Table 4. Summary of epidemiological analyses showing percentage of variation in P. falciparum (Pf) and P. vivax (Pv) gametocyte traits explained by environmental variables and two human genetic mutations.

Gametocyte Positivity
Site	Infection type	Age		Date		Asexual parasite density		HbS		α-globin 3.7 deletion
		%	P	%	P	%	P	%	P	%	P
Dielmo	Symptomatic	0.3	0.0017	0	0.16	0.3	0.015	0.3	0.047	0	0.90
	Asymptomatic	3.3	<0.001	2.4	<0.001	2.7	<0.001	<0.1	0.021	0	0.24
Ndiop	Symp	2.3	<0.001	2.3	0.007	2.7	<0.001	1.4	<0.001	0	0.92
	Asymp	0.6	0.004	2.2	<0.001	0	0.52	0.2	0.016	0	0.91
Gouye Kouly	Asymp	0	0.45	4.5	<0.001	10.4	<0.001	0	0.23	ND	ND
Suan Phung	Symp PF	3.4	<0.001	5.7	<0.001	2.0	<0.001	NA	NA	0	0.47
	Symp PV	0	0.37	1.5	0.002	5.3	<0.001	NA	NA	0	0.26

In parentheses, p is the p-value, otherwise p<10⁻³; ND – not done. NA – not applicable; the HbS mutation was not found in Suan Phung (Thailand). Age: 2 groups in Ndiop, 0–9 & 10+ years old; 3 groups in Dielmo: 0–4, 5–9, 10+; age is a continuous variable in Gouye Kouly; 2 groups in Suan Phung 0–14 & 15+. Date: by season (semester-year) in Ndiop, Dielmo and Suan Phung, and by month (3) in Gouye Kouly. Because of low numbers of homozygote mutations in HBB (beta-globin) and HBA (alpha-globin), these groups were combined with heterozygote mutation group and compared with wildtype (See Table 3). Symp – symptomatic infection; Asymp – asymptomatic infection. PF - P. falciparum; PV – P. vivax.