Table 2.

Demographic and household characteristics and mosquito-borne prevention measures for chikungunya virus–infected and noninfected participants

Characteristics and measures	Chikungunya virus–infected participants (%)	Chikungunya virus noninfected participants (%)	aRR	(95% CI)
Male gender	41	47	0.83	(0.63–0.91)
Age group (in years)
0–19	18	20	0.90	(0.50–1.63)
20–39	22	21	Ref	–
40–59	28	34	0.86	(0.53–1.40)
≥ 60	31	24	1.17	(0.75–1.85)
Employment status
Working	42	49	0.82	(0.63–1.07)
Retired	24	18	1.27	(0.94–1.73)
Not working	17	13	1.22	(0.84–1.76)
School	16	19	0.90	(0.60–1.34)
Time per day outside
1 hour	15	15	Ref	–
1–4 hours	35	36	0.98	(0.61–1.55)
5–8 hours	24	25	0.96	(0.55–1.67)
8 hours	26	24	1.04	(0.61–1.79)
Repellent usage
All the time	1	5	Ref	–
Some of the time	29	25	7.25	(1.01–1.52)
Never	71	71	6.59	(0.92–47)
Air conditioning
Central	5	5	0.97	(0.64–1.46)
Local (one to two bedrooms)	31	32	0.94	(0.41–2.17)
None	64	63	Ref	–
Presence of water-holding container in yard
Water cistern	45	48	0.91	(0.70–1.19)
Potted plants	41	40	1.02	(0.78–1.35)
Buckets	28	26	1.06	(0.80–1.42)
Septic tank	24	35	0.68	(0.50–0.92)
Trash	9	12	0.80	(0.50–1.28)
Used old tires	5	8	0.73	(0.40–1.34)
Windows open
All times	73	79	0.66	(0.36–1.22)
During the day	14	14	0.71	(0.33–1.54)
During the night	3	2	0.88	(0.27–2.83)
Never	10	5	Ref	–
Annual household income
≤ $25,000	28	23	3.97	(1.14–13)
$26,000–$50,000	19	20	3.36	(0.93–12)
$51,000–$75,000	14	16	3.16	(0.84–12)
≥ $76,000	4	17	Ref	–
Declined to answer	36	24	–	–

CI = confidence interval; aRR = adjusted relative risk ratio.