Rift Valley fever NOTE: THIS TEST IS NOT PERFORMED ON SAMPLES TAKEN FROM ANIMALS OWNED OR LOCATED IN THE STATE OF CALIFORNIA.

Test code: S0193 - Ultrasensitive detection of Rift Valley fever virus by reverse transcription coupled real time PCR

Rift Valley fever virus (RVFV) belongs to the genus Phlebovirus in the family bunyaviridae. Viruses in this family are enveloped negative single-stranded RNA viruses. All bunyaviruses have an outer lipid envelope with two glycoproteins - G(N) and G(C) - necessary for cell entry.

The virus mainly affects domesticated animals such as cattle, buffalo, sheep, goats, and camels. However, the virus also can infect and cause illness in humans. The virus is transmitted through mosquitoes, as well as through direct contact with the tissue of infected animals. Two mosquito species - Culex tritaeniorhynchus and Aedes vexans - are known to transmit the virus, but there are also other potential vectors, such as Aedes caspius.

Human infections are mainly through direct contact with tissues of infected animals. The virus has also been isolated from two bat species: the Peter's epauletted fruit bat (Micropteropus pusillus) and the aba roundleaf bat (Hipposideros abae), which are believed to be reservoirs for the virus.

The virus is generally found in regions of eastern and southern Africa where sheep and cattle are raised, but the virus exists in most of sub-Saharan Africa, including West Africa and Madagascar. Epizootic outbreaks of the disease increase the likelihood of contact between diseased animals and humans, which could lead to human mortality. Infected humans can develop hemorrhagic fever, ocular disease and/or encephalitis. However, some infected humans may only show minor symptoms.

The disease has traditionally been diagnosed through clinical observation, virus isolation or ELISA, but none of these methods is very sensitive. Molecular detection by PCR is a highly sensitive, specific and rapid alternative to the traditional methods.

Utilities:

• Help confirm the disease causing agent
• Identify Rift Valley fever virus carriers
• Help ensure that herds and animal populations are free of Rift Valley fever
• Early prevention of spread of the virus among animals
• Minimize human exposure to the virus
• Safety monitoring of biological products that derive from animals

References:
Mwaengo, D., Lorenzo, G., Iglesias, J., Warigia, M., Sang, R., Bishop, R.P. and Brun, A. (2012) Detection and identification of Rift Valley fever virus in mosquito vectors by quantitative real-time PCR. Virus Res. 169:137-143.

Specimen requirements: 0.2 ml whole blood in EDTA (purple top) tube, or 0.2 ml fresh or frozen tissue.

Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.

For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information.

Turnaround time: 2 business days

Methodology: Qualitative reverse transcription coupled real time PCR

Normal range: Nondetected