Mumps, Measles, Slow Viruses, and Prion Flashcards
Characteristics of mumps and measles
Has RNA polymerase in the virion
“rapid and major genetic change by a mechanism of genetic reassortment is impossible”
“Mumps and measles are paramyxoviruses that cause systemic infections with viremia as an essential step in pathogenesis.”
“Lifelong immunity occurs in individuals who have had the disease. Obligatory viremia allows neutralization by IgG.”
Structure of mumps and measles virus
“Mumps and measles are typical paramyxoviruses with helical nucleocapsid containing minus stranded RNA and an envelope containing virus-specified glycoproteins”
-mumps are antigenically related to parainfluenza virus.
Transmission of mumps
Via respiratory droplets
Primary multiplication is in respiratory epithelium and local lymph nodes
Obligatory viremia
Clinical symptoms of mumps
Only 30 percent are asymptomatic
Parotiditis, orchitis, pain/pressure within organs in tight capsules (parotid gland, testis)
Other organs: pancreas, meninges
Incubation is THREE weeks
Antiviral therapy/treatment for mumps and measles
None
Immunization for mumps and measles
Live attenuated; Part of MMR vaccines given to children
Clinical symptoms of measles
“Measles is probably the most contagious disease known–almost no subclinical symptoms”
Prodormal symptoms: fever, cold-like symptoms, runny nose, red eyes
Symptoms: Koplik spots, rash (maculopapular erythematous rash), conjunctivitis, photophobia
14-day incubation period.
Epidemics of measles
“epidemics occur with no antigenic variation”
“When the concentration of nonimmune susceptibles is sufficient to break down herd immunity, measles virus can be introduced and is rapidly disseminated in the population causing a new epidemic.”
Pathology of measles
“Multi-nucleated giant cells in lymphoid tissue and respiratory mucosa (virus-induced cell fusion)”
“Infection with the measles virus profoundly suppresses cell-mediated immunity.”
“Some of the measles deaths, primarily in developing countries, are caused by secondary infections acquired during this period of anergy.”
Rare lethal giant-cell pneumonia can result from lack of cell-mediated immunity
General characteristics of slow virus
Long incubation period (years)
Slow but relentless course to death
Genetic predisposition
Often reemerge from latency during immunosuppression
Name slow diseases caused by conventional viruses
AIDS from lentivirus, HIV
Progressive Multifocal Leukoencephalopathy (PML) from JC virus
Subacute Sclerlosing Panencephalitis (SSPE) from measles virus
: defined distinctly by inclusion bodies in neuropathology, risk related to measles contraction at early age.
Characteristics of prions
Causes CNS disease and produce spongiform encephalopathy
They are protein-containing particles devoid of nucleic acids
Kuru
“Kuru is a progressive degenerative disorder of the CNS, especially the cerebellum.”
“Transmitted via intracerebral injection/Ingestion of infected brains also transmits the disease.”
Cruetzfeld-Jacob Disease
“The most common human spongiform encephalopathy is CREUTZFELD-JACOB DISEASE”
“Transmitted via IATROGENIC (inadvertently caused by physicians) (iCJD) cases”
Familial genetics, could be sproadic (sCJD)
Variant CJD has been associated with mad cow disease.
