Rift Valley Fever

M. Kariuki Njenga, Janusz Paweska, Rose Wanjala, Carol Y. Rao, Matthew Weiner, Victor Omballa,Elizabeth T. Luman, David Mutonga, Shanaaz Sharif, Marcus Panning, Christian Drosten, Daniel R. Feikin,Robert F. Breiman. (2009). [https://jcm.asm.org/content/47/4/1166 Using a Field Quantitative Real-Time PCR Test To Rapidly Identify Highly Viremic Rift Valley Fever Cases]

• The researchers analyzed the effects of qRT-PCR to identify the RVF. They found that the use of qRT-PCR showed a 93.8% sensitivity and saw a correlation between the high viremia and fatality and that qRT-PCR was able to identify nearly all fatal cases. Early detection is essential for Rift Valley Fever because aggressive treatment is often needed and poor prognosis can lead to fatality. qRT-PCR was show in this study to be able to estimate levels of infections hemorrhagic fever virus. They performed a one-step qRT-PCR following a protocol by Drosten et al. and they provide the proper primers and ascension numbers to recreate this assay. The qRT-PCR did not discriminate between viral mRNA and genomic RNA. They also tested the same samples with an ELISA assay which is routinely used for RVF outbreaks and found that qRT-PCR was better at detecting RVF than ELISA.

Christophe N. Peyrefitte, Laetitia Boubis, Daniel Coudrier, Michèle Bouloy, Marc Grandadam, Hugues J. Tolou, Sébastien Plumet (2008). Real-Time Reverse-Transcription Loop-Mediated Isothermal Amplification for Rapid Detection of Rift Valley Fever Virus

• The researchers used RT-LAMP as a validation detection method to detect the L RNA segment of RVFV. This L RNA segment encodes the viral transcriptase. The assay is highly sensitive and comparable to RT-PCR. LAMP is much faster, generating results in less than 30 minutes for most dilute samples. The specificity of the primers were created by using other related arboviruses. Additionally, since this technique is used for field detection and contamination plays a role in the production of false positives, end-point reading options that do not require opening the tube like turbidity and fluorescence readings (over an agarose gel). This process of RT-LAMP was able to detect all the virus subtypes that were known at the time. Unfortunately this assay was done in 2008 and I could find no record of repetition.