Table 2. Variation in number of copies of Plasmodium vivax mdr-1 gene among isolates from residents of malaria-endemic continents and from travelers from France to those areas, 1997–2010.

Continent	Residents	Travelers	Total	p value
South America
Isolates with >1 Pvmdr-1 copy	117	41	158
No. (%; 95% CI)	69 (59; 50–68)	14 (34; 20–51)	83 (53; 44–60)	0.01*
Range	1–5	1–2	1–5
Copies, no. (%)
1	48 (41)	27 (66)	75 (47)	10–4*
2	26 (22)	14 (34)	40 (25)
3	32 (27)	0	32 (20)
4	9 (8)	0	9 (6)
5	2 (2)	0	2 (1)
Mean (95% CI)	2.0 (1.8–2.2)	1.2 (1.0–1.3)	1.8 (1.7–2.0)	<10–5†
Asia
Isolates with >1 Pvmdr-1 copy	117	60	177
No. (%; 95% CI)	37 (32; 23–45)	23 (38; 24–57)	60 (34; 26–44)	0.5*
Range	1–4	1–3	1–4
Copies, no. (%)
1	80 (68)	37 (62)	117 (66)	0.68*
2	34 (29)	22 (37)	56 (32)
3	2 (2)	1 (2)	3 (2)
4	1 (1)	0	1 (1)
Mean (95% CI)	1.3 (1.2–1.4)	1.4 (1.3–1.5)	1.3 (1.2–1.4)	0.41†
Africa
Isolates with >1 Pvmdr-1 copy	258	14	272
No. (%; 95% CI)	3 (1; 0.2–3)	8 (57; 24–100)	11 (4; 2–7)	<10–8*
Range	1–2	1–2	1–2
Copies, no. (%)
1	255 (99)	6 (43)	261 (96)	<10–8*
2	3 (1)	8 (57)	11 (4)
Mean (95% CI)	0.9 (0.9–1.0)	1.3 (1.1–1.6)	0.9 (0.9–1.0)	<10–8†

*χ² test.
†1-Way analysis of variance.