Mon Test week 4 day 1 - Viruses Flashcards
What is the Reservoir of Ebola virus? How is it spread?
Fruit bat is probably the natural reservoir May also be spread by non-human primates - blood, body fluids and tissues
Characteristics of Ebola Virus? What is a similar disease?
1) Virus undergoes massive replication in endothelial cells, phagocytes, hepatocytes 2) Necrosis of liver, kidneys, gonads, spleen, lymph nodes 3) Hemorrhage of lungs 4) Severe - 80-90% fatality Marburg Hemorrhagic Fever is similar
What are the symptoms of ebola?
- hemorrhagic rash appears over entire body - bleeding from mucous membranes - mouth nose eyes and rectum
Do we see Hantavirus in the US?
Yes unlike Ebola. Mostly North America
reservoir of Hantavirus?
Rodents appear to be the natural reservoir, especially deer mouse’s urine, droppings, and saliva
Characteristics of Hantavirus?
Fatigue, fever and muscle aches initially Later coughing, shortness of breath, fluid-filled lungs Death in ~40%
What percentage of oral cancers come from HPV? Do all HPV cause cancer?
10-15% No, mostly HPV 16 and HPV 18
What are the high risk HPV? How are they transmitted?
HIGH-RISK HPV TYPES #16 & #18 are sexually transmitted
What do low risk HPV cause?
Papillomas and warts
How common is HPV?
Very. Every sexually active person will get it at some point without the vaccine
What are HPV 16 and 18 particularly involved in?
Oropharyngeal cancer -> 70% due to HPV
What is the main cause of oral cancer?
80% smoking
Why should we continue screening for cancer for those who are vaxxed against HPV?
Maybe dysplasia before got vaccinated Maybe infected with other oncogenic strain Maybe they smoke Maybe they’d have developed cancer anyway
Whats the most likely cancer in men caused by HPV? Women?
Men: Oropharyngeal ~ 77% Women: Cervix ~ 59%
What is the pathogenesis of HPV? How does it infect?
Papillomaviruses are small, non-enveloped, circular double-stranded DNA viruses Trophic for squamous epithelial cells Enter into basal cells Transported to the nucleus. Once in the nucleus turn off different suppressor genes. E6 and E7 are suppressors, so like a car without the breaks. Proliferation.
Name two genes of HPV and the three host things they are targeting? their role in carcinogenesis?
- HPV’s E7 gene can bind to Rb - gatekeeper off duty! uncontrolled cell reproduction - HPV’s E6 protein can bind to p53 Repeated replication of cells with incorrect DNA information No apoptosis of mutated cells HPV’s E6 can also activate telomerase so it confers immortality maintains a repeated cell cycle that continues to produce viral cells. mutant cells continue to reproduce out of control.
What are the two ways an HPV disease can progress after HPV infection?
- HPV infects the cell and can cause a latent phase, so cell looks normal and sits quietly. HPV makes cells reproduce crazy. Immune system notices and starts attacking and killing off the viral cells. No HPV.
- Sometimes HPV E6 and E 7 bind to p53 and Rb and keep on replicating. Smoking or other infections like HIV help viruses. Sometimes develop malignancy, but that’s a minority.
What is the disease associated with HPV 2, 4, 40? Clinical manifestations?
Verruca vulgaris, common wart. It is also seen in oral cavity.
- Its white - more keratin than papilloma
- Elevated with crisp borders
- Flat verrucous or warty top (Jughead’s hat)
What are the treatments for papillomas and Verrucas?
- On skin:
- Surgical excision, liquid nitrogen, or keratinolytic agents.
- Intraoral:
- Surgical excision, cryotherapy or electrosurgery
What is the causative agent for Condyloma acuminatum? How does it look like? Tx?
HPV 6, 11, 42, 43, 44, 55
Genital or venerial warts.
Not high risk HPV. Infectious! Can spread from sites to sites.
papillary proliferation, cauliflower shape
Larger than papilloma and often multiple
Treatment: Surgical or medical. No laser bc particles can spread
general differences in shapes of pappiloma, verruca and condyloma?
papilloma - Pendunculates like P, no definite HPV causes it
Verruca Vulgaris - common wart, fingers are the common site, serrated top - HPV 2, 4, 40
Condyloma Acuminatum - Venerial wart, common genitals flat and scalloped top - HPV 6 & 11
What viruses cause Hecks disease? Manifestations? Risk?
HPV 13, 32
Focal Epithelial hyperplasia, oral
Not high risk
- Flat, smooth, soft, papules
- Same color as surrounding mucosa usually
- No ulceration
- No malignant transformation potential
- Usually a self-limiting viral infection
whats some sensitive info about Hecks disease?
Its mostly in endogenous populations, and in Children. Can mimic condyloma acuminatum. You can send it off to histo to make sure its not a sexual abuse in kids.
What is causing plantar wart? Where does it appear?
HPV 1, 2, 4
sole of foot
Viruses that cause cancer? What kind of cancer?
16, 18 mostly
Cervix, pharynx, oral (some)
