micro 102 lecture exam 3
Name the 3 types/ categories of viral infections
Acute viral infection
Latent Viral infection
Slow viral infection
Acute viral infection
infection, incubation, development of symptoms, recovery and then virus totally gone from system.Ex common cold or Flu
Latent viral infections
infection, incubation, probable expression of symptoms, recovery and then becomes latent or remains in body and may be reactivated at some point. Ex. Herpes, shingles
Slow Viral infections (aka persistent viral infection)
infection, really long incubation, then sick and death occurs (years or decades) Ex. Kuru: you get infected by smearing infected brains over your naked body.
Herpesviridae family
Herpes simplex type 1
Herpes simplex type 2
Varicella- zooster virus
Epstein-Barr virus (EBV)
Herpes simplex type 1
coldsores, fever blisters, become infected by kissing or sharing a straw etc. It heals but then remains in your nerve cells for the rest of your life. Tends to be reactivated when a person gets a sunburn or a fever.
Herpes simplex type 2
Genital herpes, an STD. Usually an infection of the genitals or an oral infection. One week incubation, experience a burning and tingling sensation in the infected area. Fluid filled blisters form and the fluid is highly contagious. Can be reactivated by stress, physical or emotional stress.
Varicella - zoster virus (aka herpes zoster virus)
causes chicken pox and shingles. Common childhood disease: virus is inhaled 2 week incubation, then the virus would be found localized in cutaneous nerve cells then you would see fluid filled blisters anywhere on the body.
Chicken Pox
Common childhood disease: virus is inhaled 2 week incubation, then the virus would be found localized in cutaneous nerve cells then you would see fluid filled blisters anywhere on the body.
Shingles
have to have had chicken pox to get shingles. Some people experience reactivation of the virus. Rash, fluid filled blisters are tiny, rash can follow nerve pathways, excruciatingly painful. Acyclovir: may shorten the duration and lessen the severity
Epstein-Barr virus (EBV)
Causes infectious mononucleosis, exchange of saliva by kissing or sharing drinks,. Enlarged spleen, severely lethargic,(no energy), No treatments, just bed rest. Implicated in a very rare cancer called Burkitts lymphoma and is always fatal, seen mostly in Africa
Family Adenoviridae D.S. (linear?) DNA
Spikes for attachment, causes a serious Respiratory infection. Adeno virus
Family Poxviridae D.S. linear DNA
Cow pox and small pox, very closely related if you have one you CANT get the other and they mutate very slowly. Small pox is the only example of a virus that has been eliminated from the face of the earth
Polio viruses
transmitted in feces, polio is virtually unheard of in developed countries. Neurological and muscle degeneration
Rhino viruses
cause the common cold. More than 100 strains.
It's so common because
1. No cure
2. diversity of the strains
3. lack of durable immunity
Rubeola
highly contageous, spread by resp. 11 to 14 day incubation develop cold like symptoms, sore throat, headache, cough, skin rash might occur in oral cavity, Koplik spots. Particularly dangerous to old and young people encephalitis. One in 2000 cases may result in brain damage, about 1 in 3000 cases is fatal, usually in infants.
Mumps
Infects salivary glands 16 to 18 day incubation salivary glands get painful swelling, accompanied by a fever. If it occurs in mature males 4 to 7 days of onset of symptoms the testis become painfully inflamed and swollen may result in permanent sterility.
Rubella
AKA German measles, generally milder than rubeola, air-born transmission 2 to 3 week incubation , slight fever little bit of a rash, a problem when congenital rubella syndrome occurs, if a woman has had a vaccine or had rubella before pregnancy she will have no problems but if not and she becomes prego. its bad news, the severity of the damage depends on when she got infected and how far along she is in her pregnancy. 1st trimester miscarriage, later on possible birth defects, deafness, cataracts, heart defects, mental retardation.
Family Rhabdoviridae D.S. RNA
Rabies: bullet shaped with with an envelope and spikes, most viruses are species specific, Rabies can infect any species of mammal. If exposed, you get a painful series of shots in the belly, and you may avoid being infected completely. Human rabies in the US is virtually unheard of, other parts of the world is more common. Reasons why its not very common in US
1. Were pretty good with vaccinating our animals
2. We vaccinate our wild animal population
3. The P.E.T program (post exposure treatment) If you are maybe possibly infected then they will give you the 3 week long treatment with a needle in stomach. Occurs through saliva, get bit by infected animal, 30 to 50 days incubation but can take as long as 6 years. The virus travels along peripheral nerves to the CNS (central nervous system) and causes encephalitis(brain infection) depends on where you get bitten incubation period, if you get bitten on hands or face incubation will occur faster. When infected will have throat spasms (salvation) is stimulated by inhaling cold air and drinking water. Cause of death damage to nerve cells and brain tissue. two forms of disease, furious rabies animal highly excitable. Paralytic rabies; minimally excitable.