Infant sex modifies associations between placental malaria and risk of malaria in infancy

Malaria Journal

Table 2 Association between different measures of placental malaria and incidence of malaria during infancy

Infant category	Placental malaria categories (N)	Malaria episodes	Person years of follow-up	Malaria incidence^a	Unadjusted		Adjusted^b
Infant category	Placental malaria categories (N)	Malaria episodes	Person years of follow-up	Malaria incidence^a	IRR (95% CI)	p value	IRR (95% CI)	p-value
All	No PM (351)	574	327.4	1.75	Reference group		Reference group
	Active PM (78)	152	68.9	2.21	1.27 (0.99–1.62)	0.06	1.30 (1.00-1.71)	0.05
	Past PM (mild-mod) (181)	271	157.8	1.72	0.97 (0.79–1.18)	0.74	0.94 (0.76-1.16)	0.55
	Past PM (severe) (46)	91	42.5	2.14	1.22 (0.91–1.63)	0.19	1.28 (0.89-1.83)	0.18
Male	No PM (168)	255	154.5	1.65	Reference group		Reference group
	Active PM (45)	86	39.9	2.16	1.31 (0.93–1.87)	0.13	1.27 (0.87–1.84)	0.22
	Past PM (mild-mod) (70)	129	77.7	1.66	0.98 (0.72–1.35)	0.92	1.02 (0.76–1.36)	0.90
	Past PM (severe) (17)	49	15.3	3.20	1.87 (1.29–2.71)	0.001	2.17 (1.45–3.25)	<0.001
Female	No PM (183)	319	172.9	1.84	Reference group		Reference group
	Active PM (33)	66	29.0	2.28	1.24 (0.89–1.73)	0.21	1.29 (0.87–1.91)	0.21
	Past PM (mild-mod) (91)	142	80.1	1.77	0.96 (0.73–1.24)	0.74	0.81 (0.61–1.08)	0.15
	Past PM (severe) (29)	42	27.1	1.55	0.85 (0.58–1.24)	0.40	0.74 (0.46–1.20)	0.22

CI confidence interval, IRR incidence rate ratio, mild-mod mild-moderate, PM placental malaria
^aEpisodes of malaria per person year of follow-up
^bAdjusted for gravidity, maternal IPTp, maternal parasitaemia at enrolment, and household type
No PM no parasites or pigment detected, active PM parasites detected with or without pigment, past PM (mild-mod) > 0–20% of high-power fields with pigment but no parasites, past PM(severe) > 20%–60% of high-power fields with pigment but no parasites

ISSN: 1475-2875