Date : 16. July. 2016

Dr Ghyslain Mombo Ngoma

Parasitic Infections during Pregnancy in Gabon

From the fact that adverse pregnancy outcomes are major problems in developing countries, it is important to get reliable data on the extent of the problem in country specific manner and then work on identifying the major risk factors.

Moreover, parasitic infections are still highly prevalent in sub-Saharan Africa and millions of women of childbearing age are exposed to these infections. Studies of parasites infection during pregnancy will help to grasp the influence of a total burden of parasites on shaping the birth outcomes and also will allow us to understand the biological mechanisms which control pregnancy and identify the underlying immunological processes that might explain the birth outcomes.

This thesis explores the burden of adverse pregnancy outcomes including low birthweight and preterm birth in sub-Sahara Africa and investigates their risk factors. It examines the burden during pregnancy of the major parasitic infections endemic in Gabon including malaria, loaisis and urogenital schistosomiasis and their implications for birth outcomes in addition to already identified risk factors. The thesis explores existing and potential alternative preventive strategies against parasitic infections to be integrated in the continuum of care for maternal, newborn and child care.

In addition, it starts dissecting some immune mechanisms to understand how parasites are shaping the immune system via induction of regulatory T cells in the infected hosts and in the cord blood of offspring from parasite infected mothers to pave the way towards analysis of the immune system during pregnancy and its effect on birth outcomes.

Supervised by :

Prof. Dr. Maria Yazdanbakhsh

Prof. Dr. Peter Kremsner

Dr. Michael Ramharter

Dr Ulysse Ateba Ngoa

The effect of parasiticco-infection on immune responses in Gabon : Particular emphasis on malaria and helminths

The main objective of this thesis is to improve our understanding of helminth and Plasmodium spp. Co-infection within their human host. We aimed to access how helminths manipulate the immune system of their human host and how such a manipulation could affect immune response in subjects infected with malaria parasites. Our study population was selected in an area where the burden of helminths (particularly S. haematobium, filarial intestinal helminths) and malaria are remarkably high. Characterizing immune responses of subjects living within this context is of special interest. Indeed whereas experimental studies inform us on how the immune system works in optimal conditions.

Field studies involving naturally exposed individuals might give a valuable insight into the immunological profiles encountered in endemic regions. We set out to access the humoral response to P. falciparum sexual and asexual stages antigens and the effect of S. haematobium on B cell subsets and function. On the other, we evaluate the cellular immune reactivity by analyzing the host innate and adaptive immune response in P. falciparum infected subjects in the context of concurrent chronic helminth infections.

Supervised by :

Prof. Dr. Maria Yazdanbakhsh

Prof. Dr. Peter Kremsner

Dr. Akim Ayola Adegnika