Enteric Viruses Flashcards
describe the morphology of picornaviruses, noroviruses and rotaviruses.
small, naked icosahedral RNA viruses
what are enteroviruses?
subset of picornaviruses that cause GI infection
describe the genome of rotavirus. what does it cause?
segmented genome
causes potentially dangerous dehydrating diarrhea
how contagious is norovirus? what illness does it cause?
extremely contagious with low infectious dose
short but intense bout of vomiting and diarrhea
where do enteroviruses infect in the body?
main replication is in the gut, viremia occurs with replication in lymph nodes and there is rare penetration of the CNS
describe the severity of enterovirus infection.
usually mild but occasionally devastating
how is infection of the GI viruses attenuated in the industrialized world?
hygiene and vaccination
how are GI viruses usually resolved? what are the most common complications?
self limited without medical intervention
complications are dehydration with rotovirus (pediatric anorexia and lethargy) and CNS infction with enterovirus
what predisposes patients to have a more problematic course of GI infection?
young patients are more problematic- higher lethality (Coxsackie B has 10% mortality in neonates)
what are the symptoms of Coxsacki A?
A is usually less severe- hand foot and mouth disease, herpangina and acute hemorrhagic conjunctivitis
what are the symptoms of Coxsacki B virus?
myocarditis, pleurodynia (sudden chest pain, fever, malaise and headache from striated muscle targeting) and meningitis (there is some overlap with coxsacki A)
what is hand foot and mouth disease?
vesicles on hands, feet, mouth and in the perianal region
what is herpangina?
ulcerating vesicles inside the mouth
what is plurodynia?
severe intermittent chest pain with pleural friction rub
what tests are used to isolate the GI viruses?
lumbar puncture, nasopharyngeal swabs and/or stool culture
some serologic tests are available
