03884nas a2200553   4500000000100000008004100001260001600042653002000058653000900078653001900087100001500106700002200121700001900143700001400162700001400176700001200190700002000202700001300222700001300235700001400248700001400262700001400276700001200290700001500302700001300317700001500330700001500345700001300360700001700373700001100390700001300401700001500414700001500429700001600444700001300460700001300473700001400486700001200500700001200512700001300524700002000537700001200557245010700569856007500676300001600751490000700767520254200774022001403316       2024                            d  bElsevier BV10aDiagnostic test10aYaws10aCase detection1 aHandley BL1 aGonzalez-Beiras C1 aTchatchouang S1 aHugues KA1 aBasing LA1 aSylla A1 aKouamé-Sina MS1 aAmanor I1 aNdzomo P1 aAloumba A1 aBakheit M1 aMüller C1 aBorst N1 aLandmann E1 aGmoser H1 aHärpfer T1 aBecherer L1 aLüert S1 aFrischmann S1 aBurl S1 aTabah EN1 aCrucitti T1 aKouadio AT1 aArhinful DK1 aAwondo P1 aKakou SN1 aEyangoh S1 aAddo KK1 aKnauf S1 aMitjà O1 aHarding-Esch EM1 aMarks M00aA loop-mediated isothermal amplification test for yaws: a multi-country diagnostic accuracy evaluation  uhttps://www.thelancet.com/action/showPdf?pii=S2214-109X%2824%2900324-3  ae1891-e18980 v123 a<p><strong>Background:</strong> To meet the WHO target of eradicating yaws by 2030, highly sensitive and specific diagnostic tools are needed. A multiplex&nbsp;<em>Treponema pallidum</em>–<em>Haemophilus ducreyi</em>&nbsp;loop-mediated isothermal amplification (TPHD-LAMP) test holds promise as a near-patient diagnostic tool for yaws and&nbsp;<em>H ducreyi</em>. We conducted a prospective evaluation in Cameroon, Côte d’Ivoire, Ghana, and the Republic of the Congo to determine the diagnostic accuracy of the TPHD-LAMP test, as well as to assess its acceptability, feasibility, and cost.</p>

<p><strong>Methods: </strong>Active case searching within schools and communities was used to locate participants with clinically suspicious laws-like lesions. Individuals with serologically confirmed active yaws provided paired lesion swabs between March, 2021, and April, 2023. For each participant, one swab was tested with the TPHD-LAMP at a local district laboratory and the other with reference quantitative PCR (qPCR) tests conducted at national reference laboratories. The primary outcome was TPHD-LAMP test sensitivity and specificity compared with qPCR. Laboratory technicians were interviewed using a multiple-choice survey to gauge acceptability and feasibility of the TPHD-LAMP test. Costs of each test were calculated.</p>

<p><strong>Findings:</strong> Of 3085 individuals with at least one suspected yaws lesion, 531 (17%) were serologically confirmed. We enrolled 493 participants with seropositive yaws and a further 32 with negative serology. The sensitivity of the TPHD-LAMP test for detecting&nbsp;<em>T pallidum</em>&nbsp;was 63% (95% CI 56–70) and the specificity was 66% (95% CI 61–71). Sensitivity and specificity for&nbsp;<em>T pallidum</em>&nbsp;improved to 73% (63–82; p=0·0065) and 75% (68–80; p=0·0003), respectively, in&nbsp;<em>H ducreyi</em>-negative samples. Interviews highlighted challenges in user-friendliness and practicality of the TPHD-LAMP test. The cost of the test per sample was one third of that of qPCR, although the TPHD-LAMP test entailed higher costs to establish the assay.</p>

<p><strong>Interpretation: </strong>This was the first multi-country diagnostic evaluation of a molecular test for yaws. The TPHD-LAMP testing, in its current form, falls short of the WHO target product profile criteria for yaws diagnostics. These findings highlight the importance of assessing new diagnostics in real-world conditions to ensure their suitability for programmatic use.</p>
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