Table 1. Univariate Poisson regression analysis of lagged effects of rainfall on abundance of Anopheles stephensi mosquitoes 2 weeks, 1 month, and 2 months after rainfall periods, US military base, Djibouti, September 2019–August 2020*.

Time after rainfall	Rainfall level, mm/wk	Regression analysis		Abundance
		IRR (95% CI)	p value
2 wk	40–155	0.56 (0.3–1.1)	0.09	2.3
	21.1–39.9	2.4 (1.7–3.4)	<0.0001	9.6
	5–21	1.5 (0.9–2.5)	0.11	6
	0.2–4.9	2.59 (2–3.4)	<0.0001	10.4
	0	Referent		4
1 mo	40–155	1.86 (0.9–2.2)	0.009	7
	21.1– 39.9	2.99 (2–3.8)	<0.0001	11.3
	5–21	1.13 (0.9–2.4)	0.6	4.3
	0.2–4.9	2.58 (1.5–2.7)	<0.0001	9.8
	0	Referent		3.8
2 mo	40–155	1.37 (1.2–3)	0.17	5.5
	21.1–39.9	2.75 (2.1–4.2)	<0.0001	11
	5–21	1.42 (0.7–1.9)	0.18	5.7
	0.2–4.9	2 (1.9–3.5)	<0.0001	8
	0	Referent		4

*Abundance is the average number of mosquitoes per trap night. IRR, incidence rate ratio.