Objectifs scientifiques et projet de recherche

In countries of sub-Saharan Africa, Plasmodium falciparum malaria, intestinal helminth infections and schistosomiasis are all endemic and co-infection commonly occur. This is the case in Ghana. Separately, these infections are known to be associated with significant morbidity and pregnant women are an especially vulnerable group. Schistosomiasis and soil transmitted helminth infections are associated with nutritional and cognitive impairment. Hookworms and Trichuris trichiura, for example, are associated with anaemia, primarily through intestinal blood loss as well as impaired nutrient absorption.. During pregnancy women in malaria-endemic areas, and primigravidae in particular, are more susceptible to infection with P. falciparum than when not pregnant, with consequences that include intrauterine growth retardation, low birth weight (LBW), pre-term delivery (PTD) and neonatal mortality. LBW is a particularly important risk factor for infant mortality in sub-Saharan Africa. In the context of P. falciparum-helminth co-infections, it has been suggested that helminths create a cytokine milieu that interfere with protective cytophilic antibodies directed to P. falciparum. Recent studies showed that infection by S. haematobium and T. trichura were associated with decreased levels of cytophilic antibodies directed to P. falciparum candidate vaccine antigens (MSP-1, MSP-3, GLURP and GMZ-2). Previous studies also showed that helminth infections have a negative impact on responses to tetanus, BCG and pneumococcal vaccination. Efforts to better understand and reduce the consequences of malaria during pregnancy have led researchers of IRD-UMR216, with their collaborators, to the discovery of a promising antigen, VAR2CSA which is currently in vaccine development. With its Beninese partners, the UMR216 team will conduct a Phase Ib trial in Benin in 2015 with this vaccine, but the important question of whether concomitant helminth infection affects the acquisition and maintenance of protective immunity to placental malaria remains unanswered. Few studies have assessed the effects of P. falciparum-helminth co-infections during pregnancy on maternal anemia and birth outcomes, and no study has assessed the impact of helminth infections on the acquisition of immunity to placental malaria.

Unités IRD impliquées

2R26100 : MERIT

Institutions membres

NMIMR : Noguchi Memorial Institute for Medical Research

Responsable(s)

M. x

Correspondant

M. X

M. X

Disciplines scientifiques

Biologie, médecine et santé

Thématiques de recherche

The specific objectives are to: I - Describe the epidemiology of these infections among pregnant women in the North and Central Tongue region (South Eastern Ghana) II - Determine the parasite species circulating in the area, III - Determine the molecular profiles of soil transmitted helminth and S. haematobium circulating in the area, IV - Assess antibody levels, mainly IgG, specifically directed against the VAR2CSA vaccine antigens under clinical development. V - Assess the functionality of the anti-VAR2CSA IgG in the context of co-infections