01/01/2016 - 31/12/2020
National Institutes of Health (NIH)
Pregnant women as a sentinel group for malaria surveillance in an era of changing malaria transmission
Continued monitoring of malaria in pregnancy is lacking in most endemic settings, in spite of its significant disease burden. Increases in malaria-related harmful effects observed among Mozambican pregnant women after drastic malaria declines during the last decade (1) suggest that closely monitoring of the transmission is needed to quickly identify rebounds in adverse outcomes, especially in areas embarking in malaria elimination activities. Moreover, several evidences point to IgGs against VAR2CSA (the parasite antigen that mediates sequestration of P. falciparum in the placenta) as a marker of cumulative exposure to P. falciparum during pregnancy that can provide estimates of malaria transmission. Finally, it has been shown that malaria prevalence among pregnant women has been suggested to be a good approximation of the prevalence of malaria in children obtained from household surveys (2, 3).
We hypothesize that dynamics of malaria in pregnancy and pregnancy-specific immunity reflect changes in the intensity of transmission through location and time, not only among pregnant women but also in the underlying community. The goal of this study is to provide epidemiological, molecular and immunological insights of the value of pregnant women attending health facilities to generate estimates of malaria burden and its adverse consequences in situation of varying levels of malaria transmission, with the ultimate hope of developing new tools for the monitoring of malaria in endemic countries.
To address this, we will conduct a three-year prospective observational study at three health facilities with different levels of malaria transmission in Maputo Province (Manhiça District Hospital [Manhiça District], Ilha Josina Health Center [Manhiça District] and Magude Health Center [Magude District]) to determine the relationship between malaria transmission, parasitological outcomes and the clinical impact of malaria infection in pregnant women at their first antenatal visit, delivery and during sick visits (Aim 1.1). Moreover, samples will be stored to investigate host and parasite factors influencing malaria disease during pregnancy. We will also determine the relationship between malaria estimates obtained from pregnant women, children at hospital visits, (Aim 2.1) and seroprevalences against VAR2CSA (Aim 2.2). The impact of interrupting malaria transmission on pregnancy-specific serology (Aim 2.3) will be assessed in pregnant women from Magude after mass drug administration in the community. This study will contribute to promote a pregnancy malaria research agenda by improving our scientific knowledge on determinants of malaria susceptibility during pregnancy and demonstrating the feasibility and value of an easy-to-implement new generation serological tool for malaria surveillance in malaria elimination contexts.