Microscopic examination of Gram-stained smears for anogenital gonorrhoea in men who have sex with men is cost-effective: evidence from a modelling study

Estimating Partnership Duration among MSM in Belgium-A Modeling Study

Mathematical modeling is widely used for describing infection transmission and evaluating interventions. The lack of reliable social parameters in the literature has been mentioned by many modeling studies, leading to limitations in the validity and interpretation of the results. Using data from the European MSM Internet survey 2017, we developed a network model to describe sex acts among MSM in Belgium. The model simulates daily sex acts among steady, persistent casual and one-off partners in a population of 10,000 MSM, grouped as low- or high-activity by using three different definitions. Model calibration was used to estimate partnership duration and homophily rates to match the distribution of cumulative sex partners over 12 months. We estimated an average duration between 1065 and 1409 days for steady partnerships, 4-6 and 251-299 days for assortative high- and low-activity individuals and 8-13 days for disassortative persistent casual partnerships, respectively, varying across the three definitions. High-quality data on social network and behavioral parameters are scarce in the literature. Our study addresses this lack of information by providing a method to estimate crucial parameters for network specification.

Behavioural intervention to reduce sexually transmitted infections in people aged 16–24 years in the UK: the safetxt RCT

Background

The prevalence of genital chlamydia and gonorrhoea is higher in the 16–24 years age group than those in other age group. With users, we developed the theory-based safetxt intervention to reduce sexually transmitted infections.

Objectives

To establish the effect of the safetxt intervention on the incidence of chlamydia/gonorrhoea infection at 1  year.

Design

A parallel-group, individual-level, randomised superiority trial in which care providers and outcome assessors were blinded to allocation.

Setting

Recruitment was from 92 UK sexual health clinics.

Participants

Inclusion criteria were a positive chlamydia or gonorrhoea test result, diagnosis of non-specific urethritis or treatment started for chlamydia/gonorrhoea/non-specific urethritis in the last 2 weeks; owning a personal mobile phone; and being aged 16–24 years.

Allocation

Remote computer-based randomisation with an automated link to the messaging system delivering intervention or control group messages.

Intervention

The safetxt intervention was designed to reduce sexually transmitted infection by increasing partner notification, condom use and sexually transmitted infection testing before sex with new partners. It employed educational, enabling and incentivising content delivered by 42–79 text messages over 1 year, tailored according to type of infection, gender and sexuality.

Comparator

A monthly message regarding trial participation.

Main outcomes

The primary outcome was the incidence of chlamydia and gonorrhoea infection at 12 months, assessed using nucleic acid amplification tests. Secondary outcomes at 1 and 12 months included self-reported partner notification, condom use and sexually transmitted infection testing prior to sex with new partner(s).

Results

Between 1 April 2016 and 23 November 2018, we assessed 20,476 people for eligibility and consented and randomised 6248 participants, allocating 3123 to the safetxt intervention and 3125 to the control. Primary outcome data were available for 4675 (74.8%) participants. The incidence of chlamydia/gonorrhoea infection was 22.2% (693/3123) in the intervention group and 20.3% (633/3125) in the control group (odds ratio 1.13, 95% confidence interval 0.98 to 1.31). There was no evidence of heterogeneity in any of the prespecified subgroups. Partner notification was 85.6% in the intervention group and 84.0% in the control group (odds ratio 1.14, 95% confidence interval 0.99 to 1.33). At 12 months, condom use at last sex was 33.8% in the intervention group and 31.2% in the control group (odds ratio 1.14, 95% confidence interval 1.01 to 1.28) and condom use at first sex with most recent new partner was 54.4% in the intervention group and 48.7% in the control group (odds ratio 1.27, 95% confidence interval 1.11 to 1.45). Testing before sex with a new partner was 39.5% in the intervention group and 40.9% in the control group (odds ratio 0.95, 95% confidence interval 0.82 to 1.10). Having two or more partners since joining the trial was 56.9% in the intervention group and 54.8% in the control group (odds ratio 1.11, 95% confidence interval 1.00 to 1.24) and having sex with someone new since joining the trial was 69.7% in the intervention group and 67.4% in the control group (odds ratio 1.13, 95% confidence interval 1.00 to 1.28). There were no differences in safety outcomes. Additional sensitivity and per-protocol analyses showed similar results.

Limitations

Our understanding of the mechanism of action for the unanticipated effects is limited.

Conclusions

The safetxt intervention did not reduce chlamydia and gonorrhoea infections, with slightly more infections in the intervention group. The intervention increased condom use but also increased the number of partners and new partners. Randomised controlled trials are essential for evaluating health communication interventions, which can have unanticipated effects.

Future work

Randomised controlled trials evaluating novel interventions in this complex area are needed.

Trial registration

This trial is registered as ISRCTN64390461.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 11, No. 1. See the NIHR Journals Library website for further project information.

The Cost-Effectiveness of HIV/STI Prevention in High-Income Countries with Concentrated Epidemic Settings: A Scoping Review

The purpose of this scoping review is to establish the state of the art on economic evaluations in the field of HIV/STI prevention in high-income countries with concentrated epidemic settings and to assess what we know about the cost-effectiveness of different measures. We reviewed economic evaluations of HIV/STI prevention measures published in the Web of Science and Cost-Effectiveness Registry databases. We included a total of 157 studies focusing on structural, behavioural, and biomedical interventions, covering a variety of contexts, target populations and approaches. The majority of studies are based on mathematical modelling and demonstrate that the preventive measures under scrutiny are cost-effective. Interventions targeted at high-risk populations yield the most favourable results. The generalisability and transferability of the study results are limited due to the heterogeneity of the populations, settings and methods involved. Furthermore, the results depend heavily on modelling assumptions. Since evidence is unequally distributed, we discuss implications for future research.

2021 European Guideline on the management of proctitis, proctocolitis and enteritis caused by sexually transmissible pathogens

This guideline intents to offer guidance on the diagnosis and management of patients with gastrointestinal symptoms and a suspected sexually transmitted cause. Proctitis is defined as an inflammatory syndrome of the anal canal and/or the rectum. Infectious proctitis can be sexually transmitted via genital-anal mucosal contact, but some also via digital contact and toys. Neisseria gonorrhoeae, Chlamydia trachomatis (including lymphogranuloma venereum), Treponema pallidum and herpes simplex virus are the most common sexually transmitted anorectal pathogens. Shigellosis can be transferred via oral-anal contact and may lead to proctocolitis or enteritis. Although most studies on these infections have concentrated on men who have sex with men (MSM), women having anal intercourse may also be at risk. A presumptive clinical diagnosis of proctitis can be made when there are symptoms and signs, and a definitive diagnosis when the results of laboratory tests are available. The symptoms of proctitis include anorectal itching, pain, tenesmus, bleeding, constipation and discharge in and around the anal canal. The majority of rectal chlamydia and gonococcal infections are asymptomatic and can only be detected by laboratory tests. Therefore, especially when there is a history of receptive anal contact, exclusion of anorectal infections is generally indicated as part of standard screening for sexually transmitted infections (STIs). Condom use does not guarantee protection from STIs, which are often spread without penile penetration. New in this updated guideline is: (i) lymphogranuloma venereum proctitis is increasingly found in HIV-negative MSM, (ii) anorectal Mycoplasma genitalium infection should be considered in patients with symptomatic proctitis after exclusion of other common causations such N. gonorrhoeae, C. trachomatis, syphilis and herpes, (iii) intestinal spirochetosis incidentally found in colonic biopsies should not be confused with syphilis, and (iv) traumatic causes of proctitis should be considered in sexually active patients.

Cost-effectiveness of two screening strategies for Chlamydia trachomatis and Neisseria gonorrhoeae as part of the PrEP programme in the Netherlands: a modelling study

OBJECTIVES

Pre-exposure prophylaxis (PrEP) users are routinely tested four times a year (3 monthly) for asymptomatic Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections on three anatomical locations. Given the high costs of this testing to the PrEP programme, we assessed the impact of 3 monthly screening(current practice), compared with 6 monthly on the disease burden. We quantified the difference in impact of these two testing frequencies on the prevalence of CT and NG among all men who have sex with men (MSM) who are at risk of an STI, and explored the cost-effectiveness of 3-monthly screening compared with a baseline scenario of 6-monthly screening.

METHODS

A dynamic infection model was developed to simulate the transmission of CT and NG among sexually active MSM (6500 MSM on PrEP and 29 531 MSM not on PrEP), and the impact of two different test frequencies over a 10-year period. The difference in number of averted infections was used to calculate incremental costs and quality-adjusted life-years (QALY) as well as an incremental cost-effectiveness ratio (ICER) from a societal perspective.

RESULTS

Compared with 6-monthly screening, 3-monthly screening of PrEP users for CT and NG cost an additional €46.8 million over a period of 10 years. Both screening frequencies would significantly reduce the prevalence of CT and NG, but 3-monthly screening would avert and extra ~18 250 CT and NG infections compared with 6-monthly screening, resulting in a gain of ~81 QALYs. The corresponding ICER was ~€430 000 per QALY gained, which exceeded the cost-effectiveness threshold of €20 000 per QALY.

CONCLUSIONS

Three-monthly screening for CT and NG among MSM on PrEP is not cost-effective compared with 6-monthly screening. The ICER becomes more favourable when a smaller fraction of all MSM at risk for an STI are screened. Reducing the screening frequency could be considered when the PrEP programme is established and the prevalence of CT and NG decline.

Cost-effectiveness of increased HIV testing among MSM in The Netherlands

OBJECTIVES

To assess the cost-effectiveness of increased consistent HIV testing among MSM in the Netherlands.

METHODS

Among MSM testing at sexually transmitted infection clinics in the Netherlands in 2014-2015, approximately 20% tested consistently every 6 months. We examined four scenarios with increased percentage of MSM testing every 6 months: a small and a moderate increase among all MSM; a small and a moderate increase only among MSM with at least 10 partners in the preceding 6 months. We used an agent-based model to calculate numbers of HIV infections and AIDS cases prevented with increased HIV testing. These numbers were used in an economic model to calculate costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) due to increased testing, over 2018-2027, taking a healthcare payer perspective.

RESULTS

A small increase in the percentage testing every 6 months among all MSM resulted in 490 averted HIV infections and an average ICER of &OV0556;27 900/QALY gained. A moderate increase among all MSM, resulted in 1380 averted HIV infections and an average ICER of &OV0556;36 700/QALY gained. Both were not cost-effective, with a &OV0556;20 000 willingness-to-pay threshold. Increasing the percentage testing every 6 months only among MSM with at least 10 partners in the preceding 6 months resulted in less averted HIV infections than increased testing among all MSM, but was on average cost-saving.

CONCLUSION

Increased HIV testing can prevent considerable numbers of new HIV infections among MSM, but may be cost-effective only if targeted at high-risk individuals, such as those with many partners.