Submitting Specimens for Dengue Virus Tests

Instructions for submitting dengue specimens

Please read these instructions for sending specimens for dengue testing to CDC. Complete a CDC Specimen Submission Form (CDC 50.34). Public health laboratories should submit sample test data through CDC Test Order and Reporting (CSTOR) Web Portal. For additional information visit, Test Order, Dengue Virus Detection and Serology (CDC-10307).

NOTE: Testing will not be initiated without the inclusion of:

• Date of onset of signs or symptoms
• Date that sample was obtained
• Any pertinent travel history (recent travel to areas with risk of dengue)
• Patient's name, date of birth, age, and sex
• Home address
• Complete name and mailing address of the physician, laboratory, clinic, or hospital where results should be sent.

Samples with more than a month from date of sample collection to date of arrival at CDC will not be analyzed.

To enable printing of CDC 50.34 form, each of the following fields must be completed, as directed:

1. Specimen Origin field (located on page 1, top left corner), select "HUMAN" from the drop-down menu.
2. Test Order Name field (located on page 1, top left), select "Dengue Virus Detection and Serology" from the drop-down menu.
3. Original Submitter e-mail field (located on page 1, middle right box), insert your e-mail address.

Specimen types and amounts

• Ideal timing of specimens (see table below)
• Serum is preferred for dengue NAAT and serology. At least 0.5–1.0 mL of serum only is required for serological testing.
• For serology or nucleic acid testing, the specimen should be kept cold or frozen. The sample may be placed in an insulated container with blue ice packs. Additional blue ice packs should be used in the summer to ensure specimen integrity in hot weather.
• If interested in submitting formalin-fixed tissues for pathologic or molecular evaluation for possible infectious etiologies, please contact CDC's Infectious Diseases Branch, Atlanta, GA at pathology@cdc.gov.

In case of a dengue outbreak, CDC Dengue Branch will promptly analyze samples received with the minimum above-mentioned information. If number of specimens exceeds laboratory capacity, testing may be prioritized in the following order:

• Fatal cases
• Cases in intensive care
• Hospitalized cases (with thrombocytopenia, shock, or hemoconcentration)
• All other cases

Specimen submission guidelines

1. The state or local health department should be notified of suspected dengue cases. Once there is a clinical diagnosis of suspected dengue, collect a serum sample (see #4) and submit with CDC 50.34 form. The information received on each case (especially the date of onset of symptoms and date of sample collection) is crucial to test selection and interpretation of results. Furthermore, a complete address makes it possible to identify the area where control measures should be implemented. Samples without the above-mentioned information, or with more than one month from date of collection to date of arrival at CDC, will not be analyzed.
2. We recommend that you freeze serum immediately after separation and send in dry ice. The CDC 50.34 form and the acute blood sample should reach CDC's Dengue Branch as soon as possible.
3. To diagnose dengue, laboratories require that you collect a serum sample during the acute period of the disease (0–7 days of symptoms).
   1. Inform the patient about the importance of coming back for a second sample and schedule an appointment for a specific date and time. These steps will increase the probability of obtaining a second sample.
   2. If the patient makes the first visit to the physician on or after day 7 after onset of symptoms, that sample is sufficient.
4. Acute-phase samples (taken on or before day 7 after onset of symptoms) will be used mainly for molecular testing in order to detect viral RNA. Negative samples should be tested for dengue IgM antibodies. Convalescent-phase samples (collected on or after day 7 after onset of symptoms) will be used mainly for detection of IgM anti-dengue antibodies by MAC-ELISA. See table below.
   1. Differential diagnosis for dengue and Zika, chikungunya, and West Nile viruses is available; but these tests need to be requested according to clinical presentation.
   2. Whenever there is a hospitalized, severe case, please indicate it in CDC 50.34 form.
5. CDC will report results to the submitting state or jurisdictional lab. In cases with negative test results on the acute sample, we will instruct the submitter to collect and provide a convalescent-phase sample before concluding the overall diagnosis of the patient.
6. Results will be reported only to the laboratory that sent the sample.

Testing results

Given the current volume of samples, final test reports may not be available for at least 2 weeks after specimen receipt. Reporting times for test results may increase during periods of high dengue transmission.

All results will be sent to the appropriate state or local health department.

All specimens should be submitted to CDC through state or local health departments and not submitted directly to CDC.

Shipping information

For information about shipping packages and applicable regulations, refer to the CDC's Division of Scientific Resources' Specimen Management site for specific information.

Shipping address

Send all specimens to:

Dengue Branch, CDC
1324 Cañada Street
Puerto Nuevo
San Juan, Puerto Rico 00920-3860

Further assistance

Additional assistance may be obtained from the DVBD Dengue Diagnostic and Reference Laboratory.

• Call 787-692-4102, or
• Visit CDC's Test Directory, Dengue Virus Detection and Serology (CDC-10307).

Contact information

Dengue Branch, CDC
1324 Cañada Street
Puerto Nuevo
San Juan, Puerto Rico 00920-3860

Telephone: 787-692-4102
Fax: 787-706-2496