{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T20:25:34Z","timestamp":1787775934917,"version":"build-2784847793"},"reference-count":41,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"4","license":[{"start":{"date-parts":[[2025,10,1]],"date-time":"2025-10-01T00:00:00Z","timestamp":1759276800000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0"}],"content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2025,10]]},"abstract":"<jats:sec>\n                    <jats:title>Background &amp; objectives:<\/jats:title>\n                    <jats:p>Conventionally, the humoral immune response to scrub typhus (ST) is the early appearance of IgM during the first week of infection, followed by IgG after 2-3 weeks. Recent publications reveal different trends in Immunological response to ST.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods:<\/jats:title>\n                    <jats:p>Acute and convalescent blood from 55 (Group-I) and single samples from 152 (Group-II), both clinically suspected as ST, were subjected to ST IgM ELISA, ST IgG ELISA, and ST IgG IFA. Acute samples from Group I and single samples from Group II were subjected to Real-Time PCR (q PCR) to target three genes, 56 kDa, 47 kDa, and groEl.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results:<\/jats:title>\n                    <jats:p>All 262 blood samples were positive for ST IgM ELISA. Positivity for IgG ELISA, IgG IFA and the presence of any one or more gene targets (56kDa\/47kDa\/groEL) in qPCR among the 55 acute samples was 70.9%, 36.4%, and 89.1%, respectively and 87.3%, 45.5% and 78.3% respectively in convalescent samples. In 152 unpaired samples, IgG ELISA was positive in 52.6% and 19.1% in ST IgG IFA. Among 207 samples (Group-I Acute and Group II) subjected to q PCR, groEl, 56 kDa and 47 kDa were present in 59.4%, 44.0%, and 35.7% respectively.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Interpretation &amp; conclusion:<\/jats:title>\n                    <jats:p>In view of the persistence of IgM in ST over months and, in some cases, years, there is a diagnostic dilemma in confirming ST based on single ST IgM, especially in ST-endemic regions. This is compounded by the additional presence of ST IgG in the early days of acute infection. q PCR is recommended to confirm doubtful cases of ST.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.4103\/jvbd.jvbd_179_24","type":"journal-article","created":{"date-parts":[[2025,5,2]],"date-time":"2025-05-02T07:37:59Z","timestamp":1746171479000},"page":"482-489","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":1,"title":["Diagnostic dilemma in laboratory confirmation of acute scrub typhus infection: Relevance of ST IgM, IgG antibodies and molecular markers"],"prefix":"10.4103","volume":"62","author":[{"given":"V","family":"Anitharaj","sequence":"first","affiliation":[{"name":"Department of Microbiology, Panimalar Medical College and Hospital, Chennai, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J","family":"Pradeep","sequence":"additional","affiliation":[{"name":"Sri Balaji Vidyapeeth 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