Structure & Property

Transmission

Pathogenesis

Clinical findings

Laboratory diagnosis

Treatment

Family: bunyavirus

Genome: single-strand circular, -ve polarity RNA, 3 segments

Size: 90-100nm

Helical nucleocapsid

Enveloped virion with surface projections, many with internal granules.

Known viruses:

- Hantaan

- Puumala

- Seoul

- Sin Nombre

Severe disease in China and Korea.

Each hantavirus is maintained in nature by infecting a single rodent species.

Infections in rodents asymptomatic and lifelong. Continual shedding in saliva, urine and feces.

Transmission to humans occur by inhalation of aerosols from infected rodent excreta.

Prototype virus is Hantaan virus, the cause of Korean hemorrhagic fever.

Characterized by headache, petechial hemorrhages, shock and renal failure.

Haemorrhagic fever with renal syndrome: a severe disease with fever, renal impairment, including proteinuria and oliguria, and haemorrhages, abdominal pain.

Divided into 5 phases:

- febrile: sudden onset with influenza-like syndromes, petechiae and conjunctival hemorrhage.

- hypotensive: occurs after 3-7days with tachycardia, vomiting, shock and further hemorrhagic signs.

- oliguric phase: hypotension and severe haemorrhage, abnormal renal function, most deaths in this phase.

- diuretic phase: electrolyte imbalance.

Nephropathia epidemica: a milder febrile illness with prominent signs of renal dysfunction & abdominal pain.

Hanta pulmonary syndrome:

- febrile illness with severe respiratory failure & cardiogenic shock.

- high case fatality rate of 50%

Diagnosis:

- detect viral RNA in lung tissue using PCR assay.

- immunohistochemistry on lung tissue.

- detect IgM antibody in serum.

No effective drug.

Ribavirin has been used but appears to be ineffective.