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1.
Community-randomized trials in Mwanza, Tanzania, and Rakai and Masaka, Uganda, suggested that population characteristics were an important determinant of the impact of sexually transmitted infection (STI) treatment interventions on incidence of human immunodeficiency virus (HIV) infection. We performed simulation modeling of HIV and STI transmission, which confirmed that the low trial impact in Rakai and Masaka could be explained by low prevalences of curable STI resulting from lower-risk sexual behavior in Uganda. The mature HIV epidemics in Uganda, with most HIV transmission occurring outside core groups with high STI rates, also contributed to the low impact on HIV incidence. Simulated impact on HIV was much greater in Mwanza, although the observed impact was larger than predicted from STI reductions, suggesting that random error also may have played some role. Of proposed alternative explanations, increasing herpetic ulceration due to HIV-related immunosuppression contributed little to the diminishing impact of antibiotic treatment during the Ugandan epidemics. The strategy of STI treatment also was unimportant, since syndromic treatment and annual mass treatment showed similar effectiveness in simulations of each trial population. In conclusion, lower-risk behavior and the mature HIV epidemic explain the limited impact of STI treatment on HIV incidence in Uganda in the 1990s. In populations with high-risk sexual behavior and high STI rates, STIs treatment interventions may contribute substantially to prevention of HIV infection.  相似文献   

2.
OBJECTIVES: To compare the proportion of HIV seroconversions attributable to other sexually transmitted diseases in the intervention and comparison arms of the Mwanza sexually transmitted diseases (STD) intervention trial. DESIGN: Case-control study of 96 cases of HIV seroconversion and 974 HIV-negative controls, nested within the Mwanza trial cohort. METHODS: Data on reported STD symptoms during 2 years of follow-up, and serological evidence of recent syphilis, were used to obtain odds ratios (ORs) for HIV seroconversion, adjusted for community, age, marital status, sex partners and travel. Population-attributable fractions (PAF) of HIV seroconversions associated with these STD exposures were calculated separately for the intervention and comparison arms, and for men and women. RESULTS: In men in the comparison arm, adjusted ORs for ulcers (14.8), discharge (3.3), any symptom (4.1) and any STD (4.0) were highly significant. There were no significant associations between HIV incidence and STD exposures in the intervention arm. The PAF were consistently higher in the comparison arm than the intervention arm. In men, the PAF for any STD was 39.6% [95% confidence interval (CI), 12.4-58.3)] in the comparison arm but only 12.0% (CI, 0.0-35.9) in the intervention arm. The PAF for women were lower than for men. CONCLUSIONS: These are minimal PAF estimates and they do not account for STD effects on HIV infectiousness. Nevertheless, a substantial proportion of new HIV infections in men in the comparison arm were attributable to STD. Lower PAF in the intervention arm than in the comparison arm for men provide further evidence of the role of STD cofactors in HIV transmission, supporting the hypothesis that the Mwanza intervention reduced the duration of symptomatic STD, thus reducing the HIV risk associated with such STD.  相似文献   

3.
OBJECTIVE: To assess how the impact of sexually transmitted disease (STD) treatment on HIV incidence varies between stages of the HIV epidemic. METHODS: We simulated the spread of curable STD, herpes simplex virus type 2 and HIV in the dynamic transmission model. Parameters were quantified to represent a severe HIV epidemic as in Rakai, Uganda, using demographic, behavioural and epidemiological data from a recent STD treatment trial. RESULTS: The model fitted the HIV epidemic in Rakai if we assumed a considerable behavioural risk reduction, starting at the end of the Ugandan civil war in 1986. An improvement in STD treatment reduced HIV incidence in this population by 35% over 2 years if implemented in 1981, but only by 11 and 8% in 1988 or 1998. This trend resulted partly from the hypothesized behaviour change, which markedly reduced the prevalences of bacterial STD. In a simulated epidemic without behavioural change, the corresponding treatment impacts in 1988 and 1998 would be 19 and 15%. Enhanced herpetic ulceration in immunocompromised HIV patients contributed little to the reduced impact of treatment of bacterial STD over time. CONCLUSION: In HIV epidemics beyond the first decade, the impact of STD treatment programmes on HIV transmission may depend more on behavioural risk reduction than on the stage of the epidemic. Preceding behavioural change associated with restored civil stability may have contributed to the lack of impact of STD treatment on HIV in the Rakai trial. In advanced epidemics with less behaviour change, STD treatment may still be important for HIV prevention.  相似文献   

4.
《AIDS alert》1998,13(10):suppl 1-suppl 2
The Rakai, Uganda randomized community-based trial has shown that providing intensive mass treatment for sexually transmitted diseases (STDs) was ineffective in decreasing the rate of new HIV infections. The results contradict an earlier trial in Mwanza, Tanzania, where a similar intervention brought considerable reductions in HIV rates. Critics of the Rakai trial claim that the intervention used was either the wrong intervention or handled incorrectly. Among the criticisms was that Rakai ignored the symptomatic carriers for STDs, the group considered key in the spread of HIV. Proponents of Rakai claim that the intervention did reduce both the prevalence and incidence of STDs, indicating that it was successful. Rakai was much further along in the HIV epidemic than Mwanza suggesting the avoidance of HIV is much more difficult; thus the rate of infection was harder to reduce.  相似文献   

5.
OBJECTIVES: To compare the impact of single-round mass treatment of sexually transmitted diseases (STD), sustained syndromic treatment and their combination on the incidence of HIV in rural Africa. METHODS: We studied the effects of STD interventions by stochastic simulation using the model STDSIM. Parameters were fitted using data from a trial of improved STD treatment services in Mwanza, Tanzania. Effectiveness was assessed by comparing the prevalences of gonorrhoea, chlamydia, syphilis and chancroid, and the incidence of HIV, in the general adult population in simulations with and without intervention. RESULTS: Single-round mass treatment was projected to achieve an immediate, substantial reduction in STD prevalences, which would return to baseline levels over 5-10 years. The effect on syphilis was somewhat larger if participants cured of latent syphilis were not immediately susceptible to re-infection. At 80% coverage, the model projected a reduction in cumulative HIV incidence over 2 years of 36%. A similar impact was achieved if treatment of syphilis was excluded from the intervention or confined to those in the infectious stages. In comparison with sustained syndromic treatment, single-round mass treatment had a greater short-term impact on HIV (36 versus 30% over 2 years), but a smaller long-term impact (24 versus 62% over 10 years). Mass treatment combined with improved treatment services led to a rapid and sustained fall in HIV incidence (57% over 2 years; 70% over 10 years). CONCLUSIONS: In populations in which STD control can reduce HIV incidence, mass treatment may, in the short run, have an impact comparable to sustained syndromic treatment. Mass treatment combined with sustained syndromic treatment may be particularly effective.  相似文献   

6.
The same sexual behaviours that transmit HIV are implicated in the transmission of certain other STDs, including chlamydia, gonorrhoea, and syphilis. Consequently, it is often assumed that preventive methods that are effective against HIV should be equally effective against other STDs. The purpose of this study was to examine this assumption. We applied a mathematical model of HIV/STD transmission to empirical data from a large HIV prevention intervention that stressed sexual behaviour change. We modelled the effects of two behavioural strategies - reducing the number of sex partners and increasing condom use-on the proportionate change in intervention participants' cumulative risk of acquiring HIV or a highly-infectious STD, such as gonorrhoea. The results of this modelling exercise indicate that decreasing the number of partners is a more effective strategy for reducing STD risk than it is for HIV risk. In contrast, condoms are somewhat more effective at reducing the cumulative transmission risk for HIV than for highly infectious STDs. The protection provided by condoms for multiple acts of intercourse critically depends on the infectiousness of the STD. The results of this study suggest caution in extrapolating from one STD to another, or from one behavioural risk reduction strategy to another.  相似文献   

7.
OBJECTIVES: To study the dynamics of a mass treatment programme for sexually transmitted diseases (STD) on prevalence of STD and HIV incidence in order to help explain the results of the STD mass treatment community trial in Rakai, Uganda. METHODS: The analysis is based on simulations of STD mass treatment interventions using a deterministic model describing the course of STD and HIV transmission over time and incorporating demographic, biological and behavioural parameters. The mass intervention modelled mimics that used in the Rakai community trial. RESULTS: Mass treatment decreases STD prevalence to a very low level compared with baseline but is unsuccessful at eradicating the infection. STD prevalences return to baseline fairly rapidly after each round of mass treatment. Under different realistic scenarios, the fraction of HIV cases prevented by STD mass treatment assuming uniform 80% coverage of high- and low-risk groups, over the 20-month period following the first round of treatment, was greater than 35%. If, however, differential coverage is assumed, for example that while the total coverage is still 80%, only 40 or 25% of those at high risk are treated, the HIV preventable fraction is reduced, to 19 and 15% respectively (undetectable given the statistical power of the study). The tremendous impact of differential coverage can also be observed even in the early stage of the HIV epidemic. CONCLUSIONS: In the Rakai trial, mass treatment may have had an effect, although transient, on all STD prevalences, which could have had positive repercussions for HIV incidence. This modelling exercise suggests that although an 80% coverage appears high, the differential coverage of low- and high-risk populations may seriously impair our ability to test the STD-HIV interaction hypothesis.  相似文献   

8.
OBJECTIVES: To assess the linkage of sexually transmitted disease (STD) symptoms and treatable STD to HIV incidence. DESIGN: Analysis of a randomized trial of STD control for HIV prevention, Rakai, Uganda. METHODS: Consenting adults 15-59 years of age were seen at 10-monthly home visits, interviewed regarding STD symptoms, and asked to provide samples for HIV and STD diagnoses. HIV incidence was determined in 8089 HIV-negative subjects over 10 457 person years. Adjusted rate ratios (RR) and 95% confidence intervals (CI) of HIV acquisition associated with genital ulcer disease (GUD) and discharge/dysuria were used to estimate the population attributable fraction (PAF) of HIV acquisition. HIV transmission risks associated with STD symptoms in HIV-positive partners of 167 HIV discordant couples and the numbers of sexual partners reported by HIV-positive subjects were used to estimate the PAF of HIV transmission attributable to STD. RESULTS: HIV prevalence was 16%. The risk of HIV acquisition was increased with GUD (RR 3.14; CI 1.98-4.98) and in males with discharge/dysuria (RR 2.44; CI 1.17-5.12), but not in females with discharge/dysuria. The PAF of HIV acquisition was 9.5% (CI 2.8-15.8%) with any of the three STD symptoms. The PAF for GUD was 8.8% (CI 3.7-13.8), but only 8.2% of reported GUD was caused by treatable syphilis or chancroid . The PAF for discharge/dysuria in males was 6.7% (CI 1.1-13.8), but only 25% of symptomatic males had concurrent gonorrhea or chlamydial infection. No significant differences were seen in PAF between study treatment arms. The PAF of HIV transmission associated with STD symptoms in HIV-positive persons was indirectly estimated to be 10.4%. CONCLUSION: In this mature, generalized HIV epidemic setting, most HIV seroconversion occurs without recognized STD symptoms or curable STD detected by screening. Therefore, syndromic management or other strategies of STD treatment are unlikely to substantially reduce HIV incidence in this population. However, STD is associated with significant HIV risk at the individual level, and STD management is needed to protect individuals.  相似文献   

9.
OBJECTIVE: Evidence of condom effectiveness for HIV and sexually transmitted disease (STD) prevention is based primarily on high-risk populations. We examined condom effectiveness in a general population with high HIV prevalence in rural Africa. METHODS: Data were from a randomized community trial in Rakai, Uganda. Condom usage information was obtained prospectively from 17,264 sexually active individuals aged 15-59 years over a period of 30 months. HIV incidence and STD prevalence was determined for consistent and irregular condom users, compared to non-users. Adjusted rate ratios (RR) of HIV acquisition were estimated by Poisson multivariate regression, and odds ratios of STDs estimated by logistic regression. RESULTS: Only 4.4% reported consistent condom use and 16.5% reported inconsistent use during the prior year. Condom use was higher among males, and younger, unmarried and better educated individuals, and those reporting multiple sex partners or extramarital relationships. Consistent condom use significantly reduced HIV incidence [RR, 0.37; 95% confidence interval (CI), 0.15-0.88], syphilis [odds ratio (OR), 0.71; 95% CI, 0.53-0.94] and gonorrhea/Chlamydia (OR, 0.50; 95% CI, 0.25-0.97) after adjustment for socio-demographic and behavioral characteristics. Irregular condom use was not protective against HIV or STD and was associated with increased gonorrhea/Chlamydia risk (OR, 1.44; 95% CI, 1.06-1.99). The population attributable fraction of consistent use for prevention of HIV was -4.5% (95% CI, -8.3 to 0.0), due to the low prevalence of consistent use in the population. CONCLUSIONS: Consistent condom use provides protection from HIV and STDs, whereas inconsistent use is not protective. Programs must emphasize consistent condom use for HIV and STD prevention.  相似文献   

10.
We examined the effects of repeat Voluntary HIV counseling and testing (VCT) on sexual risk behaviors and HIV incidence in 6,377 initially HIV-negative subjects enrolled in a prospective STD control for HIV prevention trial in rural Rakai district, southwestern Uganda. Sixty-four percent accepted VCT, and of these, 62.2% were first time acceptors while 37.8% were repeat acceptors. Consistent condom use was 5.8% in repeat acceptors, 6.1% in first time acceptors and 5.1% in non-acceptors. A higher proportion of repeat acceptors (15.9%) reported inconsistent condom use compared to first-time acceptors (12%) and non-acceptors (11.7%). Also, a higher proportion of repeat acceptors (18.1%) reported 2+ sexual partners compared to first-time acceptors (14.1%) and non-acceptors (15%). HIV incidence rates were 1.4/100 py (person-years) in repeat acceptors, 1.6/100 py in first time acceptors and 1.6/100 py in non-acceptors. These data suggest a need for intensive risk-reduction counseling interventions targeting HIV-negative repeat VCT acceptors as a special risk group.  相似文献   

11.
Hitchcock P  Fransen L 《Lancet》1999,353(9152):513-515
The impact of enhanced syndromic diagnosis of symptomatic sexually transmitted infections (STIs) upon the incidence of HIV infections was evaluated in 8 paired villages in Mwanza, Tanzania, over a 2-year period. Shortly thereafter, a study was conducted in Uganda's Rakai district which focused upon treating all members of 5 clusters of paired communities, including those with symptomatic and asymptomatic STIs. In August 1995, the results of the Mwanza study showed that almost 40% of HIV infections had been prevented in the communities receiving the intervention. No other HIV intervention has had such a major effect upon infection rates. In contrast, however, no HIV infections were prevented in the Rakai intervention communities. The Mwanza results could reflect the short-term impact of STD prevention and control in an immature epidemic, while the Rakai study reflects the short-term impact in a mature epidemic. The probability of transmission, the duration of infectiousness, and the number of sex partners are discussed as factors which influence the generation of an HIV epidemic in a susceptible population. The 2 studies' results indicate that STD prevention and control is feasible, effective, and affordable.  相似文献   

12.
A rural HIV epidemic in Zimbabwe? Findings from a population-based survey   总被引:6,自引:0,他引:6  
The aim of the study was to use population-based data from 689 adults to describe the socio-demographic, behavioural and biomedical correlates of HIV infection and aid identification of effective HIV control strategies for rural Zimbabwe. Dried blood spot and urine samples were collected for HIV and sexually transmitted disease (STD) testing and participants were interviewed on socio-demographic characteristics, sexual behaviour and experience of STD symptoms. HIV seroprevalence was 23.3% and was higher in females, divorcees, widows, working men, estate residents, and respondents reporting histories of STD symptoms. Female HIV seroprevalence rises sharply at ages 16-25. A third of sexually-active adults had experienced STD-associated symptoms but there were delays in seeking treatment. Herpes simplex virus type 2 (HSV-2) and Trichomonas vaginalis are more common causes than syphilis, gonorrhoea, and chlamydia, and are strongly associated with HIV infection. Local programmes promoting safer sexual behaviour and fast and effective STD treatment among young women, divorcees and working men could reduce the extensive HIV transmission in rural communities.  相似文献   

13.
The prevalence and incidence of HIV and other sexually transmitted infections (STIs) were recorded in two lake-island and eight rural mainland communities in Mwanza, Tanzania. The prevalence and incidence of HIV and syphilis were lower on the islands, but this pattern was not seen for herpes simplex virus type-2, gonorrhoea, chlamydia, male urethritis or antenatal prevalences of Trichomonas vaginalis. Island men reported fewer sexual partners than mainland men but no differences were found for women. Island men were more likely to be circumcised, island women less mobile and there were differences in marriage patterns. Possible explanations for the differences in HIV and syphilis include: slower introduction of HIV into the islands because of geographical isolation, more core-group sexual contact on the mainland, higher prevalence of male circumcision on the islands and differences in marital status. Differences in transmission dynamics may lead to geographical patterns that vary between STIs.  相似文献   

14.
Grosskurth H  Gray R  Hayes R  Mabey D  Wawer M 《Lancet》2000,355(9219):1981-1987
Two randomised controlled trials of sexually transmitted disease (STD) treatment for the prevention of HIV-1 Infection, in Mwanza, Tanzania, and Rakai, Uganda, unexpectedly produced contrasting results. A decrease in population HIV-1 incidence was associated with improved STD case management in Mwanza, but was not associated with STD mass treatment in Rakai. Some reductions in curable STDs were seen in both studies. These trials tested different interventions in different HIV-1 epidemic settings and used different evaluation methods; the divergent results may be complementary rather than contradictory. Possible explanations include: differences in stage of the HIV-1 epidemic, which can influence exposure to HIV-1 and the distribution of viral load in the infected population; potential differences in the prevalence of Incurable STDs (such as genital herpes); perhaps greater Importance of symptomatic than symptomless STDs for HIV-1 transmission; and possibly greater effectiveness of continuously available services than of intermittent mass treatment to control rapid STD reinfection. Implications of the trials for policy and future research agenda are discussed.  相似文献   

15.
目的了解综合医院性病门诊男性就诊者中,艾滋病病毒(HIV)的感染状况,分析其流行病学特征。方法 2009年1月-2010年12月,对性病门诊就诊的男性患者进行问卷调查及相应的性病学检测,对自愿接受HIV血清学检测者采用酶联免疫吸附试验(ELISA)进行HIV初筛,阳性者用蛋白印迹(WB)法进行确认。结果 1 653例就诊者中,发现梅毒107例,淋病56例,沙眼衣原体感染67例,尖锐湿疣72例,生殖器疱疹30例,共332例。共发现14例HIV感染者,均为男男性行为人群(MSM),且同时合并感染其他性病。梅毒患者合并HIV感染率为35.29%(6/17),尖锐湿疣患者的HIV感染率为32.0%(8/25)。结论 MSM的性病患者是HIV感染的重要高危人群。对临床上有男男性行为的梅毒及肛周尖锐湿疣的患者,应加强HIV的检测。  相似文献   

16.
We examined the association between education and prevalent HIV-1 infection in the Rakai district, rural Uganda based on a cross-sectional analysis of a population-based cohort. In 1990, 1397 men and 1705 women aged 13 years and older, were enrolled in 31 randomly selected communities. Strata were comprised of main road trading centres, secondary road trading villages and rural villages. Sociodemographic and behavioural data were obtained by interview and serum for HIV serostatus were obtained in the home. The analysis examines the association between sex-specific prevalent HIV infection and educational attainment, categorized as secondary, primary or none. The odds ratios (ORs) and 95% confidence intervals (95% CIs) of HIV infection were estimated, using no education as the referent group. Higher levels of education were associated with a higher HIV seroprevalence in bivariate analyses (OR 2.7 for primary and 4.1 for secondary education, relative to no education). The strength of the association was diminished but remained statistically significant after multivariate adjustment for sociodemographic and behavioural variables (adjusted OR of HIV infection 1.6 (95% CI: 1.2-2.1)) for primary education and 1.5 (95% CI: 1.0-2.2) for secondary education. Stratified multivariate analyses by place of residence indicated that the association between education and HIV prevalence was statistically significant in the rural villages, but not in the main road trading centres and intermediate trading villages. Educational attainment is a significant predictor of HIV risk in rural Uganda, in part because of risk behaviours and other characteristics among better educated individuals. Preventive interventions need to focus on better educated adults and on school-aged populations.  相似文献   

17.
OBJECTIVE: To measure the seroprevalence of human immunodeficiency virus (HIV) infection and syphilis, and to assess the behavioural risk factors for these infections among migrant-returnees and non-migrants in far western Nepal. METHODS: In April 2001, we recruited 97 male migrant-returnees and 40 non-migrants from five rural villages in Doti district where migration to Mumbai is common. For data collection, we conducted a serological examination for HIV and syphilis, and a perception and behaviour survey on HIV and other sexually transmitted infections. RESULTS: We found that 11 of 137 men (8%) were positive for HIV infection and 30 men (22%) for syphilis. The respondents, especially the migrant-returnees from Mumbai, were engaging in risky behaviours such as pre- or extramarital sex, and sex with multiple partners, including sex workers. CONCLUSIONS: This study revealed high HIV and syphilis prevalence among the male migrant-returnees and non-migrants in far western Nepal where migration to Mumbai is common. The prevalent behaviours, particularly among the migrant-returnees, imply urgent needs of the behavioural modification programme in this area to prevent the spread of HIV infection to general population.  相似文献   

18.
The Centers for Disease Control and Prevention recommends sexually transmitted disease (STD) screening among human immunodeficiency virus (HIV)-infected persons as a means of HIV prevention. HIV-infected persons in care may be an important target group in which to conduct regular STD screening to prevent enhanced transmission of HIV. We conducted STD screening for syphilis and two causes of urethritis, chlamydia, and gonorrhea, among 447 HIV-infected persons at two busy, urban clinics in San Francisco: a general HIV acquired immune deficiency syndrome (AIDS) care clinic and a methadone maintenance clinic. There were no new cases of syphilis identified and only two prevalent cases of chlamydia. While STD screening was feasible and acceptable in this population, the benefits of screening for asymptomatic gonococcal and chlamydial infection remain to be determined. Because these two pathogens only cause about 20% of urethritis, broader screening tests for urethritis, e.g., leukocyte esterase or urine microscopy, may be more useful. Finally, this study reaffirms the notion that local data should be used to evaluate national screening recommendations.  相似文献   

19.
OBJECTIVE: Few studies have described levels and determinants of perceived risk of HIV-1 among African adults for whom the sero-status is known. This study describes HIV risk perception obtained from a large rural population in south-west Uganda which also underwent serological testing for HIV. DESIGN: Cross-sectional survey. METHODS: Information on risk perception and sexual behaviour was collected by interview. Sera were obtained from all consenting adults (13 years and above) in order to assess HIV-1 prevalence. RESULTS: Of 14,818 adults with a definitive sero-status, 9.7% were HIV-1 positive and 51% considered themselves to be at risk of infection. Risk perception showed similar patterns as age- and sex-specific sero-prevalence and there was correspondence between risk factors for perceived risk and known HIV risk factors. Partner's sexual behaviour was the commonest reason for risk perception in women whereas men cited their own sexual behaviour. Abstinence from sex was much more commonly mentioned as a protective practice than condom use in men and women. CONCLUSION: Half of the adults we have studied already see infection with HIV as a real possibility in their lives and are aware of HIV risk behaviours. More efforts should be made to implement sustainable control measures rather than simply raising awareness. In addition to recommending abstinence, these include mutual faithfulness, condom use and better treatment for STDs.  相似文献   

20.
A study was conducted to determine the prevalence rate and risk factors for sexually transmitted diseases (STDs) in Haiti's rural Artibonite Valley. Women attending antenatal services at Hospital Albert Schweitzer from October to December 1996 were tested for gonorrhea, chlamydia, trichomonas, syphilis, and human immunodeficiency virus (HIV). Of the 476 women tested, 121 (25.4%) had trichomonas, 11/475 (2.3%) had gonorrhea, 51/475 (10.7%) had chlamydia, 32/474 (6.8%) were seropositive for syphilis, 20/469 (4.3%) were seropositive for HIV, and 191 (40.1%) had at least one STD. Nearly 30% of the women reported having entered a sexual relationship out of economic necessity and had increased odds of HIV infection, Odds Ratio (OR) 6.3 (P < 0.001). We postulate that due to recent economic hardship in rural Haiti, women are entering into sexual relationships out of economic necessity and that this trend is contributing to the growing HIV epidemic. We recommend STD prevention and development programs that target young people and economically disadvantaged women.  相似文献   

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