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Volume 9, Number 1—January 2003

Research

A Molecular Surveillance System for Global Patterns of Drug Resistance in Imported Malaria

Annie-Claude Labbé*, Samir Patel*, Ian Crandall*, and Kevin C. Kain*Comments to Author 
Author affiliations: *Toronto General Hospital, University of Toronto, Canada

Main Article

Table 1

Prevalence of molecular markers of drug resistance by region of malaria acquisition


Area of endemicity
n (%)
Total
Genotypes
West Africaa
East Africab
Central Africac
Southern Africad
Othere
n (%; 95%CI)f
pfmdr1
N86 (wild)
40 (59.7)
5 (29.4)
1 (20.0)
1 (33.3)
6 (75.0)
53 (53.0; 42.8 to 63.1)
86Y (mutant)
27 (40.3)
12 (70.6)
4 (80.0)
2 (66.7)
2 (25.0)
47 (47.0; 36.9 to 57.2)
pfcrt






K76 (wild)
32 (49.2)
3 (17.6)
3 (60.0)
0
1 (11.1)
39 (39.8; 30.0 to 50.2)
76T (mutant)
33 (50.8)
14 (82.4)
2 (40.0)
2 (100)
8 (88.9)
59 (60.2; 49.8 to 70.0)
dhfrg






Wild-type
17 (25.0)
3 (17.6)
3 (60.0)
1 (33.3)
2 (22.2)
26 (25.5; 17.4 to 35.1)
Single mutants
6 (8.8)
0
0
0
3 (33.3)
9 (8.8; 4.1 to 16.1)
Double mutants
25 (36.8)
8 (47.1)
1 (20.0)
2 (66.7)
3 (33.3)
39 (38.2; 28.8 to 48.4)
Triple mutants
20 (29.4)
6 (35.3)
1 (20.0)
0
1 (11.1)
28 (27.5; 19.1 to 37.2)
dhpsh






Wild-type
3 (4.4)
7 (41.2)
0
2 (66.7)
8 (88.9)
20 (19.6; 12.4 to 28.6)
Single mutants
40 (58.8)
5 (29.4)
5 (100)
1 (33.3)
0
51 (50.0; 40.0 to 60.1)
Double mutants
21 (30.9)
5 (29.4)
0
0
0
26 (25.5; 17.4 to 35.1)
Triple mutants
4 (5.9)
0
0
0
1 (11.1)
5 (4.9; 1.6 to 11.1)
No. of infected patients 71 (67.6) 17 (16.2) 5 (4.8) 3 (2.9) 9 (8.6) 105

aTwo patients had visited more than one country: Ghana (45 patients), Nigeria (21), The Gambia (2 patients), Sierra Leone (3 patients), Burkina Faso (1 patient), Mali (1 patient), and Guinea (1 patient).

bThree patients had visited more than one country: Kenya (9 patients), Uganda (6 patients), Tanzania (3 patients), Rwanda (1 patient), and Burundi (1 patient).

cCentral African Republic (2 patients), Congo (2 patients), and Cameroon (1 patient)

dAngola (2 patients) and Madagascar (1 patient).

eIndia (5 patients), Malaysia (1 patient), Bali/New Guinea (1 patient), Brazil (1 patient), and Haiti (1 patient).

f CI, confidence interval.

gdhfr: Wild-type: parasites with A16 / C50 / N51 / C59 / S108 / I164 (n = 26). Single mutants: isolates with the S108N alone (n=9). Double mutants: parasites with mutations at codons N51I and S108N (n=11), C59R and S108N (n=27), or A16V and S108T (n=1). Triple mutants: parasites with the genotypes of N51I / C59R / S108N (n=27) or C50R / N51I / S108N (n=1). Of note, the falciparum isolate with the A16V/S108T mutations was acquired in 1996 by a 12-year-old in Ghana. Those mutations in dhfr were not accompanied by the mutant codon I164L, previously associated with pyrimethamine and cycloguanil resistance (17).

hdhps: Wild-type parasites: parasites with S436 / A437 / K540 / A581 / A613 (n=20). Single mutants: isolates with the S436A (n=19) or A437G (n=32) mutation alone. Double mutants: parasites with mutations at codons S436A and A437G (n=18), A437G and K540E (n=6), or S436F and A613S (n=2). Triple mutants: parasites with S436A / A437G / A613S (n = 3), S436A / A437G / A581G (n=1), or A437G / K540E / A581G (n=1). Note: Some isolates could not be amplified at all loci and account for occasional missing values.

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