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Background students: English level III-IV GPA 3.7-4.0 *80%MedScience students came from (Middle) How do the students should develop an outline and summary assignment regarding any disorder in Pathophysiology? Objectives: students will be able to 1) Improve the learning skills and how to prepare a P.Point at college level 2) Approach the GAP between High School Pre-Med and College level 3) Enhance critical thinking proficiency Materials: Magazines, Articles, TB Eight Modules /Academic year/2 for quarter Outline and summarize diverse disorders Every other week Cooperative teaching process (English honor teacher) Emphasis Medical terminology Small learning team (4students)ÆMonthly project (P.Point Ptt) regarding the best assignment, it has been chosen by the teachers Dr Garcia Medical Science Academy-PBSD 9/8/2009 4 Case study Investigation/Brainstorming ¾ History of the virus ¾ Background ¾ Morphology ¾ Predisposing causes/Epidemiology, Florida ¾ Symptoms/Signs Clinical manifestations ¾ Transmission ¾ Diagnosis/Differential diagnosis ¾ Prevention ¾ Dr Garcia Medical Science Academy-PBSD 9/8/2009 5 An 80 y.o. female presents to the ER with a 3 days history of fatigue, abdominal cramps and bloody diarrhea. She denies any fevers and states that 10 days ago she was at a State Fair where she ate hotdogs, baked beans, coleslaw, and drank fresh apple cider. PEX: T=37 BP=140/90 P=100 ABDOMEN: generalized tenderness LABS: WBC 12,000 Lymphocytes 65% HCT 19.0 PLTS 90,000 BUN/Cr 50/3.0 LDH 400 Total. Bilirrubin 4.0 Dr Garcia Medical Science Academy-PBSD 9/8/2009 6 A) S. aureus B) Salmonella C) Norwalk virus D) Neisseria E) E.coli O157:H7 Dr Garcia Medical Science Academy-PBSD 9/8/2009 7 ¾ Norwalk – genus name for original Norwalk virus and other Norwalklike viruses. Family Calicivirus. ¾ Calicivirae found worldwide, infecting humans, primates, and cattle, among others. ¾ Increasingly being recognized as leading cause of food borne illness. Nursing homes (medical Arena) has been another place founded. Dr Garcia Medical Science Academy-PBSD 9/8/2009 8 ¾ Virus first identified in Norwalk, Ohio, 1973. ¾ Noted to commonly be a problem on cruise ships. ¾ Associated with contaminated food or water supplies. ¾ Currently, It is prevalent in Nursing homes Dr Garcia Medical Science Academy-PBSD 9/8/2009 9 Noroviruses are a group of single-stranded RNA viruses in the family Caliciviridae that cause acute gastroenteritis in humans. Norwalk virus is the prototypical strain in the genus. Norovirus infection is an important cause of acute gastroenteritis in humans and is the most frequently implicated cause of outbreaks of viral gastroenteritis worldwide. Noroviruses cause an estimated 20% of all viral gastroenteritis cases in persons older than 24 months. Norwalk virus was first associated with gastroenteritis in 1972. It was identified by electron microscopy of stool samples that had been saved from a 1968 gastroenteritis epidemic that occurred in Norwalk, Ohio. In a 2-day period, acute gastroenteritis developed in 50% of 232 students or teachers in an elementary school. The virus initially was labeled as a small, round, structured virus, and it was named after the city in which the outbreak occurred. Recently, norovirus infections have made news as the cause of several outbreaks of gastroenteritis on cruise ships. Dr Garcia Medical Science Academy-PBSD 9/8/2009 10 The Norwalk virus is shed in the stool for 24-48 hours after the onset of illness. Infection is spread by contaminated water, foods and from person to person. The virus is relatively resistant to chlorine and can contaminate swimming pools. The virus is also relatively resistant to heat and cooking of shellfish may not completely eliminate the risk of infection. Outbreaks are common in closed environments such a cruise ships and nursing homes. Florida is the provides and ideal environment for the spread of Norwalk virus. Swimming pools are very common in our state and shellfish are popular among Floridians. Finally our ports are the home to many cruise lines and major outbreaks of Norwalk virus have become a major problem for our cruise passengers. Dr Garcia Medical Science Academy-PBSD 9/8/2009 11 The frequency of norovirus disease in the United States is difficult to quantify because of the lack of readily available diagnostic assays. Recent efforts to determine the etiology of diarrheal diseases in the United States have suggested that noroviruses cause up to 17% of community cases of diarrhea and 7% of cases that require physician treatment. Among 232 outbreaks of norovirus gastroenteritis reported to the Centers for Diseases Control between 1997 and 2000, 57% were foodborne, 16% involved person-to-person spread, 3% were waterborne, and the remainder were unknown. The location of these outbreaks included restaurants (36%), nursing homes (23%), schools (13%), and resorts/cruise ships (10%). In September 2005, an outbreak of norovirus gastroenteritis affected approximately 1000 Hurricane Katrina evacuees in temporary facilities in Houston, Tex. This episode illustrates the increased risk of such outbreaks in overcrowded conditions. International Data regarding outbreaks in developing nations are not well quantified, but the outbreak rate in other industrial nations is similar to that of the United States. Dr Garcia Medical Science Academy-PBSD 9/8/2009 12 ¾ (+) ssRNA, nonenveloped virus. ¾ ~ 7.4 - 8.3 kb ¾ Many different strains. Dr Garcia Medical Science Academy-PBSD 9/8/2009 13 ¾ Nonenveloped capsid/nucleocapsid. ¾ Icosahedral, 35-39 nm diameter Picture: Norwalk virus, left and middle. Unspecified Calicivirus, right. Dr Garcia Medical Science Academy-PBSD 9/8/2009 14 ORF1 – polyprotein – similar to helicase, RNA polymerase of polio and RNA viruses ORF2 – capsid protein ORF3 – codes for protein of unknown function Dr Garcia Medical Science Academy-PBSD 9/8/2009 15 ¾ Noroviruses found in stool and vomit of infected. ¾ Very contagious – infection via eating contaminated food, contact with sick individual or contaminated surfaces. Dr Garcia Medical Science Academy-PBSD 9/8/2009 16 The viruses are transmitted via the fecal-oral route. The most common routes of infection include contact with an infected individual or contact with contaminated food and water. Noroviruses can also be spread via particles aerosolized with vomiting. The viruses are highly contagious; only 100 viral particles are likely required to establish infection. Noroviruses can survive freezing and heating temperatures of up to 140°F. Infection is characterized by damage to microvilli in the small intestine, causing malabsorption. Vomiting is related to a virus-mediated change in gastric motility and delayed gastric emptying. Notably, no histopathologic lesions are identified in the gastric mucosa of infected patients. Noroviruses do not invade the colon, therefore fecal leukocytes are typically absent and hematochezia is rare. Recurrent infections can occur throughout life because of the diversity of norovirus strains and the lack of cross-strain or longterm immunity. Frequency Dr Garcia Medical Science Academy-PBSD 9/8/2009 17 ¾ Acute gastroenteritis. ¾ Illness begins suddenly, from 12-48 hours after ingestion. Brief illness period. ¾ Very young, elderly, and those with weakened immune systems may experience more severe symptoms. ¾ Infectiousness may last up to 2 weeks, no evidence of long-term carriers. Dr Garcia Medical Science Academy-PBSD 9/8/2009 18 This virus causes watery diarrhea, abdominal cramps, nausea and vomiting. Fever headache and muscle aches are other common complaints. Examination of the stool reveals no inflammatory cells and culture is negative for bacteria known to cause infectious diarrhea. The disease is selflimiting usually lasting 2-6 days. Dr Garcia Medical Science Academy-PBSD 9/8/2009 19 ¾ Electron Microscope ¾ PCR ¾ ELISA ¾ Calicivirus is not easily studied. No efficient techniques have been developed to culture it in a lab setting. Dr Garcia Medical Science Academy-PBSD 9/8/2009 20 Laboratory Studies Isolated occurrences of gastroenteritis do not require laboratory studies. In severe cases of gastroenteritis with suspected dehydration, the following laboratory studies are indicated. • Serum electrolytes • BUN and creatinine Detection: • Detection can be achieved with polymerase chain reaction (PCR) or electron microscopy. Newer diagnostic modalities such as microarrays are currently under investigation. • Referral laboratories typically can evaluate stool isolates for noroviruses. • Because the studies are very costly, stool evaluation is not recommended unless strong public health indications exist. Epidemic outbreaks • More than 2 people living in different households who shared a common meal or 3 or more people living in the same household • Stool culture for Yersinia, Shigella, Salmonella, and Campylobacter species • Stool for occult blood • Fecal leukocytes Dr Garcia Medical Science Academy-PBSD 9/8/2009 21 In an epidemic setting, the health department may choose to further evaluate stool with PCR for noroviruses. Imaging Studies Imaging for isolated, uncomplicated gastroenteritis is not required. If acute abdomen or toxic ingestion is suspected, an abdominal series is indicated. Other Tests If the patient is a returning international traveler, stool tests for ova and parasites or specialized stool cultures for cholera may be considered. If the patient is severely immunocompromised (AIDS), stool tests for Cyclospora, cytomegalovirus (CMV), Isospora, and Cryptosporidium may be considered Histologic Findings Stool culture will be negative for infectious bacteria. Stool is typically heme-negative and fecal leukocytes will be absent. Vomitus will be heme-negative and nonbilious Dr Garcia Medical Science Academy-PBSD 9/8/2009 22 Amebiasis Gastric Outlet Obstruction Bacterial Overgrowth Syndrome Gastritis, Acute Campylobacter Infections Gastroenteritis, Bacterial Carcinoid Tumor, Intestinal Gastroenteritis, Viral Cholera Hepatitis, Viral Clostridium Difficile Colitis Inflammatory Bowel Disease Crohn Disease Irritable Bowel Syndrome Dr Garcia Medical Science Academy-PBSD 9/8/2009 23 Cryptosporidiosis Isosporiasis Cyclospora Malabsorption Cytomegalovirus Microsporidiosis Cytomegalovirus Colitis Picornavirus-Overview Diverticulitis Pseudomembranous Colitis Diverticulosis, Small Intestinal Salmonellosis Enteroviruses Shigellosis Eosinophilic Gastroenteritis Ulcerative Colitis Escherichia Coli Infections Vibrio Infections Food Allergies Food Poisoning Dr Garcia Medical Science Academy-PBSD 9/8/2009 24 Treatment consists of supportive care. Some individuals require intravenous fluids; however most individuals are able to prevent dehydration by drinking fluids. No vaccine is presently available for this virus. Dr Garcia Medical Science Academy-PBSD 9/8/2009 25 Careful and extensive cleaning of closed environments such as ships is required. Food handlers with diarrhea should stay home from work and always wash their hands. Shellfish need to be thoroughly cooked. Children with diapers should not be allowed in swimming pools and pools should be periodically hyperchlorinated. Dr Garcia Medical Science Academy-PBSD 9/8/2009 26 Dr Garcia Medical Science Academy-PBSD 9/8/2009 27 Büchen-Osmond, C. (Ed), (2003). 00.012. Caliciviridae. In: ICTVdB - The Universal Virus Database, version 3. ICTVdB Management, Columbia University, New York, NY, USA. CDC. accessed September 29, 2005. Norovirus. http://www.cdc.gov/ncidod/dvrd/revb/gastro/norovirus-qa.htm Directors of Health Promotion and Education. Accessed September 29, 2005. Norwalk Virus Infection. http://www.astdhpphe.org/infect/norwalk.html Microbiology Department, Mount Sinai Hospital. Accessed October 2, 2005. Norwalk and Noroviruses. http://microbiology.mtsinai.on.ca/bug/norwalk/nor-bug.shtml Frederick Southwick, M.D. Professor of Medicine and Chief of Infectious Diseases University of Florida College of Medicine https://www.epi.ufl.edu/?q=node/28 http://emedicine.medscape.com/article/224225-treatment Dr Garcia Medical Science Academy-PBSD 9/8/2009 28 Dr. Jairo Garcia [email protected] Palm Beach School District/Fl Dr Garcia Medical Science Academy-PBSD 9/8/2009 29