Viruses Flashcards
Four types of RNA viruses
- Positive single-stranded RNA (can be used immediately to make a protein
- Retroviruses (+ssRNA that convert genome into DNA)
- Negative single-stranded RNA (has to be translated/ altered first)
- double stranded RNA
Rhinovirus diseases
Upper respiratory tract infection (common cold)
Rhinovirus transmission, prevention and treatment
Transmission: aerosols (>1m), fomites and person to person contact (hand to hand is most common).
Prevention: hand washing. Also tend to become immune to more serotypes as we age
Treatment: none. Pleconaril can reduce length/ severity if taken at right time. Can treat symptoms but not infection
Rhinovirus signs and symptoms
Sneezing, runny nose (rhinorrhea), congestion, sore throat, headache, malaise, cough
Lesions observed in all stages of poxvirus infection
Vesicle (like a burn blister with thicker skin)
Pustule: like a whitehead pimple
Two forms of small pox
Major (severe cases with 20% mortality)
Minor: much milder, though still shows blisters
Two forms of pox viruses
Small pox
Mulluscum Contaginosum
Small pox forms of transmission
Contagious: spreads person to person through contact and saliva droplets (even on breath) incubation for 7-17 days
Smallpox prevention
Vaccines, even if given after exposure (within the 4-day window), largely eradicated in the industrialized world
what is Molluscum contagiosum and how is it treated
- Caused by molluscopox virus
- causes smooth, waxy papules, and will resolve on its own in healthy individuals
- immunocompromised people may need to have the lesions surgically removed
Types of Herpes viridae (most common DNA virus)
HHV-1: causes herpes/ hand and mouth
HHV-2: causes genital herpes
HHV-3: Varicelles Zoster: chicken pox and shingles
HHV-4: Epstein Barr Virus
HHV-5: Cytomegalovirus
HHV-6: Roseolovirus (linked to M.S.)
HHV-8: Karposi’s Sarcoma in AIDS patients
Herpes (HHV-1 and HHV-2) description and treatment
Description: causes painful blisters/ sores on mouth, hands, or genitals (mostly HHV2).
Treatment: Reduce pain/ spread through contact. Not much treatment, just prevention
Varicella Zoster/ Chicken pox (HHV-3)
Chicken pox: just irritating in children (self-limiting itchy rash) but more dangerous in adults
Shingles: latent disease- painful blistering patches along the tract of a nerve.
Vaccines for both, but otherwise manage symptoms/ pain
Epstein-Barr Virus (HHV4)
Weak immune: tongue issues/ lymphoma
Healthy: asymptomatic
Strong: over-reacts and get mononucleosis symptoms (fatigue)
Weak: chronic fatigue syndrome
Cytomegalovirus (HHV-5) description and treatment
Cells become enlarged- no damage in most healthy patients. Cells show “owl eyes”
Treatment: Virsen used to treat infections of the eye
Roseolovirus (HHV-6)
May be linked to multiple sclerosis, symptoms similar to mono, and may make patients more susceptible to AIDS
HHV-8
Causes karposi’s sarcoma (cancer), especially in those with AIDS
Papilloma virus disease and treatment/ prevention
Causes warts, with genital warts being associated with increased cervical cancer risk.
Can remove warts w/ over the counter, or surgically, and can prevent some serotypes with vaccines (HPV vaccine)
Polyloma virus diseases, treatment and prevention
BK (urinary tract) and JC (WBC) viruses cause tumors in humans and animals,
JC can cause leukoencephalopathy, which destroys white matter in the brain (paralysis and death)
Viruses that cause “colds”
- Rhinovirus
- Adenovirus
Diseases caused by adenovirus
Common cold, GI distress, viral pinkeye
See hepatitis table
Do the hepatitis table!
Three types of enteroviruses
- Poliovirus
- Coxsackievirus
- Echovirus
Four conditions caused by polio viruses and their differences`
- Asymptomatic: typical in immunocompetent people
- Minor polio: GI or respiratory infection that doesn’t include CNS
- Nonparalytic polio: leads to aseptic meningitis (no virus in spinal fl)
- Paralytic polio: may be spinal, bulbar (medulla) or both