Respiratory

Picorna

Rhinovirus

Characteristics

Acid labile

Gold flag = Distinguishing characteristic

Grows at 33 degrees C

Gold flag = Distinguishing characteristic

CPE similar to other Picornavirus

100+ serotypes

Related to Poliovirus, Enterovirus

Pathophysiology

Other factsIncubation period 2 to 3 days (up to 7 days)Viral replication peaks in respiratory tract at day 2 to 3 (may shed up to 1 month)

Specific IgA Ab (1 wk.)

Serum Ab (1 mo.)

Clinical

Young Infants

Febrile, UR

Children / Adults

Afebrile, UR

Sequelae

Exacerbation of asthma

Otitis media

Sinusitis

Diagnosis

Presumptive

Based onClinical presentationSeason

Defenitive

Tissue culture (impractical)

Serum Ab

Not helpful in acute disease

Epidemiology

Time

Spring to Early Fall

"Summer colds"

Place

Temperate climates

Person

Incidence highest in young children

Acute resp. illness

30-50%

Common Cold

Transmission

P2P

Person to person

Aerosolization

Prevention

No vaccine

Good hygiene

Resistant to common disinfectants

Think NAKED DNA

Treatment

Symptomatic (Decongestants)

No specific antiviral

Interferon effective

Enterovirus

Coronavirus

Characteristics

Peplomers

Distinct spikes

Solar corona appearance

3 Major Antigens

Nucleocapsid

2 Envelope proteins

Virulent strains

229E

OC43

Clinical

UR = Upper respiratory

Common cold

Pharyngitis

LR = Lower respiratory

Pneumonia in infants

Precipitate an acute asthma attack

Watery diarrhea

No blood

SARS

Headache

High fever

Body aches

Diarrhea

Epi

Asia

Droplet-nuclei

Diagnosis

Presumptive

Based on clinical syndrome

Less useful

Tissue culture

Difficult to isolate

Serologic assay

Not helpful in diagnosing acute infection

Epidemiology

Transmission

Aerosolization

Person to person

Time

Seasonality varies

Varies byLocationStrain

Distinct winter peak in U.S.

Prevention

Good hygiene

No vaccine

Treatment

Symptomatic

No specific antiviral

Interferon effective

Orthomyxo

Influenza

Characteristics

3 Major Antigen types

A, B, C

Pleomorphic

Segmented

allows for reassortment

Lipid-containing envelope

Protein-surface spikes

Hemagglutinin

H1, H2, H3

Neuraminidase

N1, N2

Shifts

Influenza A ONLY

Minor changes in H/N, same subtype

Drifts

Influenza A/B

Major changes in H/N --> changes subtype

Pathophysiology

Necrosis of nasal & tracheal ciliated epithelium

Decreased mucous production

Edema + mononuclear cells

Bacterial superinfection

Epidemiology

Time

Annual midwinter epidemics

Antigenic shifts

lead to...

Pandemic every 10 yrs.

Animal host potential reservoir

Influenza Type A, B, or C?

Influenza Type A

Clinical

Complications

Cardiac

Pericarditis

Myocarditis

Sudden Death

Acute myositis

Type A, B, or C?

Type B

Reyes syndrome

Bacterial superinfections

Respiratory tract

Pneumonia

Otitis media

Sinusitis

Neurologic

Encephalitis

Transverse myelitis

Guillain-Barre

Symptoms

HEENT

Headache

Sore throat

Nasal congestion

Eye irritation

Vomiting

Diarrhea

Other

Chills

Prostration (malaise)

Myalgia

Dizziness

Nonproductive cough

Findings

HEENT

Conjunctivitis (mild)

Rhinitis

Pharyngitis

Cervical adenopathy

Fever

Pulmonary

Rales

Rhonchi

Wheezing

Diagnosis

Presumptive

Based onClinical presentationSeason

Definitive

Inoculation of embryonated eggs

Tissue or cell culture (hemadsorption)

Immunofluorescent stain

ELISA or EIA (to detect Ag)

Serologic

Complement fixation

Hemagglutinin inhibition

Neutralization

Enzyme immunoassay

Prevention

Vaccine

Inactivated

Parenteral

Parenteral = non-intestinal

Intranasal

Bell's Palsy

Live attenuated

Intranasal

NO Bell's Palsy

Chemoprophylaxis

Amantidine

Ramantidine

Treatment

Influenza A ONLY

Prevents uncoating stepTargets M2 proteinMust be given w/in 48 hrs of symptoms

Amantadine

Ramantadine

Influenza A/B

Viral release stepNeuraminidase inhibitor (Sialic acid analog)

Zanamivir

Powdered inhaler

Oseltamivir

Oral agent (O for Oral)Influenza A (H1N2) --> much resistance"Tamiflu"

Avoid Aspirin!

Why?

Reye's Syndrome

Paramyxo

Parainfluenza

Characteristics

Four types

#1-4

Antigenically stable

No shifts or drifts

NONsegmented

Glycoprotein envelope

Neuraminidase

Hemagglutinin

Fusion protein

Clinical

Pharyngitis

Acute otitis media

Laryngotracheitis

Laryngotracheobronchitis (Croup)

Bronchiolitis

Pneumonia

Less severe infection

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

Type 2

Diagnosis

Presumptive

Based onClinical presentationSeason

Definitive

Tissue or cell culture

Rapid diagnostic test

IF = Immunofluorescence assay

EIA

EIA = Enzyme immunoassay

Serology

Epidemiology

Transmission

P2P

Fomites

Aerosolization

Direct contact w/ secretions

Time

Every other year

Type 1

Late Summer, Early fall

Type 1

Type 2

Spring / Early Summer

Type 3

Prevention

Wash Hands

Vaccine NCA

Vaccine is not commercially availableKilled vaccine ineffectiveLive attenuated vaccine ineffectiveSubunit vaccine promisingIntranasal vaccine promising

Treatment

Croup

Humidified air

Nebulized racemic epinephrine

Corticosteroids

Antibiotic

Only for bacterial superinfections

Antiviral?

Ribavirin effective in vitroHasn't been studied in clinical trials

RSV

Characteristics

NONsegmented DNA

Antigenic glycoprotein spikes

Attachment

G glycoprotein

Syncytium formation

Fusion (F) glycoprotein

Clinical

Neonates/Premies

Apnea

Irritable

Lethargic

Infants/Children

Pneumonia

UR symptoms

UR = Upper respiratory

Bronchiolitis

Older Children/Adults

Sore throat

Exacerbates asthma

Diagnosis

Specimen

Nasopharyngeal washing

This method is preferred.

Isolation in tissue culture

CPE is syncytium formation

Syncytium formation w/in 3-8 daysCPE = cytopathic effect

Rapid Diagnostic

DFA

Direct Immunofluorescence Assay

Immunoassay

ELISA

Enzyme-linked Immunosorbent Assay

EIA

Enzyme Immunoassay

Epidemiology

Transmission

Aerosol...

Contagious

Prevention

Active Immunity

Vaccine

Not commercially available

Passive Immunity

RSV hyperimmune Ig

RSV monoclonal Ab

Treatment

Ribavirin

For complicated infectionsAffects nucleic acid synthesis

Immunocompromised

Severely ill patient

Hypoxic

Hypercarbic

Mechanically ventilated

Human metapneumovirus

Similar to RSV

Differ by 2 structural proteins

Recent discovery

Others

Measles (Rubeola)

Mumps

Reo

Adeno

Characteristics

Large

Icosahedral

DS DNA

Serotypes

100 types

47 infect humans

Serotypes 40, 41

These two serotypes do not grow well in tissue culture.

Clinical

Respiratory

Intranuclear inclusion bodies

Acute GEitis

Mesenteric adenitis

Intussusception

Hepatitis

Hepatic necrosis

Hemorrhagic cystitis

Hemorrhagic nephritis

Orchitis

Inflammation of the testisRare

CNS

Meningoencephalitis

Cardiac

Myocarditis

Pericarditis

HEENT

Ocular disease

Disseminated

Congenital/Neonatal

Diagnosis

Tissue/cell culture

Serologic

ELISA

DNA hybridization

DFA

Epidemiology

Place

Global

Time

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

Transmission

P2P

Direct/Indirect contact with secretions

Fecal-oral route

Prevention

No vaccine

Infection control

Treatment

No specific antiviral

High dose Ig

For the immunocompromised

Herpes

HSV

Herpes Simplex Virus

EBV

Epstein-Barr Virus

HH6

Human Herpes 6