Pre-Approval
| None
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| Supplemental Information Requested | Requested: Travel history, illness onset date |
Submittal Formāā
| Specimens must be accompanied with a hard copy of the completed VRDL General Purpose Specimen Submittal Formāā (PDF) or a form generated in the VRDL Lab Web Portal. |
| Methodology (Commercial Test Name or Laboratory Developed Test (LDT)) | IFA: IgG and IgM for serum or plasma (LDT) (Diagnostic)
EIA: IgG and IgM for serum (LDT) (Diagnostic)
EIA: IgG and IgM for CSF (LDT) (Diagnostic) |
| Reflex Testing | In cases of suspected vaccine failure, measles IgG-positive specimens may be forwarded to the CDC for avidity testing |
| Acceptable Specimen Type(s) and Collection Method | Human specimens: - Serum: serum tubes (red top) or serum separator tubes (red/gray or gold top)
- Plasma : EDTA (lavender top) or heparin plasma separator tubes (green top)
- When collection of blood may be difficult (e.g., infants), blood may be collected in capillary tubes. Approximately 3 capillary tubes of blood should be collected. Capillary tubes should be capped and placed in a larger tube for protection during transport.
- CSF: sterile collection tubes
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Minimum Volume Requestedā
| - Serum: 1 mL
- Whole blood in serum separator tubes or EDTA tubes: 3-5 mL
- CSF: 1 mL
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| Transport Medium (if using) | Not Applicable |
| Specimen Labeling | Each specimen tube must be labeled with at least two unique patient identifiers, e.g., patient full name and date of birth.
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| Storage & Preservation of Specimen / Shipping Conditions | - Serum: freeze or refrigerate specimens after collection.
- Whole blood: refrigerate specimens promptly after collection. Do not freeze whole blood.
- CSF: freeze or refrigerate specimens promptly after collection.
Ship refrigerated specimens to VRDL on cold packs. Ship frozen specimens to VRDL on dry ice. |
| Shipping Instructions | Work with your local public health department to ensure samples are packaged according to instructions for Biological Substance ā Category B (UN 3373) shipment. Ship specimens and a hard copy of the completed submittal forms to:
āCDPH VRDL
ATTN: Specimen Receiving 850 Marina Bay Parkway Richmond, CA 94804 Phone: 510-307-8585
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| Turnaround Time | 5 Business Days |
| Limitations | - A negative result does not preclude the possibility of infection
- Blood collected within 3 days of rash onset may test falsely negative for measles IgM in persons with measles
- Persons previously vaccinated with a measles-containing vaccine may not mount a measurable measles IgM response
- Pregnancy may cause a falsely positive IgM result. Other diseases, such as parvovirus, infectious mononucleosis, or rheumatologic disease can cause false positive measles IgM results
- This is not a functional test to determine if a patientās serum will neutralize measles virus
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| Additional Information | The optimal test for cases of suspected measles is RT-PCR of throat swab or urine collected early in the course of disease.
Only patients suspected of measles will be tested for IgM reactivity. |
| VRDL Points of Contact | Medical and Epidemiology Liaisons: (510) 307-8585 or VRDL.submittal@cdph.ca.govāāā
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