The baboon (papio anubis) –plasmodium knowlesi model for placental malaria

Abstract

Pregnant women and foetal well-being are compromised by malaria due to downregulation of normal maternal immune response during pregnancy. Consequently cell mediated immunity (Th1) is suppressed and as a result, the mother relies on humoral immunity (Th2) for protection against pathogenic infections like malaria. However, during placental malaria the maternal immune system is able to respond to the Plasmodium parasite infection. This study sought to characterize the effect of placental malaria on pregnant baboons and infants born to placental malaria positive mothers experimentally infected with Plasmodium knowlesi blood stage parasites. Chapters one, two and three of this thesis focus on general introduction, literature review and methodology respectively. Chapter 4 describes the methods for obtaining clinical, haematological and parasitaemia indices associated with placental malaria infection in nonimmune baboons at different trimesters and the results obtained. Chapter five describes the methods for characterizing pathological features associated with placental malaria in P. knowlesi infected baboons and the results obtained. Chapter six describes the methods for determining the importance of placental malaria in protecting baboon infants against the progression of the disease via passive immunity while chapter seven describes the methods of quantifying T lymphocyte population and cytokine profile associated with P. knowlesi infection in pregnant baboons. Finally, chapter eight gives a general discussion and conclusions in the study while chapter nine describes the challenges of the study and the way forward. Date generated from this study presents haematological and clinical indices associated with P. knowlesi malaria infection in pregnant Olive baboons. It also demonstrates pathophysiology of placental malaria, infant protection during P. knowlesi infection and cytokine profiles associated with placental malaria in Olive baboons. These features mimic placental malaria infection in P. falciparum pregnant women. Therefore, we propose that the baboon-P. knowlesi model is an ideal model for experimental therapeutics in management of malaria in pregnancy.