RNA Viruses Flashcards
Rhinovirus
coronaviruses
Coryza- acute self limited URT
Infection of respiratory epithelial cells, causing increased mucous production and edema.
Infected cells release bradykinin, which produce most of the symptoms associated with colds.
Does not destroy respiratory epithelium
Influenza virus
Acute, sel-limited, URT & LRT
ENVELOPED, ssRNA
Influenza A is the most common- highly contagious
Heagglutinin (aids in viral fusion to cell membrane) & Neuraminidase
Necrosis & desquamation of ciliated respiratory tract epithelium, lymphocytic inflammatory infiltrate
Parainfluenza Virus
**CROUP-barking cough
Acute URT & LRT *children- highly contagious
ENVELOPED, ssRNA negative sense
Infect & kill ciliated epithelium, elicit an inflammatory response
Respiratory Syncytial Virus (RSV)
Bronchiolitis in infants
Necrosis and sloughing of bronchial, bronchilar and alveolar epithelium, lymphocytic inflammatory infiltrate. Multinucleated syncytial cells.
usuallty self-limited
SARS (severe acute respiratory syndrome)
Coronavirus
Pneumonia
Diffuse alveolar damage, multinucleated syncytial cells.
Transmitted through bats
Some patients develop ARDS
Measles (Rubeola)
Measles virus ssRNA
URT symptoms, fever and maculopapular rash- highly contagious
Disease of children
H & F surface glycoproteins, mediate viral attachment and fusion w/ respiratory epithelium
Rash results from the action of Tcells on virally infected vascular endothelium
Necrosis of infected respiratory epithelium, Lymphocytic inflammatory infiltrate
**Warthin-Finkeldey giant cells
**Koplik spots- characteristic mucosal lesions
Rubella (German Measles)
Rubella Virus- self-limited systemic disease associated with rash
ENVELOPLED ssRNA
*Destructive fetal pathogen- infection occurs through placenta during viremic phase of maternal illness
Spreads via respiratory route
rash results from immunologic response to the disseminated virus
Mumps
Mumps virus- self limited systemic illness, characterized by parotid gland swelling, meningoencephalitis, orchitis
ENVELOPED ssRNA
Disease of childhood- highly contagious
Infection of respiratory tract, necrosis of infected cells, Lymphocytic inflammatory infiltrate,
Rotavirus
**Most common cause of severe diarrhea worldwide
dsRNA- children, oral-fecal
Produces profuse watery diarrhea
Infects enterocytes of small bowel (duodenum & jejunum), disrupting absorption of sugars, fats and ions,
Norwalk Virus
Causes diarrheal disease in children, adults
Similar to rotavirus
Yellow Fever
Flavavirus- ENVELOPED- ssRNA-mosquito
Acute hemorrhagic fever, sometimes associated with extensive hepatic necrosis and jaundice
Multiplies within tissue & vascular endothelium, tropism for liver cells where it can produce acute hepatocellular destruction due to coagulative necrosis.
*Councilman bodies (apoptotic bodies)
Severe cases are characterized by “black vomit”-vomiting of clotted blood
Ebola Virus
Filoviridae- Zaire, Sudan- fruit bats
**Most widespread destructive tissue lesions of all viral hemorrhagic fever agents
Necrosis is most severe in the liver, kidney, gonads, spleen and lymph nodes. Lungs are uaully hemorrhagic, petechial hemorrhages, injury to microvasculature, shock
West Nile Virus
Flavaviridae- Mosquitoes & birds
Mild leukocytosis, brain stem, particularly the medulla, can be extensively involved, rash
Most cases are subclinical
Severe illness can develop acute aseptic meningitis or encephalitis, with convulsions and coma
