Structure & Property

Transmission

Pathogenesis

Clinical findings

Laboratory diagnosis

Treatment

Family: adenovirus

Genome: double-stranded linear DNA.

Size: 60-70nm

Icosahedral nucleocapsid with cubic symmetry and projecting fibres.

Nonenveloped

41 serotypes: fiber protein is main type-specific antigen.

Aerosol droplet

Fecal-oral route

Direct inoculation of conjunctivas by tonometers or fingers.

Infect the mucosal epithelium of:

- respiratory tract (both upper and lower)

- gastrointestinal tract

- conjunctivas

Acute infection leads to death of cells.

Chronic latent infection in tonsils, adenoids and kidneys.

Can cause cancer in hamsters, but not in humans.

Immunity based on neutralizing antibody is type-specific and lifelong.

Most infections resolve spontaneously.

About half are asymptomatic.

Fecal adenoviruses: mesenteric adenitis and intussusception in children.

Main symptoms:

- pharyngitis

- conjunctivitis

Upper respiratory tract:

- pharynogconjunctival fever.

- acute respiratory disease

- fever

- sore throat

Lower respiratory tract:

- atypical pneumonia

- fever

- cough

Respiratory disease (types 3, 4, 7, 21)

Epidemic keratoconjunctivitis (types 8 & 19)

Haemorrhagic cystitis (types 11 & 21)

Infantile gastroenteritis (types 40 & 41)

AIDS patients and recipients of transplants are vulnerable to adenovirus infection.

Isolation:

- mouth washings

- faeces

- throat swabs

Tissue culture:

grows slowly in human embryonic cells/Hela cells with CPE of clusters of round, ‘ballooned’ cells.

Serology:

- complement fixation

- hemagglutination

- detection of antigens in stool by ELISA.

Diagnosis by:

- isolation of virus in cell culture

- detection of a 4-fold or greater rise in antibody titer.

EM used in detection of fecal adenoviruses

No antiviral therapy

Live, nonattenuated vaccines against serotypes 4, 7 and 21 used in military.

Epidemic keratoconjunctivitis is an iatrogenic disease, preventable by strict asepsis and hand washing by those who examine eyes.