title: Serological Diagnosis of Acute Scrub Typhus in Southern India: Evaluation of InBios Scrub Typhus Detect IgM Rapid Test and Comparison with other Serological Tests.
abstract: BACKGROUND
  Scrub Typhus (ST) is being reported from different parts of India in the recent past. However, the diagnosis and confirmation of ST cases require specific serological and molecular diagnostic tests. Both rapid and conventional ELISA tests need to be properly evaluated.
  
  
  OBJECTIVE
  Evaluation of a new ST IgM Immunochromatography (ICT) test kit (InBios Scrub Typhus Detect IgM Rapid Test) and compare it with another rapid kit, conventional ELISA kit and Weil-Felix (WF) test.
  
  
  METHODS
  This prospective study was carried out in Mahatma Gandhi Medical College and Research Institute, Puducherry, during November 2015 to June 2016. Clinically suspected 220 ST patients were examined by a new kit, InBios Scrub Typhus Detect IgM Rapid Test, taking the conventional InBios Scrub Typhus Detect IgM ELISA as reference. Additional comparison was made with ImmuneMed Scrub Typhus Rapid, and WF test (single OXK titers ≥1:320). Statistical analysis was performed (Chi-square, Spearman's correlation and Kappa) using IBM SPSS Statistics 17 for Windows (SPSS Inc; Chicago, USA).
  
  
  RESULTS
  Percentage Sensitivity, Specificity, Positive Predictive and Negative Predictive Values for InBios, ImmuneMed and WF were 99.25, 93.02, 95.68, 98.77; 94.87, 94.19, 96.21, 92.05 and 50.38, 95.51, 94.29, 56.67 respectively. A total of 134 patients were positive in reference standard InBios IgM ELISA.
  
  
  CONCLUSIONS
  This new rapid ST IgM kit validated for the first time in India, showed good sensitivity and specificity. As a Point-of-Care (PoC) test, the kit would be helpful in both urban and remote rural parts of India.
authors.affiliation: Ph.D. Scholar, Department of Microbiology, Mahatma Gandhi Medical College and Research Institute , Puducherry, India .
authors.forename: Velmurugan
authors.initials: V
authors.lastname: Anitharaj
authors.affiliation: Professor, Department of Microbiology, Mahatma Gandhi Medical College and Research Institute , Puducherry, India .
authors.forename: Selvaraj
authors.initials: S
authors.lastname: Stephen
authors.affiliation: Ph.D. Scholar, Department of Microbiology, Mahatma Gandhi Medical College and Research Institute , Puducherry, India .
authors.forename: Jothimani
authors.initials: J
authors.lastname: Pradeep
authors.affiliation: Scientist, ImmuneMed Inc. , Chuncheon, Gangwon Do, South Korea .
authors.forename: Sungman
authors.initials: S
authors.lastname: Park
authors.affiliation: Scientist, ImmuneMed Inc. , Chuncheon, Gangwon Do, South Korea .
authors.forename: Seung-Han
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Scientist, ImmuneMed Inc. , Chuncheon, Gangwon Do, South Korea .
authors.forename: Young Jin
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Scientist, ImmuneMed Inc. , Chuncheon, Gangwon Do, South Korea .
authors.forename: Eun-Ye
authors.initials: EY
authors.lastname: Kim
authors.affiliation: Teaching Faculty, Department of Microbiology, Hallym University College of Medicine , Chuncheon, Gangwon do, South Korea .
authors.forename: Yoon-Won
authors.initials: YW
authors.lastname: Kim
keywords: Enzyme-linked immunosorbent assay; Immunochromatography; Orientia tsutsugamushi