Viral Diseases

Vocabulary flashcards covering the key viral families, viruses, diagnostic signs, and vaccine-related concepts discussed in the lecture notes.

Paramyxoviridae characteristics

Enveloped

helical capside

negative-sense ssRNA

linear

non-segmented

surface glycoproteins

Matonaviridae characteristics

enveloped

icosahedral capsid

positive-sense ssRNA

linear

non-segmented

surface spikes

Herpesviridae characteristics

enveloped

icosahedral capsid

linear dsDNA

LATENCY

Poxviridae characteristics

3 layer envelope

weird capsid type

linear dsDNA

has its own DNA polymerase

Poxviridae specific viruses

molluscum contagiosum

Parvoviridae characteristics

non-enveloped

icosahedral capsid

ssDNA

linear

Parvoviridae specific viruses

parvovirus B19

Herpesviridae specific viruses

herpes simplex

varicella zoster

roseola

Picornaviridae characteristics

non-enveloped

icosahedral capsid

positive-sense mRNA

linear

non-segmented

Picornaviridae specific viruses

coxsackievirus

Matonaviridae specific viruses

rubella

Paramyxoviridae specific viruses

rubeola (measles)

mumps

Reportable infections

measles

mumps

rubella

Measles surface glycoprotein

surface hemagglutinin (H)

fusion (F)

Mumps surface glycoproteins

hemagglutinin (HN)

fusion (F)

Paramyxoviridae replication

glycoproteins bind to host and trigger fusion

negative sense RNA transcribed to mRNA in cytoplasm

exits via budding

Koplik spots

Small white-blue lesions on the buccal mucosa seen in measles before the rash appears.

Mumps transmission

human only, person to person

respiratory droplets/aerosols

Parotitis

18-21 day incubation

painful swelling of parotid glands (unilateral)

NO RASH

lasts 5 days after symptoms

Mumps infections

parotitis

CNS- meningitis, encephalitis, deafness, oophoritis

Mumps risk factors

lack of or incomplete vaccination

travel near outbreaks

exposure to infected individuals

close contact situations

Mumps epidemiology

peaks in winter

less than 500,000 reported cases worldwide annually

Mumps treatment

pain relief (NO ASPIRIN)

hydration

warm or cold compresses

soft diet

MMR/MMRV Vax

MMR- measles, mumps, rubella

MMRV- measles, mumps, rubella, varicella

live, attenuated vaccine

MMR Timing

dose 1: 12

Mumps prevention

vaccination

infection control and isolation

education, public health measures

Measles characteristics

hemagglutinin

fusion protein

multi-nucleated giant cells

Measles transmission

human-only

highly contagious

respiratory secretions

Measles: infectious timeline

infectious in prodrome (before rash)

infectious days after rash disappears

Measles epidemiology

outbreak every 2-3 years in endemic areas (Europe, Asia, Africa)

young kids most likely

Measles risk factors

lack of or incomplete vaccination

close contact situations

travel to outbreak areas

Measles symptoms

high fever (105)

cough, coryza, conjunctivitis

koplik spots on buccal mucosa

descending maculopapular rash (3-5 days after fever)

Measles complications

pneumonia

encephalitis

ear infections

sub-acute sclerosing panencephalitis

Sub-Acute Sclerosing Panencephalitis

slow and progressive brain inflammation

persistent with some measles viruses

always fatal

behavior changes, seizures, spasticity, poor coordination, coma

Measles diagnosis

maculopapular rash for 3+ days

temperature 101+

koplik spots

3Cs

Measles treatment

no antivirals, only supportive

vitamin A for kids

Measles prevention

VACCINATION

post-exposure prophylaxis

infection control and isolation (airborne precautions)

Matonaviridae replication

enter via endocytosis

transcription and translation in cytoplasm

nucleocapsid buds into ER to get envelope with surface proteins

released via vesicle fusion

Rubella virus transmission

human-only

respiratory droplets/aerosols

vertical transmission to fetus

Rubella epidemiology

endemic in Africa, South East Asia

US free in 2005

Western Hemisphere free in 2015

Rubella risk factors

lack of or incomplete vaccination

close contact situations

pregnancy (especially if not vaxxed)

Rubella symptoms

14-21 day incubation

low grade fever

3 day maculopapular rash

forchheimer spots

auricular lymphadenopathy

Forchheimer Spots

petechiae on soft palate

Congenital Rubella Syndrome

Fetal infection from maternal rubella

leading to heart defects, cataracts, deafness, and other anomalies.

Rubella diagnosis

clinical symptoms

RT-PCR for viral genome in kids and adults

Rubella treatment

no antivirals

Rubella prevention

VACCINATION

Picornaviridae replication

enter via endocytosis

ssRNA translated in cytoplasm

released via lysis

Coxsackievirus A&B

A- surface infections

B- deep infections

Coxsackievirus reservoirs

human only (mainly kids and infants)

Coxsackievirus transmission

fecal-oral

respiratory droplets

fomites

direct contact

Coxsackievirus epidemiology

hand foot mouth more common in summer and early fall

Coxsackievirus risk factors

less than 5 years old

summer and fall seasons

daycare attendance

Hand, Foot, and Mouth Disease Transmission

fecal-oral

respiratory droplets

direct contact

highly contagious

Hand, Foot, and Mouth Disease characteristics

coxsackievirus

3-6 day incubation

prodrome

self-limited (7-10 days to resolve)

Hand, Foot, and Mouth Disease Symptoms

prodrome- low grade fever, malaise, sore throat

oral lesions- vesicles/ulcers on tongue, buccal mucosa, soft palate

rash- lesions on palms and soles, sometimes buttocks and genitals

Hand, Foot, and Mouth Disease Diagnosis

clinical symptoms

lesions that are small, grayish vesicles, erythematous halos

Hand, Foot, and Mouth Disease Treatment

supportive care

topical or oral analgesics

no antivirals

Coxsackievirus prevention

hygiene

avoid sharing personal items

disinfect contaminated items

self-isolate

Herpesviridae replication

fusion with cell membrane

replicates in nucleus

gains envelope by exiting nuclear membrane

released via exocytosis

Herpesviridae (non CMV) antivirals

-cyclovir

val-

Cyclovirs

activated by viral kinase and host kinase

blocks viral DNA polymerase

Val- Drugs

pro drugs

more bioavailable, less dosing

Roseola virus characteristics

HHV 6/7

infects DCs, T cells, monocytes, macrophages, NK cells

latent in lymphocytes and monocytes

first replicate in salivary gland

Roseola infantum

high fever, can cause febrile seizures

abrupt resolution

right after fever disappears

nagayama spots

Roseola infantum rash

light pink morbilliform

no vesicles

develops after fever disappears

Roseola transmission

human-only

respiratory secretions, aerosols, fomites

Nagayama spots

Roseola infantum

erythematous papules on mucosa of soft palate and uvula

Roseola prevention

standard hygiene

monitor immunosuppressed

Poxviridae replication

MCV glycoprotein specific to keratinocytes binds

fusion with host cell

replication in cytoplasm

enveloped from golgi and plasma membrane

released via exocytosis

Molluscum contagiosum virus transmission

human-only

physical or sexual contact

Molluscum contagiosum epidemiology

most common in immunocompetent school age children

Molluscum contagiosum symptoms

flesh colored lesions with central umbilication (cup shape)

not itchy or infammed

white core with ability to extract inside

infect keratinocytes

Molluscum contagiosum diagnosis

clinical symptoms

presence of henderson-patterson bodies

Henderson-Paterson bodies

Infected-cell inclusions seen in molluscum contagiosum lesions

large cells with granular eosinophilic cytoplasm containing virions

Molluscum contagiosum treatment

cryotherapy/cutterage

topical podophyllotoxin cream

cantharidin

Molluscum contagiosum prevention

avoid direct contact

disinfection

early identification

Parvoviridae replication

capsid protein binds to P antigen on RBCs

enters via endocytosis

replicates in nucleus

released via cell lysis

Parvovirus B19 characteristics

binds P antigen on erythroid progenitor cells

Parvovirus B19 transmission

human-only

vertical transmission from mother to fetus

respiratory droplets/aerosols

Parvovirus B19 infections

erythema infectiosum (slapped cheek, 5th disease)

aplastic crisis

arthritis

Erythema infectiosum (Fifth disease)

Parvovirus B19 infection

'slapped-cheek' facial rash

Aplastic crisis

Parvovirus B19 infection

especially in patients with chronic hemolytic anemia

Parvovirus B19 diagnosis

ultrasound, fetal monitoring

IgM for aplastic anemia

Parvovirus B19 treatment

intrauterine transfusion of RBCs to increase fetal survival

Parvovirus B19 prevention

hand hygiene

respiratory hygiene

avoid close contact during outbreaks

HSV Transmission

direct contact with open lesions

genital secretions or perinatal exposure

asymptomatic shedding

HSV (non STI) risk factors

skin to skin contact

low SES

weakened immune system

reactivation due to stress, UV, etc

neonates of infected mothers

Herpes Simplex Virus 1 (HSV-1) characteristics

latency in trigeminal ganglia

causes oral/gum lesions (cold sores) and gingivostomatitis

HSV 1 infections

herpes labialis

gingivomatitis

herpetic whitlow

Herpe labialis

cold sores; painful and grouped vesicular lesions

fever, malaise, lymphadenopathy

Gingivomatitis

primary infection

fever, painful sores in mouth/around mouth, difficulty eating/drinking

Herpetic whitlow

painful infection of finger/thumb

healthcare workers and kids at risk

HSV pathogenesis

blocks antigen presentation from cytotoxic T cells

inhibits interferon signaling

Herpes Simplex Virus 2 (HSV-2)

latency in lumbar and sacral ganglia

causes genital herpes

HSV diagnosis (clinical)

grouped vesicles on erythematous base that ulcerate

pain/tingling/burning before lesion

history

HSV diagnosis (lab)

Tzanck smear

presence of multinucleated giant cells

HSV treatment

-cyclovirs

HSV (non STI) prevention

avoid contact

suppressive antiviral therapy

perinatal counseling and treatment

Varicella Zoster Virus (VZV) transmission

human only

highly infectious lesions