Table 4.

Levels of Antibodies to MSP2 by Age Group and Parasitemia Status

MSP2 (3D7 Allele)		All Samples					Aparasitemic					Parasitemic
		0 y	1–3 y	4–6 y	7–10 y	P Valuea	0 y	1–3 y	4–6 y	7–10 y	P Valuea	0 y	1–3 y	4–6 y	7–10 y	P Valuea
May 2002b	No.c	30	128	117	23		30	109	93	15		0	19	24	8
	Median	0.04	0.13	0.33	0.33	<.001 d	0.04	0.10	0.28	0.29	<.001 d	0.00	0.89	1.14	1.76	.640
	IQR	(0.02–0.13)	(0.03–0.4)	(0.12–1.09)	(0.11–1.29)		(0.02–0.13)	(0.03–0.3)	(0.12–0.82)	(0.11–0.87)		(0–0)	(0.58–1.58)	(0.16–2.08)	(0.33–2.43)
October 2002b	No.c	37	110	108	36		36	105	99	31		1	5	9	5
	Median	0.04	0.05	0.14	0.14	<.001 d	0.04	0.04	0.13	0.12	<.001 d	0.01	0.62	0.21	1.65	.193
	IQR	(0.01–0.1)	(0.02–0.09)	(0.06–0.34)	(0.07–0.47)		(0.02–0.1)	(0.02–0.08)	(0.06–0.33)	(0.07–0.34)		(0.01–0.01)	(0.04–0.77)	(0.14–0.54)	(0.5–2.43)
May 2003b	No.c	27	102	105	51		26	93	88	40		1	9	17	11
	Median	0.09	0.04	0.13	0.13	<.001 d	0.10	0.04	0.10	0.14	<.001 d	0.06	0.12	0.73	1.16	.048 d
	IQR	(0.01–0.23)	(0.01–0.1)	(0.05–0.43)	(0.07–0.72)		(0.01–0.23)	(0.01–0.09)	(0.04–0.31)	(0.06–0.31)		(0.06–0.06)	(0.04–0.26)	(0.2–1.39)	(0.2–2.56)
October 2003b	No.c	23	103	110	58		23	93	91	45		10	18	13	0
	Median	0.08	0.06	0.13	0.13	<.001 d	0.08	0.06	0.10	0.18	<.001 d	0.43	0.49	1.77	0.00	.426
	IQR	(0.04–0.19)	(0.02–0.25)	(0.05–0.41)	(0.08–0.56)		(0.04–0.19)	(0.01–0.16)	(0.04–0.28)	(0.07–0.44)		(0.29–1.03)	(0.32–0.75)	(0.32–2.17)	(0–0)
May 2004b	No.c	21	93	86	79		21	88	84	69		0	5	2	10
	Median	0.01	0.04	0.08	0.08	<.001 d	0.01	0.03	0.08	0.17	<.001 d	0.00	0.22	0.49	0.43	.809
	IQR	(0–0.02)	(0–0.1)	(0.04–0.24)	(0.06–0.6)		(0–0.02)	(0–0.09)	(0.04–0.23)	(0.04–0.47)		(0–0)	(0.2–1.53)	(0.25–0.72)	(0.17–2.14)
October 2004b	No.c	15	84	87	87		15	80	87	81		0	4	0	6
	Median	0.02	0.04	0.07	0.07	<.001 d	0.02	0.03	0.07	0.13	<.001 d	0.00	0.45	0.00	1.63	.088
	IQR	(0.01–0.06)	(0.01–0.08)	(0.03–0.14)	(0.05–0.45)		(0.01–0.06)	(0.01–0.07)	(0.03–0.14)	(0.05–0.37)		(0–0)	(0.13–1.33)	(0–0)	(1.17–2.31)

Abbreviation: IQR, interquartile range.

^a P values calculated using a Kruskal–Wallis test (P ≤ .05 indicated in bold type).

^bCross-sectional survey.

^cNumber of samples tested by enzyme-linked immunosorbent assay. Data on antibodies to the FC27 allele of MSP2 are provided in the Supplementary Materials.

^d P ≤ .05 when comparing antibody levels between children aged 1–3 years and children aged 7–10 years using a Mann–Whitney U test (P values not shown).