Background
Methods
Study site
Study population and blood sample collection
Extraction of parasite DNA
Allelic genotyping of the Plasmodium falciparum msp1 and msp2 genes
Detection of alleles
Multiplicity of infection
Statistical analysis
Results
General characteristics
Frequency of msp1 and msp2 allelic families
Gene | Allelic type | Age group (years) | Total | |||
---|---|---|---|---|---|---|
< 5 | 5–19 | 20–39 | ≥ 40 | |||
n (%) | n (%) | n (%) | n (%) | n (%) | ||
(n = 6) | (n = 47) | (n = 88) | (n = 40) | (n = 181) | ||
msp1
| K1 | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
MAD20 | 0 (0) | 0 (0) | 0 (0) | 2 (5.0) | 2 (1.1) | |
RO33 | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | |
K1/MAD20 | 0 (0) | 5 (10.6) | 28 (31.8) | 17 (42.5) | 50 (27.6) | |
K1/RO33 | 1 (26.7) | 0 (0) | 1 (1.1) | 1 (2.5) | 3 (1.7) | |
MAD20/RO33 | 0 (0) | 1 (0.55) | 1 (1.1) | 3 (7.5) | 5 (2.8) | |
K1/MAD20/RO33 | 5 (83.3) | 41 (87.2) | 55 (62.5) | 17 (42.5) | 118 (65.2) | |
Total | 6 (100) | 47 (100) | 85 (96.6) | 38 (95) | 178 (97.2) | |
MOI | 3.33 | 3.81 | 3.59 | 3.03 | 3.5 | |
msp2
| 3D7 | 1 (26.7) | 7 (14.9) | 26 (29.5) | 14 (35) | 48 (26.5) |
FC27 | 1 (26.7) | 1 (2.1) | 1 (1.1) | 1 (2.5) | 4 (2.2) | |
3D7/FC27 | 4 (66.7) | 37 (78.7) | 55 (62.5) | 25 (62.5) | 121 (66.9) | |
Total | 6 (100) | 45 (95.7) | 82 (93.2) | 40 (100) | 173 (95.6) | |
MOI | 1.83 | 2.31 | 2.01 | 2.1 | 2.01 | |
Multiclonal isolates | 6 (100) | 47 (100) | 87 (98.9) | 41 (100) | 181 (100) | |
Overall MOI | 5.17 | 6.02 | 5.53 | 5.13 | 5.51 |
Genetic diversity and allelic frequency
MOI, parasite density and different distribution of allelic families across different age groups
Gene | Allelic type | Parasite density (no. of parasites/μl) | ||
---|---|---|---|---|
< 1000 | 1000–9999 | ≥ 10,000 (%) | ||
n (%) | n (%) | n (%) | ||
(n = 14) | (n = 74) | (n = 93) | ||
msp1
| MAD20 | 1 (7.1) | 0 | 1 (1.1) |
K1/MAD20 | 3 (21.4) | 22 (29.7) | 25 (27.8) | |
K1/RO33 | 1 (7.1) | 1 (1.4) | 1 (1.1) | |
MAD20/RO33 | 0 | 4 (5.4) | 1 (1.1) | |
K1/MAD20/RO33 | 9 (64.3) | 46 (62.2) | 63 (70) | |
Total | 13 (92.9) | 73 (98.6) | 90 (49.72) | |
MOI | 3.07 | 3.63 | 3.48 | |
msp2
| 3D7 | 3 (21.4) | 25 (33.8) | 20 (21.5) |
FC27 | 1 (7.1) | 2 (2.7) | 1 (1.1) | |
3D7/FC27 | 7 (50) | 45 (60.8) | 69 (74.2) | |
Total | 7 (50) | 45 (60.8) | 69 (74.2) | |
MOI | 1.73 | 1.90 | 2.31 | |
Multiclonal isolates | 14 (100) | 74 (100) | 93 (100) | |
Overall MOI | 4.43 | 5.51 | 5.77 |