Prevention of sexual transmission of mpox: a systematic review and qualitative evidence synthesis of approaches

Figures & data

Figure 1. Systematic review of interventions to prevent sexual transmission of mpox, PRISMA 2020 flow diagram*. *Adapted from Page et al. [25].

Table 1. Characteristics of included studies for question 1: do preventive interventions decrease the risk of MPVX infection?

Source	Location	Study type	Study period	Population (age range)	Sample size	Preventive intervention	Outcome measure(s)	Results
Cope et al. [16]	United States	Cross sectional	May–Jul 2022 (2 months)	Males aged ≥18 years	1921	Contact tracing	Number of reported cases, the proportion of people interviewed, the number of named contacts, named sexual contacts, unnamed contacts, and contact indices before and after vaccine campaign extension	1986 mpox cases were reported in MSM (240 before and 1746 after the expanded vaccine access). Most MSM with mpox were interviewed 228 (95%) before and 1694 (97%) after vaccination campaign. The proportion of cases who named at least one contact declined between the two periods from 75% to 40%
Ghosn et al. [17]	France	Retrospective observational	May 2022 to September 2022	Males with a median age of 39 years	472	Sexual behaviour change	Prevalence of mpox; vaccination status; self-reported behaviour change	Mpox prevalence was 16.3% (77/472) Significant change in sexual behaviour among mpox cases and mpox-free control subjects with >10 partners during the last three months(45% vs 38%, p = .0035)
Du et al. [18]	China	Cross sectional	July 31 to August 4, 2023 (one week)	Males (18–78 years old)	7538	Sexual behaviour change	Prevalence of mpox; crude and adjusted prevalence of infection based on a safe sexual behaviour index based on three ‘risk’ behaviours including condomless anal intercourse, commercial sex, and group sex (High ‘safe’ sexual behaviour involved participation in none, and low ‘safe’ behaviour involved engagement in all three).	Overall prevalence was 0.73% (55/7538); Crude prevalence was 0.35% (21/6003) in high ‘safe’ behaviour; 1.78% (26/1469) in moderate behaviour; and 12.12% (8/66) in low ‘safe’ behaviour. Multivariable-adjusted analysis comparing low ‘safe’ behaviour to moderate behaviour was aOR = 0.21; 95% CI = 0.08, 0.54; while comparing to high ‘safe’ behaviour was aOR = 0.04; 95% CI = 0.02, 0.12).

Table 2. Characteristics and findings of included studies for question 3: does testing asymptomatic individuals at risk of mpox without known exposure to MPXV reduce onward transmission?.

Source	Location	Population	Sample size	Age range (years)	Study period	Outcome measure	Outcome/results
Adamson et al. [30]	Vietnam	MSM^a in HIV PrEP programme	152 participants	Median 25·9 years (IQR 21·7–30·3)	Jul–Aug 2022 (retrospectively one month)	Population mpox prevalence	None tested positive
Agusti et al. [23]	Spain	Highly exposed MSM, non-binary individual sand transgender women in community setting	113 participants	Median 35 years (IQR 30–43)	Aug–Oct 2022 (three months prospective)	Population mpox prevalence	7 participants tested positive; 8 samples tested positive. Study estimated a total prevalence of 6.19% (95% CI: 1.75–10.64%)
Contag, Renfro, et al. [29]	United States	Participants undergoing STI testing in county public hospital and clinics	1645 (participants); 1848 (swab samples)	7–81 years	Apr–Sept 2022 (five months–retrospective)	Population mpox prevalence and presence of MPXV in swab samples	11 (0.7%) participants tested positive; 16 (0.9%) samples tested positive (4/60 anorectal, 4/66 oropharyngeal, 5/1264 urine, and 3/445 vaginal)
Contag, Lu, et al. [28]	United States	Participants undergoing GC/CT testing in tertiary academic medical centre	206 participants; 347 swab samples	7 days to 77 years	Jul–Sept 2022 (two months – retrospective)	Population mpox prevalence and presence of MPXV in swab samples	17 (8%) participants tested positive; 24 (7%) samples tested positive (11/24 oropharyngeal, and 13/24 anorectal)
De Baetselier et al. [19]	Belgium	Men undergoing anorectal or oropharygneal GC/CT testing in sexual health clinic	224 participants	NR	May 2022 (retrospectively one month)	Presence of MPXV	4 (1.8%) undiagnosed cases
Ferré et al. [20]	France	Men attending routine PrEP or HIV clinic	213 participants; 200 samples analysed	Median 38 years (IQR, 29–48)	Jun–Jul 2022 (retrospectively one month)	Presence of MPXV	13 (6.5%) tested positive
Grabmeier-Pfisterhammer et al. [24]	Austria	Asymptomatic MSM at high risk for STIs attending routine screening	90 participants	Median 38 years	Jan–Mar 2023 (retrospective)	Presence of MPXV	No MPXV positive samples
Mizushima et al. [31]	Japan	Asymptomatic MSM in community setting	1346 participants	Median age 38 (IQR 31–47)	Jan–Mar 2023 (prospectively 3 months)	Presence of MPXV	5 participants (0.37%; 95% CI 0.12–0.86) positive; 3/5 remained asymptomatic
Pestel et al. [21]	Germany	MSM with changing sexual partners (PrEP-, PEP users and PLWH)	53 participants	Median 35 years (range 19-52)	Jun–Jul 2022 (prospectively one month)	Presence of MPXV	None tested positive
Pitt-Kendall et al. [25]	England	MSM undergoing routine asymptomatic GC/CT screening	1159 participants; 2927 samples	NR	Aug–Oct 2022 (retrospective)	Population MPXV prevalence	Four specimens (4/2917, 0.14%) from two individuals (2/1158, 0.17%) positive
Rossotti et al. [26]	Italy	Asymptomatic MSM PrEP users and PLWH	72 participants	Median 37 years (IQR 32–46)	Sept–Oct 2022 (prospective)	Population MPXV prevalence	None tested positive for MPXV during the initial screening or developed symptoms during the 21-day follow-up
Thomassen et al. [27]	Denmark	MSM PrEP users undergoing routine STI screening during PrEP consultations or walk-in STI testing	224 participants	Median 36.5 years (IQR 30–45)	Sept–Oct 2022 (prospective)	Presence of MPXV	1/224 participants (0.45%) positive for MPXV (developed symptoms 3 days later)
Van Dijck et al. [22]	Belgium	MSM with HIV and PrEP users	327 participants (146 retrospective; 181 prospective)	NR	Jun–Jul 22 (one month retrospectively); Jul–Sept (two months prospectively)	Population MPXV prevalence	14 (4.3%) tested positive; 3 presymptomatic; none were asymptomatic

^aCT: Chlamydia trachomatis; GC: Neisseria gonorrhoeae; HIV: human immunodeficiency virus; IQR: interquartile range; MSM: men who have sex with men; MPXV: monkeypox virus; NR: not reported; PLWH: people living with HIV; PEP: HIV post-exposure prophylaxis; PrEP: HIV pre-exposure prophylaxis; STI: sexually transmitted infection.

Table 3. Characteristics of studies included in qualitative evidence synthesis.

Source	Location	Study aim and design	Population	Sample	Data collection period	Key findings / themes	Quality score (/12)
Zhang et al. [32]	China	To investigate the experiences of mpox patients from infection to treatment. Multicentre, cross-sectional, qualitative design. Semi-structured interviews were conducted by telephone and analysed using the thematic analysis.	Mpox patients quarantined in hospital, at home, or discharged.	15 male mpox patients. Median age = 30 (IQR: 25.5, 36), MSM (14/15), urban (15/15), bachelor’s degree or higher (9/12), monthly income ≥ CNY 5000 (10/15), HIV positive (8/15).	6–25 July 2023.	Pre-diagnosis experience: mild rashes and fever as common symptoms; limited knowledge of mpox; sex as most likely route of infection Treatment-seeking experience: delays seeking treatment due to mildness of symptoms; difficulties getting accurately diagnosed; attitude towards diagnosis Quarantine experience: damaging effects of hospital quarantine; reluctance to self-disclose infection status due to stigma and potential discrimination; importance of family support for recovery. Advice for mpox prevention and control: increase in testing channels and methods; development and introduction of vaccines; adjustments to quarantine program; improvement of treatment measures; improvement of publicity and education	7/12 (medium)
Vanhamel et al. [33]	Belgium	To describe the initial phase of the outbreak in Belgium and to provide a more in-depth description of sexual behaviour and transmission contexts. Mixed methods study, combining national routine surveillance data and narrative data from individual, semi-structured interviews. Interviews were held via telephone or online.	Individuals with laboratory-confirmed mpox cases with onset of symptoms between 10 May and 19 June 2022.	12 interview participants, all men, and all aged over 30.	24 May − 20 June 2022.	Self-perceived exposure settings and contexts: gay-oriented festival; cruising venue; home; unknown (sexual); unknown (non-sexual). Sexual interactions: anonymous encounters reduce opportunities for contact tracing; mpox-suspected symptoms among sex partners; sexual networks of MSM. Health-seeking behaviour and risk perception related to mpox: confusing mpox symptoms for other STIs; confusing mpox symptoms for other skin conditions; risk perception; provider-related diagnostic delay.	6/12 (medium)
May et al. [34]	UK	To describe knowledge, attitudes and perceptions of a sample of MSM towards mpox during the 2022–2023 outbreak in the UK, including facilitators for and barriers to the uptake of transmission-reducing behaviours; and to explore preferences for optimising and adapting public health messaging to improve the uptake of measures. Qualitative, cross-sectional design using semi-structured remote telephone/video-call methods.	People with confirmed mpox in 2022, and MSM. All aged >18 and living in UK.	Interviews were conducted with 44 MSM, average age = 34.2 (range 20–56). White British (n = 21), White Other (n = 6), Black / African / Caribbean (n = 5), Latin American (n = 5), Asian (n = 3), Other ethnic group (n = 2), White Welsh (n = 2). 13/44 reported recent contact with a confirmed mpox case, and 8/44 reported recent mpox diagnosis.	May–December 2022.	Perceived risk and severity of mpox influenced willingness to engage with some measures, e.g. healthcare seeking and vaccination uptake. Perceived acceptability of and capacity to perform measures: sexual health-related knowledge, practices, and support; stigma and sexual orientation openness; retaining intimacy; (they also include a table outlining barriers to specific measures, which include structural constraints such as vaccine availability and financial implications of isolation). Optimisation of messaging: targeted vs. inclusive messaging; focus on severe symptoms in messaging could mean that early infection goes unnoticed; Lack of information regarding mpox symptoms, including potential symptom overlaps and information on how to differentiate from other STIs; Lack of targeted messaging for those at increased risk; Absence of harm reduction messages; Official posters/ messages not as credible as those from within MSM community; Absence of information around looking after yourself (self-care) with mpox.	10.5/12 (high)
Smith et al. [35]	Australia	To explore the social and health experiences of people affected by mpox and understand how people with mpox can be better supported in healthcare. Longitudinal, qualitative design using two semi-structured interviews, 6 months apart.	People diagnosed with mpox in 2022, or close contacts.	16 participants, 13/16 diagnosed with mpox. 16/16 cisgender MSM living in Australia.	First interviews: Oct–Dec 2022. Follow-up interviews: Apr–May 2023.	Narrating acute illness and long-term effects: minor to severe periods of sickness, negative and stigmatising experiences engaging with healthcare (with good care as the exception), some participants experienced long-term effects on their sexual wellbeing and complications from mpox. The emergency context in which mpox emerged could make the disease highly distressing and difficult to manage, and produced varying forms of disruption to everyday life. Mpox was narrated as disruptive in different ways: as a minor interruption to holiday plans; a prolonged period of poor health; or as an event prompting a re-evaluation of sexual values and health.	11/12 (high)

Table A1. Question: do preventive interventions decrease the risk of mpox infection?

	Definition
Population	Persons at increased risk^a of acquiring mpox through sexual contact (e.g. sexual networks or casual, multiple partners)
Intervention:	Harm reduction or preventive interventions Reduction of number of sexual partners Condom use Change in types of sexual contact Evaluation of partner (e.g. asking about symptoms, inspecting for lesions)
Comparator	No interventions
Outcome	1) Acquisition of mpox infection 2) Complicated mpox infection (proctitis, urethritis and/or tonsillitis)
Subpopulations	People living with HIV; those with prior smallpox vaccination;

^a Individuals at increased risk of mpox acquisition through sexual contact included sexually active gay, bisexual and other men who have sex with men and people in their sexual networks, sex workers, and transgender and gender-diverse people. In the absence of epidemiological information on risk factors for mpox, this risk of exposure was proxied by a recent history of a sexually transmitted infection (STI), HIV pre-exposure prophylaxis (PrEP) use, or living with HIV.

Table A2. Question: does testing asymptomatic individuals at increased risk of mpox (without known exposure) reduce onward transmission?

	Definition
Population	Persons with mpox at risk of onward transmission through sexual contact
Intervention:	Harm reduction or preventive interventions: Abstinence for a given period of time Reduction of number of sexual partners Condom use Change in types of sexual contact/activity Disclosure to partners Covering of lesions
Comparator	No interventions
Outcome	Transmission of mpox infection to partner(s)
Subpopulations	People living with HIV

Table A3. Question: does testing asymptomatic individuals at increased risk of mpox (without known MPVX exposure) reduce onward transmission?

	Definition: Testing for asymptomatic MPXV infection among people at increased risk without known exposure
Population	Asymptomatic individuals at increased risk of acquiring and transmitting mpox through sexual contact or with history of contact with mpox patient, without known exposure
Intervention:	Testing of asymptomatic individuals at increased risk without known exposure
Comparator	Not testing asymptomatic individuals at increased risk without known exposure (testing only symptomatic individuals and asymptomatic individuals with known exposure)
Outcome	Case detection rate - increased detection of mpox infections Decreased transmission

Table D1. Cohort studies for question 1.

Author, year	1. Was selection of exposed and non-exposed cohorts drawn from the same population?	2. Can we be confident in the assessment of exposure?	3. Can we be confident that the outcome of interest was not present at start of study	4. Did the study match exposed and unexposed for all variables that are associated with the outcome of interest or did the statistical analysis adjust for these prognostic variables?	5. Can we be confident in the assessment of the presence or absence of prognostic factors?	6. Can we be confident in the assessment of outcome?	7. Was the follow up of cohorts adequate?	8. Were co-Interventions similar between groups?
Cope et al., 2023 [16]	Definitely no	Probably yes	Definitely yes	Definitely no	Definitely no	Probably no	Probably yes	Definitely no
Du et al., [18]	Definitely no	Probably yes	Probably yes	Mostly yes	Probably yes	Probably yes	Probably yes	Definitely no
Ghosn et al., 2023 [17]	Definitely no	Definitely yes	Probably yes	Mostly no	Probably no	Definitely yes	Probably yes	Definitely no

Note: Response options: definitely yes (low risk of bias); probably yes; probably no; definitely no (high risk of bias).

Table D2. Cohort studies for question 3.

Author, year	1. Was selection of exposed and non-exposed cohorts drawn from the same population?	2. Can we be confident in the assessment of exposure?	3. Can we be confident that the outcome of interest was not present at start of study	4. Did the study match exposed and unexposed for all variables that are associated with the outcome of interest or did the statistical analysis adjust for these prognostic variables?	5. Can we be confident in the assessment of the presence or absence of prognostic factors?	6. Can we be confident in the assessment of outcome?	7. Was the follow up of cohorts adequate?	8. Were co-Interventions similar between groups?
Adamson et al., 2023 [30]	Definitely no	Definitely yes	Definitely yes	Definitely no	Definitely no	Definitely yes	Definitely yes	Definitely no
Agusti et al., 2023 [23]	Definitely no	Probably yes	Probably yes	Definitely no	Definitely no	Probably yes	Definitely no	Definitely no
Contag, Lu, et al., 2022 [28]	Definitely no	Probably yes	Definitely yes	Definitely no	Definitely no	Probably yes	Probably yes	Definitely no
Contag, Renfro, et al., [29]	Definitely yes	Definitely yes	Probably yes	Definitely no	Definitely no	Probably yes	Probably no	Definitely no
De Baetselier et al., 2022 [19]	Definitely no	Definitely yes	Probably yes	Definitely no	Definitely no	Definitely yes	Definitely yes	Definitely no
Ferré et al., 2022 [20]	Definitely no	Definitely yes	Probably yes	Definitely no	Definitely no	Probably yes	Definitely no	Definitely no
Grabmeier-Pfisterhammer et al., 2024 [24]	Definitely no	Definitely yes	Definitely yes	Definitely no	Definitely no	Probably yes	Definitely no	Definitely no
Mizushima et al., 2023 [31]	Definitely no	Probably yes	Probably yes	Definitely no	Definitely no	Definitely yes	Probably yes	Definitely no
Pestel et al., 2022  [21]	Definitely no	Definitely yes	Definitely yes	Definitely no	Definitely no	Definitely yes	Definitely no	Definitely no
Pitt-Kendall et al., 2023 [25]	Definitely no	Definitely yes	Probably yes	Definitely no	Definitely no	Definitely yes	Definitely no	Definitely no
Rossotti et al., 2023 [26]	Definitely no	Definitely yes	Definitely yes	Definitely no	Definitely no	Definitely yes	Probably yes	Definitely no
Thomassen et al., 2024 [27]	Definitely no	Definitely yes	Definitely yes	Definitely no	Definitely no	Probably yes	Probably yes	Definitely no
Van Dijck et al., 2023 [22]	Definitely no	Definitely yes	Definitely yes	Definitely no	Definitely no	Definitely yes	Definitely yes	Definitely no

Note: Response options: definitely yes (low risk of bias); probably yes; probably no; definitely no (high risk of bias).

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