Detection of Antibodies Directed Towards Yellow Fever Virus by PRNT<<Return to Laboratory
Serological detection of neutralizing antibodies directed towards yellow fever virus (YF) virus by Plaque Reduction Neutralization Test (PRNT).
- Yellow fever
Serum. Minimum volume of 250 µl required.
2 mL screw cap tubes.
Store samples refrigerated until shipped for testing. Ship samples on cold pack, or with wet or dry ice.
Shipping of specimens shall be done by a TDG certified individual in accordance with TDG regulations. For additional information regarding classification of specimens for the purposes of shipping, consult either Part 2 Appendix 3 of the TDG Regulations or section 3.6.2 of the IATA Dangerous Goods Regulations as applicable.
Suspected YF infection and relevant travel history OR confirmation of vaccination titre. Please indicate vaccination history on requisition.
Completed Viral Zoonoses requisition including sender laboratory name, address and telephone number. Patient name and / or identifier (specimen reference number), date of birth, test(s) requested, collection date of specimen, date of on-set of symptoms, and clinical and travel history of patient.
To demonstrate seroconversion, both acute and convalescent samples must be tested in parallel.
Antibodies directed towards members of the flavivirus genus (dengue, West Nile virus, etc.) can cross react significantly in some serological assays. The PRNT is a more specific assay and can be used to document the presence of serum antibodies specific for a particular flavivirus. Serum samples are incubated with virus, and if neutralizing antibodies are present, they will bind to the virus and prevent viral infection of cultured cells causing a reduction in the number of plaques detected. The neutralizing titre of a sample is expressed as the reciprocal of the serum dilution at which there is a 90% reduction in the number of plaques detected. If the patient has experienced more than one flavivirus infection, cross reactive results could in fact yield uninterpretable results with this assay despite increased specificity.
Due to the cross-reactive nature of anti-flavivirus antibodies, (i.e WNV, dengue, etc.) a 4-fold rise or greater in neutralizing antibody titre is required to document a "confirmed case" of infection with associated illness.
Isolation of an arbovirus, detection of specific antibody by plaque reduction neutralization assay or detection of nucleic acid by Real Time RT-PCR in a clinical specimen would constitute firm evidence of viral association with illness and provide "confirmed case" status.
14 calendar days.
- WHO. 2007. Guidelines for plaque reduction neutralization testing of human antibodies to dengue viruses