. Enterotoxins (thermoliable and thermostable) increase the secretion of the fluids and salts into the stomach and intestine. Cytotoxins damage the membranes of the epithelial cells and violate the protein synthetic processes. The agent, producing enterotoxins are Clostridium perfringeus, Proteus. vulgaris, Proteus mirabilis, Bacillus cereus. These enterotoxins are also formed by agents from the in families of Klebsiella, Enterobacter, Citrobacter, Serrafia, Pseudomonas, Aeromonas, Edwarsiella. The majority of these enterotoxins are thermoliable. Epidemiology. Pathogenic organisms of the toxic food infections are widely spread in the nature. They may be everywhere: in the fecal matters of human and animals; in and the soil; in the water; in an air and on the different subjects. The way of the spread of the infection is alimentary. The factors of the transmission of the disease are solid products (sausages, eggs, meat and fish canned food) and liquid products (soup, milk, juices, compotes, jellies, lemonade, beer, cocktails). They are the nutritive mediums for bacteria. The susceptibility to this group of diseases is very high, sometimes till 90-100 %. The typical sign of the toxic food-borne infections is not only group but explosive character of illness due to all participants of the outbreak become ill during a short period (over a few hours). The diseases toxic food-borne infections are registered during the hole the year, but especially in summer. Pathogenesis. In toxic food infections exotoxin is contained in food, besides bacteria. Due to this the incubation period is very short. Time of the of clinical manifestations development after influence of toxins to the mucous membrane is from 30 minutes till 2-6 hours. Pathogenesis and clinical manifestations of the disease depend of the type and dose exotoxin, and also from other toxical substances microbial origin, containing in the food-stuff. Enterotoxins (thermoliable and thermostable) are connected with the epithelial cells of stomach and intestine and act to the fermental system of the epitheliocytes, but no cause morphological changes in these organs. Enterotoxin activates ferments adenylcyclase and guanylcyclase increasing formation of the biological active substance (cyclic adenosinemonophosphates and cyclic guanidinmonophosphates) in the cells of the mucous membranes. All these changes lead to the increase rate of secretion of water and salts into the stomach and intestine and to the development of diarrhea and vomiting. Pathological anatomy. Cytotoxins damage the membranes of the epithelial cells and violates synthetic processes. It may increase the permeability of the intestinal wall for different types of the toxical substances, and for oneself microorganisms, development of intoxication and violation of microcirculation and localized inflammatory alterations of the intestinal mucous membrane. Clinical manifestations. The clinical manifestations of the toxic food-borne infections caused by only enterotoxins are less severe. In the majority of the cases of the disease there is no fever and just considerable inflammatory changes of the mucous membrane of the stomach and intestine. The course of the disease become more severe due to accumulation of enterotoxin and cytotoxin in the food-stuffs. The high fever and considerable change of the mucous membrane of the gastrointestinal tract are observed. In toxic food-borne infections there is combination of the signs of the damage of the gastrointestinal tract (gastritis, gastroenteritis or gastroenterocolitis) and signs of the general intoxication and dehydration. The incubation period is from 30 minutes to 24 hours (generally 2-6 hours). The beginning of the disease is an acute. At first the nausea occurs. Frequently the replated, agonizing and unrestrained vomiting occurs. Almost at the same time with vomiting the diarrhea starts. Stool is watery from 1 to 10-15 times a day. In considerable part of patients the disease is not accompanied by severe pain in the stomach and increase of the body temperature of the body. However the disease may be with spasmatic pains in the stomach, with the raise of the body temperature upto 38-39 C. The raise of the body temperature takes place at the early hours of the disease and through 12-24 hours the temperature is reduced to normal. During objective examination of the patients the pale skin, sometimes cyanosis, cold extremities are observed. The tongue is coated. Stomach is soft and painful in the epigastrium during palpation. The cardiovascular system also suffers. There is bradycardia (during hyperthermia - tachycardia). The arterial pressure decrease. In some cases collapse of short duration develops. Due to repeated vomiting and plenty diarrhea the signs of dehydration develop. It may be possible of the appearance of the muscle’s cramps of extremities, decrease of the diuresis and reduced turgor of the skin. The liver and pancreas are not expanded. In hemogram leukocytosis, neutrophylosis and temperate accelerate ESR are noted. The duration of the disease in majority of the cases is 1-3 days. The toxical food infection may be accompanied by severe complications. Hypovolemic shock and an acute heart insufficiency, connecting with violations of electrolytic balance (hypokalemia) are observed. Diagnosis. The diagnosis of the toxic food-borne infections is made according the results of the clinical symptoms estimation, epidemiological and laboratory data. The typical signs are the impetuous development of the disease after short incubation period, presence of symptoms of gastritis, gastroenteritis or gastroenterocolitis in combination with intoxication, dehydration, disposition to the vascular dystonia. Differential diagnosis. Differential diagnosis of toxical food infection is performed with acute intestinal infections (cholera; acute shigellosis; gastrointestinal form of yersiniosis; rotoviral gastroenteritis; campylobacteriosis; dyspeptic variants of preicteric period of viral hepatitis and others), with surgical diseases (acute appendicitis; cholecystopancreatitis; thrombosis of mysentrical vessels; perforation of ulcers in the stomach and duodenum), with gynecological diseases (ectopic pregnancy; toxicosis of the pregnancy), with therapeutic diseases (myocardial infarction; hypertension crisis), with neurological diseases (acute damages of cranial blood circulation, subarachnoidal hemorrhage), with urological diseases (pyelonephritis; acute renal insufficiency). During the diagnostics it is necessary to consider the food poisoning; poisoning by mushrooms; salts of hard metals. Treatment. It is necessary to wash out a stomach and intestine to release them from microbes and toxins as soon as possible. For a lavage it is better to use isotonic solution of Sodium chloridum, boiled water or 1-2 % solution of sodium hydrocarbonate. Then give inside the activated microspherical coal (SKN brand). Alternative preparations are Sillard P, Smecta, Enterodes and other enterosorbents. Their early indication promotes the fastest improvement of health state, preserves intoxication, development of the serious form of bacterial endotoxicosis. In case of development of infection-toxic shock we should immediately infuse in blood colloid and cristaloid solutions: Polyglucin, Reopoliglycin, donor Albumin, Trisol, Acesol, Quartasol, and also glucocorticoides. Etiotropic treatment is indicated only at serious forms with development of colitic syndrome: Furazolidon or Enteroseptol. Antibiotics are indicated in case of development of sepsis - Levomycetin, Gentamicin, Ampicillin, Ofloxacin (or Tarivid). Prophylaxis. Prophylaxis of the toxical food infection is concluded in prevention of infection of the food-stuff, of the reproduction of the microorganisms in the food. It is necessary to keep the food-stuffs and prepared food at the temperature from 2 till 4 ºC. The mechanization and automatization of the food objects, the elaboration of the new methods of the preserving and storage of the food-stuff, the freezing at low temperature are conductive to the successful prophylaxis of the toxical food infection. Escherichiosis is an acute intestinal infection caused by E.coli, which mainly affect 1year-old babies. Classification includes enterohemorrhagic E.coli (EHEC), which produces cytotoxins, enterotoxigenic E.coli (ETEC) elaborating enterotoxins. Then come enteroinvasive E.coli (EIEC) invading intestinum epithelium, enteropathogenic E.coli (EPEC) that manifests epithelial adherence and leads to attaching and effacing lesions. And finally, there is enteroaggregative E.coli (EAEC) demonstrating a stacked-brick adherence to epithelium cells. All these classes are connected with different epidemic patterns and clinical syndromes. Infection is caused by contact and alimentary route. Their mothers, who violate the anti-epidemic regimen, also through contaminated food, toys, infect the babies. The disease frequently occurs in summer and autumn. Bacilli carriers are frequently noted. Older children and adults get ill principally. The incubative period is from 3 to 8 days. The disease has an abrupt onset. The body temperature increases, weakness and anorexia appear. Stools occur frequently, they are watery, yellow or orange, contain transparent mucus. If such stools occur five to seven times daily, dehydration may occur. Toxemia is manifested by restlessness, recurrent regurgitation and vomiting. The disease has a protracted course. Diagnosis is based on clinical manifestations of the disease and bacteriologic tests of feces. The additional method of laboratory diagnosis is serologic test (passive hemmagglutination test). Diagnostic titer is 1:801:160. The increase of antibody titer is discovered in 60-70% of the patients. Campylobacteriosis refers to the group of the infections caused by gram-negative bacteria of the genus Campylobacter. Among the most common bacterial infections of humans in all parts of the world, campylobacters cause, both diarrhoeal and systemic illnesses and are highly associated with gastritis and peptic ulcer disease. Originally isolated from aborted sheep fetuses in 1909, these and similar organisms were called Vibrio fetus. There are now 14 recognised species within the genus. Three types of illnesses are associated with Campylobacter species-enteric (C. jejuni), extraintestinal (C. fetus), and gastric (C. pylori). Campylobacteriosis is a worldwide zoonosis. The vast reservoir in animals is probably the ultimate source for most enteric Campylobacter infections of humans. Direct contact with infected animals may result in transmission. Household pets, especially young dogs and cats with diarrhea, have been implicated as vectors for campylobacteriosis. Since healthy dogs, cats, rodents, and birds may excrete campylobacters. As with other enteric pathogens, fecal-oral person-to-person transmission of C. jejuni has been reported. Perinatal transmission, from a mother who was not necessarily symptomatic may be due to exposure in utero, during passage through the birth canal, or during the first days of life. Among exposed persons who become ill, the incubation period varies from 1 to 7 days, a characteristic that is probably inversely related to the dose ingested. Often there is prodrome with fever, headache, myalgia, and malaise 12-24 hours before the onset of intestinal symptoms. The most common symptoms are diarrhea, malaise, fever and abdominal pain. Diarrhea myay vary from loose stools to massive watery stools or grossly bloody stools. Relapses may be seen in 5-10 % of untreated patients. C. fetus has been shown to cause a variety of other types of localized infections, including septic arthritis, spontaneous bacterial peritonitis, salpingitis, lung abscess, empyema, cellulitis, urinary tract infection, vertebral osteomyelitis and cholecystitis. A clinical diagnosis of enteric campylobacteriosis may be made by demonstration of the organisms in direct microscopy of feces or isolation of the organisms. The use of serologic methods for diagnosis is at present a research only. Treatment include a variety of antimicrobial agents, including erytromycin, the tetracyclines, aminoglycisides, chloramphenicol, nitrofurans. 5. Test questions. 1. Etiology, epidemiology, and incidence of food poisoning. 2. Pathogenesis of food poisoning. 3. Anatomic pathology of food poisoning. 4. Main clinical symptoms and signs of food poisoning. 5. Classification of food poisoning. 6. Laboratory methods of food poisoning. 7. Differential diagnosis of food poisoning. 8. Treatment of food poisoning. 9. Prevention and control of food poisoning. 10. Pre-exposure food poisoning 11. Etiology, epidemiology, and incidence of escherichiosis. 12. Pathogenesis of escherichiosis. 13. Pathological anatomy of escherichiosis. 14. Main clinical symptoms and signs of escherichiosis. 15. Laboratory diagnosis of escherichiosis. 16. Differential diagnosis of escherichiosis. 18. Treatment of escherichiosis. 19. Escherichiosis prophylaxis. 20. Etiology, epidemiology, and incidence of campylobacteriosis. 21. Pathogenesis of campylobacteriosis. 22. Pathological anatomy of campylobacteriosis. 23. Main clinical symptoms and signs of campylobacteriosis. 24. Laboratory diagnosis of campylobacteriosis. 24. Differential diagnosis of campylobacteriosis. 26. Treatment of campylobacteriosis. 27. Campylobacteriosis prophylaxis. 6. References. A. Basic: 1. Infectious diseases / E. Nikitin, M. Andreychyn – Ternopil, Ukrmedknyga, 2004. – P. 67-77; 91-94. 2. Understanding infectious disease / Paul D. Ellner, Harold C. Neu – Mosby Year Book, 1992. – P. 166-169. 3. Reese R.E. A practical approach to infectious diseases. – Little, Brown & Company, Boston-Toronto, 1986. – P. 284-286; 288-289; 299-300. 4. Berkow R. The Merck Manual of diagnosis and therapy. – Merck Sharp, 1987. – P. 88-89; 197-204; 780-782.