Decreasing Burden of Malaria in Pregnancy in Malawian Women and Its Relationship to Use of Intermittent Preventive Therapy or Bed Nets

Abstract

BackgroundThe World Health Organization recommends insecticidal bednets and intermittent preventive treatment to reduce malaria in pregnancy. Longitudinal data of malaria prevalence and pregnancy outcomes are valuable in gauging the impact of these antimalarial interventions.Methodology/Principal FindingsWe recruited 8,131 women delivering in a single Malawian hospital over 9 years. We recorded demographic data, antenatal prescription of intermittent preventive therapy during pregnancy with sulfadoxine-pyrimethamine and bed net use, and examined finger-prick blood for malaria parasites and hemoglobin concentration. In 4,712 women, we examined placental blood for malaria parasites and recorded the infant's birth weight. Peripheral and placental parasitemia prevalence declined from 23.5% to 5.0% and from 25.2% to 6.8% respectively. Smaller declines in prevalence of low birth weight and anemia were observed. Coverage of intermittent preventive treatment and bednets increased. Number of sulfadoxine-pyrimethamine doses received correlated inversely with placental parasitemia (Odds Ratio (95% CI): 0.79 (0.68, 0.91)), maternal anemia (0.81, (0.73, 0.90)) and low birth weight from 1997–2001 (0.63 (0.53, 0.75)), but not from 2002–2006. Bednet use protected from peripheral parasitemia (0.47, (0.37, 0.60)) and placental parasitemia (0.41, (0.31, 0.54)) and low birth weight (0.75 (0.59, 0.95)) but not anemia throughout the study. Compared to women without nets who did not receive 2-dose sulfadoxine-pyrimethamine, women using nets and receiving 2-dose sulfadoxine-pyrimethamine were less likely to have parasitemia or low birth weight babies. Women receiving 2-dose sulfadoxine-pyrimethamine alone had little evidence of protection whereas bednets alone gave intermediate protection.Conclusions/SignificanceIncreased bednet coverage explains changes in parasitemia and birth weight among pregnant women better than sulfadoxine-pyrimethamine use. High bed net coverage, and sulfadoxine-pyrimethamine resistance, may be contributing to its apparent loss of effectiveness.

Factors influencing the usage of different types of malaria prevention methods during pregnancy in Kenya

“…17 The utilisation of ITNs among pregnant women in Malawi was associated with a decrease in placental malaria and the low birth weight of infants. 8 It has been argued in previous literature that there is a need to understand factors which influence the use of ITNs and IPTp. 18 This study examined the effects of several demographic, socioeconomic and empowerment determinants influencing the use of different types malaria prevention measures during pregnancy.…”

“…5,6,7 The World Health Organisation (WHO) recommends the use of insecticide treated nets (ITNs) and intermittent preventive treatment (IPTp) to prevent malaria during pregnancy. 8 In Africa, the revised Abuja target was to provide 80.0% of pregnant women in endemic areas with ITNs and IPTp by 2005. 9 These measures were taken in order to avert the risk of mortality, anaemia among pregnant women and low birth weight.…”

Intermittent Preventive Treatment with Sulfadoxine-Pyrimethamine against Malaria and Anemia in Pregnant Women

“…86 Because the study used hospital-based convenience sampling, we cannot claim that these results are representative of changing malaria epidemiology in the whole community. However, by using one facility and the same approach to assess all variables throughout the study, 87 we believe that the study provides insight into malaria control and prevention.…”

Changing Trends inP. falciparumBurden, Immunity, and Disease in Pregnancy

“…4 Because of the increased susceptibility to malaria during pregnancy, 5 the consequences of a reduction in malaria immunity among pregnant women could be particularly severe, especially in the context of the human immunodeficiency virus (HIV) pandemics in Africa, 6 which can impair the maintenance of effective immune responses. 7 However, declining malaria transmission among pregnant women [8][9][10] may have an effect on malaria-related clinical outcomes that has not yet been assessed.…”