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Vivalytic MG, MH, UP/UU
– Instructions for Use
Analytical Performance Evaluation
Analytical Sensitivity (Limit of Detection)
The limit of detection (LoD) of the Vivalytic MG, MH, UP/UU test was deter-
mined as the concentration at which 95 % of the testings are expected to
yield a positive result using a Probit approach.
The LoD for each target pathogen was assessed by analyzing serial dilutions
of samples prepared from Amplirun® Total Controls (Vircell) with either
swab or urine background matrix. Each dilution was tested in 20 replicates
with two independent production LOTs of Vivalytic cartridges distributed on
three days. Table 1 shows the LoD for each target.
Inclusivity
The amplicon sequences corresponding to M . genitalium, M. hominis, U.
urealyticum, and U. parvum were analyzed in-silico (BLAST alignment) for
sequence inclusivity.
Inclusivity analysis using MegaBLAST identified 338, 34, 3, and 10 sequenc-
es for M. genitalium, M. hominis, U. urealyticum, and respectively, harboring
100 % amplicon coverage with > 96 % sequence identity for all targets
evaluated (Table 2).
Exclusivity / Analytical Specificity
To exclude cross-reactivity (exclusivity), specificity of primers and probes
was ensured by performing an in silico analysis for possible cross-reactions
(BLAST alignment). In addition, the corresponding target region of M. genita
lium, M. hominis, U. parvum, and U. urealyticum was analyzed in silico against
the genomic sequence of various other pathogens. No cross-reactivity for the
pathogens listed in Table 3 could be predicted.
Precision
Repeatability and reproducibility testing of the Vivalytic MG, MH, UP/UU test
was performed at 3 test sites. For each site, 3 different concentrations of
each target pathogen were tested by the same operator in 2 replicates on 2
days, with the same set of Vivalytic one analysers with 3 LOTs resulting in 324
observations per target pathogen. The summarized results are highlighted
in Table 4.
Interferences
Interferences were evaluated for endogenous and exogenous substances
that are potentially present in the patient sample. Refer to Table 5 for sub-
stances that have the potential to interfere with the test.
Clinical Performance Evaluation
Diagnostic Sensitivity and Specificity
The clinical performance of the Vivalytic MG, MH, UP/UU test was assessed
in a retrospective clinical study with urine and vaginal, cervical, urethral, and
rectal specimens whereas swab samples were collected in eNAT® medium
(COPAN Italia s.p.a.) and urine samples were diluted in eNAT® medium
(COPAN Italia s.p.a.), respectively.
All clinical samples were tested using the Allplex™ STI Essential Assay
(Seegene) as the reference method. Sensitivity or Positive Percent Agreement
(PPA) was calculated as 100 % x TP/ (TP+FN). Specificity or Negative Percent
Agreement was calcuated as 100 % x TN / (TN+FP). The results of the clinical
performance evaluation are shown in Table 6.
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