Outbreaks of syphilis among men who have sex with men attending STI clinics between 2007 and 2015 in the Netherlands: a space-time clustering study.

OBJECTIVES: Infectious syphilis (syphilis) is diagnosed predominantly among men who have sex with men (MSM) in the Netherlands and is a strong indicator for sexual risk behaviour. Therefore, an increase in syphilis can be an early indicator of resurgence of other STIs, including HIV. National and worldwide outbreaks of syphilis, as well as potential changes in sexual networks were reason to explore syphilis trends and clusters in more depth. METHODS: National STI/HIV surveillance data were used, containing epidemiological, behavioural and clinical data from STI clinics. We examined syphilis positivity rates stratified by HIV status and year. Additionally, we performed space-time cluster analysis on municipality level between 2007 and 2015, using SaTScan to evaluate whether or not there was a higher than expected syphilis incidence in a certain area and time period, using the maximum likelihood ratio test statistic. RESULTS: Among HIV-positive MSM, the syphilis positivity rate decreased between 2007 (12.3%) and 2011 (4.5%), followed by an increasing trend (2015: 8.0%). Among HIV-negative MSM, the positivity rate decreased between 2007 (2.8%) and 2011 also (1.4%) and started to increase from 2013 onwards (2015: 1.8%). In addition, we identified three geospatial clusters. The first cluster consisted of MSM sex workers in the South of the Netherlands (July 2009-September 2010, n=10, p<0.001). The second cluster were mostly HIV-positive MSM (58.5%) (Amsterdam; July 2011-December 2015; n=1123, p<0.001), although the proportion of HIV-negative MSM increased over time. The third cluster was large in space (predominantly the city of Rotterdam; April-September 2015, n=72, p=0.014) and were mostly HIV-negative MSM (62.5%). CONCLUSIONS: Using SaTScan analysis, we observed several not yet recognised outbreaks and a rapid resurgence of syphilis among known HIV-positive MSM first, but more recently, also among HIV-negative MSM. The three identified clusters revealed locations, periods and specific characteristics of the involved MSM that could be used when developing targeted interventions.

Ethnic and regional differences in STI clinic use: a Dutch epidemiological study using aggregated STI clinic data combined with population numbers.

OBJECTIVES: Ethnic minorities (EM) from STI-endemic countries are at increased risk to acquire an STI. The objectives of this study were to investigate the difference in STI clinic consultation and positivity rates between ethnic groups, and compare findings between Dutch cities. METHODS: Aggregated population numbers from 2011 to 2013 of 15-44 year-old citizens of Amsterdam, Rotterdam, The Hague and Utrecht extracted from the population register (N=3 129 941 person-years) were combined with aggregated STI clinic consultation data in these cities from the national STI surveillance database (N=113 536). Using negative binomial regression analyses (adjusted for age and gender), we compared STI consultation and positivity rates between ethnic groups and cities. RESULTS: Compared with ethnic Dutch (consultation rate: 40.3/1000 person-years), EM from Eastern Europe, Sub-Sahara Africa, Suriname, the Netherlands Antilles/Aruba and Latin America had higher consultation rates (range relative risk (RR): 1.27-2.26), whereas EM from Turkey, North Africa, Asia and Western countries had lower consultation rates (range RR: 0.29-0.82). Of the consultations among ethnic Dutch, 12.2% was STI positive. Positivity rates were higher among all EM groups (range RR: 1.14-1.81). Consultation rates were highest in Amsterdam and lowest in Utrecht independent of ethnic background (range RR Amsterdam vs Utrecht: 4.30-10.30). Positivity rates differed less between cities. CONCLUSIONS: There were substantial differences in STI clinic use between ethnic groups and cities in the Netherlands. Although higher positivity rates among EM suggest that these high-risk individuals reach STI clinics, it remains unknown whether their reach is optimal. Special attention should be given to EM with comparatively low consultation rates.

The Netherlands Chlamydia cohort study (NECCST) protocol to assess the risk of late complications following Chlamydia trachomatis infection in women.

BACKGROUND: Chlamydia trachomatis (CT), the most common bacterial sexually transmitted infection (STI) among young women, can result in serious sequelae. Although the course of infection is often asymptomatic, CT may cause pelvic inflammatory disease (PID), leading to severe complications, such as prolonged time to pregnancy, ectopic pregnancy, and tubal factor subfertility. The risk of and risk factors for complications following CT-infection have not been assessed in a long-term prospective cohort study, the preferred design to define infections and complications adequately. METHODS: In the Netherlands Chlamydia Cohort Study (NECCST), a cohort of women of reproductive age with and without a history of CT-infection is followed over a minimum of ten years to investigate (CT-related) reproductive tract complications. This study is a follow-up of the Chlamydia Screening Implementation (CSI) study, executed between 2008 and 2011 in the Netherlands. For NECCST, female CSI participants who consented to be approached for follow-up studies (n = 14,685) are invited, and prospectively followed until 2022. Four data collection moments are foreseen every two consecutive years. Questionnaire data and blood samples for CT-Immunoglobulin G (IgG) measurement are obtained as well as host DNA to determine specific genetic biomarkers related to susceptibility and severity of infection. CT-history will be based on CSI test outcomes, self-reported infections and CT-IgG presence. Information on (time to) pregnancies and the potential long-term complications (i.e. PID, ectopic pregnancy and (tubal factor) subfertility), will be acquired by questionnaires. Reported subfertility will be verified in medical registers. Occurrence of these late complications and prolonged time to pregnancy, as a proxy for reduced fertility due to a previous CT-infection, or other risk factors, will be investigated using longitudinal statistical procedures. DISCUSSION: In the proposed study, the occurrence of late complications following CT-infection and its risk factors will be assessed. Ultimately, provided reliable risk factors and/or markers can be identified for such late complications. This will contribute to the development of a prognostic tool to estimate the risk of CT-related complications at an early time point, enabling targeted prevention and care towards women at risk for late complications. TRIAL REGISTRATION: Dutch Trial Register NTR-5597 . Retrospectively registered 14 February 2016.

Health and health-related quality of life in pig farmers carrying livestock-associated methicillin-resistant Staphylococcus aureus.

There is limited knowledge about the effect of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) carriage on health-related quality of life (QoL). With this study, we explored whether LA-MRSA causes infections or affects health-related QoL in pig farmers. This prospective cohort study surveyed persons working on 49 farrowing pig farms in The Netherlands for 1 year (2010-2011). On six sampling moments, nasal swabs, environmental samples and questionnaires on activities and infections were collected. At the end of the study year, persons were asked about their QoL using the validated SF-36 and EQ-5D questionnaires. Of 120 persons, 44 (37%) were persistent MRSA carriers. MRSA carriage was not associated with infections, use of antimicrobials, healthcare contact and health-related QoL items in univariate or multivariate analysis, most likely due to the 'healthy worker effect'. Despite high carriage rates, the impact of LA-MRSA carriage in this population of relatively healthy pig farmers on health and health-related QoL appears limited; more research is needed for confirmation.

Post-discharge surveillance (PDS) for surgical site infections: a good method is more important than a long duration.

Post-discharge surveillance (PDS) for surgical site infections (SSIs) normally lasts 30 days, or one year after implant surgery, causing delayed feedback to healthcare professionals. We investigated the effect of shortened PDS durations on SSI incidence to determine whether shorter PDS durations are justified. We also studied the impact of two national PDS methods (those mandatory since 2009 ('mandatory') and other methods acceptable before 2009 ('other')) on SSI incidence. From Dutch surveillance (PREZIES) data (1999-2008), four implant-free surgeries (breast amputation, Caesarean section, laparoscopic cholecystectomy and colectomy) and two implant surgeries (knee replacement and total hip replacement) were selected. We studied the impact of PDS duration and method on SSI incidences by survival and Cox regression analyses. We included 105,607 operations. Shortened PDS duration for implant surgery from one year to 90 days resulted in 6­14% of all SSIs being missed. For implant-free procedures, PDS reduction from 30 to 21 days caused similar levels of missed SSIs. In contrast, up to 62% of SSIs (for cholecystectomy) were missed if other instead of mandatory PDS methods were used. Inferior methods of PDS, rather than shortened PDS durations, may lead to greater underestimation of SSI incidence. Our data validate international recommendations to limit the maximum PDS duration (for implant surgeries) to 90 days for surveillance purposes, as this provides robust insight into trends.

Use of surgical-site infection rates to rank hospital performance across several types of surgery.

BACKGROUND: Comparing and ranking hospitals based on health outcomes is becoming increasingly popular, although case-mix differences between hospitals and random variation are known to distort interpretation. The aim of this study was to explore whether surgical-site infection (SSI) rates are suitable for comparing hospitals, taking into account case-mix differences and random variation. METHODS: Data from the national surveillance network in the Netherlands, on the eight most frequently registered types of surgery for the year 2009, were used to calculate SSI rates. The variation in SSI rate between hospitals was estimated with multivariable fixed- and random-effects logistic regression models to account for random variation and case mix. 'Rankability' (as the reliability of ranking) of the SSI rates was calculated by relating within-hospital variation to between-hospital variation. RESULTS: Thirty-four hospitals reported on 13 629 patients, with overall SSI rates per surgical procedure varying between 0 and 15·1 per cent. Statistically significant differences in SSI rate between hospitals were found for colonic resection, caesarean section and for all operations combined. Rankability was 80 per cent for colonic resection but 0 per cent for caesarean section. Rankability was 8 per cent in all operations combined, as the differences in SSI rates were explained mainly by case mix. CONCLUSION: When comparing SSI rates in all operations, differences between hospitals were explained by case mix. For individual types of surgery, case mix varied less between hospitals, and differences were explained largely by random variation. Although SSI rates may be used for monitoring quality improvement within hospitals, they should not be used for ranking hospitals.

The daily updated Dutch national database on COVID-19 epidemiology, vaccination and sewage surveillance.

The Dutch national open database on COVID-19 has been incrementally expanded since its start on 30 April 2020 and now includes datasets on symptoms, tests performed, individual-level positive cases and deaths, cases and deaths among vulnerable populations, settings of transmission, hospital and ICU admissions, SARS-CoV-2 variants, viral loads in sewage, vaccinations and the effective reproduction number. This data is collected by municipal health services, laboratories, hospitals, sewage treatment plants, vaccination providers and citizens and is cleaned, analysed and published, mostly daily, by the National Institute for Public Health and the Environment (RIVM) in the Netherlands, using automated scripts. Because these datasets cover the key aspects of the pandemic and are available at detailed geographical level, they are essential to gain a thorough understanding of the past and current COVID-19 epidemiology in the Netherlands. Future purposes of these datasets include country-level comparative analysis on the effect of non-pharmaceutical interventions against COVID-19 in different contexts, such as different cultural values or levels of socio-economic disparity, and studies on COVID-19 and weather factors.

Prevalence and determinants associated with healthcare-associated infections in long-term care facilities (HALT) in the Netherlands, May to June 2010.

HAIs (healthcare-associated infections) are likely to become an increasing public health problem. Therefore, a point-prevalence study called HALT (Healthcare-associated infections in long-term-care facilities) was set up by the European Centre for Disease Prevention and Control to determine the prevalence, antibiotic use and determinants associated with HAIs. In the Netherlands, 10 nursing homes (in total 1,429 elderly residents) participated in the study between May and June 2010. Risk and protective factors were determined by calculating relative risks (RRs) and performing multilevel Poisson regression. An overall infection prevalence of 2.8% was found and 3.5% of the residents used antibiotics. Residents' characteristics such as the presence of pressure wounds (RR: 2.58; 95% CI:1.04-6.39) and other wounds (RR: 5.70; 95% CI: 2.99-10.86) were risk factors for an HAI, whereas being male (RR: 0.43; 95% CI: 0.21-0.91) was protective. Nursing home characteristics, such as the percentage of shared rooms ( ≥ 2%) (RR: 0.49; 95% CI: 0.39-0.62) and percentage of incontinent residents (≥ 3%) (RR: 0.72; 95% CI: 0.61-0.85) were protective determinants in a multivariate analysis. Special attention is therefore needed for female residents and residents with pressure and other wounds for the prevention of HAIs in Dutch nursing homes.

High prevalence of nasal MRSA carriage in slaughterhouse workers in contact with live pigs in The Netherlands.

Livestock-associated MRSA has been found in various animals, livestock farmers and retail meat. This study aimed to determine the prevalence and determinants of nasal MRSA carriage in pig slaughterhouse workers. Three large pig slaughterhouses in The Netherlands were studied in 2008 using human and environmental samples. The overall prevalence of nasal MRSA carriage in employees of pig slaughterhouses was 5.6% (14/249) (95% CI 3.4-9.2) and working with live pigs was the single most important factor for being MRSA positive (OR 38.2, P<0.0001). At the start of the day MRSA was only found in environmental samples from the lairages (10/12), whereas at the end of the day MRSA was found in the lairages (11/12), the dirty (5/12) and clean (3/12) areas and green offal (1/3). The MRSA status of the environmental samples correlated well with the MRSA status of humans working in these sections (r=0.75). In conclusion, a high prevalence of nasal MRSA carriage was found in pig-slaughterhouse workers, and working with live pigs is the most important risk factor. Exact transmission routes from animals to humans remain to be elucidated in order to enable application of targeted preventive measures.

Appropriateness of antimicrobial therapy: a multicentre prevalence survey in the Netherlands, 2008-2009.

A survey was carried out to determine the prevalence and appropriateness of antimicrobial therapy (AMT) in the Netherlands and to identify determinants for inappropriate AMT. Prevalence surveys of patients hospitalised in the Netherlands were performed three times in 2008 and 2009. Patients' demographic, infection-related and AMT-related data were collected from hospital wards. A total of 19 hospitals participated, consisting of a mix of university, teaching and general hospitals, which were distributed evenly across the country. The appropriateness of AMT was assessed using a standardised algorithm based on local AMT prescription guidelines. A total of 7,853 patients were included, of which 2,327 (29.6%) patients were on AMT (range: 20.8­39.5%). In 372 patients (16% of patients on AMT), treatment was considered inappropriate. In 265 (11.4%) patients on AMT, appropriateness of treatment was not judged because of insufficient information. The percentage of patients without a judgment varied considerably between the participating hospitals (range: 1.3­36.2%). Appropriate AMT use was significantly associated with a patient being in an intensive care unit, having a central venous catheter and being given beta-lactamase-sensitive penicillins. The use of fluoroquinolones was significantly associated with more frequent inappropriate use. There was considerable and significant variation between the participating hospitals in the amount of antimicrobials prescribed and the appropriateness of their use. To improve the completeness and reliability of such surveys, there is a need for intensive training of observers and medical staff in recording information.

Decrease of hypervirulent Clostridium difficile PCR ribotype 027 in the Netherlands.

After the first outbreaks of Clostridium difficile PCR ribotype 027 (North American pulsed-field type 1, restriction endonuclease analysis group BI) in the Netherlands in 2005, a national surveillance programme for C. difficile infection (CDI) was started. Furthermore, national guidelines were developed to rapidly recognise type 027 infections and prevent further spread. The mean incidence of CDI measured in 14 hospitals remained stable throughout the years: an incidence of 18 per 10,000 admissions was seen in 2007 and 2008. Between April 2005 and June 2009 a total of 2,788 samples were available for PCR ribotyping. A decrease was seen in the number and incidence of type 027 after the second half of 2006. In the first half of 2009, the percentage of type 027 isolates among all CDI decreased to 3.0%, whereas type 001 increased to 27.5%. Type 014 was present in 9.3% of the isolates and C. difficile type 078 slightly increased to 9.1%. We conclude that currently there is a significant decrease in type 027-associated CDI in the Netherlands.

Evaluating the impact of health reforms in the Netherlands: Assessing the impact of an alcohol ban on sexually transmitted infections in national surveillance data.

BACKGROUND: On 1 January 2014, the minimum age to buy alcohol increased (16-18 years), accompanied by a public awareness campaign (NIX18). Decreases in alcohol consumption are associated with less risky sexual behaviour. This study analyzed the association between the health reforms andChlamydia trachomatis infections (chlamydia) among young heterosexual people. METHODS: Chlamydia positivity rates, age, and gender from all STI-clinic attendees between 16 and 19 years old in the Netherlands of 2010 to 2016 were obtained. Interrupted time-series assessed immediate and gradual trends in chlamydia rates. RESULTS: Among the control group (18-19 year olds) chlamydia rates increased 0.5% each post-ban month (95% Confidence Interval [CI] 1.002-1.008, p = .001). Among 16-17 year olds there was no monthly increase post-ban (Rate Ratio 1.000, 95% CI 0.993-1.007, p = .948). In terms of confounders, only controlling for partner notification dissolved these time trends. CONCLUSIONS: We found that chlamydia rates after the alcohol ban differed between 16-17 year olds and 18-19 year olds. This demonstrates that the health reforms might have affected this secondary outcome, but obtaining certainty using national surveillance data is difficult. Specific studies should be designed, as now changes in chlamydia over time could be explained by STI-clinic policy changes, by changes on an individual level including reduced alcohol consumption or most likely by the combination of these factors.

Reflections on an evaluation of the Dutch Infectious diseases Surveillance Information System.

The Netherlands' Infectious diseases Surveillance Information System (ISIS) was developed 12 years ago as an early warning system for the country. The initial objective was to establish a surveillance system that gathered the test results of all microorganisms from all medical microbiology laboratories (MMLs) in the Netherlands on a daily basis in order to create an early warning system. This paper analyses the most important results of a recent evaluation of the system. The evaluation was based on an analysis of early warning signals to detect outbreaks, number of visits to the ISIS website, and interviews with stakeholders, documentation on the ISIS system, and analyses of the ISIS MML database. While the daily collection of data on all micro-organisms for early warning has been achieved, the connection of all 85 MMLs in the Netherlands to the central ISIS MML database has not been achieved - only 18 MMLs have been connected. This has resulted in a low coverage and non-representative selection of MMLs for the Netherlands and therefore national outbreaks were missed. Data were used to determine trends in antimicrobial resistance over time. The ISIS system was not found suitable for early warning since outbreaks were detected via other systems. However, with some adaptations the ISIS system could be suitable for the surveillance of antimicrobial resistance. Furthermore, the discontinuation of this network would cause the loss of the most important data system for antimicrobial resistance in the Netherlands, since there is no other national system that gathers data on this topic. This evaluation resulted in a restart of the network.

[Epidemiology of Clostridium difficile PCR ribotype 027 in the Netherlands 2005-present and the emergence of other subtypes]. / De epidemiologie van clostridium difficile PCR-ribotype 027 in Nederland sinds 2005 en de opkomst van andere typen.

Outbreaks of Clostridium difficile associated diarrhoea (CDAD) involving the virulent PCRribotype 027, toxinotype III were first reported in the Netherlands in 2005. This ribotype has now been detected in 26 of the 97 hospitals in the Netherlands. In 13 of the hospitals, the introduction of ribotype 027 was linked to increased CDAD incidence; this was found in 2 hospitals since December 2006. Ribotype 027 has also been detected in to nursing homes. In 2007, no evidence of ribotype 27 was found in 6 of the 12 hospitals in which ribotype 027 was confirmed in 2005-2006 and an outbreak of CDAD had occurred. The incidence of CDAD increased again in 2 hospitals that had previously had the epidemic well under control. Meanwhile, other PCR ribotypes appear to be gaining ground in the Netherlands, some of which have the same virulent characteristics as ribotype 027. Notably, ribotype 078, which appears to be associated with livestock, is becoming increasingly common.

Provision and consumption of alcohol-based hand rubs in European hospitals.

Hand hygiene is considered to be the most effective way of preventing microbial transmission and healthcare-associated infections. The use of alcohol-based hand rubs (AHRs) is the reference standard for effective hand hygiene. AHR consumption is a valuable surrogate parameter for hand hygiene performance, and it can be easily tracked in the healthcare setting. AHR availability at the point of care ensures access to optimal agents, and makes hand hygiene easier by overcoming barriers such as lack of AHRs or inconvenient dispenser locations. Data on AHR consumption and availability at the point of care in European hospitals were obtained as part of the Prevention of Hospital Infections by Intervention and Training (PROHIBIT) study, a framework 7 project funded by the European Commission. Data on AHR consumption were provided by 232 hospitals, and showed median usage of 21 mL (interquartile range (IQR) 9-37 mL) per patient-day (PD) at the hospital level, 66 mL/PD (IQR 33-103 mL/PD) at the intensive-care unit (ICU) level, and 13 mL/PD (IQR 6-25 mL/PD) at the non-ICU level. Consumption varied by country and hospital type. Most ICUs (86%) had AHRs available at 76-100% of points of care, but only approximately two-thirds (65%) of non-ICUs did. The availability of wall-mounted and bed-mounted AHR dispensers was significantly associated with AHR consumption in both ICUs and non-ICUs. The data show that further improvement in hand hygiene behaviour is needed in Europe. To what extent factors at the national, hospital and ward levels influence AHR consumption must be explored further.

Sexually transmitted infections in European HIV-infected women: incidence in relation to time from infection. European Study on the Natural History of HIV Infection in Women.

OBJECTIVES: To investigate the prevalence and incidence of sexually transmitted infections (STI) in HIV-infected women in relation to time from infection and sexual behaviour. DESIGN: The European study on the natural history of HIV infection in women is a prospective cohort study of 487 HIV-infected women with a known interval of seroconversion from 12 European countries. METHODS: Incidence was measured with person-time methods. Generalized estimating equations analysis was used to determine risk factors for STI. RESULTS: At entry, 15% of the women were diagnosed with at least one acute STI (chlamydial infection, trichomoniasis or gonorrhoea), 10% with at least one other STI (genital warts or genital ulcerations) and 13% with vaginal candidiasis. Although frequently diagnosed during follow-up, the occurrence of acute STI and vaginal candidiasis decreased, whereas the occurrence of other STI increased with ongoing time from HIV infection. Furthermore, women with a history of prostitution [relative risk (RR), 2.00; 95% confidence interval (95% CI), 1.20-3.33] and women with irregular condom use (RR, 7.74; 95% CI, 3.52-17.0) were at higher risk for an acute STI. CONCLUSIONS: Although STI diagnoses were frequent, the occurrence of acute STI declined with time from infection which might be explained by changed sexual behaviour over time. The occurrence of other STI increased with time from HIV infection, presumably due to reactivation as a result of immunosuppression.

Pregnancies before and after HIV diagnosis in a european cohort of HIV-infected women. European Study on the Natural History of HIV Infection in Women.

OBJECTIVES: Because most HIV-infected women are of reproductive age, we investigated whether their reproduction planning was affected by their HIV diagnosis. DESIGN: The European women study is a prospective, multicentre cohort of 485 HIV-infected women with a known interval of seroconversion. METHODS: The incidence of pregnancy was measured with person-time methods. Generalized estimating equation analysis was used to determine risk factors for pregnancy and pregnancy outcomes. RESULTS: In 449 women, the age-adjusted incidence of pregnancies decreased from 8.6 before HIV diagnosis to 8.2 and 6.0 per 100 person-years in 0-4 and over 4 years after HIV diagnosis, respectively (P = 0.14). The proportion of induced abortions increased from 42% before to 53% after HIV diagnosis (P < 0.05). The risk of spontaneous abortion did not increase as a result of HIV infection. Since 1995, the proportion of births increased (P = 0.009), whereas that of induced abortions decreased (P = 0.01) compared with earlier years. An increased risk of pregnancy after HIV diagnosis was found in northern and central European women compared with southern European women; there was a lower risk in single women than in women with a steady partner. Of all pregnant women, single women, women between 15 and 25 years of age, and women with multiple partners were at increased risk for induced abortion both before and after HIV diagnosis. CONCLUSION: The incidence of pregnancy decreased with HIV disease progression. Pregnancies after HIV diagnosis appear to be related largely to social and cultural attitudes. The number of induced abortions was high before HIV diagnosis and it significantly increases thereafter.

Is AIDS a floating point between HIV seroconversion and death? Insights from the Tricontinental Seroconverter Study.

OBJECTIVE: To investigate the significance of the time from seroconversion to AIDS (incubation time) and other covariates for survival from AIDS to death. METHODS: In survival analysis, survival from AIDS to death was compared for different categories of length of incubation time adjusted and unadjusted for other covariates, and significant predictors for survival from AIDS to death were investigated. RESULTS: Survival after AIDS was not affected by the incubation time in univariate as well as in multivariate analyses. Predictive factors for progression from AIDS to death were age at seroconversion, type of AIDS diagnosis, and CD4 cell count at AIDS. The relative hazard for age at seroconversion increased 1.38-fold over 10 years. Men with a CD4 cell count at AIDS of <130 x 10(6)/l had a twofold higher risk in progression to death than men with higher CD4 cell counts. Persons diagnosed with lymphoma had a sixfold higher risk of progression to death than persons with Kaposi's sarcoma or opportunistic infections. CONCLUSIONS: The incubation time as well as other factors before AIDS did not affect survival after AIDS. Survival from AIDS to death can be predicted by data obtained at the time of AIDS diagnosis, such as type of diagnosis, age and CD4 cell count. AIDS seems to be a significant point in progression to death, and not just a floating point between infection and death affected by prior factors for persons who did not receive effective therapy and did not have long incubation times.

Factors associated with HIV-1 infection among sex workers of Addis Ababa, Ethiopia.

OBJECTIVE: To study the prevalence and risk factors for HIV infection among sex workers of Addis Ababa, Ethiopia. DESIGN AND METHODS: Cross-sectional survey on socio-demographic characteristics, behaviours, and HIV serological status of sex workers attending two health centres of Addis Ababa. RESULTS: HIV prevalence among sex workers was 274 of 372 (73.7%). Several factors were significantly associated with an increased risk of being HIV-infected [among others, working in 'shared rooms', high number of clients, use of injectable hormones, and positive Treponema pallidum particle agglutination (TPPA) serology], and others with a decreased risk (being born in Addis Ababa, high level of education, peer education on sex work, condom use, use of oral pill, and use of condoms for contraception). Of interest, sex workers who were using condoms for contraception were, compared with others, more likely to use condoms consistently (65 versus 24%, respectively; P < 0.001), and less likely to be HIV-infected (55 versus 86%, respectively; P < 0.001). In multivariate analysis [log-binomial model, giving estimates of the prevalence ratio (PR)], being born in Addis Ababa (PR = 0.74; 95% confidence interval (CI), 0.61-0.91), using condoms for contraception (PR = 0.73; 95% CI, 0.64-0.85), and a positive TPPA serology (PR = 1.21; 95% CI, 1.09-1.36), remained significantly associated with HIV infection. CONCLUSIONS: HIV prevalence was remarkably high among sex workers of Addis Ababa. Condom use was higher, and HIV prevalence lower, in sex workers using condoms not only for prevention of HIV and sexually transmitted diseases, but also for contraceptive purpose. This finding is of particular interest for its implications for prevention strategies among sex workers in the developing world.

An open randomized controlled trial of zidovudine plus lamivudine versus stavudine plus lamivudine.

OBJECTIVE: To compare the antiretroviral effect and safety of zidovudine (ZDV)-lamivudine (3TC) with that of stavudine (d4T)-3TC. METHODS: In an open randomized controlled trial antiretroviral therapy-naive patients who had CD4+ counts > or = 200 x 10(6)/l and plasma HIV RNA load > or = 10000 copies/ml were randomized to receive ZDV-3TC (200 mg three times daily and 150 mg twice daily, respectively) or d4T-3TC (40 mg and 150 mg, both twice daily). If the plasma HIV RNA level at week 8 or thereafter was > 500 copes/ml, indinavir was added at the next scheduled visit. Genotypic resistance analysis of the reverse transcriptase gene was performed at week 0 and 12. Results over 24 weeks were reported. RESULTS: Forty-seven patients were treated (24 took ZDV-3TC; 23 took d4T-3TC). Plasma HIV RNA levels decreased from median 4.80 to 3.15 log10 copies/ml (ZDV-3TC, P < 0.0001) and from 4.98 to 3.03 log10 copies/ml (d4T-3TC, P < 0.0001) after 12 weeks of treatment. Indinavir was added at week 12 in 11 out of 21 patients with ZDV-3TC and in 10 out of 22 patients with d4T-3TC. Median virus load at week 24 was 2.41 log10 and 2.29 log10 copies/ml (P=0.14), respectively. Seventy-five per cent (15 out of 20; ZDV-3TC) and 95% (18 out of 19; d4T-3TC) of patients had a virus load of < 500 copies/ml. Genomic evidence for 3TC resistance was found in all patients tested (11/11 ZDV-3TC and 12/12 d4T-3TC). At week 12, CD4 cell counts had increased with a median of 110 x 10(6)/l in the ZDV-3TC group (baseline, 315 x 10(6)/l) and a median of 115 x 10(6)/l in the d4T-3TC group (baseline 290 x 10(6)/l). At week 24, the median increases were 90 and 120 x 10(6)/l, respectively. Overall the increase of CD4+ cells was higher in the d4T-3TC group (P=0.02). CONCLUSION: d4T-3TC is at least as effective as ZDV-3TC, but 3TC resistance emerged in all patients investigated. The virological response of the dual nucleoside combination is of short duration. However, after addition of indinavir the virus load could be reduced to < 500 copies/ml in the majority of patients. The increase in CD4+ cell count was significantly greater in the d4T-3TC group. To prevent 3TC resistance, the drug should not be used in regimens containing only two nucleosides, irrespective the virus load at baseline.