Pathogens are microorganisms that cause disease and we get to understand how they do so by taking a pathogenesis course. Pathogens of all classes must have mechanisms for entering their host and for evading immediate...
Questions: 17 | Attempts: 384 | Last updated: Mar 21, 2022
A 1-year-old toddler is admitted to the hospital in February following an abrupt onset of vomiting followed by watery diarrhea accompanied by low-grade fever. On admission, the child appears somnolent, has a fever of 38.8C (101.8F). His pulse is 130/min, respiratory rate 36/min, blood pressure 100/60 mmHg, and decreased skin turgor. Blood tests reveal an elevated white blood cell count (15,000/L) with 75% polymorphonuclear leukocytes. A stool sample is sent to the microbiology lab for analysis. Results reveal watery stools with no mucus, blood, leukocytes or parasites. A rapid antigen test is positive for a naked, segmented, dsRNA virus, so no stool culture is required. The diarrhea suffered by this child can be partially attributed to a viral protein (rotavirus NSP4) that alters the permeability of intestinal epithelial cell tight junctions and inhibits the glucose-coupled Na+ transport of these same cells, thereby increasing osmotic gap. What best describes this virulence mechanism?
Today we’ll be taking another look at our ever-growing list of medical quizzes, turning our attention to a group of illnesses including Ebola, Marburg, Lassa fever and yellow fever, all of which are examples of viral...
Questions: 16 | Attempts: 346 | Last updated: Mar 21, 2022
Working as an entomologist in Thailand, you are responsible for catching Aedes aegypti female mosquitoes in a study aimed at determining the prevalence of arthropod-borne viruses (arboviruses) in local mosquito populations. Results show that 6.5 % of female Aedes aegypti mosquitoes captured carried enveloped, spherical single-stranded, positive-sense RNA viruses about 50 nm in diameter. In this instance, Aedes aegypti female mosquitoes would serve as vector for which of the following diseases?