B3: Respiratory Viruses

Respiratory

Herpes

HH6

Human Herpes 6

EBV

Epstein-Barr Virus

HSV

Herpes Simplex Virus

Adeno

High dose Ig

For the immunocompromised

Infection control

Fecal-oral route

Direct/Indirect contact with secretions

Year-round (Symbol = "around the clock")

Global

DNA hybridization

EM

Tissue/cell culture

Congenital/Neonatal

Disseminated

Ocular disease

CNS

Meningoencephalitis

GU

Orchitis

Hemorrhagic nephritis

Hemorrhagic cystitis

Hepatic necrosis

Hepatitis

Intussusception

Mesenteric adenitis

Acute GEitis

Intranuclear inclusion bodies

Serotypes

Serotypes 40, 41

These two serotypes do not grow well in tissue culture.

47 infect humans

100 types

DS DNA

Icosahedral

Large

Reo

Paramyxo

Others

Mumps

Measles (Rubeola)

Human metapneumovirus

Recent discovery

Similar to RSV

Differ by 2 structural proteins

RSV

Ribavirin

Severely ill patient

Mechanically ventilated

Hypercarbic

Hypoxic

Immunocompromised

Passive Immunity

RSV monoclonal Ab

RSV hyperimmune Ig

Active Immunity

Not commercially available

Contagious

Aerosol...

Rapid Diagnostic

Immunoassay

Enzyme Immunoassay

ELISA

Enzyme-linked Immunosorbent Assay

DFA

Direct Immunofluorescence Assay

Isolation in tissue culture

CPE is syncytium formation

Specimen

Nasopharyngeal washing

This method is preferred.

Older Children/Adults

Exacerbates asthma

Infants/Children

UR symptoms

Neonates/Premies

Lethargic

Irritable

Apnea

Antigenic glycoprotein spikes

Syncytium formation

Fusion (F) glycoprotein

Attachment

G glycoprotein

NONsegmented DNA

Parainfluenza

Antiviral?

Antibiotic

Only for bacterial superinfections

Croup

Corticosteroids

Nebulized racemic epinephrine

Humidified air

Vaccine NCA

Vaccine is not commercially available

Wash Hands

Spring / Early Summer

Type 3

Late Summer, Early fall

Every other year

Type 1

Direct contact w/ secretions

Fomites

Serology

Rapid diagnostic test

EIA

EIA = Enzyme immunoassay

IF

IF = Immunofluorescence assay

Tissue or cell culture

Less severe infection

Which type? 1, 2, 3, or 4?

Type 2

Bronchiolitis

Laryngotracheobronchitis (Croup)

Laryngotracheitis

Acute otitis media

Glycoprotein envelope

Fusion protein

NONsegmented

Antigenically stable

No shifts or drifts

Four types

#1-4

Orthomyxo

Influenza

Avoid Aspirin!

Why?

Reye's Syndrome

Oseltamivir

Zanamivir

Powdered inhaler

Ramantadine

Amantadine

Chemoprophylaxis

Ramantidine

Amantidine

Vaccine

Live attenuated

NO Bell's Palsy

Inactivated

Intranasal

Bell's Palsy

Parenteral

Parenteral = non-intestinal

Definitive

Serologic

Enzyme immunoassay

Neutralization

Hemagglutinin inhibition

Complement fixation

ELISA or EIA (to detect Ag)

Immunofluorescent stain

Tissue or cell culture (hemadsorption)

Inoculation of embryonated eggs

Findings

Pulmonary

Wheezing

Rhonchi

Rales

Fever

Cervical adenopathy

Rhinitis

Conjunctivitis (mild)

Symptoms

Other

Nonproductive cough

Dizziness

Myalgia

Prostration (malaise)

Chills

Vomiting

HEENT

Eye irritation

Nasal congestion

Sore throat

Complications

Neurologic

Guillain-Barre

Transverse myelitis

Encephalitis

Bacterial superinfections

Pneumonia

Respiratory tract

Reyes syndrome

Acute myositis

Type A, B, or C?

Type B

Cardiac

Sudden Death

Myocarditis

Pericarditis

Animal host potential reservoir

Influenza Type A, B, or C?

Influenza Type A

Antigenic shifts

lead to...

Pandemic every 10 yrs.

Annual midwinter epidemics

Bacterial superinfection

Edema + mononuclear cells

Decreased mucous production

Necrosis of nasal & tracheal ciliated epithelium

Protein-surface spikes

Drifts

Major changes in H/N --> changes subtype

Influenza A/B

Shifts

Minor changes in H/N, same subtype

Influenza A ONLY

Neuraminidase

N1, N2

Hemagglutinin

H1, H2, H3

Lipid-containing envelope

Segmented

allows for reassortment

Pleomorphic

3 Major Antigen types

A, B, C

Coronavirus

Symptomatic

Distinct winter peak in U.S.

Seasonality varies

Varies by

Less useful

Serologic assay

Not helpful in diagnosing acute infection

Tissue culture

Difficult to isolate

Based on clinical syndrome

SARS

Epi

Droplet-nuclei

Asia

Diarrhea

Body aches

High fever

Headache

GI

Watery diarrhea

No blood

LR

LR = Lower respiratory

Precipitate an acute asthma attack

Pneumonia in infants

UR

UR = Upper respiratory

Pharyngitis

Common cold

Virulent strains

OC43

229E

3 Major Antigens

2 Envelope proteins

Nucleocapsid

Peplomers

Solar corona appearance

Distinct spikes

Picorna

Enterovirus

Rhinovirus

Treatment

Interferon effective

No specific antiviral

Symptomatic (Decongestants)

Prevention

Resistant to common disinfectants

Think NAKED DNA

Good hygiene

No vaccine

Epidemiology

Transmission

Aerosolization

P2P

Person to person

Acute resp. illness

Common Cold

30-50%

Person

Incidence highest in young children

Place

Temperate climates

Time

Spring to Early Fall

"Summer colds"

Diagnosis

Defenitive

Serum Ab

Not helpful in acute disease

Tissue culture (impractical)

Presumptive

Based on

Clinical

Sequelae

Sinusitis

Otitis media

Exacerbation of asthma

Children / Adults

Afebrile, UR

Young Infants

Febrile, UR

Characteristics

Pathophysiology

Other facts

Serum Ab (1 mo.)

Specific IgA Ab (1 wk.)

Related to Poliovirus, Enterovirus

100+ serotypes

CPE similar to other Picornavirus

Grows at 33 degrees C

Acid labile

Gold flag = Distinguishing characteristic