AN EVALUATION OF THE TREATMENT AND PREVENTION OF SEXUALLY TRANSMITTED DISEASE

ABSTRACT

Sexually transmitted infections (STIs) constitute a huge health and economic burden for developing countries: 75–85% of the estimated 340 million annual new cases of curable STIs occur in these countries, and STIs account for 17% economic losses because of ill health. The importance of STIs has been more widely recognised since the advent of the HIV/AIDS epidemic, and there is good evidence that the control of STIs can reduce HIV transmission. The main interventions which could reduce the incidence and prevalence of STIs include primary prevention (information, education and communication campaigns, condom promotion, use of safe microbicides, and vaccines), screening and case finding among vulnerable groups (for example, pregnant women), STI case management using the syndromic approach, targeted interventions for populations at high risk (for example, sex workers), and in some circumstances (targeted) periodic mass treatment. The challenge is not just to develop new interventions, but to identify barriers to the implementation of existing tools, and to devise strategies for ensuring that effective STI control programmes are implemented in the future.

CHAPTER ONE

INTRODUCTION

This paper reviews the extent of the burden of sexually transmitted infections (STIs) in developing countries, with a focus on Africa, and the main strategies that can be used in STI control programmes. We present some of the evidence of the impact and (cost) effectiveness of key STI interventions that have been used in developing countries. We did not intend to perform a systematic review of STI interventions but, rather, decided to include relevant studies and trials that could best illustrate key control strategies in various parts of the world. We first conducted a search of Medline with no date restriction with the key words “sexually transmitted infections” (or diseases) and “interventions” and “developing countries.” We consulted the Cochrane Library for randomised trials on STI and relevant topics (for example, partner notification). We made use of WHO publications on HIV and STI, existing systematic reviews, and our own personal libraries.

STIs IN DEVELOPING COUNTRIES: THE EXTENT OF THE PROBLEM

The World Health Organization (WHO) estimates that approximately 340 million new cases of the four main curable STIs (gonorrhoea, chlamydial infection, syphilis, and trichomoniasis) occur every year, 75–85% of them in developing countries (fig 1).¹ STIs impose an enormous burden of morbidity and mortality in developing countries, both directly through their impact on reproductive and child health, and indirectly through their role in facilitating the sexual transmission of HIV infection. The high prevalence of STIs has contributed to the disproportionately high HIV incidence and prevalence in Africa. Conversely, HIV may have contributed to some extent to STI increases, especially of viral agents such as herpes simplex virus (responsible for genital herpes) or human papillomaviruses (some strains being responsible for genital warts, others for cervical, anal, or penile cancers). The greatest impact is on women and infants. The World Bank has estimated that STIs, excluding HIV, are the second commonest cause of healthy life years lost by women in the 15–44 age group in Africa, responsible for some 17% of the total burden of