Gestational malaria remains a major public health problem since it leads to severe risks for the mother, the fetus or the newborn child. This study investigated the epidemiology of malaria in Gabon and estimated the level of adherence to IPT-SP in pregnant women. We noted an average of about 200 deliveries per year, which represents between four and five deliveries per week and is representative of the low demography of Fougamou.
The mean age of the pregnant women in our study was about 25.8 ± 6.7 years. This result is consistent with previous data from rural areas in Burkina Faso, in Benin and in the capital of Gabon, Libreville, and its surroundings, in 2011 [31–33]. In Gabon, this data highlights the fact that there does not seem to be a significant difference in the distribution of age of the pregnancy between urban and rural areas.
In this work, we noticed that nearly half of the women included in the study lived in villages. The rural context of Fougamou is confirmed by the socio-demographical factors (a majority of women were unemployed).
However, the analysis of the hematological parameters revealed a good general health state, suggesting an efficient medical follow-up of these women.
The excellent level of adhesion to IPT-SP consolidates this hypothesis. Previous data from Gabon showed that the level of adherence to IPT-SP was very high, resulting in a minimization of the consequences of malaria associated with pregnancy [34]. In other African countries such as Kenya or Burkina Faso, similar results were reported [35–37]. The level of adherence to IPT-SP in our study was 94.4%. This proportion is higher than the value previously reported in Libreville and in Burkina Faso [31, 37]. This result in Fougamou fits the goal set by OMS, which aimed to have 80% of women receive at least 2-doses of IPTp-SP during pregnancy.
Although the national directive indicates that pregnant women have to receive at least 3 doses of IPT-SP, in this study, we found that women received a maximum of 3 doses, which is an erroneous reading of the national directive. In this study, the proportion of women having received IPT-SP during the first quarter of pregnancy is similar to that observed in Libreville where 5.9 % of the women had received IPT-SP in the first quarter. After delivery, half the women had received 3 doses of IPT-SP.
Data showed that the majority of women without IPT-SP were between one and 25 weeks of amenorrhea, which could suggest a late start in their antenatal care.
This observation is revealing of the rural context of Fougamou. The time between consultations confirms the high attendance of women to prenatal visits in Fougamou, which ranged from one to nine visits.
The low prevalence of plasmodial infection observed in our study could be a consequence of the adherence of women to IPT-SP. Moreover, nulliparae (primigravidea), without IPT or under IPT, remain the most exposed to malaria. Similar results were observed in Burkina Faso, in Benin, in Malawi and in Gabon [31, 33, 38–41]. This could be explained by the fact that multigravidae develop, over subsequent pregnancies, a protective immunity against placental malaria infection. These women develop antibodies which are able to specifically inhibit the cytoadhesion on Chondroitin Sulfate A [42–44]. The more women age and have parity, the more they are protected from malaria.
The overall malaria rate in women having benefited from IPT-SP obtained in our study is similar to the rates of malaria infections reported in Burkina Faso, in Mali, in Kenya and in Malawi [39, 41, 45–47]. However, lower rates than ours were reported in Burkina Faso in 2013 (4.7 %) and in Benin (4,1 %) [33, 37].
The low prevalence of plasmodial infection observed in this study could also be a consequence of adhesion to other recommended malaria prevention measures. Indeed, an overall coverage rate in bed nets of about 70 % was observed. This very high coverage rate could have reduced the development of plasmodial infection. Several studies reported the association of IPT-SP and the use of bed nets to protect women against plasmodial infection during their pregnancy [48, 49]. However, this rate contrasts the women’s knowledge on malaria because during the questionnaire only 74.3 % of the women answered the three questions which define the level of knowledge on malaria correctly (What is malaria? How can you avoid it? How does it manifest itself?). These data suggest that women follow IPT without a clear understanding of its role and might indicate that the impact of public health messages is erroneous.
The positive impact of IPT-SP in pregnant woman is confirmed in this study by the fact that all the pregnant women infected by P. falciparum were asymptomatic and that the average parasitemia was low. This is consistent with previous data indicating that in areas of stable transmission, plasmodial infection in pregnant women is often asymptomatic [50].