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What are specific examples of DNA viruses?
- 1. Herpes Virus: Simplex I and II (Cold sores, warts), Varicella zoster virus (Chickenpox, shingles), Epstein-Barr Virus (Infectious Mononucleosis), CMV mononucleosis
- 2. Adenovirus: Conjunctivitis, diarrhea
- 3. Parvovirus: Pox virus
- 4. HPV, warts
What are the properties of the Herpes Virus?
- -ds DNA virus
- -Enveloped, close contact
- -Establish latency in cells: causes the primary disease and then becomes latent, that hides itself somewhere. Under certain circumstances, it will come out and cause disease. Recurrent infections
What are the diseases caused by Herpes Simplex 1 (HSV 1)?
- -Oral gingivostomatitis: Herpes Labialis, cold sores. Incubation: 2-12 days, duration of disease: 10-14 days, Very painful with fever and sore throat
- -Usually get from family when younger
What are other sites for Herpes Simplex 1?
- -Eczema Herpeticum-burn patients
- -Herpes gladitorium: Wrestlers
- -Herpes whitlow: Medical personnel, skin break in fingers
- -Encephalitis: Nerves, occasionally goes up to the brain, 80% die w/o treatment
- -Herpes keratitis: Ulcers in the eye, lasts 2-3 weeks, can lead to blindness especially during recurrence
What is Herpes Simplex Type II (HSV II)?
- -Genital herpes in sexually active adults: blister like sores on genital organs
- -Disseminated disease of newborn: At birth, does not cross the placenta. 85% get disseminated disease involving liver, spleen, CNS, permanent sequelae
- -Disseminated disease of immunocompromised patients: may lead to encephalitis
What is the recurrence of HSV (Herpes Labialis, cold sores)?
- -The virus stays dormant in nerve cell where the immune system cannot attack
- -The virus can be reactivated by stress, UV light, cold, fever, hormonal fluctuation, certain foods
- -Once latency is established, recurrence is possible
- -Happens in Both I and II.
What is the epidemiology of HSV?
- -First infection will cause seroconversion from negative to positive.
- -HSV I 90% above the waist
- -HSV II 90% below the waist
- -80% of humans have antibodies to HSV I by age 5, 25% will have recurrence
- -IN US 600,000 new cases of HSV II each year
- -1 in 4 american have HSV II
What is the treatment of HSV Infections?
- -Acyclovir is the best in general for all types, worry about resistance.
- -Keratitis- lododeoxyuridine (IUdR) also
- -Encephalitis: Acyclovir, IV or dies
- -Disseminated disease: too late for newborn, acyclovir for immunocompromised
What is the treatment of recurrent HSV?
- -Acyclovir (topical or oral), works only if given early. Can be given to prevent recurrence of genital herpes
- -All these drug inhibit viral DNA replication.
What is the prevention of HSV?
- -Always wear gloves
- -Teach patient about open lesions, avoid spread
- -Avoid sexual contact with someone infected
- -If pregnant mother, do a C-section
- -Condoms can reduce spread by 80-90%
- -Avoid undue stress, excess sunlight, greasy foods, sharing makeup
- -Vaccine is currently being tested
What is Varicella-Zoster Virus (VZV)?
- -Primary disease: Chicken pox
- -Recurrence: Shingles (Older age)
What is chicken pox?
- -One of the most highly contagious disease known. 96% of exposed individuals contract the disease, most young children.
- --Virus, URT, Blood, internal organs and skin
- -Incubation period: 15-18 Days
- -Disease lasts 2-3 weeks
What are symptoms of chicken pox?
- -Rash, a few to 1000s of lesions
- -Raised vesicles that are soft and watery, mostly on skin.
- -Highly contagious 1-2 days before rash, 6 days to disappear
- -Usually a mild disease, may lead to pneumonia or encephalitis in kids
- -In older adults more serious
- -Pregnant mother can spread via placenta, a serious progressive disease can be spread, a common cause of hearing loss
What is shingles?
- -Recurrent disease
- -Virus remains latent in cranial nerve cells and following activation, causes lesions at nerve endings
- -Painful rash on one side of the face or body (ab, shoulder) and lasts 3-5 weeks. Rash may go away, but still painful
- -May or may not have a fever
- -Mostly in older adults
- -Can pass on chicken pox to children
How do you compare chicken pox and shingles?
- -No ab with chicken pox, high titer in shingles
- -Chicken pox is generalized infection, while shingles is localized
- -Chicken pox spread by blood, shingles by nerves
- -Chicken pox is very contagious, shingles is not
- -Most people get chicken pox by 10, shingles is older age.
What is the treatment of VZV?
- -Supportive for both chicken pox and shingles
- -Never us aspirin for kids- reyes syndrome scare, use tylenol
- -Trim fingernails and frequent showers
What is the prevention of VZV?
- -Vidarabine is recommended as an antiviral agent for Newborns and immunocompromised. Given by Zoster immune globulin (ZIG)- passive immunization
- -Live attenuated vaccine- Varivax, available in 1995, 85% effective for chicken pox
- -Shingle' vaccine Zostavax is used to prevent shingles in people older than 60. 50% effective
What is Epstein-Barr Virus (EBV)
- -Causes 90% of infectious mononucleosis
- -Age group 15-29 year olds
- -College disease or kissing disease.
- -Transmitted by saliva, large amts needed
- -Oropharynx-lymh-blood-latent in B lymphocytes 1 and 2
What is the treatment of EBV?
- -May give gamma globulin
- - A new drug-ampligen
What are the symptoms of EBV mononucleosis?
- -Sore throat
- -Swollen lymph glands
What is infectious mononucleosis?
- -Very mild disease in the young adults feel very tired, more severe cases require bed rest and maybe hospitalization
- -Not a very contagious disease, only 10% risk of getting from a family member
- -Long incubation period
What is Cytomegalo Virus (CMV)?
- -causes other 10% of infectious mono
- -Mild mono, self limiting
- -Major problem in renal transplant patients
- -Virus is transmitted transplacentally (Problem is mom is negative and is infected), leading cause of congenital viral infections, need blood test to determine if mother has been infected or not.
- -May cause vision loss, mental retardation, and death
What is the treatment of CMV?
-Gancyclovir: chemically very similar to acyclovir, inhibits viral DNA replication
What are other important human herpes viruses?
- - Human Herpes Virus-6 (HHV-6): infect t cells, roseola in infants, self limiting
- -HHV 7: Lymphocytic leukemia
- -HHV 8: Kapsoi's Sarcoma (skin cancer) in AIDS patients (Purple skin blotches)
What is the adenoviruses?
- -ds DNA containing, naked virus
- -70 different serotypes, very similar
- -10-15% of all respiratory infections
- -Originally isolated from adenoid tissue, remains latent in adenoid tissues for life, no recurrent disease
- -Transmitted by respiratory droplets and fecal-oral
- -incubation 5-10 days
- Virus-URT-GI- shed in feces
What are the diseases caused by adenovirus?
- 1. pharyngitis: sore throat, self limiting, fever, does not need meds
- 2. Kerato-conjunctivitis: swimming pool conjunctivitis, shipyard disease
- 3. Acute respiratory disease (ARD): many new army recruits get this
- 4. Pneumonia: highest morality rate with this disease. Occurs primarily in infants
What is the transmission of adenoviruses?
- -Naked virus, highly transmissible
- -Fecal oral route
- -Direct contact with secretions
- -Kerato conjunctivitis outbreaks occur frequently in the offices of eye doctors
What is the prevention of adenoviruses?
- -Avoid contact with secretions
- -Sterilize medical and dental equipment
What is the treatment of adenoviruses?
- -No drug has proven effective in curing adenovirus infections
What is a parvovirus?
- - ss DNA containing, naked virus
- -Smallest known DNA- containing virus
- -Very common infection, 80-90% of humans get infected by the time they are 5-6 years old
What are the two diseases of parvoviruses?
- -Human origin
- -Adeno-assiciated virus (AAV)
- -Parvovirus B19
What is adeno-associated virus?
- -So far no known disease (1/2 of us carry it)
- -Carriers actually have reduced frequency of certain cancers
What are diseases of Parvovirus B 19?
- -Erythema infectiosum- Fifth disease, fifth most common disease in children, in day-care centers, rash, slapped cheek syndrome, self limiting, 3-5 days
- -Transient aplastic crisis: Serious problem in people with RBC defect
- -Polyarthralgia: Joint pain in adults
- -Non immune hydropsfetalis: 18% of cases, presence of excess extracellular fluid in two or more sites in developing fetus. Passes transplacentally. Spontaneous abortions
- -Chronic bone marrow failure: AIDS patients
- -Thrombocytopenia: low platelet counts, bleeding disorders
What is the transmission of parvovirus B19?
- -Most likely through the upper respiratory tract (Fifth disease)
- -Trans-placental (Non-immune hydrops fetalis)
- -Blood transfusion (transient aplastic crisis)
What is the prevention and treatment of parvovirus B19?
- -No treatment except for RBC transfusion in transient aplastic crisis
- -Vaccine is currently being tested
What is HPV?
- -ds DNA naked capsid virus
- -More than 100 DNA types, not serotypes, can not be grown in tissue culture cells
What are the three types of warts caused by HPV?
- -Common warts, kids
- -Plantar warts: sole of feet or palm of hand
- -Veneral warts: genital area: vagina, penis, anus. Also called condyloma acuminata.
- Most prevalent viral STD
- More prevalent than genital herpes STD
What is the association of HPV and cancer?
- While most warts are benign and usually regress, or can be removed by surgery or by freezing them off with liquid N2, patients with certain strains of venereal warts are predisposed to cervical or anal cancer
- -Very serious!