Burden of Malaria in Pregnancy

The Malaria in Pregnancy Consortium (MIPc) highlighted its ongoing research activities at the recently held 5th Pan-African Malaria Conference in Nairobi.  While results on issues like new malaria treatment and preventive regimens are still in the works, the MIPc did report on preliminary efforts to measure the burden of malaria in pregnancy.

Although international agencies like WHO have given estimates of malaria in pregnancy (MIP) risk, one has not always been sure of how these figures were derived. The MIPc has begun to gather and reanalyze current data to get a better picture of the situation in 2007 since we expect that there will definitely be changes as progress is made toward malaria elimination.

The standard figures have been an annual 50 million pregnant women at risk globally, with 25-30 million in Africa. This may have been nased on live births reported. Other unknowns, according to the MIPc is whether Plasmodium vivax was considered and whether distinctions were made between stable and unstable transmission areas.

Advances made with the Malaria Atlas Project have helped as have UNDP population data for women aged 15-49 years.  There was also the challenge of going beyond live births to counting all pregnancies, whether these terminated early or went to term. MIPc was able to determine that around 13% of pregnancies may end in miscarriage. This is important since malaria itself may lead to miscarriage – live births only would not pick this up.

mip-burden-calculations-by-mipc.jpgThe attached chart shows calculations presented by MIPc. They noted that the African P. falciparum numbers were not much different than have been estimated to date.  more work on these data is underway, but the information presented in Nairobi provides us with the beginnings of a baseline prior to achievement of universal malaria intervention coverage and entry into the malaria elimination phase of intervention.

Another interesting MIP presentation was given by Patrick Duffey during the final plenary session of the MIM conference.  He summarized research that has identified a genetically different form of P. falciparum that infects pregnant women, especially those pregnant for the first time. Some immunity is developed in later pregnancy. This research should contribute to vaccine development.

Dr Duffey also shared information that similar biomarkers for pre-eclampsia are found in women who are pregnant for the first time and have malaria.

The MIM conference has been an important venue for stressing the continued importance of addressing and preventing malaria in pregnancy as a central strategy in our efforts to eliminate malaria overall.

——- see for example …
Muehlenbachs A, Fried M, Lachowitzer J, Mutabingwa TK, Duffy PE. Natural selection of FLT1 alleles and their association with malaria resistance in utero. Proc Natl Acad Sci U S A. 2008 Sep 23;105(38):14488-91. Epub 2008 Sep 8.

Avril M, Kulasekara BR, Gose SO, Rowe C, Dahlbäck M, Duffy PE, Fried M, Salanti A, Misher L, Narum DL, Smith JD. Evidence for globally shared, cross-reacting polymorphic epitopes in the pregnancy-associated malaria vaccine candidate VAR2CSA. Infect Immun. 2008 Apr;76(4):1791-800. Epub 2008 Feb 4.

Kabyemela ER, Muehlenbachs A, Fried M, Kurtis JD, Mutabingwa TK, Duffy PE. Maternal peripheral blood level of IL-10 as a marker for inflammatory placental malaria. Malar J. 2008 Jan 29;7:26.

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