Virology / Serology - Special Serology
Diagnostic and immune status serologic assays are performed for various bacterial, rickettsial and viral agents. Assay methods vary depending upon the specific test requested.
Specimen Acceptance Policy
Only serum and CSF may be submitted for serologic testing. Specimens submitted to the Virology/Serology Branch must be accompanied by a fully completed submission DHHS Form #3445. Failure to supply the requested patient information may result in significantly delayed specimen testing. Tests must be requested by name. Nonspecific requests for "viral studies" or "viral serologies" will not be accepted. Consult with the laboratory if there is a question as to which test is appropriate.
Screening for immunity to measles, mumps, rubella, and varicella zoster is not available on a routine basis. Exceptions to this policy apply to local health departments only and include the following:
- Immune status testing for rubella antibody is available for prenatal patients with no documentation of vaccination or previous immune status testing. Use DHHS Form #1188. To request a hard copy of this form Click Here.
- "Stat" varicella zoster virus (VZV) immune status testing is available for prenatal clients and pregnant health department employees who lack a clear history of varicella zoster infection and have been exposed to a known case of VZV.
Reminder: There is only a 96-hour window from the time of exposure for the administration of varicella zoster immunoglobulin (VZIG). In many cases, there may not be adequate time for testing. In cases in which testing is appropriate and results are urgently needed, the submitter must contact either the Virology/Serology Branch Head or the Serology supervisor at(919) 733-7544, so that testing can be scheduled for timely results. Use DHHS Form #3445. (Testing at the State Laboratory will not be possible during off hours, weekends and holidays). Note that the VZV index case is probably shedding the virus in respiratory secretions for two days (infrequently up to five days) prior to eruption of lesions. As a consequence, the 96 hour window from the time of exposure begins with the "true time" of initial exposure.
- Immune status testing for measles, mumps, rubella, or VZV is available for both clients and health department employees when vaccination is contradicted (e.g., pregnancy, immunosuppression or allergy to vaccine components). Reason for contraindication must be noted on the test request. Use DHHS Form #3445.
Specimens submitted for testing that are not labeled with correct patient identification information will not be tested. Patient identification includes full first and last name or a unique identifying number, if the patient must remain confidential. Specimens which, for any reason, are deemed unsuitable or inappropriate for serologic testing will not be tested. Rejected specimens will be properly stored for seven days pending verbal and/or written notification of the submitter. Unless alternate arrangements are initiated by the submitter upon notification of specimen rejection, the specimen will be discarded at the end of the holding period.
Specimen Collection
To collect serum, draw blood into a red top vacuum tube allowing the tube to fill completely. Let stand for 30 minutes to ensure complete clotting of the blood. Centrifuge for 5-10 minutes at 1000-1500 x g. Transfer the serum to a plastic screw capped vial. Hemolyzed, icteric, or lipemic serum may be unacceptable for certain serologic assays.
Clearly label each vial of serum with the patient's name (first and last) and the date collected. Complete a DHHS Form #3445 submission form specifying all required patient information and which infectious agents are suspected.
The serodiagnosis of a current or recent infection generally requires the simultaneous testing of paired serum samples, principally, acute and convalescent serum samples. The acute serum should be collected no later than 3-5 days after the onset of illness. The convalescent serum should be collected 2-4 weeks after onset. Where paired sera are advised or required, it is to the advantage of both the submitter and this laboratory if the acute serum is stored frozen by the submitter until the convalescent serum is collected. Both serum samples may be submitted with one submission form.
For certain agents such as measles and rubella, specific IgM assays on a single acute serum specimen may provide evidence of a recent infection. Additionally, single "high" antibody titers to viral, and rickettsial agents may be considered presumptive evidence of recent infection. Immune status determinations require a single serum sample only and should be clearly designated on the request form. Antibody determinations on cerebrospinal fluid may be of value in diagnosing viral encephalitis and other central nervous system diseases. Cerebrospinal fluids for serologies should always be accompanied by a serum collected the same day.
Specimen Shipping
Send the properly identified vials of patient sera and the completed DHHS Form #3445 in the "Special Serology" (blue colored) mailing containers via the State Courier or U.S. Mail to:
State Laboratory of Public Health
306 N. Wilmington St.
PO Box 28047
Raleigh North Carolina 27611-8047
Courier # 52-41-41
Specimens may be shipped refrigerated or at ambient temperature
Serum transport tubes, blue colored specimen mailers, DHHS Form #3445 for serology (except TRUST), and DHHS Form #1188 for rubella immune status are available from the Laboratory Mailroom, PO Box 28047, Raleigh, North Carolina 27611-8047, telephone: (919) 733-7656.
Specimen Reporting
Assay turn-around-time after receipt of the specimen(s), methodology used, serum requirements, and test interpretation vary considerably between tests. The following chart lists the special serologic assays performed by this Branch. A brief statement of the "normal" values for each assay is given under the heading "Negative Reference Range". The test method, specimen requirements and turn-around-times are also listed for each assay performed.
| Description Antibody Test | Test Method | Negative Reference Range | Specimen Requirements | Turn-Around-Time |
|---|---|---|---|---|
| Brucella abortus | Aggl-Quan | < 1:20 | 2 mL serum; PSA | 8 working days |
| California encephalitis virus (LAX) | IFA-Qual or HI-Quan | < 1:16 < 1:10 |
2 mL serum/ CSF; PSA | 8 working days |
| California encephalitis virus, IgM | IFA-Qual or HI-Quan | < 1:16 < 1:10 |
2 mL serum/ CSF; PSA | 8 working days |
| Coxiella burnetti (Q fever) | IFA-Quan | interpreted by report | 2 mL serum; PSA | 8 working days |
| Eastern equine encephalitis (EEE) | IFA-Qual or HI-Quan | < 1:16 < 1:10 |
2 mL serum/ CSF; PSA | 8 working days |
| Eastern equine encephalitis (EEE) IgM | IFA-Qual or HI-Quan | < 1:16 < 1:10 |
2 mL serum/ CSF; PSA | 8 working days |
| Ehrlichia chaffeensis | IFA-Quan | interpreted by report | 2 mL serum | 5 working days |
| Franciscella tularensis | Aggl-Quan | < 1:20 | 2 mL serum; PSA | 8 working days |
| Influenza | HI-Quan | < 1:10 | 2 mL serum; PSA | 8 working days |
| Measles, IgM | IFA-Qual | Interpreted by report | 2 mL serum | 2 working days |
| Measles, Immune Status | IFA-Qual | Interpreted by report | 2 mL serum | 5 working days |
| Mumps, Immune Status | IFA-Qual | Interpreted by report | 2 mL serum | 5 working days |
| Rickettsia rickettsii (RMSF) | IFA-Quan | Interpreted by report | 2 mL serum | 5 working days |
| Rickettsia typhi (Typhus) | IFA-Quan | Interpreted by report | 2 mL serum | 5 working days |
| Rubella, Immune Status | IFA-Qual | Interpreted by report | 2 mL serum | 2 working days |
| Rubella IgM | IFA-Qual | Interpreted by report | 2 mL serum | 2 working days |
| St. Louis encephalitis (SLE) | IFA-Qual or HI-Quan | < 1:16 < 1:10 |
2 mL serum/ CSF; PSA | 8 working days |
| St. Louis encephalitis (SLE), IgM | IFA-Qual or HI-Quan | < 1:16 < 1:10 |
2 mL serum/ CSF; PSA | 8 working days |
| Varicella zoster, Immune Status | IFA-Qual or LA-Qual | Interpreted by report | 2 mL serum | 5 working days |
| Western equine encephalitis (WEE) | IFA-Qual or HI-Quan | < 1:16 < 1:10 |
2 mL serum/ CSF; PSA | 8 working days |
| Western equine encephalitis (WEE), IgM | IFA-Qual or HI-Quan | < 1:16 < 1:10 |
2 mL serum/ CSF; PSA | 8 working days |
| West Nile Virus (WNV) | IFA-Qual or HI-Quan | < 1:16 < 1:10 |
2 mL serum/ CSF; PSA | 8 working days |
| West Nile Virus (WNV), IgM | IFA-Qual or HI-Quan | < 1:16 < 1:10 |
2 mL serum/ CSF; PSA | 8 working days |
| Ab - Antibody | IFA - Indirect Fluorescent Antibody |
| Aggl - Agglutination | IgM - Immunoglobulin M |
| CF - Complement Fixation | LA - Latex Agglutination |
| DFA - Direct Fluorescent Antibody | PSA - Paired Sera Advised |
| EIA - Enzyme Immunoassay | Quan - Quantitative |
| HI - Hemagglutination Inhibition | Qual - Qualitative |
See also:
- Virus Culture
- Rabies Virus
- Chlamydia/Gonorrhea
- HIV
- Hepatitis
- Syphilis
- Special Serology
- CDC Referral
- Arbovirus
