spreadsheet Flashcards
what are the subclasses of retroviruses?
oncoviruses (HTLV-1/2)
lentiviruses (HIV-1/2)
what viruses are in the lentivirus subclass?
HIV-1/2
are HIV enveloped?
yes
what is the nucleic acid/structure of HIV?
+ssRNA, two identical copies
how does HIV virus multiply
viral envelope glycoprotein gp120 binds host CD4, cellular CXCR4 or CCR5 (chemokine co-receptors) needed for absorption, gp41 mediates envelope fusion, HIV is a nondefective virus
how is HIV transmitted?
sexual contact, blood, tears, vaginal secretions, breast milk, transplacental, perinatal
what diseases does HIV cause?
HIV, AIDS
what is the general epidemiology of HIV?
3 stages… early stage with mono-like symptoms + high viremia, middle stage 3-10 years latency with decline in CD4 cells, late stage is AIDS and immunodeficiency… HIV-1 infected women progress to AIDS faster than men of same viral load
what is the epidemiology of HIV?
AIDS patients have increased susceptibility to opportunistic infections and tumors (Kaposi’s sacoma, B-cell lymphoma, autoimmune thrombocytopenia, chronic lymphadenopathy, dementia/diffuse brain disease in later stages of infection)
what is the pathogenesis of HIV?
gradual depeltion of CD4+ cells, suppression of cell-mediated immunity (variable progression to AIDS), cytopathic effect, CTL destruction of infected cells, apoptosis of CD4 cells, HIV also targets CD4 Th17 cells (imp for mucosal imm – bacteria)
what are the signs and symptoms of HIV?
Primary infection: mono-like or flu-like with fever/enlarged lymph nodes/tiredness/headache
what are the lab diagnoses for HIV?
ELISA (forv viral antigens gp41 or p24), Western blot (less sensitive but more specific than ELISA), PCR for HIV RNA
what is the chemotherapy for HIV?
HAART, nucleoside analog RT inhibitors (AZT), non-nucleoside RT inhibitors, protease inhibitors, entry inhibitors (Fuzeon), integrase inhibitors (isentress), CCR5 inhibitors (maraviroc)
what are the subclasses of poxviruses?
smallpox virus
molluscum contagiosum virus (MCV)
are poxviruses enveloped?
Enveloped and Non-enveloped (can withstand adverse conditions better)
nucleic acid/structure of poxviruses?
dsDNA, largest nucleic acid content of all animal viruses
virion structure of poxviruses?
No symmetry (only virus family like this)
how do poxviruses multiply?
Virus carries DdRp in virion to make mRNA (only DNA virus that encodes own RNApol), virus multiplies in cytoplasm (forms inclusion body when histologically stained)
how is smallpox transmitted?
airborne
how is MCV transmitted?
Intimate cutaneous contact (Ow-owwww!!!) often among young children, wrestlers, and lovers
what diseases does smallpox cause?
Smallpox (papules, vesicles, pustules)
what diseases does MCV cause?
Molluscum contagiosum
general epidemiology of smallpox?
Oral mucosa lesions likely cause of spreading infection, smallpox has been eradicated by immunization (ring vaccination around any cases found), no non-human reservoirs and no subclinical infections
general epidemiology of MCV?
Self-limiting disease (may take months/years to subside)
epidemiology of smallpox?
Respiratory infection leads to more severe infection, vaccination halted in US in 1971 (vaccine protects for 10-20 years, partial immunity for longer), weaponized by Soviets (Yarr!), current policy to vaccinate medical and other personnel, use ring vaccination to prevent outbreak
epidemiology of MCV?
Diagnosis difficult, virus grows poorly in culture
pathogenesis of smallpox?
Primary infection in upper respiratory tract with growth in mucosa/lymph nodes, then viremia allows to spread to lungs/liver/spleen, secondary infection in skin (via viremia) causes papules/pustules/vesicles
incubation period of MCV?
2-8 weeks
signs and symptoms of smallpox?
Papules, vesicles, pustules
signs and symptoms of MCV?
pearly white papules
vaccine for smallpox?
Live-attenuated (use vaccinia virus)
chemotherapy for smallpox?
Passive immunization with human vaccinia-immune globulia for severe infections
what kinds of viruses are in the rhabdovirus class?
rabies
is rabies enveloped?
yes
nucleic acid/structure of rabies?
-ssRNA
virion structure of rabies?
Helical nucleocapsid, bullet-shaped
how does rabies virus multiply?
Packaged with RdRp, cytoplasmic Negri bodies
how is rabies transmitted?
Bite from infected animal (virus in saliva) - viremia not required
general epidemiology of rabies?
Infections in humans and dogs nearly always fatal, long incubation allows successful immunization after infection, treatment will not work after virus invades CNS, 30,000 people in US treated per year for possible infection… SINGLE antigenic type
epidemiology of rabies?
Prophylactic immunization recommended for residents where rabies is common and for vets… bite wounds should be washed to remove virus… transmission in US from wild animals, dogs required to be vaccinated… most rabies in US from bats
pathogenesis of rabies?
Travels from bite site into nerve cells, travels to CNS, then can go from CNS to salivary glands
incubation period of rabies?
Weeks to months
signs and symptoms of rabies?
Initial symptoms: fever, anorexia, hydrophobia… late symptoms is coma/paralysis/death…., causes encephalitis
lab diagnosis of rabies?
Negri bodies (cytoplasmic inclusions) in nerve cells , fluorescent Ab to confirm inclusion bodies are rabies virus
vaccines for rabies?
Killed vaccine (human diploid cell vaccine, highly immunogenic and very safe)
chemotherapy for rabies?
Passive immunization (hyperimmune human serum; given to delay symptoms)
