This work aimed to study asymptomatic malaria among pregnant women consulting Saint Camille Medical Centre at Ouagadougou in Burkina Faso. We have shown that the prevalence of asymptomatic malaria among women was 30% and 24% using an RDT and microscopy, respectively. The difference was not significant but could be explained by the persistence of histidine rich protein 2 (HRP-2) antigen of P. falciparum
after the parasite clearance [9
]. The RDT used had a sensitivity of 100% and a specificity of 92% compared to conventional microscopy. Our results are comparable to those from studies in Cote d'Ivoire and Senegal with sensitivities of 100% and 96% and specificities of 88% and 87%, respectively, [10
We evaluated through a questionnaire the use of ITNs in pregnant women. Only 42% of the women used an ITN. Several reasons explain the low use of ITNs: psychological effects of suffocation, ignorance of the risks of malaria during pregnancy, and the cost of the net. Utilization of ITNs varies between studies, 58% and 9% in Burkina [6
] and 16% in Nigeria [13
The fight against malaria in pregnant women involves the use of insecticide-treated nets and intermittent preventive treatment (IPT) with sulfadoxine-pyrimethamine (SP). Thus, all pregnant women living in areas of stable malaria transmission should receive at least two doses of IPT as recommended by the World Health Organization [14
Only 27% of the pregnant women have taken the first dose of SP and less than half of the women used iron supplement and folic acid. This low use of iron and SP can be explained by the fact that most of the women began their prenatal checks from the fifth month of the pregnancy for various reasons including the ignorance of risk associated with poorly managed and monitored pregnancy and a lack of financial resources.
The use of SP as an intermittent preventive treatment by pregnant women was associated with a reduced prevalence of P. falciparum
asymptomatic infection compared to those who did not receive SP (13% versus 29%, P
= 0.0182). Our results are comparable to those obtained in Ghana [15
] where 15% versus 45% of P. falciparum
infection was observed among pregnant women in the presence or absence of the intermittent preventive treatment, respectively.
WHO defined anaemia in pregnant women as a haemoglobin level <11
]. We found that 61% (123/201) of the pregnant women in the study were anaemic. Interestingly, this anaemia was correlated with the presence of P. falciparum
asymptomatic. Indeed, 33% of all pregnant anaemic women were positive for P. falciparum
compared with 10% of anaemic women without parasitaemia. The prevalence of anaemia observed in this study is comparable to those of previous studies obtained 66% [17
], 64% [12
] in Burkina Faso, and 64% [18
] in Benin. The correlation between P. falciparum
and anemia found in this study is similar to those reported in Nigeria [19
We did not find a significant correlation between anaemia and gravida. This is in accordance with a previous report on P. falciparum
asymptomatic malaria in Nigerian pregnant women [21
]. However, other studies have shown higher rates of anaemic women in primiparous women compared to multiparous ones [19
Nutrical deficiencies including iron and folic acid have been linked to anaemia. Our study shows that 83% of pregnant women had a normal serum iron but 62% of them had a low level of folate; this is in discordance with what has been previously reported on Nigerian pregnant women [24
High levels of homocysteine (HCY) play a role in pregnancy complications such as an increased risk of eclampsia, spina bifida malformation, children with low birth weight, stillbirths, and premature births [25
]. Most pregnant women (90%) had normal values of homocysteine (≤12μ
mol/L). The mean value of homocysteine (10.5μ
mol/L) found in pregnant women is higher than the value of 3.6μ
mol/L obtained in healthy women in Burkina Faso [26
]. This difference could be explained by physiological changes during pregnancy. However, the average homocysteine levels found in our study were lower than those found in Nigeria (14.1μ
] and the difference could be due to the high prevalence of moderate hyperhomocysteinaemia among adolescents and adults of both sexes in the Nigerian population [27
]. Indeed studies conducted in Burkina showed that plasma homocysteine (HCY) varies according to gender, age, and nutritional habits [26
]. We did not find an association between haemoglobin type and anaemia in pregnant women. With regard to blood groups, we found that pregnant women of blood group O were less infected than those of non-O blood groups, but this difference was not significant. However, that study in Nigeria found that pregnant women group O were more infected by P. falciparum
Our findings are interesting because we have demonstrated as previously reported in other studies [4
] that P. falciparum
asymptomatic malaria is responsible for anaemia in pregnant women in Burkina Faso. However, there are some potential limitations in our study to be considered. First, P. falciparum
asymptomatic malaria was identified using RDT and optical microscopy. The sensitivity of these tests is low for the detection of very low parasitaemia. Indeed, a recent study has shown a higher prevalence of asymptomatic malaria detected by polymerase chain reaction (PCR) compared with other diagnostic methods [9
]. Thus, the prevalence of asymptomatic malaria reported in our study may be underestimated. In addition, to define anaemia we only measured haemoglobin levels among pregnant women.
Several studies documented an impact of asymptomatic malaria on haematological markers like blood count, ferritin, and transferrin levels [30
]. But our study did not include the evaluation of those parameters.
A subsequent study could focus on the role of folic acid in reducing anaemia among pregnant women with mild or asymptomatic malaria. Intermittent preventive treatment of malaria in pregnant women is ensured by SP. Therefore, monitoring of SP resistance by P. falciparum is necessary among pregnant women.