Individual efficacy of intermittent preventive treatment with sulfadoxine-pyrimethamine in primi- and secundigravidae in rural Burkina Faso: impact on parasitaemia, anaemia and birth weight.

OBJECTIVE: To assess the efficacy at individual level of intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP) in primi- and secundigravidae in rural Burkina Faso. METHODS: Data of 1441 women enrolled in a health centre randomized trial and delivering a live-singleton between September 2004 and October 2006 were analysed at individual level. Prevalence of peripheral and placental parasitaemia, anaemia (PCV <33%), low-birth weight (<2500 g; LBW), mean packed cell volume (PCV) and birth weight were compared in relation to the number of directly observed SP doses. RESULTS: Two or more doses of SP significantly reduced the risk of placental parasitaemia [adjusted odds ratio (AOR) = 0.04, 95%CI = 0.003-0.60, P = 0.023] and anaemia at delivery (AOR = 0.31, 95%CI = 0.18-0.52, P < 0.001). IPTp was associated with reduced risk of LBW in primigravidae (AOR = 0.11, 95%CI = 0.07-0.17, P < 0.001) but not secundigravidae (AOR = 0.70, 95%CI = 0.26-1.91, P = 0.452). For each increment in number of SP doses mean PCV increased by 1.0% (95%CI = 0.4-1.7, P = 0.005) at 32 weeks gestation, by 1.2% (95%CI = 0.2-2.2, P = 0.025) at delivery and mean birth weight by 220 g (95%CI = 134-306 P < 0.001) in primigravidae and by 102 g (95%CI = 55-148, P = 0.001) in secundigravidae. CONCLUSION: The risk of malaria infection was significantly reduced by IPTp with SP in primi- and secundigravidae in rural Burkina Faso. The impact on clinical outcomes is lower and mainly limited to primigravidae for LBW. Incomplete uptake of IPTp-SP and limited effect in low risk groups together may substantially dilute the measurable impact of effective interventions. This needs to be taken into account when evaluating interventions at community level.

A community effectiveness trial of strategies promoting intermittent preventive treatment with sulphadoxine-pyrimethamine in pregnant women in rural Burkina Faso.

BACKGROUND: Intermittent preventive treatment with sulphadoxine-pyrimethamine for pregnant women (IPTp-SP) is currently being scaled up in many countries in sub-Saharan Africa. Despite high antenatal clinic (ANC) attendance, coverage with the required two doses of SP remains low. The study investigated whether a targeted community-based promotion campaign to increase ANC attendance and SP uptake could effectively improve pregnancy outcomes in the community. METHODS: Between 2004 and 2006 twelve health centres in Boromo Health District, Burkina Faso were involved in this study. Four were strategically assigned to community promotion in addition to IPTp-SP (Intervention A) and eight were randomly allocated to either IPTp-SP (Intervention B) or weekly chloroquine (Control). Primi- and secundigravidae were enrolled at village level and thick films and packed cell volume (PCV) taken at 32 weeks gestation and at delivery. Placental smears were prepared and newborns weighed. Primary outcomes were peripheral parasitaemia during pregnancy and at delivery, placental malaria, maternal anaemia, mean and low birth weight. Secondary outcomes were the proportion of women with > or = 3 ANC visits and > or = 2 doses of SP. Intervention groups were compared using logistic and linear regression with linearized variance estimations to correct for the cluster-randomized design. RESULTS: SP uptake (> or = 2 doses) was higher with (Intervention A: 70%) than without promotion (Intervention B: 49%) (OR 2.45 95%CI 1.25-4.82 p = 0.014). Peripheral (33.3%) and placental (30.3%) parasite rates were significantly higher in the control arm compared to Intervention B (peripheral: 20.1% OR 0.50 95%CI 0.37-0.69 p = 0.001; placental: 20.5% OR 0.59 95%CI 0.44-0.78 p = 0.002) but did not differ between Intervention A (17.4%; 18.1%) and Intervention B (20.1; 20.5%) (peripheral: OR 0.84 95%CI 0.60-1.18 p = 0.280; placental: OR 0.86 95%CI 0.58-1.29 p = 0.430). Mean PCV and birth weight and prevalence of anaemia and low birth weight did not differ between study arms. CONCLUSION: The promotional campaign resulted in a major increase in IPTp-coverage, with two thirds of women at delivery having received > or = 2 SP. Despite lower prevalence of malaria infection this did not translate into a significant difference in maternal anaemia or birth weight. This data provides evidence that, as with immunization programmes, extremely high coverage is essential for effectiveness. This critical threshold of coverage needs to be defined, possibly on a regional basis.