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72 Cards in this Set

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Poxviruses: Variola
Nucleic acid - dsDNA
Trans. - Respiratory droplets
Disease - Smallpox
Treatment - Supportive
Vaccine - Mass vaccination (attenutated)
Herpesviruses
Nucleic acid - ds DNA
This family includes:
Simplexvirus
Varicellovirus
Epstein-Barr Virus
Cytomegalovirus
Roseolovirus
Papillomaviruses: Human papilloma virus
Nucleic acid - ds DNA
Target - epithelial cells
Trans. - Direct contact, STD
Disease - Warts, genital warts, cervical cancer
Treatment - Cryotherapy (freeze off infected cells), for cancer raditiona and chemo.
Vaccine - NEW, just approved
Adenoviruses: Adenoviruses
Nucleic acid - ds DNA
Target - Respiratory and intestinal epithelial cells, conjunctiva
Trans. - Respiratory droplets
Diseases - Common cold, pink eye, mild gastroenteritis
Treatment - Supportive care
Vaccine - None
Parvoviruses: B19 / erythrovirus
Nucleic Acid - ss DNA
Target - RBCs, erythroid progenitor cells, endothelial cells, placental cells
Trans. - Respiratory droplets
Disease - Erythema infectiosum (Fifth's disease)
High risk - Adults, Pregnant women, Sickle-cell disease patients, immunocomprimised patients.
Treatment - Supportive, blood tranfusions (anemic), passive immunity
Hepadnaviruses: Hepatitis B virus
Nucleic acid - ds DNA and ss DNA
Target - Liver cells
Trans. - Blood and bodily fluids
Disease - Hepatitis B, Liver cancer
Treatment - Long-term antiviral therapy
Vaccine - Yes
Picornaviruses (2 familes)
Nucleic Acid - +ss RNA
Rhinovirus and Enteroviruses (Poliovirus, Hep. A, coxsackieviruses and echoviruses)
Caliciviruses: Norwalk virus
Nucleic acid - +ss DNA
Trans. - Fecal-oral
Disease - Gastroenteritis, Norovirus, Enteric hepatitis (Hep. E)
Treatment - Supportive
Vaccine - No
Astroviruses: Astrovirus
Nucleic acid - +ss DNA
Trans. - Fecal-oral
Disease - Gastroenteritis, Norovirus, Enteric hepatitis (Hep. E)
Treatment - Supportive
Vaccine - No
Togaviruses
Nucleic acid - +ss RNA
Trans. - Resp. droplets
Disease - Rubella virus, German measles
Complications - pg. women, birth defects/miscarriage; Adults, encephalitis
Vaccine - yes, attenuated
Coronaviruses
Corona-like halo
Nucleic Acid - +ssRNA
Trans. - Resp. droplets and secretions
Diseases - usually mild, notable exception SARS
Treatment - Supportive
Vaccine - None
Retroviruses: HIV
Nucleic acid - +ssRNA, segmented
Trans. - Blood and body fluids
Disease - HIV-1 and HIV-2 (both lead to AIDS)
Treatment - HAART (Highly Active Anti Retroviral Therapy); AZT (nucleotide analogs); protease inhibitors, RT inhibitors
Vaccine - None
Paramyxoviruses
They include:
Morbillivirus (measles virus)
Paramyxovirus(parainfluenza)
Rubulavirus (mumps virus)
Pneumovirus (respiratory syncytial virus)
Rhabdoviruses
Rabies virus
Nucleic Acid: -ssRNA
Target: CNS
Trans.: Bite, Organ trans.
Disease: Rabies
Treatment: Immunization - passive and active
Vaccine: Yes
Filoviruses: Ebola and Marburg viruses
Nucleic Acid: -ssRNA
Targets: Viral glycoprotein destroys cell-cell junctions
Trans.: Blood and body fluids
Disease: Hemorraghic fever
Treatment: Supportive
Vaccine: No
Orthomyxoviruses
Influenza A & B
Nucleic Acid: -ssRNA, segmented
Trans.: Resp. droplets
Disease: Influenza - destroys lung epithelial cells, increased risk for secondary infections
Treatment: Supportive, Antivirals (Tamiflu/Rimantidiene), Antibiotics for secondary infections
Vaccine: Yes
Bunyaviruses
Hantavirus
Nucleic Acid: -ssRNA, segmented
Trans.: Resp. droplets
Disease: HPS (Hantavirus pulmonary syndrome - a rapid, severe and often fatal pneumonia)
Arenaviruses
Hepatitis D virus
CONTAIN RIBOSOMES!
Nucleic Acid: -ssRNA, segmented
Trans.: Body fluids
Disease: Hep. D (but requires Hep. B for virulence); Liver cancer
Vaccine: HepB vaccine
Reoviruses
Rotavirus and coltivirus
Nucleic Acid: dsRNA
What is a virus?
A tiny infectious acellular agent with nucleic acid surrounded by proteinaceous capsomeres that form a covering called a capsid.
How do viruses differ from bacteria?
Capsid
Nucleic Acid
Why are viral infections so difficult to treat?
Because viruses utilize their host cells' enzymes and ribosomes to metabolize and replicate. Therefore, drugs that are effective against viral replication are likely toxic to the host as well.
Why can’t antibiotics be used to treat viral infections?
xxx
How is the pathogenesis of Epstein Barr virus related to the state of the host’s immune system?
The virus invades B lymphocytes, where it lays latent and surpresses apoptosis (cell death). Mono results between the humoral and cellular branches of the specific immune system, in which the cytotoxic T cells of the cell-mediated branch of specific immunity kill infected B lymphocytes of the humoral branch, a type of "civil war".
Which viruses are associated with an increased cancer risk?
Human papillomavirus
Hepadnavirus (Hep. B)
Arenavirus (Hep. D)
Which viruses cause the common cold?
Rhinovirus
Coronavirus
Echovirus
Which are the 3 most common causes of colds?
Rhinovirus
Coronavirus
Echovirus
Which viruses induce the formation of syncytia in host cells?
Simplex virus
Retrovirus
Paramyxovirus
Pneumovirus
Which virus produces spherical particles, filamentous particles, and Dane particles?
Hepadnavirus (Hep. B)
Which of these particles are infectious virions and which are decoys?
Decoys - spherical and filamentous
Infectous - Dane
What is postpolio syndrome and when does it strike?
Neurons with new sprouts degenerate because they are overburdened causing gradual crippling deterioration. It strikes 10-40 years after the patient came down with polio.
Name three groups at-risk for complications from parvovirus B19 infections. Explain.
Pregnant women- can cross the placenta causing miscarriage or severe anemia.
Sickle-cell patients - (Aplastic crisis) sever acute drop in RBCs which requires immediate blood transfusion.
Immunocomprimised individuals
What are zoonoses?
Diseases spread from animals to humans
What does “arbovirus” mean?
Arthropod born
For which population is the rubella virus a concern and why?
Pregnant women - can cause miscarriage or birth defects
Adults - can cause encephalitis
What is unique about transcription in the retroviruses?
Retroviruses reverse the flow of information, transcribing dsDNA from ssRNA
What are the two primary glycoproteins on HIV and what role do they play in the pathogensis of the virus?
gp41 - mediates attachment
gp120 - responsible for mutation
Life cycle of HIV
1. Attachment and penetration
2. Uncoating
3. Synthesis of dsDNA and entry into nucleus
4. Latency
5. Synthesis
6. Assembly and budding
7. Maturation of the virion
What is the importance of reverse transcriptase for HIV?
Reverse transcriptase - complex enzyme which transcribes ds DNA from RNA. Transcription occurs as the enzyme moves along an RNA molecule. The following steps acutally happen simultaneously.
1. An RNA-DNA hybrid is made from the +RNA genome using tRNA carried by the virion as a primer for DNA synthesis. The DNA protion of the hybrid molecule is negative DNA.
2. The RNA portion of the hybrid molecule is degraded by reverse transcriptase, leaving -ssDNA.
3. The reverse transcriptase transcribes a complementary +DNA strand to form dsDNA, and the tRNA primer is removed.
What are the 5 main stages of HIV infection (See Figure 25.1).
1. Burst of viron production and release from infected cells. Primary infection includes fever, fatigue, weight loss, diarrhea and body aches.
2. Immune system response - producing antibodies and the number of free virions plummets. No symptoms.
3. Latent virus continues to replicate and virions are released into the blood, the body cannot adequately replenish Helper T cells.
4. The rate of antibody formation falls precipitously as helper T function is lost.
5. HIV production climbs, and the patient dies form infections the body can no longer resist.
Which virus is associated with Koplik’s spots?
Morbillivirus - measles
What is SSPE?
Subacute Sclerosing Panencephalitis
What causes SSPE?
Caused by the defective measles virus (mutated strain)
Why is post-exposure vaccination effective at preventing rabies in a person bitten by an infected animal?
Because unless the virus has gotten to the brain and symptoms show the body will mount the defense
What property of the filoviruses causes uncontrolled bleeding in infected patients?
Viral gp destroys cell-cell junctions
Name the two primary antigens found on the envelope of the influenza virus.
Hemagglutinin (HA)
Neuraminadase (NA)
Distinguish between antigenic shift and antigenic drift.
Antigenic shift - dramatic change
Antigenic drift - gradual change
How does the segmented nature of the influenza genome contribute to antigenic shift?
antigenic shift is the reassortment of genomes and since the influenza virus' genome are segmented into 8 parts there are a number of different combinations.
What is unique about arenaviruses?
They contain ribosomes
biological weapons
using a biological agent, such as bacterium or birus, to intentionally harm or death. A bilogical weapon can be either a biological agent itself or the toxins it produces.
biological warfare
using biological weapons in a war between sovereign nations.
bioterrorism
use of biological weapons by a terriost cell or organization.
Name 5 microorganisms and diseases which have been developed as biological weapons.
Bacillus anthracis - Anthrax
Variola - Smallpox
Clostridium botulinum - Botulism
Salmonella typhi - Typhoid fever
Ebola - Viral hemorrhagic fever
Simplexvirus
Herpesvirus:
Nucleic Acid - ds DNA (most prevalent DNA vurus!!)
Trans. - Close bodily contact
Diseases - HSV-1 - "cold sores" or "fever blister" - casual contact
HSV-2 - "genital herpes" - STD
Whitlow - (health care workers)
Treatment - Antiviral (Zovirax), valacyclovir (Valtrex), and famciclovir(Famvir) to alleviate symptoms, but does not cure.
Vaccine - None
Varicellovirus (Varricella Zoster Virus)
Herpesviruses:
Nucleic acid - ds DNA
Trans. - Respiratory droplets
Diseases - Varicella (chikcen poxs); Herpes Zoster (Shingles)
Treatment - Supportive, NO ASPIRIN (because a correlation has been found with chicken pox and Reyes syndrome)
Vaccine - Yes, attenuated
Epstein-Barr virus
Herpesvirus:
Nucleic acid - ds DNA
Target - B-cells
Trans. - Saliva
Diseases - Oral hairy leukoplakia, Burkitt's lymohoma, Mono
Treatment - Burkitt's, chemo; mono, supportive
Vaccine - None
Cytomegalovirus
Herpesvirus
Nucleic acid - ds DNA
Trans. - Body fluids
Diseases - Brain encepalitis, gastrointeritis.
High risk - Newborns, birth defects; Organ trans., rejection; HIV+, retinitis (blindness) and pneumonia/mono
Treatment - Supportive, Antiviral
Vaccine - None
Roseolovirus
Herpesvirus
Nucleic acid - ds DNA
Trans. - Resp. droplets
Diseases - Roseola
Treatment - Supportive
Vaccine - None
Rhinovirus
Picornaviruses
Rhinovirus - (#1 cause of common cold)
Trans. - Respiratory secretions (VERY CONTAGIOUS - infectious dose is 1)
Disease - Common Cold
Treatment - Supportive
Vaccine - None
Polioviruses
Picornaviruses, enterovirus
Nucleic Acid - +ss RNA
Target - Motor neurons
Trans. - Fecal-oral
Disease - Asymptomatic infections (80-90%), Minor flu-like illness (10-15%), Aseptic (viral) meningitis (3-4%) and Paralytic polio (1-2%)
Treatment - Supportive (Iron lungs)
Vaccines - IPV (exclusively in the U.S.) is injected, OPV is attenuated oral (used in developing countries for herd-immunity)
Hep. A, coxsackieviruses and echoviruses)
Hepatitis A virus
Picornaviruses, enterovirus
Nucleic Acid - +ss RNA
Target - Liver
Trans. - Fecal-oral (shellfish)
Disease - Infectious hepatitis (not spread through body fluids, spread through food) Hep. A
Treatment - Supportive, Passive immunity (anti-Hep A. antibodies)
Vaccine - Inactivated
Coxsackieviruses
Picornaviruses, enterovirus
Nucleic Acid - +ss RNA
Trans. - fecal-oral
Disease - Coxsackie A virus (Lesions and fever, herpangina - lots of sores in the mouth, Hand-foot-and-mouth disease - rash on palms of hands and soles of feet); Coxsackie B viruses (Myocarditis, Pericardial infections); Both can cause viral meningitis
Treatment - Supportive,
Vaccine - No
Echoviruses
Picornaviruses, enterovirus
Nucleic Acid - +ss RNA
Trans. - fecal-oral
Disease - Cold, Viral meningitis
Treatment - Supportive
Vaccine - No
What is the importance of integrase for HIV?
Inserts the provirus into a human chromosome. Integrase enzyme is carried on a virion.
What is the importance of protease for HIV?
Protease is a viral protein packaged in a virion, and releases reverse transcriptase and capsomeres after the virion buds from the cell. This process allows final assembly, rendering HIV virulent.
Flavivrus
Hep. C virus
Nucleic acid - +ss RNA
Trans. - Blood and body fluid
Disease - Hep. C (chronic liver infection, LEADING CAUSE for liver transplant)
Treatment - Interferon/Ribavirin combo
Vaccine - None
Arbovirus
Arthropod born
Nucleic acid - +ssRNA
1. Eastern equine encephalitis (vector is mosquitos, host are birds)
2. Western equine enceph. (vector is mosquitos, host birds)
3. West Nile enceph. (vector mosq., host birds)
4. St. Louis enceph. (vector mosq., host birds)
Mobillivirus
Paramyxoviruses - FORM SYNCYTIA
Nucleic Acid: -ssRNA
Trans. - Resp. droplets
Disease - Measles (Koplik's spots, rash)
Complications - Pneumonia, encephalitis, SSPE
Treatment - Supportive
Vaccine - Yes
Rubulavirus
Paramyxoviruses - FORM SYNCYTIA
Nucleic acid: -ssRNA
Target - Salivary glands
Trans. Resp. droplets (2-3 week incubation)
Disease - Mumps
Complications - Meningitis, encephalitis, orchitis, deafness, swelling of pancrease and ovaries
Treatment - Supportive
Vaccine - Yes...though effectiveness is being questioned due to recent outbreak
Pneumovirus
Paramyxoviruses - FORM SYNCYTIA
Nucleic acid: -ssRNA
Trans. - Resp. droplets/secretions
Disease - Respiratory Syncytial Virus
LEADING CAUSE of fatal respitatory disease in infants and children worldwide
Treatment - Supportive, Ribavirin (antiviral in extereme cases)
Vaccine - Passive immunization only ($900 per shot)
Rotavirus
Reovirus
Nucleic Acid: dsRNA
Trans.: Fecal-oral
Disease: Gastroenteritis
Complications: Intussusception (intestions folding in on themsleves)
Treatment: Supportive
Vaccine: Rotasheild (w/drawn in '99; RotaTeq NEW, safer
Coltivirus
Reovirus
Nucleic Acid: dsRNA
Trans.: Tick bite
Disease: CO tick fever
Treatment: Supportive
Vaccine: None