Viral GASTROENTERITIS By: Dr. Yasir Hakim, MD Pathology& Microbiology. Assistant Professor and Chairman Department of Microbiology College of Medicine Dar Uloom –University – KSA د. ياسر عبدالله – دكتوراة علم الأمراض والأحياء الدقيقة الطبية والطفيليات. رئيس قسم الأحياء الدقيقة الطبية والطفيليات اسم ورقم المقرر – Course Name and No. 4/22/2019

Def of viral gastroenteritis (stomach flu). Inflammation of stomach or intestines inhibits nutrient absorption and excessive H2O and electrolyte loss & marked by watery diarrhea, abdominal cramps, nausea or vomiting, and sometimes fever Bacterial Viral Parasites

Types

Causes of gastroenteritis

Common Bacterial pathogens Campylobacter Salmonella Shigella Yersinia Pathogenic E.coli Cause 10 – 15 % of diarrheal illness Under developed nations consider vibrio species

Parasitic agents Giardia intestinalis, Cryptosporidium parvum, Entamoeba histolytica, and Cyclospora cayetanensis most commonly cause acute diarrheal illness in children. These agents account for a relatively small proportion of cases of infectious diarrheal illnesses among children in developing countries.

Viral Agents Rotavirus Norwalk virus Enteric Adenovirus Astrovirus Gastroenteritis, 2002

Pathophysiology The clinical manifestations for viral gastroenteritis are due to the effects that the viruses, along with specific cytotoxins, have on the enterocytes of the intestine. The virus uses the enterocytes to replicate, leading to interference with brush border enzyme production, which in turn leads to malabsorption and osmotic diarrhea(  poorly absorbed solutes in the bowel lumen that inhibit normal water and electrolyte absorption). Gastroenteritis, 2002

Risk factors People who may be more susceptible to gastroenteritis include: Young children. Children in child care centers or elementary schools .Schoolchildren, churchgoers or dormitory residents. Anywhere that groups of people come together in close quarters can be an environment for an intestinal infection to get passed. Older adults. Adult immune systems tend to become less efficient later in life. Anyone with a weakened immune system. If your resistance to infection is low — for instance, if the immune system is compromised by HIV/AIDS, chemotherapy or another medical condition — Gastroenteritis, 2002

Clinical Presentation: Symptoms Nausea / Vomiting Cramping abdominal pain Increased peristalsis Absence of blood(non bloody) and fecal Leukocytes Key to differential with bacterial infections Gastroenteritis, 2002

Physical Signs Non-bloody Stools Dehydration(tested by skin turgor sign is skin's elasticity commonly on the lower arm or abdomen is checked) Decreased urination Mental status changes Dry mucous membranes Lethargy Gastroenteritis, 2002

اسم ورقم المقرر – Course Name and No. 4/22/2019

Gastroenteritis, 2002

Diagnostic Testing Focused Bloody diarrhea? Fecal leukocytes? If non-inflammatory, no culture Lab Tests? Viral Detection? Test for rotavirus Gastroenteritis, 2002

Management Self limiting course Replace fluids and electrolytes Oral Rehydration (ORT)- ORS Commercially available ORT Pedialyte (45 meq Na ) Ricelyte (50 meq Na ) Gastroenteritis, 2002

اسم ورقم المقرر – Course Name and No. 4/22/2019

Management Severe Dehydration ORT can be successful IV fluids Shock Uremia Fluid loss > 10 ml/kg/hr Gastroenteritis, 2002

Refeeding ORT: continue during diarrhea Continue breast feeding Formula fed : Lactose free Gastroenteritis, 2002

Antidiarrheal Agents Anticholenergic agents Ineffective Contraindicated in children Absorbents agents Kaopectate Gastroenteritis, 2002

Antidiarrheal Agents Anti-motility Agents Loperimide Lomotil Gastroenteritis, 2002

Vaccination RotaTeq® (RV5) vaccine is given in 3 doses at ages 2 months, 4 months, and 6 months. Rotarix® (RV1) is given in 2 doses at ages 2 months and 4 months Gastroenteritis, 2002

Reference Henley, C.E., Gastroenteritis. Manual of Family Practice. Taylor, Robert B., Little, Brown, 2nd Edition, 2000. Gastroenteritis, 2002

مع امنياتى لكم بالتوفيق د. ياسر عبدالله حاكم 21-11-2018 اسم ورقم المقرر – Course Name and No. 4/22/2019