Viruses Flashcards
Whats the typical lifecycle of an animal virus?
Attachment Penetration/Entry Uncoating Biosynthesis Maturation/Release
What type of virus is HIV?
RNA Retrovirus
What is HIV’s life cycle?
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
What are the stages of disease for HIV?
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
What’s characteristic of herpesvirus infections? and also of the herpes virus?
Herpesvirus infections are latent infections.
The virus is icosahedral and enveloped with spikes. Also dsDNA
HHV 1 and HHV 2
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
Chickenpox/Shingles
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.
HHV-4
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
HHV-5
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
HHV-8
Targets lymphocytes and other cells
Kaposi’s sarcoma
- cutaneous lesion
- Associated with AIDS.
hepatitis A
Fecal oral transmitted
Inactivated virus vaccine
RNA virus
Hepatitis B
Vaccine Congenital Chronic liver disease Cancerous DNA virus
Transmitted in blood and breat milk
-i.e. Needles
Hepatitis C
No vaccine RNA virus Blood, sexually and fecal/oral transmission Chronic liver disease and cancer. Leading cause of liver transplants Treated with interferon a
Hepatitis D
Getting vaccine for B eradicates the chances of getting D
RNA virus
Sexually and blood transmission
Hepatitis E
RNA virus
Fecal/oral transmission
High mortality in pregnant women
Protection with HapA vaccine
Influenza
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)
Measles
RNA virus Respiratory transmission Macular rash and koplik's spots Encephalitis 1:1000 -hearing loss Progressive degeneration of the nervous system
Mumps
RNA virus
Fever and swelling/tenderness of salivary glands
Complications: meningitis and orchitis (testicles - infertility)
Rebulla
-German Measles
RNA virus
Congenital Rubella Syndrome - fetal death, premature delivery and congenital defects.
Respiratory transmitted
Attenuated vaccine
Warts
Verrucae - horny projections on skin HPV human papillomaviridae
Infects epithelial and mucous membranes. Benign epithelial tumors and cancers
Transmitted by direct contact
What are the types of warts?
Plantar warts
Verrucae warts
Flat or plane warts
Anogenital condylomata - genital warts
Genital Warts
Sexually transmitted HPV
Cause cervical cancer. types 16 and 18
Poliomyelitis
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
What are the Zoonotic diseases?
Ebola and Marburg viruses Hantavruses Lasso fever virus Nipah virus RNA viruses
Human viral infections in animal reservoirs before transmission to humans
Ebola Hemorrhagic Fever
-Marburg fever
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
Zika Virus
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.
Prions
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
TSE
-prions
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
