Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are frequent causes of acute and chronic hepatitis worldwide and leading causes for hepatic cirrhosis and cancer. There is a distinct geographical variation in HBV and HCV incidence and prevalence in the European Union (EU) and European Economic Area/European Free Trade Association (EEA/EFTA) member states and neighbouring countries. The HBV carrier prevalence ranges from 0.1 to 8.0% and that of HCV from 0.1 to 6.0%. Within the last few years, the HBV incidence has decreased while the HCV incidence has increased. Both diseases are concentrated in certain subpopulations, such as injecting drug users, with tens of times higher prevalence than in the general population. Most EU and EEA/EFTA countries have a surveillance system for HBV and HCV infections, but due to differences in system structures, reporting practices, data collection methods and case definitions used, the surveillance data are difficult to compare across countries. The harmonisation and strengthening of HBV and HCV surveillance at the European level is of utmost importance to obtain more robust data on these diseases.

In 2002-2005, a cross-sectional study to assess the potential for HIV transmission was carried out among 557 female and male-to-female transgender commercial sex workers (CSW) in three cities in the Netherlands. Female CSW (F-CSW), drug-using female CSW (DU), and transgender sex workers were recruited in street-based and establishment-based sites. An anonymous questionnaire was administrated by interviewers and a saliva sample was collected for HIV antibody testing. The overall HIV prevalence was 5.7% (31/547; 10 samples were excluded because of "intermediate" test results). HIV was more prevalent among transgender (18.8%, 13/69) and DU (13.6%, 12/88) sex workers than among F-CSW (1.5%, 6/390). Of the HIV positive CSW, 74% were unaware of their infection. Consistent condom use with clients was 81%. Regular condom failure with clients was reported by 39%. In multivariate analyses, transgender sex workers (OR = 22.9), drug-using CSW who ever injected drugs (OR = 31.1), African (OR = 19.0), and South European ethnicity (OR = 7.2) were independently associated with HIV. Condom failure (PRR = 2.0), anal sex (PRR = 2.1), and drug use (PRR = 3.8) were associated with inconsistent condom use with clients. There is a potential risk for further spread of HIV, through clients and (private) partners of sex workers, to the general population. Targeted health promotion activities are indicated for transgender sex workers and drug-using female CSW; active HIV testing must be continued.

In 1994 Chlamydia trachomatis specimens from 175 men and 135 women attending a clinic for treatment of sexually transmitted disease were genotyped by polymerase chain reaction-based restriction fragment length polymorphism of the omp1 gene. Information about the patients was collected at their initial visit. The associations between C. trachomatis genotype and patients' self-reported symptoms, clinical signs, and characteristics were studied. Genotypes E, F, and D/D-predominated (men: 71%; women: 60%). Five specimens (1.6%) showed evidence of mixed infections. Among men, complaints of urethral discharge and dysuria were most commonly associated with genotypes H and J (100% vs. 59%-68% for the other genotypes; P = .03); in addition, > or = 10 leukocytes per microscopic field were least often observed for genotypes G/Ga (19% vs. 59%-65% for the other genotypes; P = .01). Women's reports of lower abdominal pain were more often associated with F, G group genotypes (32%) than with B-complex (6%) or C-complex (13%) genotypes (P = .02). Certain symptoms of genital C. trachomatis infection were related to the infecting genotype. Further work will be necessary and should involve markers of the host immune response.

The presence of HSV-2 antibodies had a strong association with past sexual behaviour and, for both sexes, with receptive anal intercourse. HSV-2 antibodies may be used as a surrogate marker of sexual risk behaviour in comparing different populations over time.

Older male travellers of Surinamese and Antillean origin are at high risk for cross-border heterosexual transmission of HIV/STIs. They should be targeted by prevention programmes, which are focused on sexual health education and HIV/STI testing, to raise their risk awareness and prevent transmission.

To gain insight into hepatitis B virus (HBV) transmission in the Netherlands, epidemiological data and sera were collected from reported cases of acute HBV infections in the Netherlands in 2004. Cases were classified according to mode of transmission. A fragment of the S-gene of HBV (648 bp) was amplified, sequenced, and subjected to phylogenetic analysis. Of the 291 acute HBV cases reported in 2004, 158 (54%) were available for genotyping. Phylogenetic analysis identified 6 genotypes: A (64%), B (3%), C (3%), D (21%), E (5%) and F (5%). Of HBV infected men having sex with men, 86% were infected with genotype A, accounting for 43% of all patients infected with this genotype. There were only three reported cases of injecting drug use of which one was available for sequencing (genotype A). Unlike the genotype A cluster, sequences within the genotype B-E clusters were heterogenic. Within genotype F, several isolates had identical sequences, but patients could not be epidemiologically linked. Sexual transmission, particularly by men having sex with men was the most important transmission route for HBV. Injecting drug use plays a minor role. Genotype A is predominant in the Netherlands, especially among men having sex with men. In addition to imported strains, there seems to be a pool of related but non-identical strains circulating among chronic carriers in the migrant population, from which occasionally new patients are infected, primarily by heterosexual transmission.

The authors conclude that data on sexual behavior can be collected reliably among sexually transmitted disease clinic attendees, although reporting bias does occur. The frequency of sexual intercourse was not sufficiently reliable and should be interpreted as an estimate only.

A mathematical model that takes transmission by sexual contact and vertical transmission into account was employed to describe the transmission dynamics of hepatitis B virus (HBV) and vaccination against it. The model is an extension of a model by Williams et al. (Epidemiol Infect 1996: 116; 71-89) in that it takes immigration of hepatitis B carriers from countries with higher prevalence into account. Model parameters were estimated from data from The Netherlands where available. The main results were that, given the estimates for the parameters describing sexual behaviour in The Netherlands, the basic reproduction number R0 is smaller than 1 in the heterosexual population. As a consequence, the immigration of carriers into the population largely determines the prevalence of HBV carriage and therefore limits the possible success of universal vaccination. Taking into account the prevalence of hepatitis B carriage among immigrants and an age-dependent probability of becoming a carrier after infection, we estimate that a fraction of between 5 and 10% of carrier states could be prevented by universal vaccination.