micro final viral disease p. 3 (viral diseases)

influenza virus characteristics?

neg sense ssRNA witha segmented genome, enveloped, 3 infectious strains. named for hemagglutinin and neuraminidase gp’s (glcycoproteins)

influenza tissue tropism

respiratory epithelial cells

influenza transmission

respiratory droplets. strain A infects pigs, birds and humans and is pandemic or season flu

strain B and C infect only humans

influenza disease

virus replicates in respiratory epithelium

influenza S/S

fever, headache, body aches, cough/sneeze

what is the body aches in influenza caused by?

cytokine storms in the body

influenza diagnosis?

ELISA, PCR, IFA

influenza treatment

antiviral oseltamivir which inhibits neuraminidase. aspirin should not be used for children due to risk of Reye’s Syndrome

influenza prevention (2)

2 vaccines: whole, killed injected vaccine and live, attenuated intranasal vaccine. both are multivalent and 70% effective

what is Reye’s Syndrome?

it is a condition where progressive encephalopathy with hepatic dysfunction occurs

what are children supposed to use if they can’t use aspirin?

children use tylenol

which phase is best to use the treatments for influenza?

prodromal phase

what type of mutations are common in the RNA genome?

point mutations

describe antigenic drift

this is when more and more points in the RNA sequence change through constant replication where the RNA sequence eventually gets more and more resistance to antiviral drugs

what is reassortment?

this is when two different strains of a virus exchange genetic material to create a new strain

usually when two viruses try to infect one cell, the first virus wins and the other virus doesn’t infect it. what animal is an anomaly and allows for two viruses to enter one cell?

pigs

measles etiological agent?

neg sense ssRNA linear, enveloped, Paramyxovaviridae

measles tissue tropism

lymphocytes, endothelial, epithelial and neuronal cells in vitro

measles transmission

droplets

measles S/S

fever, sore throat, conjunctivitis, Koplik’s spots (mouth), maculopapular rash

measles disease

rubeola (R₀ of 12-18) - virus first infects respiratory tract, spreads to lymph node and blood to cause viremia. can infect CNS. subacute sclerosing panencephalitis can occur 7-10 years after measles. death can also occur from pneumonia

measles virus induces what CPE?

syncytia

measles diagnosis?

signs or viral antigen in respiratory/blood samples

measles treatment?

no antivirals; no aspirin for children

measles prevention?

MMR(V) which is live, attenuated vaccine

varicella zoster virus (human herpesvirus 3) etiological agent

linear dsDNA, enveloped, Herpesviridae

VZV tropism

respiratory epithelial and epidermal cells; neurons

VZV transmission

droplets

VZV disease (varicella = ?, zoster = ?)

1. chickenpox (varicella)

2. shingles (zoster) later in life

VZV pathogenesis?

1. varicella viremia, virus infects epidermis, which establishes a latency in sensory neuron cell bodies

2. zoster is the reactivation of virus following dermatome

VZV S/S?

vesicular lesions; fever

VZV diagnosis?

appearance of lesions. shingles means the lesions dont cross the midline of body

VZV treatment?

No aspirin for varicella in children and acyclovir is used for zoster

VZV prevention?

vaccines for children is Varivax or MMRV. Adults over 50 use Shingrex and adults over 60 use Zostavax. all vaccines for VZV are live, attenuated

what is Acyclovir?

antiviral from the 60s used to treat HSV1, 2, and VZV. it interferes with viral replication. structurally it is a guanine without the 3' hydroxyl groups to terminate DNA synthesis. doesn’t get rid of the latent infection

what is valacyclovir?

same thing as acyclovir but lasts longer and needs to be administered less

Herpes simplex virus 1 and 2 characteristics

linear dsDNA, enveloped, Herpesviridae

HSV transmission

contact with infected epithelial surface or vert transmission from placental birth

HSV disease

genital herpes usually from HSV 2 and cold sores are usually from HSV 1.

HSV pathogenesis

1. virus replicates on epithelial surface, travels to enervating sensory neurons, becomes latent in the sensory neuron cell bodies for the hosts life

2. reactivation can occur sometime in their life usually in the same area that the neurons innervate

HSV S/S

vesicular lesions

HSV diagnosis

appearance of lesions

HSV treatment

acyclovir or valacyclovir

prevention for HSV

virus may be shed without lesions. abstinence and condoms can reduce transmission risk.

what nobel prize is harald zur hansen for?

discovering HPV causing cervical cancer

who discovered HIV?

Francoise Barre-Sinoussi and Luc Montagnier

HPV characteristics

circular dsDNA, nonenveloped, Papoviridae with over 100 different types

HPV tropism

epidermal stem cells

HPV transmision

contact and epithelial surface breaks

HPV disease

10-20M cases in US/year

warts, cancers, plus others

HPV diagnosis

pap smear appearance of wart

HPV treatment

surgery, freezing, checmical warts or precancerous cells; no activirals

HPV prevention

subunit vaccine like Gargasil 9 used for 9-45 year olds. Genitally acquired HPV is prevented through abstinence and condoms

what is the chance that women in US will get HPV by 50?

80%

what is the causality for HPV and cervical cancer?

it is necessary

HIV characteristics

2 copies of linear pos sense ssRNA, enveloped, Retroviridae

HIV tropism

CD4 T cells and co-receptors such as CXCR4 or CCR5.

HIV transmission

contact with infected body fluids and vert transmission

HIV disease

infects CD4 T cells to cause killing of CD4 which leads to acquired immunodeficiency syndrome (AIDS) after a CD4 level of less than 200 cells/ul blood. death caused by opportunistic infections after immune system is compromised

in stage 1 of HIV, what foes up and what goes down?

CD4 cell count drops significantly and the disease cells level increase steeply

in stage 2 HIV, what happens to the levels?

this is clinical latency where the CD4 cells have arisen again and are slowly declining as the disease cell number remains very low

in stage 3 HIV, what has happened to the levels?

the CD4 cell count dropped below 200 to signal AIDS and the disease cell count has shot up again.

HIV diagnosis?

antibody response in patient from over the counter tests. ELISA tests which need to be confirmed by Western blot

HIV treatment?

many drugs which inhibit RT, protease, fusion, or integrase

HIV prevention?

no vaccine but 100% abstinence prevents it and condoms lower it. pre-exposure prophylaxis (PREP) is another prevention (AZT or vaginal gel tenofivir)