Table 1. General characteristics of included studies for meta-analyses; * = specification of treatment strategy required reporting of what antibiotics (if any) were given to enrolled patients; PCR = polymerase chain reaction; ELISA = enzyme-linked immunosorbent assay, IFA = immunofluorescence assay, ICT = immunochromatographic test, PCR = polymerase chain reaction, WFT = Weil–Felix test.
| Study | Country | Study design | Study setting | Study cohort population | Study enrolment period | Number of patients | Median or mean age (SD) [IQR] | Number of females (%) | Number of deaths (%) | Diagnostic test | Specified treatment strategy* |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Kim 2013 [20] | South Korea | Retrospective cohort | Tertiary hospital | Mixed | 2004–2008 | 22 | 70.2 (Not specified) | 14 (62.6%) | 0 (0.0%) | PCR | Yes |
| Viswanathan 2013 [29] | India | Retrospective cohort | Unspecified | Mixed | 2011–2012 | 17 | 41.8 (17.7) | 7 (41.2%) | 0 (0.0%) | IgM ELISA or WFT | Yes |
| Misra 2014 [21] | India | Cross sectional | Tertiary hospital | Mixed | 2012–2013 | 37 | 37.7 [3 – 71] | 19 (51.4%) | 0 (0.0%) | ICT or WFT | Yes |
| Dittrich 2015 [17] | Laos | Prospective study | Tertiary hospital | Mixed | 2003–2011 | 31 | 16.0 [8.0–30.0] | 9 (29.0%) | 3 (1.0%) | IFA | No |
| Abhilash 2015 [11] | India | Retrospective cohort | Tertiary hospital | Mixed | 2005–2011 | 189 | 41.0 (6.3) | 81 (42.9%) | 11 (5.8%) | IgM ELISA | Yes |
| Sharma 2015 [26] | India | Prospective study | Tertiary hospital | Mixed | 2009–2011 | 23 | 39.5 [Not specified] | 10 (43.5%) | 0 (0.0%) | WFT | Yes |
| Jamil 2015 [19] | India | Prospective study | Tertiary hospital | Mixed | 2013–2014 | 13 | 34.8 (16.2) | 5 (38.5%) | 2 (6.5%) | ICT or WFT | Yes |
| Bhat 2016 [14] | India | Prospective study | Teaching hospital | Paediatric | Unspecified | 27 | 9.4 (5.2) | 11 (40.7%) | 2 (7.4%) | IgM ELISA | No |
| Rana 2016 [24] | India | Prospective study | Teaching hospital | Mixed | 2013–2014 | 37 | 48.1 [22 – 80] | 30 (81.1%) | 0 (0.0%) | IgM ELISA | Yes |
| Lee 2017 [8] | South Korea | Retrospective cohort | Tertiary hospital | Mixed | 2009–2014 | 16 | 35.5 [Not specified] | 10 (62.5%) | 0 (0.0%) | IFA | Yes |
| Rose 2017 [25] | India | Retrospective cohort | Tertiary hospital | Paediatric | 2010–2015 | 63 | 8.9 (4.1) | 39 (61.9%) | 0 (0.0%) | IgM ELISA or WFT | Yes |
| Gangwar 2020 [23] | India | Retrospective cohort | Tertiary hospital | Paediatric | 2018 | 146 | 7.0 [4.0–11.0] | 68 (46.6%) | 13 (8.9%) | IgM ELISA | Yes |
| Thakur 2020 [27] | India | Cross sectional | Multicentre | Mixed | 2013–2018 | 210 | 29.8 (16.6) | 90 (42.9%) | 14 (6.7%) | IgM ELISA | No |
| Valappil 2017 [28] | Unspecified | Prospective study | Unspecified | Mixed | Unspecified | 28 | 40.2 (17.6) | 14 (50.0%) | 0 (0.0%) | IgM ELISA | No |
| Bhat 2017 [15] | India | Prospective study | Teaching hospital | Paediatric | Unspecified | 19 | 7.8 (4.9) | 5 (26.3%) | 1 (5.2%) | IgM ELISA | No |
| Mittal 2018 [22] | India | Retrospective cohort | Tertiary hospital | Paediatric | 2016 | 230 | 5.0 [3.0–10.0] | 116 (50.4%) | 35 (15.2%) | IgM ELISA | Yes |
| Dinesh Kumar 2018 [16] | India | Prospective study | Tertiary hospital | Paediatric | Unspecified | 14 | 6.9 (2.7) | 7 (50.0%) | 0 (0.0%) | IgM ELISA | No |
| Alam 2020 [12] | India | Prospective study | Teaching hospital | Paediatric | 2016–2018 | 66 | 5.0 (3.8) | 20 (30.3%) | 7 (10.6%) | IgM ELISA | Yes |
| Arora 2021 [13] | India | Prospective study | Tertiary hospital | Mixed | 2014–2016 | 33 | 46.5 (17.2) | 18 (54.5%) | 2 ((6.1%) | IgM ELISA | No |