Use of discrete-event simulation to evaluate strategies for the prevention of mother-to-child transmission of HIV in developing countries

Abstract

HIV/AIDS affects over 40 million people worldwide, and more than 70% of these people live in Africa. Mother-to-child transmission of HIV accounts for over 90% of all HIV infections in children under the age of 15 years. However, implementing HIV prevention policies in Africa is extremely difficult because of the poor medical and socio-economic infrastructure. In this paper, we present a discrete-event simulation model that evaluates the relative benefits of two potentially affordable interventions aimed at preventing mother-to-child transmission of HIV, namely anti-retroviral treatment at childbirth and/or bottlefeeding strategies. The model uses rural Tanzanian data and compares different treatment policies. Our results demonstrate that strategic guidelines about breastfeeding are highly dependent on the assumed increase in infant mortality due to bottlefeeding, the efficacy of anti-retroviral treatment at childbirth, and the maternal health stage. The cost of averted infections, though low by Western standards, may represent significant obstacles to policy implementation in developing countries.

Keywords:

• vertical HIV/AIDS transmission
• discrete event simulation
• cost-effectiveness analysis
• epidemic policy model
• decision-support-system

Acknowledgements

The first investigation on this project was started during Marion Rauner's Erwin-Schroedinger Visting Scholarship, funded by the Austrian Science Fund, at the Department of Industrial Engineering and Engineering Management, Stanford University. We are grateful to Helmut Dier for his help in the development of the evaluation tool and to David Crabbe for his support in programming parts of the input and simulation tool. Thanks are also due to Ruth Davies and Margaret Brandeau for valuable comments on this work. We also thank our colleagues for providing us with the necessary computer power for the simulation runs. We are very grateful to Ruth Davies for allowing us to use the POST software and to Keith Cooper for his assistance in speeding up the simulation run times. We also thank the Evangelical Lutheran Church in Tanzania, the Christian Social Services Commission, the Gesellschaft fuer technische Zusammenarbeit (GtZ), the Institute of Medical Mission (DIFÄM) and the Evangelical Lutheran Church of Bavaria for enabling and funding the field work which was necessary to provide sufficient data for this work. We are also grateful to the Editor Ruth Davies and the anonymous reviewers for their most valuable comments on this paper.