Filovirus - Laboratory diagnosis, Infection, Control

Laboratory diagnosis of Filovirus

The laboratory diagnosis of Filovirus begins with the collection of specimens.

Specimen

Specimen/samples for Filovirus diagnosis includes:

• blood

• body fluids (saliva, urine, genital swabs/secretion, semen, breast milk)

• autopsy/biopsy tissues

Virus isolation

• Filovirus can be isolated in cell cultures i.e. on Vero or Vero E6 cells

• they are considered Category A agents and require biosafety Level 4 for virus isolation

• lab animal models (primates)

Serodiagnosis

Numerous methods used for laboratory diagnosis of Filovirus include:

• Ab detection by ELISA on both acute (IgM) and convalescent (IgG) serum

  They are used to confirm the diagnosis

• IFAT- Indirect fluroscent Ab test

Ag detection

• Filovirus Ag detection by ELISA-based methods to confirm results from RT-PCR

• IFA – Immunofluorescence assay; classically used to detect Ag in formalin-fixed tissue samples

Molecular tests

• Molecular tests such as RT-PCR on blood samples- are most frequently used as it is sensitive, specific, and rapid

  Nucleic acids can be detected in blood as early as 3 days post-onset of symptoms

• Positive results should always be confirmed by an independent assay (eg ELISA)

Treatment of Filovirus

No treatment for Filovirus is available other than supportive care directed toward effective blood volume and electrolyte balance.

Control of Filovirus

The control of Filovirus can be done by:

• Isolation of potentially infected patients

• Disinfection => UV irradiation; heat (>60°C for 30 mins)