Term
| How does the following virus generally enter its human host: coronavirus? |
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Definition
| Fecal-oral route through the GI tract. It is a localized disease. Also, through the respiratory tract. 12-3 |
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Term
| How does the following virus generally enter its human host: enterovirus? |
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Definition
| Fecal-oral through the GI tract, or contact with the eyes. It is systemic. 12-3 |
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Term
| How does the following virus generally enter its human host: reovirus? |
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Definition
| Fecal-oral through the GI tract. It is systemic. 12-3 |
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Term
| How does the following virus generally enter its human host: adenovirus? |
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Definition
| Fecal-oral through the GI tract, or contact with the eyes. It is systemic. 12-3 |
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Term
| How does the following virus generally enter its human host: rhinovirus? |
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Definition
| Upper respiratory tract. Causes local infection. 12-3 |
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Term
| How does the following virus generally enter its human host: hantavirus? |
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Definition
Respiratory tract. Causes infection in URT, LRT, or systemically.
12-3 |
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Term
| How does the following virus generally enter its human host: RSV (Respiratory Synctial Virus)? |
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Definition
| Respiratory tract. Causes infection in URT, or LRT. 12-3 |
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Term
| How does the following virus generally enter its human host: coxsackievirus? |
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Definition
Respiratory tract. Causes infection in URT.
12-3 |
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Term
| How does the following virus generally enter its human host: arenavirus? |
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Definition
Respiratory tract. Causes infection in URT.
12-3 |
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Term
| How does the following virus generally enter its human host: parainfluenza? |
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Definition
Respiratory tract. Causes infection in URT or LRT.
12-3 |
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Term
| How does the following virus generally enter its human host: influenza? |
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Definition
Respiratory tract. Causes infection in URT, and LRT.
12-3 |
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Term
| How does the following virus generally enter its human host: rubella? |
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Definition
Respiratory tract. Causes a systemic infection.
12-3 |
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Term
| How does the following virus generally enter its human host: mumps? |
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Definition
Respiratory tract. Causes a systemic infection.
12-3 |
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Term
| How does the following virus generally enter its human host: foot and mouth disease virus? |
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Definition
Respiratory tract. Causes a systemic infection.
12-3 |
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Term
| How does the following virus generally enter its human host: VZV? |
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Definition
Respiratory tract. Causes a systemic infection.
12-3 |
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Term
| How does the following virus generally enter its human host: pox virus? |
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Definition
Respiratory tract. Causes a systemic infection.
12-3 |
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Term
| How does the following virus generally enter its human host: HPV? |
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Definition
Sexual contact. Causes a localized infection.
12-3 |
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Term
| How does the following virus generally enter its human host: HIV? |
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Definition
Sexual contact, or other bodily fluid via needle, etc. Causes a systemic infection.
12-3 |
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Term
| How does the following virus generally enter its human host: HSV? |
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Definition
Sexual contact, or contact with eyes or mucous membranes. Can cause a systemic infection.
12-3 |
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Term
| How does the following virus generally enter its human host: HBV? |
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Definition
Sexual contact, or blood or other body fluid contact. Causes a systemic infection.
12-3 |
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Term
| How does the following virus generally enter its human host: rabies? |
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Definition
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Term
| How does the following virus generally enter its human host: bunyavirus? |
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Definition
Insect vector or animal bite.
12-3 |
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Term
| How does the following virus generally enter its human host: togavirus? |
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Definition
Insect vector or animal bite.
12-3 |
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Term
| How does the following virus generally enter its human host: flavivirus? |
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Definition
Insect vector or animal bite.
12-3 |
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Term
| Name three factors that affect dissemination of a virus. |
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Definition
Portal of entry.
Host immunity.
Cell-specific virus receptors.
12-4 |
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Term
| Name 5 viruses that can infect and spread through the nervous system. |
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Definition
| Rabies, HSV, VZV, and arbovirus, poliovirus. 12-4 |
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Term
| What are 4 possible general things that may occur to a virally infected host cell? |
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Definition
| Lysis; There may be no change at all; Cell dysfunction or morphological changes w/o cell death (eg hyperplasia as in HPV genital warts, mucous secretion); Transformation to cancer 12-5 |
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Term
| More specifically, what morphologic or dysfunctional changes may occur to a host cell infected with a virus? |
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Definition
| Hyperplasia Excessive mucous secretion Syncytia formation (fusion of cells) Inclusion body formation 12-5 |
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Term
| Name six ways to detect the presence of virus particles or virion components to diagnose viral infections. (Directly without culture). |
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Definition
| Light microscopy for host cell morphology Immunofluorescence Electron microscopy Hemagglutination ELISA Specific stains such as Tzank smear for giant multinucleated cells and ground glass for inclusion bodies 12-6 |
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Term
| Name the four general techniques for diagnosing viral infection. |
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Definition
| Tissue culture Direct detection of viral particles or components Direct detection of viral genome Detection of anti-viral host antibodies 12-6 |
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Term
| Name four patterns of infections caused by viruses. |
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Definition
Acute infection progressing to death (Ebola, Hantavirus) Acute infection followed by clearance
Persistent chronic infection (HBV, HCV, HIV)
Latent infection and reactivation (HIV, HSV, EBV, CMV, other herpes) 12-7 |
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Term
| Name the genus and family of poliovirus. |
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Definition
| Enterovirus genus and Picornavirus family. 12-8 |
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Term
| If an antibody response is mounted against poliovirus, what proportion of CNS infections will be prevented relative to no antibody response? |
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Definition
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Term
| Name the 3 rare nervous system manifestations of poliovirus infection. |
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Definition
Meningitis/encephalitis
Paralytic poliomyelitis: Acute flaccid paralysis
Post polio syndrome: Additional progressive muscle wasting due to anterior horn damage 12-9 |
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Term
| Name the drug that has activity against picornaviruses (like polio)? |
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Definition
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Term
| What kinds of things cause latent viruses to become reactivated? |
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Definition
| Reactivation due to stress, cellular injury, or the availability of a cell-type permissive for replication. 12-10 |
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Term
| Name the family and subfamily of HIV. |
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Definition
Family is retrovirus, and subfamily is lentivirus.
12-10 |
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Term
| How does the switch from early to late proteins in HIV production occur? |
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Definition
| The early proteins include rev which influences the splicing of mRNA to make late proteins which lead to capsid assembly. 12-11 |
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Term
| Viral polymerases have higher error rates. But why would DNA viruses that also use some host machinery have a higher mutation rate? |
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Definition
| Proofreading may be less accurate in virus infected cells (kind of like a bus driver not driving as well if they're being held up with a gun). The rate at which viruses replicate lends itself to high mutation errors. 12-12 |
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Term
| What causes antigenic shift? |
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Definition
Reassortment of genomic material of multiple viruses.
12-12 |
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Term
| What causes antigenic drift? |
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Definition
Point mutations acquired from one virus over time.
12-13 |
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Term
| Name six mechanisms viruses may use to escape the immune system. |
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Definition
| Undergo a latent period; Infect sites protected from immune system (CNS) Rapidly evolve to change important antigenic epitopes; Reassortment of viral genes to undergo antigenic shift; Produce defense molecules that interfere with immune function (i.e. antigen presentation); Infect and destroy immune cells (HIV) |
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Term
| What's the window period in a viral infection? |
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Definition
| The period of time before circulating antibodies appear. |
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Term
| How does polio virus enter the body and then invade? |
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Definition
| Enters through ingestion (oral-fecal route). Unenveloped so can withstand the acid environ. of the stomach. Attaches by binding to the Poliovirus receptor (Pvr) and is endocytosed (undergoes a conformational change). Goes mostly to the mesenteric lymph nodes of sm. intestine for replication. Can infect and spread through CNS. |
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Term
| What are the clinical manifestations of poliovirus? |
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Definition
After infection, about 90% are asymtomatic, and 10% have GI issues (vomiting, diarrhea)
If infects CNS, may have meningitis, encephalitis (symptoms: headache, fever) This is usually self limiting and lasts a few days to two weeks. May also have paralytic poliomyelitis or post polio syndrome.
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Term
| What is paralytic poliomyelitis? |
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Definition
| acute flaccid paralysis due to motor neuron and muscle damage (1/200 ppl with polio CNS infection) |
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Term
| What is post polio syndrome? |
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Definition
| Rare. paralysis and muscle wasting that occurs decades after infection due to aging of damaged neuromuscular anterior horn and muscle cells. |
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Term
| Describe the structure of the HIV nucleocapsid. What kind of genetic material is inside the nucleocapsid? |
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Definition
Wedge-shaped
two ssRNA (+), can be homo or heterodimer. |
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Term
| Describe reassortment of viral genes. |
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Definition
| Causes antigenic shift. Can only occur in viruses with segmented RNA genomes (e.g. influenza). It's swapping of segments b/w 2 different viruses that infect the same cell. |
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Term
| What are the methods HIV uses to evade the immune system? |
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Definition
Latency (in resting T cells)
Antigenic variation
Viral defense molecules that infere w/ immune function
Infection of immune cells |
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