Epidemiology
Although
vaginitis
is common, affecting millions of women every year, little information
about the prevalence of mixed vaginitis is available. A literature
review to assess the occurrence and
frequency
of mixed vaginitis revealed that most investigators reported coinfection
rather than mixed vaginitis, and the proportion of mixed vaginitis
infections ranged from 6.30% to
35.06%(6, 7). As noted above, one challenge is that studies have failed
to correlate symptoms with microbe types.
Therefore, most reports do not
distinguish between mixed vaginitis and coinfection.
The
representative data are depicted in Table 1. The following
factors are
limitations
that prevent the obtention of a
clear picture of the actual
prevalence of mixed vaginitis.
1. The types of vaginitis
observed have not been concordant.
Evaluations have traditionally focused on VVC, BV, and TV. Most studies
have reported that VVC plus BV is the most prevalent form of
vaginitis(2). Another condition, AV, was recently characterized by
Donders in 2002(8). When AV is included, epidemiologic estimates shift
considerably. Some studies indicated AV plus BV, VVC plus AV, and VVC
plus BV were the most frequent coinfections(9). It is possible that some
clinicians are unaware of AV, thus sometimes misdiagnosing it as BV,
affecting the epidemiological data.
2. There is great variability in the rates of infection
in
different populations. One study
found a relatively low rate of mixed vaginitis (6.30%) in Brazil(6),
while another found a higher rate (35.06%) in Shanghai(7). Research is
required to demonstrate prevalence and outcomes in various populations,
such as pregnant women, hypoestrogenic women, asymptomatic women, and so
on.
3. The
diagnostic
criteria and tools to determine the prevalence of mixed vaginitis
differ. The classical standards for vaginal infection diagnosis are
physical examination, microscopy, and culture methods, which are usually
performed in hospitals. Recent research has shown that some new
molecular assays (Affirm VPIII, Aptima) for the diagnosis of mixed
vaginitis have performed well, identifying proportions ranging from 9.26
to 27.23%(10, 11). In addition, the skill level of technicians is also
an influencing factor(12).
4. The vaginal and cervical microbiome is an intricate
ecosystem containing various normal and dysbiotic microbes in different
ratios. At present, in the mixed vaginitis-related literature,
only
4 common types of vaginitis are included. If one includes the cervical,
but not strictly vaginal, pathogens such as HSV-2 virus, CT, NG,
mycoplasma, and HPV may be included, and higher frequencies of mixed
infections may be reported(13).
5. There is a lack of physician understanding and
implementation of current guidelines(12).
This
is likely due, in part, to the fact that the majority of these
infections are diagnosed empirically without objective data. Moreover,
mixed vaginitis symptoms can be nonspecific and vary by patient.
Empirical evidence in this population has likely led to many
misdiagnoses.