Maryland Department of Health (MDH) Laboratories Administration Guidelines and Instructions for Lassa virus testing
General: CDC Lassa virus case definition:
Lassa virus, a member of the Arenaviridae family, can cause viral hemorrhagic fever (VHF). The virus is endemic to West Africa. It is usually transmitted by the Mastomys natalensis (multi-mammate rat). The virus is spread by contact with excretions or materials contaminated with the excretions of an infected rodent or inhalation of contaminated dust and bite wounds. Infection can also occur after exposure to virus in the blood, tissue, secretions and excretions of a Lassa virus infected individuals. Symptoms of a Lassa infection usually start within 1-3 weeks after contact with the virus. Because of the non-specific clinical features, early diagnosis is difficult. Most Lassa virus infections are mild and go undiagnosed. However, approximately 20% of infected individuals develop serious symptoms that include a high fever, hemorrhaging, facial swelling, retrosternal chest pain, and neurological complications such as tremors and encephalitis. The most common complication of Lassa fever is hearing loss. Because the symptoms of Lassa fever are so varied and nonspecific, clinical diagnosis is often difficult. Lassa fever is also associated with occasional epidemics, during which the case-fatality rate can reach 50% in hospitalized patients.
For more information: https://www.cdc.gov/vhf/abroad/assessing-vhf-returning-traveler.html
What testing can MDH Laboratories Administration Perform:
The Maryland MDH Laboratories Administration does not perform any testing for Lassa virus. Specimens are shipped to the CDC Viral Special Pathogens Branch (VSPB) for PCR and/or serological testing .
The following forms must also be completed:
CDC 50.34 Form
https://www.cdc.gov/laboratory/specimen-submission/form.html
VSPB Supplemental Form
https://www.cdc.gov/ncezid/dhcpp/vspb/pdf/specimen-submission-508.pdf
MDH 4677 Serological Testing Fillable Lab Requisition: The MDH Laboratories Administration Form # 4677 Serological Testing must be completed and submitted with each specimen. Click on the links below for an example of the completed form #4677 and the electronic fillable form.
https://health.maryland.gov/laboratories/docs/MDH%204677%20Serological%20Testing%20Form%20and%20Instructions%202-2018.pdf
Lab Requisition Completed Form #4677
When can the MDH Laboratories Administration Conduct Testing for Lassa virus:
Lassa virus testing can only be conducted with prior authorization from MDH physician–epidemiologists. Contact the MDH Infectious Disease Bureau at 410-767-6700 during business hours and after hours call the Epidemiologist on-call (443-827-2682) or the MDH Physician- on- call (443-717-4778) for the initial infectious disease consultation.
Do not collect and submit specimens for Lassa virus testing until an infectious disease consultation with the MDH physician-epidemiologist has been conducted and approval has been obtained to provide testing for the case.
What steps to take if you suspect a Lassa virus case:
To request Lassa virus testing for a suspect case, contact the MDH Infectious Disease Bureau at
410-767-6700 during business hours and after hours call the Epidemiologist on-call (443-827-2682) or the MDH Physician- on- call (443-717-4778) for the initial infectious disease consultation.
After the consultation if Lassa virus testing has been authorized, if needed the MDH Laboratory will contact your institution’s laboratory to make any additional logistical arrangements for expedited testing.
Specimen Collection and Handling:
Test category |
Suitable/Specimen type |
Volume/Collection |
Lassa Fever Serology (ELISA) |
Blood and Serum |
Serum (red top or serum separator tube)
Whole blood (purple, green, or blue top tube)
Minimum of 4 mL |
Lassa Fever Identification (Molecular typing, PCR) |
Frozen tissue, blood, serum |
Whole blood (purple, yellow, or blue top tube)
Serum (red top or serum separator tube)
Minimum of 4 mL
Fresh frozen tissue at least 1 cm3 |
Notes:
- Transport samples to the laboratory on wet ice or cold packs. If an unavoidable delay of several days is anticipated, the specimen should be kept frozen and then packed in an insulated container with dry ice and proper cushioning material for shipment
Packaging and Shipping:
Specimens must be packaged in a triple packaging system to ensure that under normal conditions of transport they cannot break, be punctured or leak their contents (Refer to page 10 in the Lab Services Guide),
Guide to Public Health Laboratory Services
https://www.cdc.gov/labtraining/training-courses/packing-shipping-division-6.2-materials.html
Label container as follows:
“MEDICAL EMERGENCY, BIOLOGICAL HAZARD, REFRIGERATE ON ARRIVAL”
Attention: OLEPR