ABSTRACT
Exhaled air of individual cattle infected experimentally with foot-and-mouth disease virus (FMDV) was sampled to assess the feasibility of a rapid, non-invasive general screening approach for identifying sources of FMDV infection. The air sampler used was a handheld prototype device employing electrostatic particle capture in a microchip chamber of 10-15 µL and was shown to effectively capture a high percentage of airborne microorganisms. The particles were eluted subsequently from the chip chamber and subjected to real-time RT-PCR. Sampling exhaled air for as little as 1 min allowed the detection of FMDV in cattle infected experimentally. Detection in exhaled air from individual cattle was compared to FMDV detection in serum and saliva for 3 different strains of FMDV (O1/Manisa/69, C/Oberbayern/FRG/1960 and SAT1/Zimbawe/1989). Detection of FMDV in exhaled air was possible for all strains of FMDV used for experimental infection but the period that detection was possible varied among the strains. Detection in exhaled air generally peaked on day 2-4 post infection. The perspectives of monitoring for FMDV in the breath of infected cattle are discussed in the context of real-time epidemiological contingencies.
Subject(s)
Breath Tests/instrumentation , Cattle Diseases/diagnosis , Foot-and-Mouth Disease Virus/isolation & purification , Foot-and-Mouth Disease/diagnosis , Aerosols , Animals , Cattle , Cattle Diseases/transmission , Cattle Diseases/virology , Cell Line , Cricetinae , Foot-and-Mouth Disease/transmission , Foot-and-Mouth Disease/virology , Foot-and-Mouth Disease Virus/genetics , Genome, Viral/genetics , Reproducibility of ResultsABSTRACT
BACKGROUND: Current detection and genotyping methods of genogroup (G) I and II noroviruses (NoVs) consist of a 2-step approach including detection of viral RNA by TaqMan realtime RT-PCR (RT-qPCR) followed by conventional RT-PCR and sequencing of partial regions of ORF1 or ORF2. OBJECTIVE: To develop novel long-template one-step TaqMan assays (L-RT-qPCR) for the rapid detection and direct genotyping of GI and GII NoVs and to evaluate the sensitivity and specificity of the assays. STUDY DESIGN: GI and GII-specific broadly reactive L-RT-qPCR assays were developed by combining existing NoV primers and probes targeting the open reading frame (ORF)1-ORF2 junction as well as region C at the 5'-ORF2. The assays were validated using GI and GII RNA transcripts and a coded panel of 75 stool samples containing NoV strains representing 9 GI genotypes and 12 GII genotypes, as well as sapoviruses, astroviruses, polioviruses, and rotaviruses. L-RT-qPCR products were typed by sequencing. RESULTS: The novel GI and GII L-RT-qPCR assays detected and typed all but one of the NoV positive panel samples. As few as 5-500 RNA copies could be accurately typed by sequencing of amplicons. CONCLUSIONS: We developed novel one-step TaqMan RT-qPCR assays for the sensitive detection and direct genotyping of GI and GII NoVs from clinical and environmental matrices.
Subject(s)
Caliciviridae Infections/diagnosis , Caliciviridae Infections/virology , Clinical Laboratory Techniques/methods , Norovirus/classification , Norovirus/isolation & purification , Reverse Transcriptase Polymerase Chain Reaction/methods , Virology/methods , DNA Primers/genetics , Humans , Norovirus/genetics , Open Reading Frames , Sensitivity and SpecificityABSTRACT
We describe the first case of rabies diagnosed in a cat in Greenland. The cat showed aggressive behaviour one month after the visit of a rabid fox on the premises. Rabies is enzootic in Greenland, the arctic fox being the natural host of rabies virus. Cats are imported in increasing numbers to Greenland and the reported case stresses the need for concern in relation to a hitherto unrecognised risk of exposure to rabies virus and stresses the need to comply with the obligatory anti-rabies vaccination regimes for cats in Greenland.
