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BV can be diagnosed
using a new and rapid analytical method based on ion mobility
spectrometry.
New technology for diagnosis of
bacterial vaginosis.
Chaim W, Karpas Z, Lorber A.
European
Journal of Obstetrics & Gynecology and Reproductive Biology
2003;111:83-87.
Summary:
Question
How well do high levels of biogenic amines in vaginal discharge, as
measured by ion mobility spectrometry (IMS), predict the presence of
bacterial vaginosis (BV)?
Design
The results of IMS, which was used to detect levels of trimethylamine (TMA),
putrescine, and cadaverine in vaginal fluid, were compared with those of
the conventional Amsel test for the diagnosis of BV.
Participants
One hundred seventy-four women referred to a vaginitis clinic and
presenting with symptoms such as long lasting discharge, itching, burning,
odor, and others, were tested.
Description of Tests and Diagnostic
Standard
Vaginal discharge samples were obtained from the posterior fornix using
cotton-tipped swabs after introduction of a speculum. One swab was placed
in a vial and used for the measurement of the biogenic amine content by
ion mobility spectrometry. The swab was washed with 6 drops of water and
KOH was added to enhance volatilization of the TMA and other amines. A
stream of air, to which the gas nonylamine was added, carried the vapors
into the ionization region of the IMS, where ions were formed by
collisions with nonylamine ions. The ions drifted under the influence of
an electric field until they reached the collector plate, where the ion
current increased when ions of a given type hit the plate. The mobility
spectrum is a plot of the ion current as a function of time. Ion identity
is derived from the drift time, and the peak area is proportional to the
concentration of the compound in the sample. A specimen was considered
BV-positive by the IMS test when its mobility spectrum indicated an
elevated level of TMA. Diagnosis of BV was based on the presence of three
out of four Amsel criteria following standard procedure for clinical
diagnosis.
Main Outcome Measures
The results of the IMS test were compared with the results of the clinical
examination.
Main Results
Twenty-two (12.6%) of 174 women were diagnosed by the Amsel test as
BV-positive. The results of the IMS test compared to diagnosis of BV by
Amsel criteria are shown in the table. The TMA peak was reduced to
background level in a follow-up specimen taken nine weeks after the
administration of treatment from a BV-positive woman, who initially had a
strong TMA peak.
Authors' Conclusions
IMS is an easily standardized, objective
method for the diagnosis of BV that can be performed with minimum training
and produce results in less than two minutes. An important advantage is
that low levels of TMA, which is an end product of anaerobic bacterial
metabolism, have been found to indicate either a recent history of or the
early development of BV.
Source of
funding: Q-Scent Ltd., Rotem
Industrial Park, Arava, Israel
For correspondence: Walter Chaim,
Department of Obstetrics and Gynecology, Faculty of Health Sciences,
Soroka University Medical Center, Ben Gurion University of the Negev, P.O.
Box 151, Beer Sheba 84101, Israel. E-mail address: walter@bgumail.bgu.ac.il.
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