Viral infections of the skin and digestive system

first disease

measles

third disease

rubella

fifth disease

parvovirus B 19

sixth disease

Human herpes virus → roseola infantum

measles virus description

paramyxovirus (-)ssRNA enveloped virus

measles replicates in the

cytoplasm

establish in the respiratory tract

infection of measles:

respiratory droplets

measles other name

Rubeola

measles/rubeola (first disease) characteristic symptom

Koplik spots on mucous membranes

maculopapular rash covers the entire body

complications in measles

acute disseminated encephalomyelitis

subacute slcerosing panencephalitis

acute disseminated encephalomyelitis

autoimmune disease

progressive, degenerative disease of CNS

demyelination of neurons

subacute sclerosis panencephalitis

chronic, progressive brain inflammation

decrease in cognitive skills and loss of CNS

measles dx

clinical presentation

virus ab testing

serological testing

RTPCR

acute infection in measles, serological testing results

detection of measles IgM in pt serum

greater than 4 fold rise in titer in IgG between acute and convalescent serum samples

what immunoglobulin is immediate in measles infection

IgM

rubella virus other names

third disease

German measles

rubella virus is caused by

togavirus (+)ssRNA

rubella infection

inhalation of aerosolized droplets

rubella pathogenesis

infects URT

spreads to local lymph nodes

rubella characteristic symptoms

fever with pale pink maculopapular rash from the face to extremities

rubella virus complications

congenital rubella syndrome (CRS)

CRS symptoms

transplacental virus transmission resulting in

cataracts, mental retardation, stillbirth, deafness, and death within 1st year of infant

rubella vaccine name

MMR (measles, mumps, rubella)

mumps virus infection

aerosols, virus shed in saliva

mumps replication

URT → bloodstream → parotid gland

infectious parotitis

infection of the paratiroid gland in mumps

mumps characteristic symptom

swelling of the salivary glands (parotitis)

pain when chewing or swallowing

mumps complications

meningitis

encephalitis

orchitis (swelling of testicles)

oophoritis (inflammation of the ovaries)

Parvovirus is the

smallest DNA virus

human parvovirus B19 pathogenesis

viruses reaches respiratory tract

attachment & replication in erythrocyte progenitor cells in BM

what does parvovirus bind to on RBCs

P antigen

Parvovirus nickname

fifth disease

parvovirus characteristic symptom

slapped check rash

reticular rash (net like)

parvovirus complications

aplastic crisis with chronic hemolytic anemia

Roseola infantum nickname

sixth disease

roseola infantum characteristic symptoms

3-5 days of high fever, followed by sudden maculopapular rash all over the body that blanches when touched

where does roseola infantum replicate

salivary glands

transmitted via saliva

roseola infantum associated with

HHV6 and HHV7

roseola infantum can become

latent infection within myeloid and BM progenitor cells (T cells and monocytes)

chickenpox/ shingles causative agent

varicella zoster virus (VZV)

chickenpox other name

varicella

shingles other name

herpes zoster

chickenpox symptoms

fever

maculopapular rash

intense itching

thin walled vesicles on an erythematous base leading to a crust

shingles cause

reoccurrence of latent varicella in dorsal root ganglia

shingles symptoms

rash limited to dermatome along the trunk

shingles complication

intense pain in the area → postherpetic neuralgia (PHN) can last for years

varicella zoster virus pathogenesis: infection

inhalation of virus through respiratory droplets

virus infects tonsils and mucosa of the respiratory tract

varicella zoster virus pathogenesis 2

virus spreads to lymphatic system → bloodstream → skin where it causes tissue damage

varicella zoster virus becomes

latent in nerve ganglia and can reactivate in adults after age 45 manifesting as shingles

chickenpox infects —- while shingles infects —

children

15-20% of adults who had chickenpox

varicella zoster virus dx

clinical presentation → characteristic lesions

antibody testing

varicella zoster virus: chickenpox tx

self limited

supportive treatment for symptoms relief

reyes syndrome: varicella zoster virus complication

brain selling or loss of living function following chickenpox, especially when aspirin used to treat it

shingles tx

acyclovir

symptom management

prevention of varicella zoster virus

VZV vaccine at 1 yr old, then booster at 4-6 yrs

adults 50+ have 2 doses of shingles vaccine

herpes simplex virus description

enveloped linear dsDNA

HSV 1

above waist

HSV2

below waist

herpes simplex infects

skin and mucous membranes

able to infect CNS

herpes simplex lytic infections in

fibroblasts and epithelial cells

latent infections in neurons

trigerminal ganglia =

cold sores

sacral ganglia =

genital herpes

herpes simplex can be reactivated

virus migrates from the neuron to the initial site of infection

herprs simplex virus shedding

asymptomatic shedding

clinical syndromes of HSV

cold sores

herpetic keratitis

herpetic whitlow

herpes gladiator

eccema herpeticum

genital herpes

herpes encephalitis

neonate infection

HSV dx

direct microscopic exam of cells from base of lesion

HSV dx: what is seen in microscopic exam

multinucleated giant cells and cowry type A includison bodies

tx for HSV

prompt tx with high dose acyclovir in pediatric pts

human papilloma virus (HPV) virus structure

small, non enveloped dsDNA

human papilloma virus infection

close contact:

fomites

breaks in the skin or mucosa

sexual intercorse

during delivery

human papilloma virus infection and replication

squamous epithelial cells and mucous membranes

HPV has over 100 serotypes. what are some of the clinical syndromes

warts

benign head and neck tumors

cerical dysplasia and neoplasia

most common STI in the world

HPV serotypes that cause common warts

HPV 1 - 4

HPV serotypes causing genital warts

HPV 6 and HPV 11

condylomata acuminata

small, flat, flesh covered bumps or tiny, cauliflower like bumps in genitalia or anus

oncogenic HPV: what serotypes are common in cervical cancers

HPV 16 or HPV 18

HPV oncogenes are

viral proteins which play a critical role in driving cell transformation and promoting carcinogenesis

HPV dx

pap smears

Pap smears detect

koliocytotic (vacuolated cytoplasm) squamous epithelial cells

preventive measures for HPV

Gardasil or cervarix

coxsackievirus causes

hand foot and mouth disease

herpangina (mouth blisters))

coxsackievirus description

picornavirus (+)RNA

pleurodynia (devils grip) associated with coxsackievirus

sudden onset of chest or abdominal pain

complications associated with coxsackievirus

myocardial and pericardial infection

viral meningitis

rotavirus description

non enveloped, segments, dsRNA

rotavirus spread

fecal oral

rotavirus stats

by age 5 all children have been infected

rotavirus causes

gastroenteritis

dx rotavirus

viral antigen in stool

is there a vaccine for rotavirus

yes

rotavirus

virus lyses intestinal epithelial cells

viral NSP4 protein promotes calcium influx and alteration in water absorption

severe dehydration and electrolyte loss

asymptomatic in adults

norovirus descripton

naked capsid, (+)ssRNA

norovirus is

highly contagious, tiny dose needed (10 viral particles)

norovirus outbreaks

food contamination

norovirus causes damage to

intestinal brush boarder → gastroenteritis

shedding of norovirus

continues up for 2 weeks after resolution

dx norovirus

RT PCR