Prevention Latin America

Estimating the burden and impact of malaria in pregnancy in Latin America.

Project Coordinators:

Dr Meghna Desai (CDC, USA), Prof Clara Menendez (IS Global, Spain)

Site PIs:

Flor Martínez-Espinosa (Gerência de Malária, Fundação de Medicina Tropical do Amazonas, Manaus (FMTAM), Brazil), Norma Padilla (Universidad del Valle de Guatemala (CES-UVG), Guatemala), Yezid Solarte and Myriam Arevalo (Instituto de Inmunología, Cali (CIV), Colombia Sócrates Herrera), Mats Wahlgren and Qijun Chen (Karolinska Institute, Stockholm (KI), Sweden), Carlo Severini (Istituto Superiore di Sanità, Rome (ISS), Italy)

Objective

The study aims were to understand the prevalence of P. vivax infection in pregnant women in five countries in order to formulate treatment programmes in areas with lower stable and unstable malaria transmission levels and / or higher risk of P. vivax infection.

Study design

This was a multicentre health facility-based prospective observational study in pregnant women from Guatemala, Colombia, Brazil (with funding from BMGF), and India and Papua New Guinea (with additional funding from EU). Malaria and anaemia were determined during pregnancy and fetal outcomes assessed at delivery. A total of 9388 women were enrolled at antennal care (ANC), of whom 53% (4957) were followed until delivery.

Results and Conclusion

The prevalence of P. vivax mono-infection in maternal blood at delivery was low overall however, molecular methods revealed a significant number of submicroscopic infections (0.4% by microscopy vs 6.9% by PCR). Similarly, the prevalence of P. falciparum mono-infection by microscopy was also low at delivery (0.5%) and no mixed infections were found by microscopy in any country other than PNG (found in placental smears). Women with P. vivax clinical malaria at enrolment had increased risk of anaemia, but P. vivax sub microscopic infections were not associated with increased risk of moderate to severe anaemia or low birth weight.

Clinical p. vivax was associated with maternal anaemia, which may be deleterious for infant's health. Use of molecular methods for the detection of P. vivax during pregnancy detected more infections than microscopy and could be considered in programmes targeted at improving maternal health and malaria elimination in endemic countries.

Publications

Bardaji, A., et al. (2017). "Burden and impact of Plasmodium vivax in pregnancy: A multi-centre prospective observational study." PLoS Negl Trop Dis 11(6): e0005606.

Requena, P., et al. (2017). "Naturally Acquired Binding-Inhibitory Antibodies to Plasmodium vivax Duffy Binding Protein in Pregnant Women Are Associated with Higher Birth Weight in a Multicenter Study." Front Immunol 8: 163.

Botto-Menezes, C., et al. (2016). "Costs Associated with Malaria in Pregnancy in the Brazilian Amazon, a Low Endemic Area Where Plasmodium vivax Predominates." PLoS Negl Trop Dis 10(3): e0004494.

Requena, P., et al. (2016). "Plasmodium vivax VIR Proteins Are Targets of Naturally-Acquired Antibody and T Cell Immune Responses to Malaria in Pregnant Women." PLoS Negl Trop Dis 10(10): e0005009.

Menegon, M., et al. (2016). "Microsatellite Genotyping of Plasmodium vivax Isolates from Pregnant Women in Four Malaria Endemic Countries." PLoS One 11(3): e0152447.

Requena, P., et al. (2014). "Pregnancy and malaria exposure are associated with changes in the B cell pool and in plasma eotaxin levels." J Immunol 193(6): 2971-2983.

Castellanos, M. E., et al. (2012). "Plasmodium vivax congenital malaria in an area of very low endemicity in Guatemala: implications for clinical and epidemiological surveillance in a malaria elimination context." Malar J 11: 411.