Table 3.

Unadjusted odds ratios of the association between submicroscopic P. falciparum infection and fever within strata of covariates

Characteristic	Proportion with fevera (%)	OR (95% CIb)	Proportion with objective feverc	OR (95% CI)
Season
Rainy
Submicroscopic	73/756 (9.7)	1.22 (0.94–1.58)	11/751 (1.5)	1.30 (0.68–2.47)
No parasitaemia	458/5683 (8.1)	Ref	64/5648 (1.1)	Ref
Dry
Submicroscopic	23/652 (3.5)	0.51 (0.33–0.78)	5/652 (0.8)	0.65 (0.26–1.60)
No parasitaemia	478/7148 (6.7)	Ref	84/7115 (1.2)	Ref
District
Blantyre
Submicroscopic	15/282 (5.3)	0.98 (0.56–1.69)	1/282 (0.4)	0.38 (0.05–2.76)
No parasitaemia	261/4637 (5.6)	Ref	43/4615 (0.9)	Ref
Chikhwawa
Submicroscopic	61/727 (8.4)	0.94 (0.69–1.27)	12/725 (1.7)	0.97 (0.5–1.80)
No parasitaemia	328/3762 (8.7)	Ref	64/3746 (1.7)	Ref
Thyolo
Submicroscopic	20/399 (5.0)	0.62 (0.39–1.0)	3/396 (0.8)	0.81 (0.25–2.63)
No parasitaemia	347/4432 (7.8)	Ref	41/4402 (0.9)	Ref
Age groups
6 months–5 years
Submicroscopic	19/181 (10.5)	1.15 (0.70–1.88)	1/181 (0.55)	0.40 (0.06–2.97)
No parasitaemia	281/3040 (9.2)	Ref	41/3040(1.3)	Ref
6–15 years
Submicroscopic	26/597 (4.4)	0.86 (0.56–1.31)	4/596 (0.6)	0.50 (0.81–1.40)
No parasitaemia	191/3796 (5.0)	Ref	50/3776 (1.3)	Ref
16 years & above
Submicroscopic	51/630 (8.1)	1.05 (0.78–1.42)	11/628 (1.8)	1.85 (0.96–3.54)
No parasitaemia	464/5995 (7.7)	Ref	57/5957 (0.9)	Ref

OR: odds ratio

^aFever: At least one of these 3: reported fever in the past 2 weeks, reported fever in the past 48 h and temperature measured at the time of the interview and specimen collection

^b95% CI: 95% confidence interval from mixed effect logistic regression adjusted for clustering within household and EA

^cObjective fever: Measured temperature ≥ 37.5° (14, 166 participants)