Sex Transm Infect: A modified rapid diagnostic test to detect syphilis and yaws

Background: Syphilis and yaws are human treponemopathy and remain important causes of
morbidity and mortality worldwide.
Syphilis is caused by the pallid subsp.
pallidum of Treponema pallidum and is transmitted mainly through skin-to-skin contact or mother-to-child transmission during pregnancy, causing congenital syphilis
.
Yaws is an endemic and neglected tropical disease caused by the subsp.
pertenue subsp.
treponemone, characterized by soft tissue and bone lesions
.
Both infections are curable and preventable
.
Current rapid tests for syphilis and yaws can detect treponemal and non-treponemal antibodies
.

Objective: To critically review the literature on rapid diagnostic tests (RDTs) that can better distinguish between active infections
of syphilis or yaws.

Methods: We conducted a systematic review and meta-analysis and searched five databases
from January 2010 to October 2021 (updated in July 2022).
Bivariate meta-analysis
of the sensitivity and specificity of the summary using a generalized linear mixed model.
Heterogeneity was assessed
using the I2 statistic.
We assessed risk of bias using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) and the Classification of Recommendations, Assessments, Development and Evaluation (GRADE) to assess the certainty of the evidence
.

Results: We included 17 studies for meta-analysis
.
For syphilis, the combined sensitivity and specificity of the Treponema pallidum component were 0.
93 (95% CI: 0.
86 to 0.
97) and 0.
98 (95% CI: 0.
96 to 0.
99),
respectively.
For nontreponemal components, pooled sensitivity and specificity were 0.
90 (95% CI: 0.
82 to 0.
95) and 0.
97 (95% CI: 0.
92 to 0.
99),
respectively.
For yaws, the combined sensitivity and specificity of treponemal fractions were 0.
86 (95% confidence interval, CI: 0.
66 to 0.
95) and 0.
97 (95% CI: 0.
94 to 0.
99),
respectively.
For nontreponemal components, pooled sensitivity and specificity were 0.
80 (95% CI: 0.
55 to 0.
93) and 0.
96 (95% CI: 0.
92 to 0.
98),
respectively.

Table 1 Summary of studies included in meta-analysis (n=17)

Figure 1 Forest plot
of sensitivity and specificity of Treponema pallidum.

Figure 2 Nontreponemal sensitivity and specificity forest plot for syphilis

Figure 3 Forest plot
of treponemal sensitivity and specificity for yaws.
*Unpublished studies

Figure 4 Forest plot
of nontreponemal sensitivity and specificity for yaws.
*Unpublished studies
.

Conclusions: RDT can distinguish between active infection and previously treated infection and can optimize management
by providing same-day treatment and reducing unnecessary treatment.

Original source: Zhang Y, Goh SM, Mello MB, et al.
Improved rapid diagnostic tests to detect syphilis and yaws: a systematic review and meta-analysis.
Sex Transm Infect 2022 Sep 30