Metaanalysis and metaregression in interpreting study variability in the impact of sexually transmitted diseases on susceptibility to HIV infection

The direct cost of chlamydial infections: estimates for the employer-sponsored privately insured population in the United States, 2003-2007

Claims data between 2003 and 2007 were used to estimate the direct medical cost per case of chlamydial infections. Estimated total cost per episode for those who were treated was $142 (male, $157; female, $141). This estimate does not include intangible cost, lost productivity, and the cost of potential sequelae.

Trichomonas vaginalis screening and prevention in order to impact the HIV pandemic: Isn't it time we take this infection seriously?

Trichomonas vaginalis (TV) is the second most common sexually transmitted infection (STI) in the world. It is associated with significant morbidity in women: pelvic inflammatory disease (PID), concurrent vaginitis and sexually transmitted infections (STIs), post-operative infection, and pregnancy complications. TV infection has been implicated in HIV acquisition and transmission in men and women. There are multiple mechanisms to explain this association. TV is not routinely screened for in asymptomatic patients; however, infected individuals are most often asymptomatic. Due to the association with the spread of HIV infection, screening should not be limited to symptomatic patients or those seeking treatment for STIs. There are a variety of tests available to detect TV. Treatment of TV has demonstrated lower rates of HIV acquisition in at risk women. In HIV positive men and women, treatment decreases the amount of genital HIV shedding and subsequent infectivity. Initiation of an effective TV screening and treatment program in HIV positive and HIV susceptible populations may limit further transmission of HIV.

The relative contribution of viral and bacterial sexually transmitted infections on HIV acquisition in southern African women in the Methods for Improving Reproductive Health in Africa study

We assess the relative contribution of viral and bacterial sexually transmitted infections (STIs) on HIV acquisition among southern African women in a nested case-control study within the Methods for Improving Reproductive Health in Africa (MIRA) trial. Cases were women with incident HIV infection; controls were HIV-uninfected at the time of case seroconversion selected in a 1 to 3 case to control ratio (risk-set sampling), matched on study site and time of follow-up. Conditional logistic regression models were used to calculate adjusted odds ratios (AORs) and population-attributable fractions (PAF). Among 4948 enrolled women, we analysed 309 cases and 927 controls. The overall HIV incidence rate was 4.0 per 100 women-years. The incidence of HIV infection was markedly higher in women who had prevalent Herpes simplex virus type 2 (HSV-2) (AOR: 2.14; 95% confidence interval [CI]: 1.55–2.96), incident HSV-2 (AOR: 4.43; 95% CI: 1.77–11.05) and incident Neisseria gonorrhoeae (AOR: 6.92; 95% CI: 3.01–15.90). The adjusted PAF of HIV incidence for prevalent HSV-2 was 29.0% (95% CI: 16.8–39.3), for incident HSV-2 2.1% (95% CI: 0.6–3.6) and for incident N. gonorrhoeae 4.1% (95% CI: 2.5–5.8). Women's greatest risk factors for HIV acquisition were incident bacterial and viral STIs. Women-centred interventions aimed at decreasing HIV incidence in young African women need to address these common co-morbid conditions.

Interactions of HIV, other sexually transmitted diseases, and genital tract inflammation facilitating local pathogen transmission and acquisition

Despite several decades of clinical trials assessing the impact of etiological treatment of sexually transmitted diseases (STDs) to decrease HIV acquisition and transmission, almost all of these trials have not proven to be efficacious. Increasing evidence suggests that specific STD treatment alone may not be sufficient to alter the genital tract inflammatory milieu that is created by STDs. This paper examines the associations between STDs and HIV susceptibility and infectiousness, and considers the role of chronic and refractory inflammation to create an environment that potentiates HIV and STD transmission and acquisition by reviewing biological, observational, and clinical trial data.

Epidemiological synergy of Trichomonas vaginalis and HIV in Zimbabwean and South African women

BACKGROUND

Trichomonas vaginalis (T. vaginalis) is the most common nonviral sexually transmitted infection in the world. Despite the coexisting global epidemics of T. vaginalis and HIV, little attention has focused on the emerging evidence that T. vaginalis increases susceptibility to, and potentially transmission of, HIV.

METHODS

We evaluated T. vaginalis infection in the context of a multisite, randomized controlled trial amongst women in South Africa and Zimbabwe, to determine first, if risk of HIV acquisition was increased among women recently infected with T. vaginalis, and second, if risk of T. vaginalis acquisition was increased among women infected with HIV.

RESULTS

After controlling for potential confounders, participants infected with T. vaginalis were more likely to test positive for HIV at their following visit, compared to participants uninfected with T. vaginalis (adjusted hazard ratio = 2.05; 95% CI, 1.05-4.02). Similarly, HIV-positive participants were twice as likely to have acquired T. vaginalis infection at the following visit, compared to HIV-negative participants (adjusted hazard ratio = 2.12; 95% CI, 1.35-3.32).

CONCLUSIONS

We found an increased risk of both HIV acquisition associated with T. vaginalis infection and risk of T. vaginalis acquisition associated with HIV infection. This bidirectional relationship represents a potentially important factor in sustaining the HIV epidemic in populations where T. vaginalis is endemic.

Treatment of sexually transmitted infections for HIV prevention: end of the road or new beginning?

Observational and biological data provide compelling evidence of the importance of sexually transmitted infections (STIs) in HIV transmission, but only one of nine intervention trials has shown an effect. This article reviews the observational studies, critically examines the nine randomized controlled trials evaluating the impact of STI treatment interventions on HIV incidence, and discusses implications for HIV prevention policy, programs and future research. The role of other vaginal infections is also briefly considered. In aggregate, the evidence strongly supports the concept that STI treatment prevents HIV infection. However, issues in trial design and conduct, including HIV epidemic phase, STI prevalence, intervention in comparison groups, and power have affected five of the six trials of treatment of curable STIs. In the three herpes intervention trials, antivirals for HSV suppression were insufficiently potent to alleviate persistent genital inflammation in HIV-negative HSV2-positive persons, and the reduction in HIV levels in HIV-positive persons was insufficient to reduce HIV transmission. It is time for a new phase of exploration of how, when, and in whom to include STI control as a key component of HIV prevention, driven by basic research to elucidate the mechanisms by which STIs and vaginal infections facilitate HIV transmission. From a policy perspective, treatment of curable STIs is an essential part of primary healthcare and is a cheap, simple, and effective intervention when appropriately targeted and delivered. It should be promoted as an essential component of HIV control programs in communities in which the burden of STIs is substantial.

Contribution of sexually transmitted infections to the sexual transmission of HIV

PURPOSE OF REVIEW

We review recent evidence about the link between sexually transmitted infections (STI) and HIV transmission and consider implications for control programmes.

RECENT FINDINGS

New studies and meta-analyses confirm the association of HIV acquisition and transmission with recent STIs, although there is considerable heterogeneity between organisms and populations. Much of the recent evidence relates to herpes simplex virus type 2 (HSV-2), for which the population-attributable risk percentage (PAR%) for HSV-2 is between 25 and 35 in Africa. Mathematical models show how transmission attributable to STI varies with HIV epidemic phase, and HSV-2 becomes increasingly important as the epidemic matures. HSV-2 suppressive therapy reduces HIV concentrations in plasma and the genital tract in people coinfected with HSV-2, in part due to direct inhibition of HIV reverse transcriptase. Recent trials of HSV-2 suppressive therapy have not shown an impact on the risk of HIV acquisition, nor in controlling transmission from dually infected people to their serodiscordant heterosexual partners.

SUMMARY

Although there is a plausible link between STI and HIV risk, intervention studies continue to be disappointing. This fact does not disprove a causal link, but mechanisms of action and the design and implementation of interventions need to be better understood.

Evaluation and Management of Anal Intraepithelial Neoplasia in HIV-Negative and HIV-Positive Men Who Have Sex with Men

The incidence of human papillomavirus (HPV)–associated anal cancer in men who have sex with men (MSM) is striking and has not been mitigated by the use of highly active antiretroviral therapy. Detection and treatment of high-grade anal intraepithelial neoplasia (HGAIN) may reduce the incidence of anal cancer. Anal cytology is a useful tool to detect HGAIN; annual screening of HIV-positive MSM and biennial screening of HIV-negative MSM appears to be cost-effective. MSM with abnormal cytology should be referred for high-resolution anoscopy and biopsy. Individuals with HGAIN should receive treatment; treatment modalities for HGAIN demonstrate moderate efficacy and are usually well tolerated, but greater study is required to determine which treatment is optimal. Large prospective studies are needed to document the efficacy of screening and treatment of HGAIN on anal cancer incidence. The HPV vaccine holds promise for primary prevention of anal cancer in MSM, but significant implementation challenges remain.

The potential role of biomarkers in HIV preventive vaccine trials

BACKGROUND

Successful conduct of HIV vaccine efficacy trials entails identification and enrollment of at-risk populations, assessment of appropriate end points as measures of vaccine efficacy for prevention of HIV acquisition, and amelioration of disease course among infected vaccinees, as well as identification of potential confounders or effect modifiers. Although not invariably useful and bringing their own cost in terms of measurement and validation, a variety of biomarkers may aid at each stage of trial conduct.

METHODS

A review of selected articles, chosen based on quality, relevance of the biomarker to HIV vaccine trials, and availability of the publication, was conducted. The authors also drew experience from current trials and other planned or ongoing trials.

CONCLUSIONS

Biomarkers are available to assess HIV incidence in potential study populations, but care is needed in interpreting results of these assays. During trial conduct, sexually transmitted infections such as herpes simplex virus type 2 may act as effect modifiers on primary and secondary end points, including HIV incidence and set point viral load. The utility of sexually transmitted infection biomarkers will likely depend heavily on local epidemiology at clinical trial sites. Analyses from recent large HIV vaccine efficacy trials point to the complexities in interpreting trial results and underscore the potential utility of biomarkers in evaluating confounding and effect modification.

Current issues and considerations regarding trichomoniasis and human immunodeficiency virus in African-Americans

Trichomonas vaginalis has long been recognized as one of the most prevalent sexually transmitted infections. However, it is only in recent years that it has been appreciated that Trichomonas may play a critical role in amplifying human immunodeficiency virus (HIV) transmission. Given the evidence that T. vaginalis likely promotes HIV infection, the apparent high level of Trichomonas infection in the African-American community is cause for concern. Even if T. vaginalis increases the risk of HIV transmission by a small or modest amount, it translates into a sizable population effect since Trichomonas is so common in this community. Therefore, control of trichomoniasis may represent an important avenue of control for the prevention of HIV transmission, particularly among African-Americans.

Denialism undermines AIDS prevention in sub-Saharan Africa

Some denialists, widely reviled, contend that HIV does not cause AIDS. Other denialists, widely respected, contend that HIV transmits so poorly through trace blood exposures that iatrogenic infections are rare. This second group of denialists has had a corrosive effect on public health and HIV programmes in sub-Saharan Africa. Guided by this second group of denialists, no African government has investigated unexplained HIV infections. Denialists have withheld and ignored research findings showing that non-sexual risks account for substantial proportions of HIV infections in Africa. Denialists have promoted invasive procedures for HIV prevention in Africa--injections for sexually transmitted infections, and adult male circumcision--without addressing unreliable sterilization of reused instruments. By denying that health care causes more than rare infections, denialists blame (stigmatize) HIV-positive African adults for causing their own infections through sexual behaviour. Denialism must be overcome to ensure safe health care and to combat HIV-related stigma in Africa.

The effect of genital tract infections on HIV-1 shedding in the genital tract: a systematic review and meta-analysis

This article reviews the effect of genital tract infections and associated clinical conditions on the detection and concentration of HIV-1 shedding in the genital tract. A search of the PubMed, Embase, and AIDSearch databases was conducted. Meta-analysis was performed on those studies that reported the effect of genital tract infections on the detection of HIV-1 shedding. Thirty-nine studies met the inclusion criteria. The odds of HIV-1 detection in the genital tract were increased most substantially by urethritis (OR 3.1, 95% CI: 1.1-8.6) and cervicitis (OR 2.7, 95% CI: 1.4-5.2). The odds of HIV-1 detection were also increased significantly in the presence of cervical discharge or mucopus (OR 1.8, 95% CI: 1.2-2.7), gonorrhoea (OR 1.8, 95% CI: 1.2-2.7), chlamydial infection (OR 1.8, 95% CI: 1.1-3.1), and vulvovaginal candidiasis (OR 1.8, 95% CI: 1.3-2.4). Other infections and clinical conditions were found to have no significant effect on the detection of HIV-1, although HSV-2 shedding was found to increase the concentration of HIV-1 shedding, and genital ulcer disease was found to increase the odds of HIV-1 detection significantly after excluding one biased study (OR 2.4, 95% CI: 1.2-4.9). This analysis shows that infections that are associated with significant increases in leukocyte concentrations in the genital tract are also associated with significant increases in HIV-1 shedding. These infections are likely to be particularly important in promoting the sexual transmission and mother-to-child intrapartum transmission of HIV-1, and should therefore be the focus of HIV prevention strategies.

Trichomonas vaginalis infection and human immunodeficiency virus acquisition in African women

BACKGROUND

Trichomoniasis vaginalis is the most common nonviral sexually transmitted infection (STI) worldwide, with a particularly high prevalence in regions of human immunodeficiency virus (HIV) endemicity. However, its impact as a cofactor for HIV acquisition is poorly understood.

METHODS

Samples from 213 women who experienced HIV seroconversion (cases) during a longitudinal study involving 4450 women in Uganda and Zimbabwe were matched with samples from HIV-uninfected women (controls). All samples underwent polymerase chain reaction (PCR) analysis for Trichomonas vaginalis DNA. For cases, analyzed samples were from the visit in which HIV seroconversion was detected and the visit preceding detection of seroconversion; for controls, one analyzed sample was from the visit matched by follow-up duration to the cases' seroconversion visit, and the other sample was from the visit immediately preceding the matched visit.

RESULTS

The prevalence of T. vaginalis infection before HIV infection was 11.3% in cases and 4.5% in controls (P = .002). In multivariable analysis controlling for hormonal contraception, other STIs, behavioral, and demographic factors, the adjusted odds ratio for HIV acquisition was 2.74 (95% confidence interval, 1.25-6.00) for T. vaginalis-positive cases. The presence of behavioral risk factors for HIV infection, study recruitment from a referral population at high-risk for HIV, primary sex partner-associated risk for HIV infection, and herpes simplex virus type 2 seropositivity were also predictive of incident HIV infection.

CONCLUSIONS

T. vaginalis infection is strongly associated with an increased risk for HIV infection in this general population of African women. Given the high prevalence of T. vaginalis infection in HIV-endemic areas, T. vaginalis control may have a substantial impact on preventing HIV acquisition among women.

Costs and health consequences of chlamydia management strategies among pregnant women in sub-Saharan Africa

OBJECTIVES

Chlamydia is the most common bacterial sexually transmitted infection worldwide and a major cause of morbidity-particularly among women and neonates. We compared costs and health consequences of using point-of-care (POC) tests with current syndromic management among antenatal care attendees in sub-Saharan Africa. We also compared erythromycin with azithromycin treatment and universal with age-based chlamydia management.

METHODS

A decision analytical model was developed to compare diagnostic and treatment strategies, using Botswana as a case. Model input was based upon (1) a study of pregnant women in Botswana, (2) literature reviews and (3) expert opinion. We expressed the study outcome in terms of costs (US$), cases cured, magnitude of overtreatment and successful partner treatment.

RESULTS

Azithromycin was less costly and more effective than erythromycin. Compared with syndromic management, testing all attendees on their first visit with a 75% sensitive POC test increased the number of cases cured from 1500 to 3500 in a population of 100,000 women, at a cost of US$38 per additional case cured. This cost was lower in high-prevalence populations or if testing was restricted to teenagers. The specific POC tests provided the advantage of substantial reductions in overtreatment with antibiotics and improved partner management.

CONCLUSIONS

Using POC tests to diagnose chlamydia during antenatal care in sub-Saharan Africa entails greater health benefits than syndromic management does-and at acceptable costs-especially when restricted to younger women. Changes in diagnostic strategy and treatment regimens may improve people's health and even reduce healthcare budgets.

In search of a corrected prescription drug elasticity estimate: a meta-regression approach

An understanding of the relationship between cost sharing and drug consumption depends on consistent and unbiased price elasticity estimates. However, there is wide heterogeneity among studies, which constrains the applicability of elasticity estimates for empirical purposes and policy simulation. This paper attempts to provide a corrected measure of the drug price elasticity by employing meta-regression analysis (MRA). The results indicate that the elasticity estimates are significantly different from zero, and the corrected elasticity is -0.209 when the results are made robust to heteroskedasticity and clustering of observations. Elasticity values are higher when the study was published in an economic journal, when the study employed a greater number of observations, and when the study used aggregate data. Elasticity estimates are lower when the institutional setting was a tax-based health insurance system.

Chlamydia and gonorrhoea in pregnant Batswana women: time to discard the syndromic approach?

BACKGROUND

Chlamydia and gonorrhoea are major causes of morbidity among women in developing countries. Both infections have been associated with pregnancy-related complications, and case detection and treatment in pregnancy is essential. In countries without laboratory support, the diagnosis and treatment of cervical infections is based on the syndromic approach. In this study we measured the prevalence of chlamydia and gonorrhoea among antenatal care attendees in Botswana. We evaluated the syndromic approach for the detection of cervical infections in pregnancy, and determined if risk scores could improve the diagnostic accuracy.

METHODS

In a cross-sectional study, 703 antenatal care attendees in Botswana were interviewed and examined, and specimens were collected for the identification of C trachomatis, N gonorrhoeae and other reproductive tract infections. Risk scores to identify attendees with cervical infections were computed based on identified risk factors, and their sensitivities, specificities, likelihood ratios and predictive values were calculated.

RESULTS

The prevalence of chlamydia was 8%, and gonorrhoea was found in 3% of the attendees. Symptoms and signs of vaginal discharge did not predict cervical infection, and a syndromic approach failed to identify infected women. Age (youth) risk factor most strongly associated with cervical infection. A risk score with only sociodemographic factors had likelihood ratios equivalent to risk scores which incorporated clinical signs and microscopy results. However, all the evaluated risk scores were of limited value in the diagnosis of chlamydia and gonorrhoea. A cut-off set at an acceptable sensitivity to avoid infected antenatal care attendees who remained untreated would inevitably lead to considerable over-treatment.

CONCLUSION

Although in extensive use, the syndromic approach is unsuitable for diagnosing cervical infections in antenatal care attendees in Botswana. None of the evaluated risk scores can replace this management. Without diagnostic tests, there are no adequate management strategies for C trachomatis and N gonorrhoeae in pregnant women in Botswana, a situation which is likely to apply to other countries in sub-Saharan Africa. Screening for cervical infections in pregnant women is an essential public health measure, and rapid tests will hopefully be available in developing countries within a few years.

Trichomoniasis and bacterial vaginosis in pregnancy: inadequately managed with the syndromic approach

OBJECTIVE

To measure the prevalence of Trichomonas vaginalis (TV) infection and bacterial vaginosis (BV) among pregnant women in Botswana, and to evaluate the syndromic approach and alternative management strategies for these conditions in pregnancy.

METHODS

In a cross-sectional study, 703 antenatal care attendees were interviewed and examined, and specimens were collected to identify TV, BV, Candida species, Chlamydia trachomatis and Neisseria gonorrhoeae. Information on reproductive tract infections earlier in pregnancy was obtained from a structured interview and the antenatal record.

FINDINGS

TV was found in 19% and BV in 38% of the attendees. Three-fourths of women with TV or BV were asymptomatic. Syndromic management according to the vaginal discharge algorithm would lead to substantial under-diagnosis and over-treatment of TV and BV. Signs of vaginal discharge were more predictive of the presence of these conditions than were symptoms. Among the 546 attendees on a repeat antenatal visit, 142 (26%) had been diagnosed with vaginal discharge earlier in their pregnancy--14 of them twice. In 143 cases, an attendee was diagnosed with vaginal discharge in the second or third trimester; however, metronidazole had been prescribed only 17 times (12%).

CONCLUSION

Diagnosis and treatment of TV and BV among pregnant women in sub-Saharan Africa presents major challenges. Half the pregnant women in this study were diagnosed with TV or BV, but these conditions were not detected and treated during antenatal care with syndromic management. Also, health workers did not adhere to treatment guidelines. These results indicate that management guidelines for TV and BV in antenatal care should be revised.

Uncovering and responding to needs for sexual and reproductive health care among poor urban female adolescents in Nicaragua

BACKGROUND

To meet the needs of female adolescents from low-income urban areas for sexual and reproductive health (SRH) care, vouchers providing free-of-charge access to SRH care at 19 primary care clinics were distributed in Managua, Nicaragua. These vouchers substantially increased the use of services, demonstrating that many adolescents are willing to use such services, if readily accessible. The voucher redemption made it possible to identify the nature of existing, but largely unmet, needs for SRH care.

METHOD

The medical files from 3301 consultations with female adolescents were analysed using descriptive statistical methods and multiple logistic regression.

RESULTS

Female adolescents presented SRH problems that merited medical attention. The mean number of problems presented was 1.5 per consultation: 34% of the vouchers were used for contraceptives, 31% for complaints related to sexually transmitted infection (STI) or reproductive tract infection (RTI), 28% for advice/counselling, 28% for antenatal check-up and 18% for pregnancy testing. A new category of health care users emerged: sexually active girls who were neither pregnant nor mothers and who sought contraceptives or STI/RTI treatment. Contraceptive use doubled among the sexually active non-pregnant voucher redeemers. Consultation with a female doctor younger than 36 years was associated with a higher chance of having contraceptives prescribed.

CONCLUSION

Accessible and appropriate SRH care has the potential to make an important contribution to the increased contraceptive use, decreased risk of unwanted teenage pregnancies and decreased prevalence of STIs/RTIs among underserved adolescents. Once adolescents access the services, providers have a crucial role in ensuring current and continuing needs are met.

What is the achievable effectiveness of the India AIDS Initiative intervention among female sex workers under target coverage? Model projections from southern India

BACKGROUND

The India AIDS Initiative (Avahan) prevention programme funded by the Bill and Melinda Gates Foundation aims to reduce HIV prevalence in high risk groups such as female and male sex workers and their clients, to limit HIV transmission in the general population.

OBJECTIVES

To assess the potential effectiveness of the Avahan intervention at the level of coverage targeted, in different epidemiological settings in India.

METHODS

A deterministic compartmental model of the transmission dynamics of HIV and two sexually transmitted infections, and sensitivity analysis techniques, were used, in combination with available behavioural and epidemiological data from Mysore and Bagalkot districts in the Indian state of Karnataka, to evaluate the syndromic sexually transmitted infection (STI) management (STI treatment), periodic presumptive treatment of STI (PPT), and condom components of the Avahan intervention targeted to female sex workers (FSW).

RESULTS

If all components of the intervention reach target coverage (that is, PPT, STI treatment and condom use), the intervention is expected to prevent 22-35% of all new HIV infections in FSW and in the total population over 5 years in a low transmission setting like Mysore, and to be half as effective in high transmission settings such as Bagalkot. The results were sensitive to small variations in intervention coverage. The condom component alone is expected to prevent around 20% of all new HIV infections over 5 years in Mysore and around 6% for the STI component alone; compared with 7%-14% for the PPT component alone. Multivariate sensitivity analyses suggested that interventions may be more effective in settings with low FSW HIV prevalence and small FSW populations, whereas HIV prevalence was most influenced by sexual behaviour and condom use parameters for FSW.

CONCLUSION

The Avahan intervention is expected to be effective. However, to be able to demonstrate effectiveness empirically in the different settings, it is important to achieve target coverage or higher, which in the case of PPT could take a number of years to achieve. These preliminary model predictions need to be validated with more detailed mathematical models, as better data on sexual behaviour, condom use, STI and HIV trends over time, and intervention coverage data accumulate over the course of the programme.

Declining Prevalence of HIV-Infected Individuals at Risk of Transmitting Drug-Resistant HIV in Denmark during 1997–2004

Background

Transmission of drug-resistant HIV is a potential threat to the substantial clinical benefit of highly active antiretroviral therapy (HAART). To explore the background for the low rates of drug resistance transmission (2–5%) in our population, we estimated acquisition of HIV drug resistance and examined temporal trends in the prevalence of patients at risk of transmitting drug-resistant HIV.

Methods

The study population included all 4,025 patients from The Danish HIV Cohort Study seen during the period 1995–2004. Virological failure to a given drug class was defined as a viral load (VL) >1,000 copies/ml for 120 days while on a HAART regimen including that drug class. In addition, receiving nucleoside reverse transcriptase inhibitors (NRTIs) for 180 days before HAART counted as NRTI failure irrespective of VL. Having experienced failure was considered a proxy for harbouring drug-resistant virus in subsequent observation time. Patients with a current VL >1,000 copies/ml were considered at risk of transmitting HIV.

Results

We found a decrease from 1997 to 2004 in the prevalence of potential transmitters of drug-resistant HIV. The number of these patients with previous NRTI failure decreased from 429 (24% of all patients) in 1998 to 213 (8.0% of all patients) in 2004. Previous protease inhibitor (PI) failure peaked at 279 (14%) in 1999, declining to 142 (5.3%) in 2004. Previous NNRTI failure peaked at 121 patients (4.7%) in 2002, and occurred in 113 patients (4.2%) in 2004. Of all 686 potential transmitters in 2004, 31% had previously experienced NRTI failure, 21% PI failure, and 16% non-NRTI failure.

Conclusion

In the population of HIV-infected individuals in Denmark with complete follow-up, the number at risk of transmitting drug-resistant virus declined over time.