GHENT UNIVERSITY Karoline FONCK - International Centre for ...
GHENT UNIVERSITY Karoline FONCK - International Centre for ... GHENT UNIVERSITY Karoline FONCK - International Centre for ...
In developing countries, the STI epidemiology is influenced by a number of socio-cultural and economic conditions, making STIs one of the main public health priorities (Van Dam 1999). The incidence and prevalence of STIs are generally high both in urban and rural populations, although there is considerable variation. Rates of complications and long-term sequelae are high as well because diagnosis and effective treatment are often delayed. Substantial gender inequalities exist which render women more vulnerable to STIs and reduce women’s access to information and health care services. STI care is provided by a large variety of health care providers, many of who are poorly trained in STI case management and the quality of care is questionable. Healthcare-seeking behavior is often inadequate owing to frequently asymptomatic nature of STI in women, the generally low awareness of genital health and the stigma associated with genital symptoms. Public resources are limited and health care budgets are low. 1.4. STI and HIV interaction The interaction between STI and HIV is complex. Both HIV and the traditional STIs share a common mode of transmission through sexual contact. They share the same behavioral risks. The reciprocal relation or “epidemiological synergy” between HIV infection and other STIs has been described (Wasserheit 92, Fleming 1999). First, HIV induces alterations in the natural history, diagnosis or response to therapy of other STIs, although more so for ulcerative STIs. Second, an array of studies has shown that both ulcerative and nonulcerative STIs increase the risk of HIV transmission and acquisition, although non-ulcerative STIs increase risk primarily for the receptive partner. Still, since the prevalence and incidence of non-ulcerative STIs is much higher than genital ulcer disease (GUD) in many populations, their impact on HIV transmission may be more important on a population level (Piot & Holmes 1984, Laga 1993, Clottey & Dallabetta 1993). As observational studies are inherently subject to a number of potential limitations and they cannot directly measure the effect of STI control on HIV incidence in the larger population, community level randomized controlled intervention trials have been conducted. In Mwanza, Tanzania, improved continuous management of symptomatic bacterial STI at the primary health care level was introduced. After 24 months, this intervention resulted in a 38% reduction in HIV incidence in the intervention arm. Significant reductions were documented in the prevalence of serologically diagnosed syphilis and of symptomatic urethritis in the previous year. These results were not associated with changes in sexual behavior or condom use (Grosskurth 1995, Mayaud 1997). A subsequent HIV-intervention trial in the Rakai INTRODUCTION 7
district of Uganda randomized villages to mass treatment of STIs every 10 months versus placebo. After three mass treatment rounds that spanned 20 months, the study showed no effect on HIV incidence. Significant reductions were observed in the prevalence of serologically diagnosed syphilis and trichomoniasis and in the incidence of trichomoniasis but not in syphilis (Wawer 1999). The differences in outcome in the two studies are intriguing but are not invalidating the effectiveness of STI control (Fleming 1999). At least four explanations contributed to the divergent results. First, continuous access to improved STI treatment services would be more effective than intermittent mass treatment. Second, symptomatic STIs may be more important than asymptomatic infections in facilitating HIV transmission, as they often reflect recently acquired or incident infections and therefore, recent risky sexual behavior. Third, STI may play a greater role in HIV transmission in earlier than in later phases of an HIV epidemic. As HIV epidemics mature, exposure becomes increasingly independent of cofactors as STI. The Rakai district was experiencing a far more advanced HIV epidemic than the Mwanza region with HIV baseline prevalence rates of 16% and 4% respectively. Finally, STI incidence, prevalence and etiological spectrum are critical determinants of the impact of any STI treatment intervention on HIV transmission. Available data suggest that while syphilis prevalence rates were comparable, gonorrhea and chlamydia prevalence may have been slightly higher in Mwanza, and the proportion of genital ulcers due to HSV-2 was probably substantially higher in Rakai. The extensive observational and intervention trial data leave little doubt that other STIs facilitate HIV transmission. Hence, interventions, which lead to the reduction of the levels and duration of these STI, should have an impact on the HIV epidemic. Therefore, the question is no longer whether STI detection and treatment should be an essential component of HIV prevention programs but rather how this component should be implemented to have maximal impact. WHO recognized the need for a common approach in AIDS and STI prevention and control programs as 1) the predominant mode of transmission of HIV and STI is sexual; 2) many measures of prevention are the same, as the target audiences for these interventions; 3) clinical services for STIs are important points of contact with persons at high risk; 4) early diagnosis and treatment of STIs are an important strategy for prevention of HIV transmission; 5) trends in STI incidence and prevalence are easier to monitor than HIV seroprevalence or incidence and can be useful early indicators of changes in sexual behavior (WHO 1997, 1999). INTRODUCTION 8
- Page 1 and 2: GHENT UNIVERSITY STI PREVENTION AND
- Page 3 and 4: AIDS Acquired Immune Deficiency Syn
- Page 5 and 6: 1.1. Sexually Transmitted Infection
- Page 7: countries, the rate of reporting co
- Page 11 and 12: By identifying where significant
- Page 13 and 14: 4.5%, 3.9%, 67.7% and 30.1% while t
- Page 15 and 16: female primary health care or anten
- Page 17 and 18: The research data have been publish
- Page 19 and 20: 2.1. OBJECTIVES 2.1.1. General obje
- Page 21 and 22: 2.2.3. Laboratory procedures The mi
- Page 23 and 24: C HAPTER 3 PREVALENCE AND RISK FACT
- Page 25 and 26: After registration by the clinic cl
- Page 27 and 28: The majority of the women were infe
- Page 29 and 30: eing single, ever having been treat
- Page 31 and 32: prevalence found in a family planni
- Page 33 and 34: 3.2. Declining Syphilis Prevalence
- Page 35 and 36: Training Nurses at the antenatal cl
- Page 37 and 38: We believe that the observed declin
- Page 39 and 40: Wasserheit 1992, Laga 1993). In Nai
- Page 41 and 42: Table 1: Demographic data of 471 pa
- Page 43 and 44: women. Overall, significantly fewer
- Page 45 and 46: Stigmatization by health staff also
- Page 47 and 48: 4.2. Health-Seeking Behavior and Se
- Page 49 and 50: Between September and November 1998
- Page 51 and 52: Table 2: Healthcare-seeking behavio
- Page 53 and 54: Thirteen women had engaged in sex w
- Page 55 and 56: Men reported more extramarital affa
- Page 57 and 58: C HAPTER 5 DIAGNOSIS AND MANAGEMENT
In developing countries, the STI epidemiology is influenced by a number of socio-cultural and<br />
economic conditions, making STIs one of the main public health priorities (Van Dam 1999).<br />
The incidence and prevalence of STIs are generally high both in urban and rural populations,<br />
although there is considerable variation. Rates of complications and long-term sequelae are<br />
high as well because diagnosis and effective treatment are often delayed. Substantial gender<br />
inequalities exist which render women more vulnerable to STIs and reduce women’s access<br />
to in<strong>for</strong>mation and health care services. STI care is provided by a large variety of health care<br />
providers, many of who are poorly trained in STI case management and the quality of care is<br />
questionable. Healthcare-seeking behavior is often inadequate owing to frequently<br />
asymptomatic nature of STI in women, the generally low awareness of genital health and the<br />
stigma associated with genital symptoms. Public resources are limited and health care<br />
budgets are low.<br />
1.4. STI and HIV interaction<br />
The interaction between STI and HIV is complex. Both HIV and the traditional STIs share a<br />
common mode of transmission through sexual contact. They share the same behavioral<br />
risks. The reciprocal relation or “epidemiological synergy” between HIV infection and other<br />
STIs has been described (Wasserheit 92, Fleming 1999). First, HIV induces alterations in the<br />
natural history, diagnosis or response to therapy of other STIs, although more so <strong>for</strong><br />
ulcerative STIs. Second, an array of studies has shown that both ulcerative and nonulcerative<br />
STIs increase the risk of HIV transmission and acquisition, although non-ulcerative<br />
STIs increase risk primarily <strong>for</strong> the receptive partner. Still, since the prevalence and<br />
incidence of non-ulcerative STIs is much higher than genital ulcer disease (GUD) in many<br />
populations, their impact on HIV transmission may be more important on a population level<br />
(Piot & Holmes 1984, Laga 1993, Clottey & Dallabetta 1993).<br />
As observational studies are inherently subject to a number of potential limitations and they<br />
cannot directly measure the effect of STI control on HIV incidence in the larger population,<br />
community level randomized controlled intervention trials have been conducted. In Mwanza,<br />
Tanzania, improved continuous management of symptomatic bacterial STI at the primary<br />
health care level was introduced. After 24 months, this intervention resulted in a 38%<br />
reduction in HIV incidence in the intervention arm. Significant reductions were documented in<br />
the prevalence of serologically diagnosed syphilis and of symptomatic urethritis in the<br />
previous year. These results were not associated with changes in sexual behavior or condom<br />
use (Grosskurth 1995, Mayaud 1997). A subsequent HIV-intervention trial in the Rakai<br />
INTRODUCTION 7
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