{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T14:56:17Z","timestamp":1791989777530,"version":"4.4.0"},"reference-count":27,"publisher":"Oxford University Press (OUP)","issue":"3","license":[{"start":{"date-parts":[[2025,3,17]],"date-time":"2025-03-17T00:00:00Z","timestamp":1742169600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000060","name":"National Institute of Allergy and Infectious Diseases","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100000060","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["U19AI144177"],"award-info":[{"award-number":["U19AI144177"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["U19 RFA-AI-18-005"],"award-info":[{"award-number":["U19 RFA-AI-18-005"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100021281","name":"Gates Foundation","doi-asserted-by":"publisher","award":["INV-036560"],"award-info":[{"award-number":["INV-036560"]}],"id":[{"id":"10.13039\/100021281","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,3,17]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>As syphilis rates have increased globally, chancroid has dramatically declined as a cause of genital ulcer disease (GUD).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We recruited patients aged \u226518 years presenting to a sexually transmitted infection clinic with GUD from Lilongwe, Malawi, from November 2019 through April 2022. Lesion exudates were tested by darkfield microscopy (DFM) and polymerase chain reaction (PCR) for Treponema pallidum (TP) and by PCR for Haemophilus ducreyi (HD), herpes simplex virus, and Chlamydia trachomatis. We evaluated the sensitivity and specificity of DFM relative to TP PCR, the distribution of GUD etiologies by PCR, and the performance of our HD PCR relative to Allplex Genital Ulcer assay (Seegene Inc) using the Cohen's kappa statistic.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>We enrolled 568 participants; the median age was 27 years (interquartile range: 23, 34), 61% (345\/564) were men, and 13% (60\/464) had human immunodeficiency virus (HIV) or were newly diagnosed with HIV. DFM identified TP in 55 (10%) participants, with a sensitivity and specificity of 12% and 94%, respectively. PCR identified TP in 367 (65%), HD in 128 (23%), herpes simplex virus in 98 (17%), and Chlamydia trachomatis in 36 (6%) of participants with only 1\/36 (2.8%) with serovar L1, L2, or L3 consistent with lymphogranuloma venereum; no etiology was identified in 48 (8%). External validation confirmed the high HD prevalence (Cohen's kappa 0.78, 89% agreement).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Syphilis and chancroid are common etiologies of GUD in Malawi. Our findings underscore the value of highly sensitive molecular diagnostic methods to periodically assess GUD causes among patients with sexually transmitted infections in countries using syndromic management.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/cid\/ciaf114","type":"journal-article","created":{"date-parts":[[2025,3,16]],"date-time":"2025-03-16T16:14:20Z","timestamp":1742141660000},"page":"e604-e611","source":"Crossref","is-referenced-by-count":4,"title":["High Prevalence of\n                    <i>Haemophilus ducreyi<\/i>\n                    Among Patients With Suspected Primary syphilis in Malawi, 2019\u20132022"],"prefix":"10.1093","volume":"82","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6542-8193","authenticated-orcid":false,"given":"Mitch M","family":"Matoga","sequence":"first","affiliation":[{"name":"Reproductive and Sexual Health Clinic, University of North Carolina Project Malawi , Lilongwe ,","place":["Malawi"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7648-0651","authenticated-orcid":false,"given":"Jane S","family":"Chen","sequence":"additional","affiliation":[{"name":"Institute of Global Health and Infectious Diseases, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1206-2175","authenticated-orcid":false,"given":"Arlene C","family":"Se\u00f1a","sequence":"additional","affiliation":[{"name":"Institute of Global Health and Infectious Diseases, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Beatrice","family":"Ndalama","sequence":"additional","affiliation":[{"name":"Reproductive and Sexual Health Clinic, University of North Carolina Project Malawi , Lilongwe ,","place":["Malawi"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Naomi","family":"Nyirenda","sequence":"additional","affiliation":[{"name":"Reproductive and Sexual Health Clinic, University of North Carolina Project Malawi , Lilongwe ,","place":["Malawi"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Naomi","family":"Bonongwe","sequence":"additional","affiliation":[{"name":"Reproductive and Sexual Health Clinic, University of North Carolina Project Malawi , Lilongwe ,","place":["Malawi"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Esther","family":"Mathiya","sequence":"additional","affiliation":[{"name":"Reproductive and Sexual Health Clinic, University of North Carolina Project Malawi , Lilongwe ,","place":["Malawi"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Blessings","family":"Kamtambe","sequence":"additional","affiliation":[{"name":"Bwaila STI Clinic, Bwaila District Hospital, Lilongwe District Health Office , Lilongwe ,","place":["Malawi"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Edward","family":"Jere","sequence":"additional","affiliation":[{"name":"Reproductive and Sexual Health Clinic, University of North Carolina Project Malawi , Lilongwe ,","place":["Malawi"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gabriel K","family":"Banda","sequence":"additional","affiliation":[{"name":"Reproductive and Sexual Health Clinic, University of North Carolina Project Malawi , Lilongwe ,","place":["Malawi"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Isaac","family":"Thengolose","sequence":"additional","affiliation":[{"name":"Reproductive and Sexual Health Clinic, University of North Carolina Project Malawi , Lilongwe ,","place":["Malawi"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-9155-4174","authenticated-orcid":false,"given":"Jenny","family":"Coelho","sequence":"additional","affiliation":[{"name":"Institute of Global Health and Infectious Diseases, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5325-6753","authenticated-orcid":false,"given":"Christopher M","family":"Hennelly","sequence":"additional","affiliation":[{"name":"Institute of Global Health and Infectious Diseases, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel","family":"Schr\u00f6der","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Faculty of Medicine and Health, \u00d6rebro University Hospital , \u00d6rebro ,","place":["Sweden"]},{"name":"WHO Collaborating Centre for Gonorrhea and Other STIs, \u00d6rebro University , \u00d6rebro, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1710-2081","authenticated-orcid":false,"given":"Magnus","family":"Unemo","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Faculty of Medicine and Health, \u00d6rebro University Hospital , \u00d6rebro ,","place":["Sweden"]},{"name":"WHO Collaborating Centre for Gonorrhea and Other STIs, \u00d6rebro University , \u00d6rebro, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Juan C","family":"Salazar","sequence":"additional","affiliation":[{"name":"Connecticut Children's Medical Center , Hartford, Connecticut ,","place":["USA"]},{"name":"Department of Pediatrics, University of Connecticut Health , Farmington, Connecticut ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Justin D","family":"Radolf","sequence":"additional","affiliation":[{"name":"Connecticut Children's Medical Center , Hartford, Connecticut ,","place":["USA"]},{"name":"Department of Pediatrics, University of Connecticut Health , Farmington, Connecticut ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jonathan B","family":"Parr","sequence":"additional","affiliation":[{"name":"Institute of Global Health and Infectious Diseases, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina ,","place":["USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0059-5991","authenticated-orcid":false,"given":"Irving F","family":"Hoffman","sequence":"additional","affiliation":[{"name":"Reproductive and Sexual Health Clinic, University of North Carolina Project Malawi , Lilongwe ,","place":["Malawi"]},{"name":"Institute of 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