Table 3.

Risk factors for rickettsial infection.

Risk factors (n = 2565)		Scrub typhus		Spotted fever		Q fever		Murine typhus
		AOR (95% CI)	p value	AOR (95% CI)	p value	AOR (95% CI)	p value	AOR (95% CI)	p value
Sex	Male	Reference
	Female	1.06 (0.82–1.36)	0.655	0.82 (0.61–1.10)	0.192	0.83 (0.58–1.18)	0.295	2.09 (1.26–3.46)	0.004
Age group (years)	15–25	Reference
	26–35	1.16 (0.70–1.92)	0.567	1.67 (0.95–2.92)	0.073	1.23 (0.62–2.45)	0.547	2.19 (0.94–5.11)	0.070
	36–45	2.55 (1.60–4.08)	< 0.001	1.39 (0.78–2.47)	0.263	1.74 (0.92–3.30)	0.089	1.94 (0.82–4.57)	0.131
	46–55	2.89 (1.78–4.67)	< 0.001	2.39 (1.37–4.19)	0.002	1.24 (0.62–2.49)	0.544	2.70 (1.15–6.33)	0.023
	56–65	3.88 (2.40–6.30)	< 0.001	2.10 (1.18–3.73)	0.012	1.55 (0.79–3.07)	0.204	1.37 (0.53–3.55)	0.523
	> 65 years	3.39 (1.93–5.95)	< 0.001	1.92 (0.95–3.87)	0.068	2.03 (0.98–4.22)	0.058	3.27 (1.18–9.06)	0.023
Place of residence	Rural	2.39 (1.73–3.30)	< 0.001	2.46 (1.41–4.31)	0.002	Reference		1.77 (1.07–2.91)	0.026
	Urban	Reference				1.38 (0.86–2.21)	0.179	Reference
Peri-forested	No	1.39 (0.90–2.13)	0.134	Reference		1.63 (0.66–4.00)	0.292	1.47 (0.59–3.64)	0.406
	Yes	Reference		0.71 (0.35–1.43)	0.336	Reference
Area surveyed	Erode	1.13 (0.39–3.28)	0.830	NA	NA	3.59 (0.68–19.01)	0.132	3.72 (0.46–30.25)	0.218
	Jawadhi	10.38 (4.43–24.29)	< 0.001	10.85 (2.65–44.48)	0.001	Reference		NA	NA
	Kalrayan	9.62 (4.28–21.59)	< 0.001	16.90 (4.21–67.86)	< 0.001	12.51 (2.98–52.56)	0.001	4.59 (0.47–44.94)	0.191
	Palamathi	6.11 (2.36–15.82)	< 0.001	2.39 (0.60–9.49)	0.218	0.47 (0.04–5.70)	0.551	NA	NA
	Nilgiris	Reference		2.24 (0.53–9.49)	0.274	4.18 (0.94–18.57)	0.060	3.71 (0.37–36.77)	0.263
	Salem	8.69 (3.21–23.55)	< 0.001	Reference		5.60 (1.01–31.10)	0.049	Reference
	TVmalai	24.10 (9.97–58.27)	< 0.001	3.97 (1.16–13.52)	0.028	0.93 (0.16–5.56)	0.935	26.94 (3.63–200.23)	0.001
	Vellore	15.11 (6.46–35.34)	< 0.001	2.31 (0.66–8.01)	0.189	4.12 (0.81–20.89)	0.088	3.78 (0.48–29.90)	0.207

Significant values are in bold.