What Is the Meaning of a Positive Rabies RT-PCR?
The RT-PCR positive test results from the saliva specimens of both patients confirmed the clinical diagnosis of rabies. Other than brain and skin biopsies, saliva has the highest rate of positivity, of approximately 75% [10,16]. Saliva can reach a 100% sensitivity when three successive samples are tested [10,16]. A recent study showed that RT-PCR on skin biopsies reached more than 98% sensitivity and 100% specificity, which correlates well with the gold standard of the immunofluorescence test on brain biopsies [10]. The diagnostic value of urine is limited, as less than 10% of rabies patients have a RT-PCR positive urine at admission [10]. The sensitivity of buccal swabs is lower than that of saliva [10]. A false-positive result may occur because of poor laboratory technique and contamination, and hence stringent operating procedures must be in place and appropriate controls should be included at every stage from extraction of the nucleic acid through to the amplification stages. Neith
