{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T19:15:07Z","timestamp":1785870907141,"version":"3.56.0"},"reference-count":22,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2023,3,16]],"date-time":"2023-03-16T00:00:00Z","timestamp":1678924800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"ICMR-VCRC Intra-mural funding","award":["IM 2106"],"award-info":[{"award-number":["IM 2106"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["TropicalMed"],"abstract":"<jats:p>Scrub typhus (St) is a re-emerging mite-transmitted public health problem in Southeast Asia with escalating case incidences in the endemic areas. Though, more than 40 genotypes of the causative agent Orientia tsutsugamushi (Ot) have been documented, the information on the circulating genotypes in India is scanty. A hospital-based retrospective screening was undertaken to map the circulating molecular subtypes of the etiological agent in serologically confirmed scrub typhus (St) human cases, by targeting the GroEL gene of O. tsutsugamushi using the nested polymerase chain reaction method. Nine out of 34 samples (26%) yielded positive results and DNA sequencing analysis of six positive samples out of nine revealed that the sequences were related to three major genotypes, such as Karp (HSB1, FAR1), Kato (Wuj\/2014, UT76), and Kawasaki (Kuroki, Boryong, Gilliam, and Hwasung). Additionally, the St-positive samples exhibited 100% and 99.45%; 97.53% and 97.81%; 96.99% nucleotide identity with the closely related Karp, Kato, and Kawasaki-related sequences, respectively. Overall, 94% of the nucleotides were conserved, and the variable site was 20\/365 (5.5%). The prevalence of multiple genotypes among human cases further stresses the need to conduct in-depth studies to map the genotypes and their clinical relevance, and the contributing risk factors for the emergence of St cases in this area.<\/jats:p>","DOI":"10.3390\/tropicalmed8030174","type":"journal-article","created":{"date-parts":[[2023,3,16]],"date-time":"2023-03-16T02:40:11Z","timestamp":1678934411000},"page":"174","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Molecular Detection of Multiple Genotypes of Orientia tsutsugamushi Causing Scrub Typhus in Febrile Patients from Theni District, South India"],"prefix":"10.3390","volume":"8","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6612-4645","authenticated-orcid":false,"given":"Krishnamoorthy","family":"Nallan","sequence":"first","affiliation":[{"name":"ICMR-Vector Control Research Centre, Field Unit, Madurai 625 002, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gopinathan","family":"Rajan","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Government Medical College and Hospital, Theni 625 512, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lallitha","family":"Sivathanu","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Government Medical College and Hospital, Theni 625 512, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0638-9590","authenticated-orcid":false,"given":"Panneer","family":"Devaraju","sequence":"additional","affiliation":[{"name":"ICMR-Vector Control Research Centre, Puducherry 605 006, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Balaji","family":"Thiruppathi","sequence":"additional","affiliation":[{"name":"ICMR-Vector Control Research Centre, Field Unit, Madurai 625 002, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2485-7581","authenticated-orcid":false,"given":"Ashwani","family":"Kumar","sequence":"additional","affiliation":[{"name":"ICMR-Vector Control Research Centre, Puducherry 605 006, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paramasivan","family":"Rajaiah","sequence":"additional","affiliation":[{"name":"ICMR-Vector Control Research Centre, Field Unit, Madurai 625 002, India"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,3,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Xu, G., Walker, D.H., Jupiter, D., Melby, P.C., and Arcari, C.M. (2017). A review of the global epidemiology of scrub typhus. PLoS. Negl. Trop. Dis., 3.","DOI":"10.1371\/journal.pntd.0006062"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"76","DOI":"10.7324\/JABB.2022.100509","article-title":"An epidemiological outbreak of scrub typhus caused by Orientia tsutsugamushi\u2014A comprehensive review","volume":"10","author":"Panda","year":"2022","journal-title":"J. Appl. Biol. Biotech."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2148","DOI":"10.3201\/eid2609.200918","article-title":"Molecular description of a novel Orientia species causing scrub typhus in Chile","volume":"26","author":"Abarca","year":"2020","journal-title":"Emerg. Infect. Dis."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"4404","DOI":"10.1128\/JCM.01526-10","article-title":"Isolation of a novel Orientia species (O. chuto sp. nov.) from a patient infected in Dubai","volume":"48","author":"Izzard","year":"2010","journal-title":"J. Clin. Microbiol."},{"key":"ref_5","unstructured":"National Centre for Disease Control (NCDC) (2022, May 28). Annual Report 2016\u201317, Available online: https:\/\/ncdc.gov.in\/WriteReadData\/linkimages\/Annual%20report2016-17.pdf."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1016\/j.mjafi.2018.12.018","article-title":"Scrub typhus strikes back: Are we ready?","volume":"75","author":"Tilak","year":"2019","journal-title":"Med. J. Armed Forces India"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"151467","DOI":"10.1016\/j.ijmm.2020.151467","article-title":"Orientia tsutsugamushi: The dangerous yet neglected foe from the East","volume":"311","author":"Banerjee","year":"2021","journal-title":"Int. J. Med. Microbiol."},{"key":"ref_8","unstructured":"(2022, May 10). Rise in Scrub Typhus Cases in TN Worries Officials. Available online: https:\/\/www.newindianexpress.com\/cities\/chennai\/2019\/nov\/29\/rise-in-scrub-typhus-cases-in-tn-worries-officials-2068559.html."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1395","DOI":"10.1086\/424748","article-title":"Scrub typhus: Prevalence and diagnostic issues in rural Southern India","volume":"39","author":"Isaac","year":"2004","journal-title":"Clin. Infect. Dis."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1179\/2047773212Y.0000000001","article-title":"Molecular detection and analysis of spotted fever group Rickettsia in patients with fever and rash at a tertiary care Centre in Tamil Nadu, India","volume":"106","author":"Prakash","year":"2012","journal-title":"Path. Glob. Health"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"76","DOI":"10.4103\/0971-5916.193292","article-title":"Epidemiology & risk factors of scrub typhus in south India","volume":"144","author":"Varghese","year":"2016","journal-title":"Ind. J. Med. Res."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"591","DOI":"10.4103\/0971-5916.171289","article-title":"Outbreak of scrub typhus in Puducherry & Tamil Nadu during cooler months","volume":"142","author":"Stephen","year":"2015","journal-title":"Ind. J. Med. Res."},{"key":"ref_13","unstructured":"(2022, June 11). Available online: https:\/\/tnrtp.org\/wp-content\/uploads\/2020\/07\/THENI-FINAL.pdf."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"123","DOI":"10.4269\/ajtmh.12-0728","article-title":"Laboratory diagnosis and genotype identification of scrub typhus from Pinggu district, Beijing, 2008 and 2010","volume":"89","author":"Li","year":"2013","journal-title":"Am. J. Trop. Med. Hyg."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1547","DOI":"10.1093\/molbev\/msy096","article-title":"Molecular evolutionary genetics analysis across computing platforms","volume":"35","author":"Kumar","year":"2018","journal-title":"Mol. Boil. Evol."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Devasagayam, E., Dayanand, D., Kundu, D., Kamath, M.S., Kirubakaran, R., and Varghese, G.M. (2021). The burden of scrub typhus in India: A systematic review. PLoS Negl. Trop. Dis., 15.","DOI":"10.1371\/journal.pntd.0009619"},{"key":"ref_17","first-page":"597","article-title":"Molecular characterization of Orientia tsutsugamushi serotypes causing scrub typhus outbreak in southern region of Andhra Pradesh, India","volume":"144","author":"Usha","year":"2016","journal-title":"Ind. J. Med. Res."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"64","DOI":"10.3201\/eid2101.140580","article-title":"Molecular epidemiology and genetic diversity of Orientia tsutsugamushi from patients with scrub typhus in 3 regions of India","volume":"21","author":"Varghese","year":"2015","journal-title":"Emerg. Infect. Dis."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Kim, G., Ha, N.Y., Min, C.K., Kim, H.I., Yen, N.T., Lee, K.H., Oh, I., Kang, J.S., Choi, M.S., and Kim, I.S. (2017). Diversification of Orientia tsutsugamushi genotypes by intragenic recombination and their potential expansion in endemic areas. PLoS Negl. Trop. Dis., 11.","DOI":"10.1371\/journal.pntd.0005408"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Qian, L., Wang, Y., Wei, X., Liu, P., Magalhaes, R.J., Qian, Q., Peng, H., Wen, L., Xu, Y., and Sun, H. (2022). Epidemiological characteristics and spatiotemporal patterns of scrub typhus in Fujian province during 2012\u20132020. PLoS Negl. Trop. Dis., 29.","DOI":"10.1371\/journal.pntd.0010278"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"513","DOI":"10.1186\/s13071-019-3751-x","article-title":"Scrub typhus ecology: A systematic review of Orientia in vectors and hosts","volume":"12","author":"Elliott","year":"2019","journal-title":"Parasites Vectors"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Chen, H.F., Peng, S.H., Tsai, K.H., Yang, C.F., Chang, M.C., Hsueh, Y.L., Su, C.L., Wang, R.Y., Shu, P.Y., and Yang, S.L. (2022). Molecular epidemiology of scrub typhus in Taiwan during 2006\u20132016. PLoS Negl. Trop. Dis., 16.","DOI":"10.1371\/journal.pntd.0011025"}],"container-title":["Tropical Medicine and Infectious Disease"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2414-6366\/8\/3\/174\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T18:56:18Z","timestamp":1760122578000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2414-6366\/8\/3\/174"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,3,16]]},"references-count":22,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2023,3]]}},"alternative-id":["tropicalmed8030174"],"URL":"https:\/\/doi.org\/10.3390\/tropicalmed8030174","relation":{},"ISSN":["2414-6366"],"issn-type":[{"value":"2414-6366","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,3,16]]}}}