Malaria in Pregnancy

Abstract

Pregnant women have a higher risk of malaria compared to non-pregnant women. This review provides an update on knowledge acquired since 2000 on P. falciparum and P.vivax infections in pregnancy. Maternal risk factors for malaria in pregnancy (MiP) include low maternal age, low parity, and low gestational age. The main effects of MIP include maternal anaemia, low birth weight (LBW), preterm delivery and increased infant and maternal mortality.P. falciparum infected erythrocytes sequester in the placenta by expressing surface antigens, mainly variant surface antigen (VAR2CSA), that bind to specific receptors, mainly chondroitin sulphate A. In stable transmission settings, the higher malaria risk in primigravidae can be explained by the non-recognition of these surface antigens by the immune system. Recently, placental sequestration has been described also for P.vivax infections. The mechanism of preterm delivery and intrauterine growth retardation is not completely understood, but fever (preterm delivery), anaemia, and high cytokines levels have been implicated.Clinical suspicion of MiP should be confirmed by parasitological diagnosis. The sensitivity of microscopy, with placenta histology as the gold standard, is 60% and 45% for peripheral and placental falciparum infections in African women, respectively. Compared to microscopy, RDTs have a lower sensitivity though when the quality of microscopy is low RDTs may be more reliable. Insecticide treated nets (ITN) and intermittent preventive treatment in pregnancy (IPTp) are recommended for the prevention of MiP in stable transmission settings. ITNs have been shown to reduce malaria infection and adverse pregnancy outcomes by 28–47%. Although resistance is a concern, SP has been shown to be equivalent to MQ and AQ for IPTp. For the treatment of uncomplicated malaria during the first trimester, quinine plus clindamycin for 7 days is the first line treatment and artesunate plus clindamycin for 7 days is indicated if this treatment fails; in the 2nd and 3rd trimester first line treatment is an artemisinin-based combination therapy (ACT) known to be effective in the region or artesunate and clindamycin for 7 days or quinine and clindamycin. For severe malaria, in the second and third trimester parenteral artesunate is preferred over quinine. In the first trimester, both artesunate and quinine (parenteral) may be considered as options. Nevertheless, treatment should not be delayed and should be started immediately with the most readily available drug.

Peripheral Parasitaemia and Its Association With Plasma Cytokines Levels in Malaria-Infected Pregnant Women in Aba, Abia State, Nigeria

“…In sub-Saharan Africa, 25 million pregnant women are currently at risk for malaria, accounting for 10,000 maternal and 200,000 neonatal deaths per year (Matangila et al, 2014;Mbah et al, 2015). In such regions of high transmission and endemicity, sub-clinical malarial infection is common (Takem and D'Alessandro, 2013) and individuals living in such regions usually develop protective immunity to malaria by adolescence; however, this protection is partially abrogated in women during pregnancy, resulting in pregnancy-associated malaria (PAM) (Jaworowski et al, 2009;Takem and D'Alessandro, 2013). Pregnancy-associated malaria results in tremendous obstetrical and paediatric morbidity, including maternal anaemia, intrauterine growth retardation, low birth weight, prematurity, miscarriage, and stillbirth (Tonga et al, 2013;Mbah et al, 2015;White, 2015; Chedraui, Daily and Wylie, 2016; Prahl et al, 2016).…”

Murine Model for Preclinical Studies of Var2CSA-Mediated Pathology Associated with Malaria in Pregnancy

“…The area under the parasitemia curve (AUC) was used as a proxy for blood parasite mass during the infection period in order to compare parasite expansion in P. berghei-and P. berghei-VAR-infected mice. Susceptibility to infection, as determined by parasite expansion in peripheral blood, was increased in pregnant (P) mice compared to nonpregnant (NP) females, irrespective of the infection dose and parasite line (P P. berghei versus NP P. berghei at 10 6 IEs, P Ͻ 0.01; P P. berghei-VAR versus NP P. berghei-VAR at all doses, P Ͻ 0.001; P P. berghei versus NP P. berghei at 10 5 and 10 4 IEs, P Ͻ 0.001) (Fig. 4A to C).…”

“…In areas of unstable malaria transmission, pregnant women can develop severe malaria due to low immunity to the parasite, which has been associated with increased mortality during pregnancy (4,5), miscarriages, preterm deliveries, low birth weight, stillbirth, and death of neonates (6). These features can be recapitulated in a mouse model of severe placental malaria (PM) (7), which consists of infection of BALB/c mice syngeneically pregnant with parasites of the ANKA strain of the rodent malaria parasite Plasmodium berghei.…”

Malaria in Pregnant Women

“…This infection affects about 350 to 500 million people with 1 to 3 million deaths, every year (1,2). Malaria infection during pregnancy is a major public health concern with significant risks for the pregnant woman and her fetus (1)(2)(3). Annually, about 125 million women (25 million pregnant women) are at risk of malaria around the world.…”

“…Over 90% of the world's malaria-related deaths in the world occur in sub-Saharan Africa. It has been reported that in this region malaria can cause as many as 10,000 cases of malaria-related deaths in pregnancy per year, usually due to severe maternal anemia (1)(2)(3)(4)(5). Pregnant women have a reduced immune response to malaria infection.…”