Epidemiology of malaria in an area of seasonal transmission in Niger and implications for the design of a seasonal malaria chemoprevention strategy

Table 1 Repartition of malaria confirmation rate, incidence, parasites densities and relative risk by age group in Zindarou, July 2007 to December 2009

Age group	Population	Number of	Number of positive	Asexual parasite density	Annual	RR	p-
(at t = 0)	size	presumptive cases	slides (%)	(p/μl) [CI95%]	incidence (°/°°)	[CI95%]*	value**
<2 years	31	60	34 (56.7)	18, 664 [8, 074–26, 738]	439	2.88 [2.45-3.39]	<0.00012
2-4 years	64	171	97 (56.7)	19, 084 [12, 847–2,5 320]	606	3.98 [3.42-4.65]	<0.0001
5-9 years	62	106	41 (38.7)	5, 312 [1, 641–8, 984]	265	1.74 [1.46-2.09]	<0.0001
10-14 years	58	85	22 (25.9)	4, 027 [1, 136–6, 918]	152	1.0 [0.81-1.23]	0.96
≥15 years	226	543	86 (15.8)	7, 846 [2, 804–12, 888]	152	1.0	-
Total	441	965	280 (29.0)	12, 358 [9, 390–15, 326]	254	-	-

* RR: Risk of malaria by age group relative to risk of malaria in adults (≥15 years).
** p-values were calculated using the Z-score on RR. A p-value < 0.05 was considered significant.

ISSN: 1475-2875