Viruses

Question 1

Whats the typical lifecycle of an animal virus?

Answer 1

Attachment 
Penetration/Entry
Uncoating
Biosynthesis 
Maturation/Release

Question 2

What type of virus is HIV?

Answer 2

RNA Retrovirus

Question 3

What is HIV’s life cycle?

Answer 3

Gp120 attaches to CD4+ cells and co-receptors CCR5 and CXCR-4

Reverse transcriptase transcribes the RNA into dsDNA which integrates into the genome as a provirus

Latency ad asymptomatic

Direct synthesis of viral RNA and synthesis of new viral particles
-budding eventually lysis cell

Question 4

What are the stages of disease for HIV?

Answer 4

Acute -2-8 weeks after infection, brief illness with rapid multiplication and dissemination of virus through body.

Asymptomatic - latent period. 6 mons to 10 or more years. HIV detectable in blood. Viral replication continues

Chronic symptomatic - AIDS complex
Months to years. CD4+ cell numbers decrease

AIDS - fourth and last. Fewer than 200 CD4+ cells/microliter

Question 5

What’s characteristic of herpesvirus infections? and also of the herpes virus?

Answer 5

Herpesvirus infections are latent infections.

The virus is icosahedral and enveloped with spikes. Also dsDNA

Question 6

HHV 1 and HHV 2

Answer 6

Herpes Simplex: Human Herpes Virus 1 and 2

Cold sores or fever blisters (lips)
Herpes gladiatorum (skin)
Hertetic whitlow (fingers)
Herpes encephalitis

Latent in trigeminal nerve
HSV-1, oral sites

Genital Herpes - HSV-2

• congenital
• latent in sacral nerve
• complication: encephalitis

Question 7

Chickenpox/Shingles

Answer 7

Varicella and Herpes Zoster
HHV-3
Humans are the reservoir and source
Respiratory transmission

Shingles is reactivation of chickenpox that was in the cranial and sensory neurons.

Question 8

HHV-4

Answer 8

Mononucleosis by Epstein-Barr virus

Infects B cells and epithelial cells

Mouth to mouth contact - saliva

Complication: Burkitt’s lymphoma
-immunocompirmised and malaria and AIDS

Question 9

HHV-5

Answer 9

Cytomegalovirus 
HCMV
Any and All cells 
Formation of nuclear inclusaion bodies 
Infected cells swell
Latent in WBC
Congenital 
In semen and cervical fluid, spread by transfusions and organ transplants

Question 10

HHV-8

Answer 10

Targets lymphocytes and other cells

Kaposi’s sarcoma

• cutaneous lesion
• Associated with AIDS.

Question 11

hepatitis A

Answer 11

Fecal oral transmitted
Inactivated virus vaccine
RNA virus

Question 12

Hepatitis B

Answer 12

Vaccine 
Congenital 
Chronic liver disease 
Cancerous 
DNA virus 

Transmitted in blood and breat milk
-i.e. Needles

Question 13

Hepatitis C

Answer 13

No vaccine 
RNA virus 
Blood, sexually and fecal/oral transmission 
Chronic liver disease and cancer. 
Leading cause of liver transplants 
Treated with interferon a

Question 14

Hepatitis D

Answer 14

Getting vaccine for B eradicates the chances of getting D
RNA virus
Sexually and blood transmission

Question 15

Hepatitis E

Answer 15

RNA virus
Fecal/oral transmission
High mortality in pregnant women
Protection with HapA vaccine

Question 16

Influenza

Answer 16

Respiratory system disease
RNA Virus
HA and NA spikes
shows antigenic drift (mutations of same virus in geogrpahic area) and antigenic shift (two strains infects same cell)

Question 17

Measles

Answer 17

RNA virus 
Respiratory transmission 
Macular rash and koplik's spots
Encephalitis 1:1000 
-hearing loss 
Progressive degeneration of the nervous system

Question 18

Mumps

Answer 18

RNA virus
Fever and swelling/tenderness of salivary glands
Complications: meningitis and orchitis (testicles - infertility)

Question 19

Rebulla

-German Measles

Answer 19

RNA virus
Congenital Rubella Syndrome - fetal death, premature delivery and congenital defects.
Respiratory transmitted
Attenuated vaccine

Question 20

Warts

Answer 20

Verrucae - horny projections on skin HPV human papillomaviridae

Infects epithelial and mucous membranes. Benign epithelial tumors and cancers

Transmitted by direct contact

Question 21

What are the types of warts?

Answer 21

Plantar warts
Verrucae warts
Flat or plane warts
Anogenital condylomata - genital warts

Question 22

Genital Warts

Answer 22

Sexually transmitted HPV

Cause cervical cancer. types 16 and 18

Question 23

Poliomyelitis

Answer 23

Polio
-infantile paralysis 
Poliovirus 
Plus stranded RNA enterovirus 
3 types with no cross immunity 

Fever, headache, sore throat, vomiting and loss of appititie
-possible paralysis

Live vaccine and killed vaccine

Question 24

What are the Zoonotic diseases?

Answer 24

Ebola and Marburg viruses 
Hantavruses 
Lasso fever virus
Nipah virus 
RNA viruses 

Human viral infections in animal reservoirs before transmission to humans

Question 25

Ebola Hemorrhagic Fever

-Marburg fever

Answer 25

Host vascular system is damaged to vascular leaking (hemorrhage) and dysfunction (coagulopathy)

Ss negative sense RNA
Severe and %80 fatal
Direct contact
Internal hemorrhagic get

Fever, vomiting,muscle or joint pain,skin rash and diarrhea

Question 26

Zika Virus

Answer 26

Symptoms: fever, rash, joint pain, conjunctivitis

Complications: GBS, Microcephaly

Transmitted by aedes mosquito

Mother to child, sexual contact and blood transfusions

Releatively recent. First case 1947, 14 in 2007.

Question 27

Prions

Answer 27

Degenerative disease in humans and animals

bovine spongiform encephalopathy or mad cow diseases BSE
Creutzfelt-Jakob disease CJD and variant CJD
Fatal familial insomnia
Kuru
GSS

Normal PrPc then PrPSc causes normals to change.

Causes neural loss

Question 28

TSE

-prions

Answer 28

Transmissible spongiform encephalopathy
=prion disease

PrPSc pass through intestinal wall rapidly and enter lymph nodes
Can transfers to spinal cord and brain

CJD in humans

• sporadic
• familial
• iatrogenic (through medical treatments )

Signs - rapid prgoessive dementia, visual problems, speech abnormalities, muscle tremors, agitations, depression