Serum: freeze or refrigerate specimens promptly 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.
Work with your local public health department to ensure samples are packaged according to instructions for Biological Substance – Category B (UN 3373) shipment.
Ship specimens and a hard copy of the completed submittal forms to:
CDPH VRDL ATTN: Specimen Receiving 850 Marina Bay Parkway Richmond, CA 94804 Phone: 510-307-8585
ATTN: Specimen Receiving
850 Marina Bay Parkway
Richmond, CA 94804
Does not distinguish between dengue serotypes.
Flavivirus antibodies are often cross-reactive.
PRNT is performed with paired viruses that are closely related and geographically co-circulating. Results for both viruses are reported. Traditionally, where neutralizing antibodies are detected for both viruses, a four-fold difference in titer is presumed to indicate the identity of the exposure; however, due to the possibility of an anamnestic antibody response, single specimens are screened at low dilutions and identity is only reported when neutralization is detected for only one virus. Dual reactivity is reported as evidence of undifferentiated flavivirus exposure.
Laboratory results with clinical and environmental correlation must be used together with current case definitions to confirm or rule out cases.