Socio-demographic characteristics of the patients included in the study
A total of 150 patients were enrolled in this study. The male sex was predominant with a frequency of 56.67% and a sex ratio which is 1.30. The mean age of the patients was 10 years ± 9 years. Patients in the age group [5–15 years] were the most found, i.e. 64% (96/150) The median age was 8 years with a minimum of 6 months and a maximum of 68 years. The average axillary temperature is 38.54°C ± 0.80°C. As for the average weight of the patients, it is 27.04 Kg. Patients with a weight of less than 25 Kg were the most represented. Regarding the frequency of patients at the study sites, the CSPS of Zabré dominates with a number of 48 patients or 45.33%, followed by the CSPS of Donsin with 22. The CSPS of Bazoulé, Bendogo and Pabré present respectively 13.33%, 2.67% and 16.67%.
Prevalence of the Plasmodium falciparum chloroquine resistance transporter (Pfcrt) gene associated with the resistance of P. falciparum to Chloroquine and Amodiaquine
The prevalence of the mutant strains (Pfcrt 76T) was observed at 46.67% (70/150). As for the wild-type strain (Pfcrt K76) and the mixed strain (Pfcrt K76T), they were respectively observed at 0.67% and 52.67%.
Distribution of mutant strains ( Pfcrt 76T ) according to age and sex
The age group ]5–15 years] has the highest Pfcrt 76T mutation frequency, i.e. 61.43% (43/70), followed by the age group ]0–5 years] with a frequency of 25.71% (18/70). It was observed a frequency of 10% for patients in the range of ]15–25 years] and 1.43% each for the age groups of ]25–35 years] and ]55–68 years].
The wild strain was very weakly observed and there is a predominance of the mixed strain in patients in the age range ]5–15 years] with a frequency of 60.75%. There is a significant observed link between age and Pfcrt 76T mutation (P = 0.000).
The male sex being the most observed among the patients, we obtained a mutation frequency of 55.71% against the female sex showed 44.28%. The mixed strain was also observed more in men than in women. We did not observe a significant link between sex and mutation (P = 0.673)
Distribution of mutant strains ( Pfcrt 76T ) according to parasite density (DP) and study sites
The parasitic density range ]2000–52000 P/µl] presenting the most effective shows us a mutation of 58.57%, followed by the parasitic density ]52000–102000] with a frequency of 24.28%. The mutation frequencies of 13.33%, 2.67% and 16.67% are respectively for the parasite density slices (parasites /µl) ]102000–152000], ]152000–202000] and ]202000–252000]. There is no significant link observed between the mutation and the parasite density (P = 0.310). The CSPS of Zabré showed a higher proportion of mutant strain (51.42%) compared to the other CSPS where our study took place. This superiority is also observed at the level of the wild and mixed CSPS strain from Zabré compared to the other study sites. Then, at the level of the mutant strain, we observe the CSPS of Donsin which comes in second position with a frequency of 22.85%, followed by the CSPS of Bazoulé (12.85%), Pabré (11.42%) and Bendogo which comes in last position with 1.42%. The comparison of the mutation frequency concerning the study site shows us that there is no significant link (P = 0.699).
Prevalence of Plasmodium falciparum multidrug resistance 1(Pfmdr1) gene associated with the resistance of P. falciparum to Chloroquine, Quinine, Amodiaquine Lumefantrine and dihydroartemisinin-piperaquine
The mutation of the Pfmdr1 gene (Pfmdr1 86Y) was very weakly observed (2/150), i.e. a prevalence of 1.33%. The wild-type strain (Pfmdr1 N86) is the most found (148/150) with a frequency of 98.67%. However, there is no mixed strain observed and the double mutation Pfcrt 76T + Pfmdr1 86Y was also very weakly found, i.e. 0.66%.
Distribution of mutant strains ( Pfmdr-186Y ) according to age and sex
The two mutations observed were found in the age range ]5–15 years]. The wild strain is also observed mainly in the age range [5–15 years] with a frequency of 63.51% (94/148). The male and female sexes shared the mutation, i.e. 50% each, unlike the wild strain where 56.75% and 42.66% are observed respectively. For this purpose, there is no significant link of the Pfmdr-186Y mutation observed at the level of age (P = 1) and sex (P = 0.848).
The frequency of mutant strains ( Pmdr1-86Y ) depending on the parasite density and the study site
The mutations observed are distributed between the parasite density range ]2000–52000] and ]52000–102000] parasites/ µl, i.e. a frequency of 50% each. These two observed mutations are found in the Bazoulé CSPS. A significant difference in the mutation was therefore observed depending on the study site (P = 0.010). As for the wild strain, the majority is found in the parasite density range ]2000–52000] i.e. 66.22%.
Prevalence of the Plasmodium falciparum dihydropteroate synthase (Pdhps) gene associated with the resistance of P. falciparum to sulfadoxine-pyrimethamine (SP)
Pdhps gene is present in two types of mutations namely: Pfdhps 437G and Pfdhps 540E. Here in our study, we observed only one mutation which is that of Pfdhps 437G or 0.67% (1/150). This mutant strain observed is much lower than the prevalence of the wild-type strain (Pfdhps A437) which is 93.33% (149/150). As for the wild strain (Pfdhps K540), it is found at 97.33% (146/150), followed by 2.67% (4/150) of mixed strain. The only Pfdhps 437G mutation was identified in the male patient in the age range ]5–15 years] with an accuracy of 13 years. It was observed in the patient coming from the pabré CSPS having a parasite density of 88888 parasites / µl thus being in the range ]52000–102000] parasites / µl.
Prevalence of the Plasmodium falciparum dihydrofolate reductase (Pfdhfr) gene associated with the resistance of P. falciparum to sulfadoxine -pyrimethamine (SP)
We have explored four types of mutations of the Pfdhfr gene namely Pfdhfr 51I, Pfdhfr 59R, Pfdhfr 108N and Pfdhfr 164L, and we have obtained respectively a frequency of 20% (30/150), 82% (123/150), 4,67% (7/150) and 0%. Thus, it is therefore found that there is no Pfdhfr 164L mutation observed and that the Pfdhfr 59R mutation is the most found concerning the Pfdhfr 51I and Pfdhfr 108N mutations. For this purpose, we observed a double mutation (51I + 59R) at the Pfdhfr gene level, i.e. a prevalence of 16.66% (25/150). We have also generally observed a triple mutation (Pfdhps 437G + Pfdhfr 59R + Pfdhfr 108N) with a low frequency which is 0.67% (1/150). Figure 2. below shows us the distribution of the different strains, namely mutant, wild-type and mixed strains of the Pfdhfr gene.
Distribution of the mutant strains (51I, 59R, 108N) of the Pfdhfr gene according to the age and sex of the patients
The mutations Pfdhfr 59R, Pfdhfr 51I, and Pfdhfr 108N were respectively observed at 65,85% (81/123), 60% (18/30), and 71.43% (5/7) in the age group ]5–15 years]. This age group has more mutation compared to other age groups. As for the distribution according to sex, the male sex was the most found at the level of the different mutations with a predominance of Pfdhfr 59R. However, there is no significant link observed with age (P = 0.833) and sex (P = 0.733) compared to the Pfdhfr 59R mutation. Table 5 below shows the distribution of the different strains according to age and sex.
Table 5
Distribution of different strains of the Pfdhfr gene according to age and sex.
Gene Pfdhfr |
| Pfdhfr 51I (%) N = 30 | Pfdhfr N51 (%) N = 74 | Mixed (%) N = 46 |
Age range | | | |
]0–5] | 07 (23.33) | 14 (18.92) | 13 (28.26) |
]5–15] | 18 (60) | 51 (68.92) | 27 (58.70) |
]15–25] | 04(3.33) | 06 (8.11) | 04 (8.70) |
]25–35] | 01(3.33) | 1(1.35) | 1 (2.17) |
]35–45] | 00 | 00 | 00 |
]45–55] | 00 | 02 (2.70) | 00 |
]55–68] | 00 | 00 | 1 (2.17) |
Sex | | | |
Male | 16 (53.33) | 45 (60.81) | 24 (28,24) |
Female | 14 (46.66) | 29 (39.18) | 22 (33.85) |
| Pfdhfr 59R (%) N = 123 | Pfdhfr C59 (%) N = 22 | Mixed (%) N = 05 |
Age range | | | |
]0–5] | 23 (18.70) | 11 (50) | 00 |
]5–15] | 81 (65.85) | 10 (45.45) | 05 (100) |
]15–25] | 13 (10.57) | 1 (4.54) | 00 |
]25–35] | 3 (2.44) | 00 | 00 |
]35–45] | 1(0.81) | 00 | 00 |
]45–55] | 2 (1.63) | 00 | 00 |
]55–68] | 1(0.81) | 00 | 00 |
Sex | | | |
Male | 70 (56.91) | 13 (59.09) | 02 (40) |
Female | 53 (43.08) | 9 (40.90) | 03 (60) |
| Pfdhfr 108N (%) | Pfdhfr S108 (%) | Pfdhfr I164 (%) |
Age range | N = 7 | N = 143 | N = 150 |
]0–5] | 02 (28.57) | 32 (22.38) | 34 (22.67) |
]5–15] | 05 (71.43) | 91 (63.64) | 96 (64) |
]15–25] | 00 | 14 (9.79) | 14 (9.33) |
]25–35] | 00 | 3 (2.10) | 3(2) |
]35–45] | 00 | 00 | 00 |
]45–55] | 00 | 02(1.40) | 02 (1.33) |
]55–68] | 00 | 1(0.70) | 01 (0.67) |
Sex | | | |
Male | 05 (71.42) | 80 (55.94) | 85 (56.66) |
Female | 02 (28.57) | 63 (44.05) | 65 (43.33) |
N = Total number |
Distribution of mutant strains (51I, 59R, 108N), of the Pfdhfr gene according to parasite density and study sites
The parasite density range ]2000–52000 parasites / µl] has the highest mutation rate at the level of the three types of mutations observed, namely Pfdhfr 51I, Pfdhfr 59R and Pfdhfr 108N with respectively 53,33% (16/30), 68,29 (84/123) and 71.42 (5/7).
Pfdhfr 51I and 59R mutant strains being the most observed were found in Zabré with respective frequencies of 100% (30/30) and 40.65% (50/123). The Pfdhfr 108N mutation, for its part, is not observed in Zabré but rather in Bazoulé and Pabré with respective frequencies of 57.14% (4/7) and 42.85% (3/7). A significant difference was observed in the Pfdhfr 51I mutation (P = 0.000) and Pfdhfr 108N (P = 0.02) depending on the study sites, which was not the case for the Pfdhfr 59R mutation (P = 0.036).