FW: NATAP: Saliva-based hepatitis C test developed
- Saliva-based hepatitis C test developed
23 December 2005
Israeli scientists have developed a saliva-based test to detect the
hepatitis C virus, and say it could be appropriate for mass screening
programmes in developing countries.
Hepatitis C is common in the developing world, but the conventional method
of detecting the virus in a blood sample is often inaccessible to poorer
Current tests use a sample of the patient's serum, the liquid part of blood
in which blood cells are suspended, and detect antibodies that the body
produces in reaction to the virus.
But such tests are costly, complicated and rely on an array of medical
equipment and skilled personnel.
Now researchers led by Arieh Yaari of Soroka University Medical Center,
Israel, have shown that saliva can be used instead of serum to detect the
They carried out their study on 37 dialysis patients, people without kidney
function whose blood must be passed through a machine to filter out waste
Such patients have a high incidence of hepatitis C and may resemble ill
people in developing countries in their immune response levels.
Yaari and colleagues report 100 per cent success at detecting hepatitis C in
the saliva of patients who had symptoms of the disease. This is comparable
to the results of testing serum.
In patients who had the virus but had yet to develop symptoms, the saliva
test was accurate in 94 per cent of cases, while the conventional serum test
detected only 63 per cent of infections.
Yaari's team say that as it is cheap and easy to obtain saliva samples,
detecting hepatitis C infections using this technique might be economically
and clinically important in developing nations.
They add that as the research involved only 37 patients, a larger study is
needed to confirm the results. This could focus on a different high-risk
population, for example people in developing countries, say the researchers.
They published their findings online on Monday (19 December) in the Journal
of Virological Methods.
Hepatitis C (HCV) is common in developing countries, where blood sampling
and expensive sophisticated methods for detection are less available.
Hemodialysis patients have high prevalence of HCV and may resemble sick
populations in developing countries in relation to immunosuppression and
antibodies production. For these reasons anti-HCV antibodies were assayed in
saliva of hemodialysis patients by ImmunoComb II assay that is less
laborious, relatively inexpensive and easy to perform If the findings are
confirmed by larger studies this method may be useful especially in
Serum and saliva samples were obtained from 37 hemodialysis patients and
assayed by ImmunoComb II kit. In positive PCR patients the saliva test had
100% sensitivity, which was as good as serum anti-HCV Axsym testing. Saliva
testing had a similar or better specificity than the serum method.
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