High prevalence of Plasmodium falciparum gametocyte infections in school-age children using molecular detection: patterns and predictors of risk from a cross-sectional study in southern Malawi

Table 4 Predictors of gametocyte density among those PCR-positive for P. falciparum, n = 219

	PCR+, n	Gametocyte carriers, n (%)	Gametocytes/μL, mean (σ)	Adjusted relative density estimate (95% CI)^a	p value
Season
Dry, 2012	52	22 (42.3%)	13.5 (306.2)	1.00 (ref)
Rainy, 2013	167	77 (46.1%)	19.5 (1395.6)	1.13 (0.87–1.47)	0.36
Age
Young children, 6 months to <5 years old	21	9 (42.9%)	21.8 (958.6)	1.03 (0.68–1.54)	0.90
School-age children, 5–15 years old	127	68 (53.5%)	18.9 (571.4)	0.69 (0.53–0.89)	0.005
Adults, ≥16 years old	71	22 (31.0%)	15.4 (2237.5)	1.00 (ref)
Household construction
Finished	76	28 (36.8%)	12.2 (317.8)	1.00 (ref)
Unfinished	143	71 (49.7%)	21.2 (1555.4)	1.31 (1.03–1.65)	0.025
Antimalarial in previous 2 weeks ^b
Yes	8	3 (37.5%)	30.4 (3156.8)	2.46 (1.34–4.50)	0.004
No	211	96 (45.5%)	17.6 (1073.0)	1.00 (ref)
Zero-inflated binomial model characteristics
Logit predictors: Age category, household construction
Dispersion				0.25 (0.19–0.34)
Vuong test Z-score (vs. negative binomial model)				6.04	<0.0001

CI Confidence interval; PCR Polymerase chain reaction
Italized values are those where the 95% CI does not contain 1.0
^aEstimates based on zero-inflated negative binomial model with age category and household construction included in the logit portion of the model, based on finding in Table 3. Estimates are adjusted for all other factors in this table
^bAntimalarials included were lumefantrine–artemether, chloroquine, quinine, or sulfadoxine–pyrimethamine

ISSN: 1475-2875