Pathology Notes

Norovirus/Norwalk virus Updated: 01/29/2024 © Jun Wang, MD, PhD   General features Most common cause of epidemic nonbacterial gastroenteritis Norovirus   Single-stranded RNA and hexagonal capsid 5 genogroups, I, II and IV are human pathogens Highly contagious, Fecal-oral transmission Usually not severely ill Lasting 24-72 hours, usually self-limited Associated with shellfish, prepared foods, etc Diarrhea due to transient malabsorption of D-xylose and fat and inhibition of brush-border enzymes including alkaline phosphatase and trehalase Key clinical features Usually not severely ill Nausea, vomiting, moderate watery diarrhea (4-8 stools/day) Signs of volume depletion: tachycardia, hypotension, ONLY in severe cases Stools usually do NOT contain mucous or leukocytes Diagnosis Usually clinical diagnose Confirmation needed for immunocompromised patients with severe or persistent symptoms Multi-pathogen molecular tests to confirm Other pathogens need to be ruled out

Sepsis Updated: 06/28/2022 © Jun Wang, MD, PhD   Definition Life threatening organ dysfunction caused by a dysregulated host response to infection General features Organ dysfunction identified by acute change of 2 or more points in total SOFA score or qSOFA Likely prolonged ICU stay Relatively high mortality rate Commonly associated with infections of injury or internal organs and perforation/rupture of abdominal/pelvic structures Most commonly caused by bacterial infections, but can be caused by virus or fungi Systemic Inflammatory Response Syndrome (SIRS) A term being abandoned since 2016 Still being used clinically Poor mortality prediction comparing with Sequential Organ Failure Assessment (SOFA) Clinical responses to either infectious or non-infectious causes Sequential Organ failure Assessment (SOFA) A systemic evaluation of organ function Performed in critically ill patients with suspected sepsis Systems involved o    Cardiovascular: Blood pressure o