{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T08:50:00Z","timestamp":1791967800751,"version":"4.3.4"},"reference-count":39,"publisher":"Wiley","issue":"9","license":[{"start":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T00:00:00Z","timestamp":1788825600000},"content-version":"vor","delay-in-days":7,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T00:00:00Z","timestamp":1788220800000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"DOI":"10.13039\/100000865","name":"Bill and Melinda Gates Foundation","doi-asserted-by":"publisher","award":["INV\u2010018978"],"award-info":[{"award-number":["INV\u2010018978"]}],"id":[{"id":"10.13039\/100000865","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100010269","name":"Wellcome Trust","doi-asserted-by":"publisher","award":["311673"],"award-info":[{"award-number":["311673"]}],"id":[{"id":"10.13039\/100010269","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Influenza Resp Viruses"],"published-print":{"date-parts":[[2026,9]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Laboratory\u2010based influenza surveillance in low\u2010 and middle\u2010income countries may have limited timeliness and geographic coverage. We evaluated whether over\u2010the\u2010counter (OTC) respiratory medication sales track seasonal influenza activity and provide early warning of influenza onset in South Africa.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Daily OTC medication sales were obtained from a national pharmaceutical chain and analysed nationally and in Gauteng, KwaZulu\u2010Natal and Western Cape. Weekly laboratory\u2010confirmed influenza cases were obtained from sentinel surveillance programmes for 2012\u20132019 and 2022\u20132023. Seasonal characteristics were compared using the Moving Epidemic Method. Lead\u2013lag relationships were assessed using Pearson cross\u2010correlation, with 3\u2010week smoothing and first differencing as sensitivity analyses. Forecasts at 1\u2010 to 5\u2010week horizons were evaluated using influenza\u2010only, OTC\u2010only, combined influenza\u2010plus\u2010OTC generalized linear model (GLM), Random Forest and na\u00efve persistence models. Performance was assessed using root mean square error and area under the receiver operating characteristic curve (AUC).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>OTC sales preceded increases in influenza detections nationally and provincially. Sales\u2010defined seasons began and peaked earlier in 70% of national seasons and 67%\u201389% across provinces. Primary analyses indicated that OTC sales preceded influenza detections by 2\u20133\u2009weeks (mean peak correlations, 0.77\u20130.81). After first differencing, OTC changes preceded influenza changes in 5\u20138 of 10 seasons across locations (correlations, 0.42\u20130.50). Influenza\u2010only models produced the lowest forecast errors. OTC\u2010informed models achieved AUC\u2009\u2265\u20090.90 at 1\u2010 to 2\u2010week horizons. All significant squared\u2010error comparisons favoured na\u00efve persistence.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>OTC respiratory medication sales may complement virological surveillance by supporting earlier identification of seasonal influenza activity but should not replace laboratory surveillance.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1111\/irv.70313","type":"journal-article","created":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T08:41:01Z","timestamp":1788856861000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Assessing the Utility of Over\u2010The\u2010Counter Medication to Track Influenza Season Timing in a South African Population"],"prefix":"10.1111","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3221-6813","authenticated-orcid":false,"given":"Malebo Sephule","family":"Makunyane","sequence":"first","affiliation":[{"name":"Division of Allergology and Clinical Immunology, Department of Medicine, Faculty of Health Sciences University of Cape Town  Cape Town South Africa"},{"name":"Allergy and Immunology Unit University of Cape Town Lung Institute  Cape Town South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Neville","family":"Sweijd","sequence":"additional","affiliation":[{"name":"School for Climate Studies Stellenbosch University  Stellenbosch South Africa"},{"name":"Alliance for Collaboration on Climate and Earth Systems Science (ACCESS) Council for Scientific and Industrial Research  Cape Town South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jhandre","family":"Bredenkamp","sequence":"additional","affiliation":[{"name":"Clicks Retailers Clicks Group Limited  Cape Town South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7588-2480","authenticated-orcid":false,"given":"Sibongile","family":"Walaza","sequence":"additional","affiliation":[{"name":"Centre for Respiratory Diseases and Meningitis National Institute for Communicable Diseases of the National Health Laboratory Service  Johannesburg South Africa"},{"name":"School of Public Health, Faculty of Health Sciences University of the Witwatersrand  Johannesburg South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0376-2302","authenticated-orcid":false,"given":"Cheryl","family":"Cohen","sequence":"additional","affiliation":[{"name":"Centre for Respiratory Diseases and Meningitis National Institute for Communicable Diseases of the National Health Laboratory Service  Johannesburg South Africa"},{"name":"School of Public Health, Faculty of Health Sciences University of the Witwatersrand  Johannesburg South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2658-0723","authenticated-orcid":false,"given":"Jonny","family":"Peter","sequence":"additional","affiliation":[{"name":"Division of Allergology and Clinical Immunology, Department of Medicine, Faculty of Health Sciences University of Cape Town  Cape Town South Africa"},{"name":"Allergy and Immunology Unit University of Cape Town Lung Institute  Cape Town South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,9,8]]},"reference":[{"key":"e_1_2_13_2_1","unstructured":"WHO \u201cGlobal Influenza Strategy 2019\u20102030 \u201d (2019). 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