{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,8]],"date-time":"2026-04-08T03:56:16Z","timestamp":1775620576107,"version":"3.50.1"},"reference-count":29,"publisher":"Public Library of Science (PLoS)","issue":"4","license":[{"start":{"date-parts":[[2023,4,28]],"date-time":"2023-04-28T00:00:00Z","timestamp":1682640000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:sec id=\"sec001\">\n<jats:title>Background<\/jats:title>\n<jats:p>In May 2022, the monkeypox virus (MPXV) spread into non-endemic countries and the global community was quick to test the lessons learned from the SARS-CoV-2 pandemic. Due to its symptomatic resemblance to other diseases, like the non-pox virus varicella zoster (chickenpox), polymerase chain reaction methods play an important role in correctly diagnosing the rash-causing pathogen. INSTAND quickly established a new external quality assessment (EQA) scheme for MPXV and orthopoxvirus (OPXV) DNA detection to assess the current performance quality of the laboratory tests.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec002\">\n<jats:title>Methods<\/jats:title>\n<jats:p>We analyzed quantitative and qualitative data of the first German EQA for MPXV and OPXV DNA detection. The survey included one negative and three MPXV-positive samples with different MPX viral loads. The threshold cycle (Ct) or other measures defining the quantification cycle (Cq) were analyzed in an assay-specific manner. A Passing Bablok fit was used to investigate the performance at laboratory level.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec003\">\n<jats:title>Results<\/jats:title>\n<jats:p>141 qualitative datasets were reported by 131 laboratories for MPXV detection and 68 qualitative datasets by 65 laboratories for OPXV detection. More than 96% of the results were correctly identified as negative and more than 97% correctly identified as positive. An analysis of the reported Ct\/Cq values showed a large spread of these values of up to 12 Ct\/Cq. Nevertheless, there is a good correlation of results for the different MPXV concentrations at laboratory level. Only a few quantitative results in copies\/mL were reported (MPXV: N = 5; OPXV: N = 2), but the results correlated well with the concentration differences between the EQA samples, which were to a power of ten each.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec004\">\n<jats:title>Conclusion<\/jats:title>\n<jats:p>The EQA results show that laboratories performed well in detecting both MPXV and OPXV. However, Ct\/Cq values should be interpreted with caution when conclusions are drawn about the viral load as long as metrological traceability is not granted.<\/jats:p>\n<\/jats:sec>","DOI":"10.1371\/journal.pone.0285203","type":"journal-article","created":{"date-parts":[[2023,4,28]],"date-time":"2023-04-28T17:28:32Z","timestamp":1682702912000},"page":"e0285203","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":4,"title":["Results of the first German external quality assessment scheme for the detection of monkeypox virus DNA"],"prefix":"10.1371","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3492-9796","authenticated-orcid":true,"given":"Laura","family":"Vierbaum","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1977-7931","authenticated-orcid":true,"given":"Nathalie","family":"Wojtalewicz","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anne","family":"Kaufmann","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sabine","family":"Goseberg","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Patricia","family":"Kaiser","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hans-Peter","family":"Grunert","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ulf","family":"D\u00fchring","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anika","family":"Zimmermann","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Annemarie","family":"Scholz","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6227-3125","authenticated-orcid":true,"given":"Janine","family":"Michel","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andreas","family":"Nitsche","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Holger F.","family":"Rabenau","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Martin","family":"Obermeier","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ingo","family":"Schellenberg","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Heinz","family":"Zeichhardt","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Martin","family":"Kammel","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2023,4,28]]},"reference":[{"key":"pone.0285203.ref001","author":"WHO","year":"2020","journal-title":"WHO Director-General\u2019s opening remarks at the media briefing on COVID-19"},{"issue":"2","key":"pone.0285203.ref002","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1111\/j.1699-0463.1959.tb00328.x","article-title":"A pox\u2010like disease in cynomolgus monkeys.","volume":"46","author":"Magnus Pv","year":"1959","journal-title":"Acta Pathologica Microbiologica Scandinavica."},{"issue":"4","key":"pone.0285203.ref003","first-page":"465","article-title":"Human monkeypox: secondary attack rates","volume":"66","author":"Z Jezek","year":"1988","journal-title":"Bull World Health Organ"},{"issue":"1","key":"pone.0285203.ref004","article-title":"Human Monkeypox: Current State of Knowledge and Implications for the Future","volume":"1","author":"K Brown","year":"2016","journal-title":"Trop Med Infect Dis"},{"issue":"2","key":"pone.0285203.ref005","doi-asserted-by":"crossref","first-page":"e0010141","DOI":"10.1371\/journal.pntd.0010141","article-title":"The changing epidemiology of human monkeypox-A potential threat? 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