Ln. Sellner et al., DETECTION OF ROSS-RIVER-VIRUS IN CLINICAL-SAMPLES USING A NESTED REVERSE TRANSCRIPTION-POLYMERASE CHAIN-REACTION, Clinical and diagnostic virology, 4(3), 1995, pp. 257-267
Background: Ross River virus (RRV) is a mosquito borne alphavirus that
has been found in Australia, Papua New Guinea and the Pacific Islands
. It is the aetiological agent of epidemic polyarthritis, a debilitati
ng illness whose symptoms are arthritis, arthralgia, lethargy, rash an
d fever which may persist for weeks or months. Diagnosis is made on a
serological basis, but in many cases is presumptive rather than defini
te. Objectives: To apply the polymerase chain reaction (PCR) to detect
ion of RRV in human sera to assess its suitability for application in
disease diagnosis. Study design: Sensitivity of the nested RT-PCR assa
y was determined by detection of virus of known titre diluted in uninf
ected serum. Clinical serum samples from patients serologically diagno
sed of having RRV infection were tested by nested RT-PCR to assess its
diagnostic value. Results: Sensitivity of the nested RT-PCR assay was
determined to be detection of 0.01 PFU of virus stock in 100 mu l ser
um. Clinical samples tested showed that 10 of 26 (38%) serum samples w
ith low or negative (non-diagnostic) virus-specific antibody titres we
re PCR-positive, whereas all 22 specimens with high antibody titres we
re PCR-negative. PCR positivity was unaffected by repeated freezing an
d thawing of samples. Conclusions: While PCR cannot replace serology a
s a means of RRV diagnosis, it may be useful in conjunction with serol
ogical testing, particularly for forming definitive diagnoses in those
samples with low (inconclusive) antibody titres. It is faster and mor
e sensitive than virus isolation by tissue culture, and could also pro
ve useful in investigations of disease pathogenesis.