VHF Specimen Collection

Scope of guidance

This guidance applies to viral hemorrhagic fevers (VHFs) caused by infections with:

• Filoviruses (ebolaviruses and marburgviruses),
• Arenaviruses [Lassa, Lujo, and South American hemorrhagic fever viruses (Guanarito virus, Sabia virus, Junin virus, Chapare virus, Machupo virus)],
• Rift Valley fever virus, and
• Crimean Congo hemorrhagic fever virus.

This guidance also applies to other high-consequence diseases that require a specialized laboratory, are highly pathogenic, and have no vaccine or treatment currently available, like Nipah virus disease.

Before collecting specimens

Before collecting specimens for VHF or high-consequence disease testing, healthcare providers must complete a thorough screening and notify their health department [24-hour Epi On Call contact list]. CDC consultation will be coordinated through your health department to determine that the individual meets criteria for testing.

Public health authorities will determine where and if testing for a VHF or other high-consequence disease will occur.

Presumptive testing for certain diseases within these categories is available at select Laboratory Response Network reference laboratories throughout the United States.

Specimens to collect

For adults, collect two 4 mL tubes of whole blood in a plastic tube preserved with EDTA. For pediatric patients, collect a minimum of 1 mL whole blood in a pediatric-sized collection tube preserved with EDTA.

• Do not transport or ship specimens in glass containers or in heparinized tubes.
• Do not separate and remove serum or plasma from the primary collection container.

Safety considerations

PPE during specimen collection

Wear appropriate PPE when collecting clinical specimens from suspect or confirmed cases. Depending on the patient's stage of illness, refer to PPE guidelines below:

Transporting suspect VHF or other high-consequence specimens through healthcare facility

• Perform a site-specific risk assessment to determine the PPE to be worn during specimen transport within the facility. Required PPE may vary among facilities. Recommendations for PPE include disposable fluid-resistant closed lab coats, disposable gloves, covered legs and closed-toed shoes.
• In compliance with OSHA Bloodborne Pathogens Standard (29 CFR 1910.1030), package sealed specimen containers in a durable, leakproof secondary container.
• Before removing patient specimens from the site of care:
  • Plan the route from the patient area to the location where the specimens will be packaged for shipping to avoid high-traffic areas.
  • Decontaminate the outside of the specimen containers with an approved disinfectant, as described in Interim Guidance for Environmental Infection Control in Hospitals.
• For added safety/security, carry specimens in a durable, leakproof secondary container to the laboratory or packaging area by hand. DO NOT use pneumatic tube systems (automated or vacuum specimen delivery system) to transport specimens.
• Once the specimen has been removed from the transport secondary container, disinfect the container.
• Immediately report potential exposures to blood, body fluids, or other infectious materials according to your institution's policies and procedures.

Virus inactivation

VHFs and many other high consequence infectious diseases result from infection by an enveloped virus ­­– the easiest type of virus to inactivate — and are readily inactivated by standard chemical decontamination procedures used in laboratories and hospitals. When disinfectants damage their lipid envelope and/or denature proteins, the virus is no longer infectious. EPA's Disinfectants for Emerging Viral Pathogens List Q contains products with disinfection claims against specific pathogens. EPA's List L contains additional disinfectants qualified for use against Ebola virus. It is widely accepted that disinfectants that can inactivate Ebola should also inactivate other VHFs or other HCIDs. Check product registration against the pathogen.

Storage

If short-term storage is necessary, keep specimens at 2-8°C for shipping to the LRN laboratory. Specimens must be tested at CDC within 7 days of the date of specimen collection and may be temporarily stored prior to shipment to CDC.

Specimens sent to CDC for testing must be sent on dry ice and arrive at <-20°C.

Next steps

If the specimen test result is negative and the patient's symptoms have been present for less than 72 hours, a second sample should be collected 72 hours after symptom onset and in consultation with public health officials.

Any presumptive positive test result for a VHF or other high-consequence diseases must be confirmed by CDC to inform public health decisions.