Questioning risk compensation: pre-exposure prophylaxis (PrEP) and sexually transmitted infections among men who have sex with men, capital region of Denmark, 2019 to 2022.

BackgroundPre-exposure prophylaxis (PrEP) effectively prevents HIV, but its association with sexually transmitted infections (STIs) has raised concerns about risk compensation, potentially impacting the expansion of PrEP programmes.AimWe examined the relationship between PrEP and the incidence of chlamydia, gonorrhoea and syphilis.MethodsIn this prospective cohort study, we compared STI rates before and after PrEP initiation among users in the capital region of Denmark (2019-2022), calculating incidence rate ratios adjusted for age and testing frequency (aIRR). To pinpoint when increases began, we plotted weekly STI rates, adjusting the timeline to correspond with PrEP initiation.ResultsThe study included 1,326 PrEP users with a median age of 35 years. The STI incidence rate per 100,000 person-years rose from 35.3 before to 81.2 after PrEP start, with an aIRR of 1.35 (95% CI: 1.18-1.56). Notably, this increase preceded PrEP initiation by 10-20 weeks. Specific aIRR for chlamydia, gonorrhoea and syphilis were 1.23 (95% CI: 1.03-1.48), 1.24 (95% CI: 1.04-1.47) and 1.15 (95% CI: 0.76-1.72), respectively. In subanalyses for anatomical sites aIRR was 1.26 (95% CI: 1.01-1.56) for rectal chlamydia and 0.66 (95% CI: 0.45-0.96) for genital gonorrhoea.ConclusionWe found a 35% increase in STI incidence associated with PrEP use. It started before PrEP initiation, challenging the assumption that PrEP leads to risk compensation. Instead, the data suggest that individuals seek PrEP during periods of heightened sexual risk-taking. Consequently, PrEP programmes should include sexual health consultations, STI testing, treatment and prevention strategies to prevent HIV and improve sexual health.

Short course antibiotic treatment of Gram-negative bacteraemia (GNB5): a study protocol for a randomised controlled trial.

INTRODUCTION: Prolonged use of antibiotics is closely related to antibiotic-associated infections, antimicrobial resistance and adverse drug events. The optimal duration of antibiotic treatment for Gram-negative bacteremia (GNB) with a urinary tract source of infection is poorly defined. METHODS AND ANALYSIS: Investigator-initiated multicentre, non-blinded, non-inferiority randomised controlled trial with two parallel treatment arms. One arm will receive shortened antibiotic treatment of 5 days and the other arm will receive antibiotic treatment of 7 days or longer. Randomisation will occur in equal proportion (1:1) no later than day 5 of effective antibiotic treatment as determined by antibiogram. Immunosuppressed patients and those with GNB due to non-fermenting bacilli (Acinetobacter spp, Pseudomonas spp), Brucella spp, Fusobacterium spp or polymicrobial growth are ineligible.The primary endpoint is 90-day survival without clinical or microbiological failure to treatment. Secondary endpoints include all-cause mortality, total duration of antibiotic treatment, hospital readmission and Clostridioides difficile infection. Interim safety analysis will be performed after the recruitment of every 100 patients. Given an event rate of 12%, a non-inferiority margin of 10%, and 90% power, the required sample size to determine non-inferiority is 380 patients. Analyses will be performed on both intention-to-treat and per-protocol populations. ETHICS AND DISSEMINATION: The study is approved by the Danish Regional Committee on Health Research (H-19085920) and the Danish Medicines Agency (2019-003282-17). The results of the main trial and each of the secondary endpoints will be submitted for publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ClinicalTrials.Gov:NCT04291768.

Incidence of Childbirth, Pregnancy, Spontaneous Abortion, and Induced Abortion Among Women With Human Immunodeficiency Virus in a Nationwide Matched Cohort Study.

BACKGROUND: Reproductive health in women with human immunodeficiency virus (HIV) (WWH) has improved in recent decades. We aimed to investigate incidences of childbirth, pregnancy, spontaneous abortion, and induced abortion among WWH in a nationwide, population-based, matched cohort study. METHODS: We included all WWH aged 20-40 years treated at an HIV healthcare center in Denmark from 1995 to 2021 and a matched comparison cohort of women from the general population (WGP). We calculated incidence rates per 1000 person-years and used Poisson regression to calculate adjusted incidence rate ratios (aIRRs) of childbirth, pregnancy, spontaneous abortion, and induced abortion stratified according to calendar periods (1995-2001, 2002-2008, and 2009-2021). RESULTS: We included 1288 WWH and 12 880 WGP; 46% of WWH were of African origin, compared with 1% of WGP. Compared with WGP, WWH had a decreased incidence of childbirth (aIRR, 0.6 [95% confidence interval, .6-.7]), no difference in the incidence of pregnancy (0.9 [.8-1.0]) or spontaneous abortion (0.9 [.8-1.0]), but an increased incidence of induced abortion (1.9 [1.6-2.1]) from 1995 to 2021. The aIRRs for childbirth, pregnancy, and spontaneous abortion increased from 1995-2000 to 2009-2021, while the aIRR for induced abortion remained increased across all time periods for WWH. CONCLUSIONS: From 1995 to 2008, the incidences of childbirth, pregnancy, and spontaneous abortion were decreased among WWH compared with WGP. From 2009 to 2021, the incidence of childbirth, pregnancy, and spontaneous abortion no longer differed among WWH compared with WGP. The incidence of induced abortions remains increased compared with WGP.

Outcomes following severe acute respiratory syndrome coronavirus 2 infection among individuals with and without HIV in Denmark.

OBJECTIVE: To compare the risk of a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test and coronavirus disease 2019 (COVID-19) outcomes in people with HIV (PWH) with the general population, and estimate the association with vaccination status. DESIGN: A nationwide, population based, matched cohort study. METHODS: We included all Danish PWH ≥18 years ( n  = 5276) and an age and sex-matched general population cohort ( n  = 42 308). We used Cox regression analyses to calculate (adjusted) incidence rate ratios [(a)IRR] and further stratified and restricted the analyses. RESULTS: We observed no major difference in risk of first positive SARS-CoV-2 test [aIRR: 0.8 (95% confidence interval (CI): 0.8-0.9)], but a higher risk of first hospital contact with COVID-19 and hospitalization with severe COVID-19 for PWH vs. controls [IRR: 2.0; (1.6-2.5), 1.8 (1.4-2.3)]. Risk of first hospitalization decreased substantially in PWH with calendar time [first half of year 2022 vs. 2020 IRR: 0.3; (0.2-0.6)], whereas the risk compared to population controls remained almost twofold increased. We did not observe increased risk of death after SARS-CoV-2 infection [aIRR: 0.7 (95% CI: 0.3-2.0)]. Compared to PWH who had received two vaccines PWH who receiving a third vaccine had reduced risk of first positive SARS-CoV-2 test, death (individuals ≥60years) and hospitalization [aIRR: 0.9 (0.7-1.0); 0.2 (0.1-0.7); 0.6 (0.2-1.2)]. CONCLUSION: PWH have almost the same risk of a positive SARS-CoV-2 test as the general population. Although risk of hospital contacts and severe outcomes following SARS-CoV-2 infection is increased, the risk of death does not seem to be substantially increased. Importantly, a third vaccine is associated with reduced risk of infection, and death.

Length of stay in Denmark before HIV diagnosis and linkage to care: a population-based study of migrants living with HIV, Denmark, 1995 to 2020.

BackgroundMigrants face an increased risk of HIV infection and late presentation for HIV care.AimTo examine delays in HIV diagnosis, linkage to care (LTC), and risk of late presentation for migrants living with HIV in Denmark.MethodsWe conducted a population-based, nationwide study of adult migrants (n = 2,166) presenting for HIV care between 1 January 1995 and 31 December 2020 in Denmark. Time from immigration to HIV diagnosis and from diagnosis to LTC, and late presentation were assessed, stratified by migrants' geographical regions of origin, using descriptive statistics.ResultsThe demographics of the migrant population changed over time. Overall, migrants diagnosed with HIV after immigration to Denmark resided a median of 3.7 (IQR: 0.8-10.2) years in Denmark before diagnosis. Median time from HIV diagnosis to LTC was 6 (IQR: 0-24) days. Migrants diagnosed with HIV infection before immigration had a median of 38 (IQR: 0-105) days from arrival in Denmark to LTC. The corresponding median times for 2015-20 alone were 4.1 (IQR: 0.9-13.1) years, 0 (IQR: 0-8) days, and 62 (IQR: 25-152) days, respectively. The overall proportion of late presentation among migrants diagnosed with HIV after immigration was 60%, and highest among migrants from sub-Saharan Africa and East and South Asia.ConclusionHIV diagnosis is still substantially delayed in Danish migrants, while LTC is timely. The proportions with late presentation are high. These results call for targeted interventions to reduce the number of migrants with undiagnosed HIV infections and of late presenters.

Low incidence of HCC in chronic hepatitis C patients with pretreatment liver stiffness measurements below 17.5 kilopascal who achieve SVR following DAAs.

BACKGROUND AND AIMS: To evaluate the ability of pretreatment liver stiffness measurements (pLSM) to predict hepatocellular carcinoma (HCC), incident decompensation and all-cause mortality in chronic hepatitis C (CHC) patients who achieved sustained virological response (SVR) after treatment with direct-acting antivirals (DAAs). METHODS: 773 CHC patients with SVR after DAA treatment and no prior liver complications were identified retrospectively. Optimized cut-off of 17.5 kPa for incident HCC was selected by maximum Youden's index. Patients were grouped by pLSM: <10 kPa [reference], 10-17.4 kPa and ≥17.5 kPa. Primary outcomes were incident hepatocellular carcinoma and secondary outcomes were incident decompensated cirrhosis and all-cause mortality, analyzed using cox-regression. RESULTS: Median follow-up was 36 months and 43.5% (336) had cirrhosis (LSM>12.5 kPa). The median pLSM was 11.6 kPa (IQR 6.7-17.8, range 2.5-75) and pLSM of <10 kPa, 10-17.4 kPa and 17.5-75 kPa was seen in 41.5%, 32.2% and 26.3%. During a median follow-up time of 36 months, 11 (1.4%) developed HCC, 14 (1.5%) developed decompensated cirrhosis, and 38 (4.9%) patients died. A pLSM of 17.5 kPa identified patients with a high risk of HCC with a negative predictive value of 98.9% and incidence rate of HCC in the 17.5-75 kPa group of 1.40/100 person years compared to 0.14/100 person years and 0.12/100 person years in the 10-17.4 kPa and <10 kPa groups, p<0.001. CONCLUSION: Pretreatment LSM predicts risk of HCC, decompensation and all-cause mortality in patients with SVR after DAA treatment. Patients with a pLSM <17.5 kPa and no other risk factors for chronic liver disease appear not to benefit from HCC surveillance for the first 3 years after treatment. Longer follow-up is needed to clarify if they can be safely excluded from post treatment HCC screening hereafter.

[Tularaemia in two patients referred on suspicion of cancer mammae and cancer occulta].

Tularaemia (rabbit fever) is a rare infection caused by Francisella tularensis, which can be transmitted from hares and rats to humans by ticks. We present two case reports of patients with tularaemia. Both were initially referred on suspicion of cancer. A 52-year-old woman, who had had a prior tick bite, was referred on suspicion of breast cancer, and a 28-year-old man was referred on suspicion of occult cancer because of fever and lymphadenopathy in the groin. Tularaemia should be considered as a differential diagnosis in cases of unexplained fever and regional lymphadenopathy, especially in patients with a history of tick bites.

Influence of Referral Pathway on Ebola Virus Disease Case-Fatality Rate and Effect of Survival Selection Bias.

Case-fatality rates in Ebola treatment centers (ETCs) varied widely during the Ebola virus disease (EVD) outbreak in West Africa. We assessed the influence of referral pathway on ETC case-fatality rates with a retrospective cohort of 126 patients treated at the Mathaska ETC in Port Loko, Sierra Leone. The patients consisted of persons who had confirmed EVD when transferred to the ETC or who had been diagnosed onsite. The case-fatality rate for transferred patients was 46% versus 67% for patients diagnosed onsite (p = 0.02). The difference was mediated by Ebola viral load at diagnosis, suggesting a survival selection bias. Comparisons of case-fatality rates across ETCs and clinical management strategies should account for potential survival selection bias.

Mortality Rates in Patients With Chronic Hepatitis C and Cirrhosis Compared With the General Population: A Danish Cohort Study.

BACKGROUND: Knowledge about mortality rates (MRs) in patients with chronic hepatitis C (CHC) with cirrhosis is limited. This study aimed to estimate all-cause MRs among patients with CHC with or without cirrhosis in Denmark compared with the general population. METHODS: Patients registered in the Danish Database for Hepatitis B and C with CHC and a liver fibrosis assessment were eligible for inclusion. Liver fibrosis was assessed by means of liver biopsy, transient elastography, and clinical cirrhosis. Up to 20 sex- and age-matched individuals per patient were identified in the general population. Data were extracted from nationwide registries. RESULTS: A total of 3410 patients with CHC (1014 with cirrhosis), and 67 315 matched individuals were included. Adjusted MR ratios (MRRs) between patients with or without cirrhosis and their comparison cohorts were 5.64 (95% confidence interval [CI], 4.76-6.67) and 1.94 (1.55-2.42), respectively. Cirrhosis among patients was associated with an MRR of 4.03 (95% CI, 3.43-4.72). A cure for CHC was associated with an MRR of 0.64 (95% CI, 0.40-1.01) among cirrhotic patients and 2.33 (1.47-3.67) compared with the general population. CONCLUSIONS: MRs were high among patients with CHC with or without cirrhosis compared with the general population. Curing CHC was associated with a reduction in MR among cirrhotic patients, but the MR remained higher than the general population.

Vertical transmission of hepatitis B virus during pregnancy and delivery in Denmark.

OBJECTIVE: In Denmark, pregnant women have been screened for hepatitis B virus (HBV) since 2005, and children born to HBV-infected mothers offered hepatitis B immunoglobulin at birth, vaccination against HBV at birth and after 1, 2 and 12 months. The purpose of this study was to determine the risk of vertical HBV transmission in children born to mothers with chronic HBV infection, to investigate the antibody response in the children and to investigate possible maternal predictive risk factors for HBV transmission. MATERIALS AND METHODS: Through the Danish Database for Hepatitis B and C, we identified 589 HBV-infected women who had given birth to 686 children, of whom 370 children were born to 322 women referred to hospital. 132 (36%) children, born to 109 mothers, were included in the study; 128 children had blood samples tested for HBsAg, anti-HBc (total), anti-HBs and HBV-DNA and four children had saliva samples tested for anti-HBc. RESULTS: We found vertical HBV transmission in Denmark to be 2.3% [95% CI: 0.5, 6.5], a high proportion of HBsAg-negative children with low levels of anti-HBs (18.4%) and a high proportion (15.2%) with resolved HBV infection. No maternal risk factor was statistically significantly associated with HBV vertical transmission. CONCLUSION: In a HBV low prevalence setting as Denmark, despite a national vaccination program, vertical HBV transmission occurred in 2.3% of children born to HBV-infected mothers. In addition, a high proportion of the children had insufficient anti-HBs levels and a high proportion had serological signs of resolved HBV infection.

Hospital admission among HIV-exposed uninfected children compared with HIV-unexposed children.

OBJECTIVE: The main objective of this study was, on a national level, to investigate the risk of in-hospital admissions and use of antibiotics during the first 4 years of life among HIV-exposed uninfected (HEU) children compared with a matched control group of HIV-unexposed children. DESIGN: A nationwide register-based cohort study. METHODS: All HEU children born in Denmark from 2000 to 2012 were individually matched to five HIV-unexposed controls. Outcomes were risk of hospital admission (any, because of an infectious disease, observation/nonspecific diagnosis) and use of antibiotics during the first 4 years of life. Incidence rate ratios (IRRs) were estimated using Poisson regression analysis. RESULTS: In total, 317 HEU children and 1581 matched controls were included. HEU children had a three-fold increased risk of overall admissions {incidence rate ratio (IRR) 3.49 [95% confidence interval (CI) 2.98-4.08]}. There was no difference in risk of admission because of infectious diseases [IRR 1.11 (95% CI 0.73-1.70)] and no difference in use of antibiotics [IRR 0.88 (95% CI 0.73-1.04)]. The excess risk per 100 person-years of admission was primarily caused by an increased risk of admission because of observation/nonspecific diagnosis [excess incidence rate 22.6 (95% CI 18.2-27.0), IRR 6.06 (95% CI 4.84-7.61)]. CONCLUSION: HEU children had an increased risk of overall hospital admission mainly due to an increased risk of admission because of observation/nonspecific diagnosis. There was no increased risk of admission due to infectious disease. The excess risk of admission among HEU may be related to prophylactic treatment and/or HIV testing rather than somatic disease related to HIV or exposure to antiretroviral therapy.

The Danish PEP Registry: Experience with the use of post-exposure prophylaxis following blood exposure to HIV from 1999-2012.

BACKGROUND: The risk of occupational exposures to blood cannot be eliminated completely and access to post-exposure prophylaxis (PEP) to prevent HIV transmission is important. However, PEP administration has been associated with frequent adverse effects, low compliance and difficulties to ensure a proper risk assessment. This nationwide study describes 14 years of experience with the use of PEP following blood exposure in Denmark. METHODS: A descriptive study of all PEP cases following non-sexual exposure to HIV in Denmark from 1999-2012. RESULTS: A total of 411 cases of PEP were described. There was a mean of 29.4 cases/year, increasing from 23 cases in 1999 to 49 cases in 2005 and then decreasing to 16 cases in 2012. Overall 67.2% of source patients were known to be HIV-positive at the time of PEP initiation, with no significant change over time. The median time to initiation of PEP was 2.5 h (0.15-28.5) following occupational exposure. Adverse effects were reported by 50.9% with no significant difference according to PEP regimen. In 85.1% of cases with available data, either a full course of PEP was completed or PEP was stopped because the source was tested HIV-negative. Only 6.6% stopped PEP early due to adverse effects. CONCLUSIONS: PEP in Denmark is generally prescribed according to the guidelines and the annual number of cases has declined since 2005. Adverse effects were common regardless of PEP regimens used and new drug regimens should be considered.

Perception of sexuality and fertility in women living with HIV: a questionnaire study from two Nordic countries.

INTRODUCTION: As the human immunodeficiency virus (HIV)-positive population ages, issues concerning sexuality and fertility, among others, are becoming relevant. HIV is still surrounded by stigma and taboos, and there have been few studies conducted in industrialized settings concerning these questions. We therefore wanted to investigate the perception of sexuality and fertility in women living with HIV (WLWH) in an industrialized setting, using a questionnaire. METHODS: WLWH were recruited at their regular outpatient clinic visits, at the major Departments of Infectious Diseases in Denmark and Finland, from January 2012 to October 2013. A questionnaire was developed, study participants were informed of the nature of study and, if they agreed to participate and signed a consent form, they filled in the questionnaire. Demographic information on the participants was obtained from patient files (in Finland) or from a national HIV cohort (in Denmark). Statistical analysis was performed using STATA, version 11. RESULTS: In total, 560 women were included in the study. The median age was 44 years. The majority were of white European origin, with fully suppressed HIV viral load, CD4 cell count >350 µL and mild or no symptoms of their HIV infection. A total of 62% were sexually active, stating condom use as their sole form of contraception. Of the sexually inactive women, one-third were in steady relationships. Eighty percent reported prior pregnancies, of which the majority had one or more children. Most children were born prior to the women's HIV diagnosis and the mode of conception was predominantly natural. One-quarter of the participating women desired pregnancy, while more than half did not. The remaining quarter either stated that they already had the desired number of children or chose not to answer the question. Fourteen percent stated that their HIV diagnosis ended their wish for children; of these women, the median time of diagnosis was between 1995 and 1996. Pregnancy had been attempted unsuccessfully in one-quarter of study participants. The final question inquired what the risk of mother-to-child transmission was, with all precautions taken. Fifteen percent estimated the risk to be above two percent. CONCLUSIONS: In conclusion, the majority of WLWH in industrialized settings in Denmark and Finland have few HIV-related symptoms, are sexually active and have a strong desire for children.

Genetic variants in the apoptosis gene BCL2L1 improve response to interferon-based treatment of hepatitis C virus genotype 3 infection.

Genetic variation upstream of the apoptosis pathway has been associated with outcome of hepatitis C virus (HCV) infection. We investigated genetic polymorphisms in the intrinsic apoptosis pathway to assess their influence on sustained virological response (SVR) to pegylated interferon-α and ribavirin (pegIFN/RBV) treatment of HCV genotypes 1 and 3 infections. We conducted a candidate gene association study in a prospective cohort of 201 chronic HCV-infected individuals undergoing treatment with pegIFN/RBV. Differences between groups were compared in logistic regression adjusted for age, HCV viral load and interleukin 28B genotypes. Four single nucleotide polymorphisms (SNPs) located in the B-cell lymphoma 2-like 1 (BCL2L1) gene were significantly associated with SVR. SVR rates were significantly higher for carriers of the beneficial rs1484994 CC genotypes. In multivariate logistic regression, the rs1484994 SNP combined CC+TC genotypes were associated with a 3.4 higher odds ratio (OR) in SVR for the HCV genotype 3 (p=0.02). The effect estimate was similar for genotype 1, but the association did not reach statistical significance. In conclusion, anti-apoptotic SNPs in the BCL2L1 gene were predictive of SVR to pegIFN/RBV treatment in HCV genotypes 1 and 3 infected individuals. These SNPs may be used in prediction of SVR, but further studies are needed.

Nationwide experience of treatment with protease inhibitors in chronic hepatitis C patients in Denmark: identification of viral resistance mutations.

BACKGROUND AND AIMS: The first standard of care in treatment of chronic HCV genotype 1 infection involving directly acting antivirals was protease inhibitors telaprevir or boceprevir combined with pegylated-interferon and ribavirin (triple therapy). Phase III studies include highly selected patients. Thus, treatment response and development of viral resistance during triple therapy in a routine clinical setting needs to be determined. The aims of this study were to investigate treatment outcome and identify sequence variations after triple therapy in patients with chronic HCV genotype 1 infection in a routine clinical setting. METHODS: 80 patients, who initiated and completed triple therapy in Denmark between May 2011 and November 2012, were included. Demographic data and treatment response were obtained from the Danish Database for Hepatitis B and C. Direct sequencing and clonal analysis of the RT-PCR amplified NS3 protease were performed in patients without cure following triple therapy. RESULTS: 38 (47%) of the patients achieved cure, 15 (19%) discontinued treatment due to adverse events and remained infected, and 27 (34%) experienced relapse or treatment failure of whom 15 of 21 analyzed patients had well-described protease inhibitor resistance variants detected. Most frequently detected protease variants were V36M and/or R155K, and V36M, in patients with genotype 1a and 1b infection, respectively. CONCLUSIONS: The cure rate after triple therapy in a routine clinical setting was 47%, which is substantially lower than in clinical trials. Resistance variants towards protease inhibitors were seen in 71% of patients failing therapy indicating that resistance could have an important role in treatment response.

[Safety engineered devices prevent needle stick injuries].

Needle stick injuries are common among health-care personnel. There is a potential risk of transmitted infection, which is why directives and guidelines have formulated advices and law suggestions to prevent the accidents. Among these advices is implementation of safety engineered devices that have been suggested to reduce the risk significantly, which is proved by several clinical trials. The health-care workers' influence on choosing the instrument type is important, as is training in the use of the instruments and information about the risk procedures.

[Primary Epstein-Barr virus infections with neurological complications in two middle-aged men]. / Primær Epstein-Barr-virus-infektion med neurologiske komplikationer hos to midaldrende mænd.

Primary infections with Epstein-Barr virus (EBV) often lead to infectious mononucleosis with sore throat, lymphadenopathy and hepatitis, especially in youngsters. However, neurological complications can occur even in immunocompetent individuals. We report two case stories of two middle-aged men with primary EBV infections who presented severe neurological manifestations of the disease, but both fully recovered. Hepatitis was present in both cases, but not the classical mononucleosis. The cases stress that clinicians should be aware of these rare courses of primary EBV infections.

Imported melioidosis in Danish travellers: a diagnostic challenge.

Infections with Burkholderia pseudomallei (melioidosis) are rare events in Scandinavian countries, but the bacterium may be contracted during travel to endemic areas, i.e. Southeast Asia (especially Thailand) and northern Australia. Here, 5 travel-related cases occurring within the last 3 y in Denmark are reported, with particular emphasis on diagnostic and therapeutic challenges posed to health staff with little experience in the management of melioidosis. A newly developed B. pseudomallei-specific polymerase chain reaction test was applied and was able to correctly identify all isolates.

The Danish PEP registry: experience with the use of postexposure prophylaxis (PEP) following sexual exposure to HIV from 1998 to 2006.

BACKGROUND: Studies indicate that antiretroviral postexposure prophylaxis (PEP) after sexual exposure to HIV reduce the risk of infection considerably. Since 1998 PEP after sexual HIV exposure within the preceding 24 hours, has been available in Denmark. PEP can only be prescribed at clinical centers with specialists experienced in HIV treatment. The objective of this study is to describe the use of PEP after sexual exposure from 1998 to 2006. METHODS: The Danish PEP registry collects data from all cases of PEP use in Denmark after exposure to HIV through a structured questionnaire. RESULTS: There were 374 cases of PEP use after sexual exposure. The incidence increased from 5 cases in 1997 to 87 in 2006. PEP was used by heterosexuals (40%) as well as men who have sex with men (57%). The HIV-status of the source was unknown in 41% of the cases of which 90% involved a source belonging to a high risk group, and 63% involved exposure by receptive anal intercourse. PEP was administered within 24 hours in 95% of the cases and the median time to initiation (N = 225) was 11.0 hours (range 0.5-60.0). PEP was completed by 65%. CONCLUSIONS: This nationwide study showed a steady but moderate increase in the use of PEP after sexual HIV-exposure from 1998 to 2006. Time to initiation of PEP was low and the PEP prescription practice was targeted toward high risk exposures.