Mpox (monkeypox) knowledge, concern, willingness to change behaviour, and seek vaccination: results of a national cross-sectional survey

Introduction

Mpox (formerly ‘monkeypox’) is a viral zoonotic disease first identified in humans in 1970 and is endemic in central and west African countries.¹ In May 2022, health authorities identified an emerging mpox outbreak in non-endemic countries, in which >95% cases were recorded among gay and bisexual and other men who have sex with men (GBMSM).^1,2 In July 2022, the World Health Organization declared mpox a public health emergency of international concern.² Australia made mpox a nationally notifiable disease in June 2022 and declared the mpox outbreak a Communicable Disease Incident of National Significance (CDINS) in July 2022.³ In late November 2022, the CDINS declaration was withdrawn.³

Mpox spreads primarily through direct contact with infected skin and bodily fluids, and by large respiratory droplets.⁴ Despite initial concerns of fomite transmission via contaminated surfaces, to date no such transmission has been confirmed during the current outbreak.^4,5 Mpox infection is self-limited, with most mpox symptoms typically resolving within 2–4 weeks.^6–8 Clinical care, including hospitalisation may be required to manage secondary bacterial infections, ocular and gastrointestinal involvement and severe pain.^6,7 A systematic review found that 14% of mpox cases have resulted in hospitalisation, but only 6% of cases in the 2022 outbreak required hospitalisation.⁹ Mpox is rarely fatal.^6,7 The 2022 mpox outbreak resulted in more than 85 000 mpox cases being recorded in 103 non-endemic countries, with more than 140 fatalities.¹⁰ Globally, the number of incident infections in the 2022 outbreak peaked in August at around 1000 cases daily, and declined after that.¹¹ Australia recorded its first mpox cases in May 2022, and 145 cases by July 2023, approximately two-thirds of which were acquired overseas.¹⁰

Vaccinia vaccines, developed to protect against smallpox, offer protection against mpox.^12,13 In August 2022, the Australian Government acquired a limited supply of third-generation, non-replicating Modified Vaccinia Ankara (MVA) vaccine, and from August 2022 the vaccines were targeted to people at highest risk of exposure to mpox virus or severe mpox illness.^14,15 As was observed during the coronavirus disease 2019 (COVID-19) pandemic, particularly before widespread vaccine availability,^16,17 we anticipated that GBMSM would likely follow public health advice, promoted via community organisations, and adapt their behaviour to reduce their risk of acquiring mpox virus until they are vaccinated; for example by reducing the number of untraceable sexual partners and attendance at sex-on-premises venues and sex parties. Based on experience with COVID-19, we anticipate most GBMSM will be willing to be vaccinated against mpox.^18,19

Since this study was originally conceived, other research has begun to examine mpox knowledge and vaccine intention among gay and bisexual men. A Dutch study conducted in July 2022 found that participants had difficulty correctly identifying images of mpox from other skin conditions, and 70% of the 394 participants were willing to be vaccinated against mpox.²⁰ High vaccine acceptance (82%) was observed in a large survey of 32 902 GBMSM across Europe conducted between 30 July 2022 and 12 August 2022.²¹ The highest levels of vaccine acceptance were observed in northern, Mediterranean and western Europe (84–87%), and the lowest levels were in central, eastern, and south-east Europe (66–67%).²¹ In the same study, vaccine willingness was related to perceived mpox severity, concern about acquiring mpox, and having been diagnosed with a sexually transmissible infection (STI) in the past 12 months, among other factors. In the United Kingdom, 1932 participants (90% of whom were GBMSM) were surveyed in June–July 2022.²² Most of the participants (86%) were willing to be vaccinated. Bisexual and heterosexual-identifying participants, people who struggled to afford their basic needs, and participants who identified as being from a non-White heritage group were less willing to be vaccinated, among other factors.²² Within Australia, 563 gay and bisexual men and transgender women from the state of Victoria were surveyed in August–October 2022, with recruitment mainly occurring in clinics. This study found high levels of recognition of mpox transmission routes and symptoms, that 37% of the sample had been vaccinated against mpox, and 68% of the unvaccinated participants were willing to be vaccinated.²³

To identify education and health promotion needs for people at risk of mpox across Australia, and help guide the national vaccination program, we examined what GBMSM and non-binary people knew about mpox virus and what behavioural changes they would be prepared to undertake in response to the outbreak. We anticipated that greater concern about mpox would be associated with a greater willingness to modify behaviour and to seek vaccination.

Materials and methods

Results

The survey was completed by 2287 of 3232 eligible people who commenced it (70.8% completion rate). The median age of the 2287 participants was 40 years (IQR = 31–51), 1894 (82.8%) identified as gay, 2189 (95.7%) were male, 1701 (74.4%) were Australian born, 1550 (67.8%) were university educated, 1647 (72.0%) reported full-time employment, and 1877 (82.1%) lived in the capital city of their state/territory. Most participants lived in New South Wales (860; 37.6%) or Victoria (760; 33.2%). In total, 1944 (85%) were HIV-negative, 179 (7.8%) were HIV-positive, and 164 (7.2%) were untested or did not know their status. Within the prior 12 months, more than two thirds of the sample had been tested for HIV (1634; 71.5%) or other STIs (1616; 70.7%). In total, 1241 (54.3%) participants had ever used PrEP and 914 (40%) were taking PrEP at the time of the survey. Further details of participant characteristics are shown at Appendix 2, Table S1 (see Supplementary materials).

Recognition of mpox symptoms and transmission routes

The 2268 undiagnosed participants were asked to identify potential mpox symptoms and transmission routes. The most commonly identified symptoms were skin lesions (2087; 92%), skin rash (1977; 87.2%), and fever (1647; 72.6%). Fig. 1 shows other symptoms and uncertainty about potential symptoms (ranging from 5% to 43% for ‘don’t know’ responses).

Fig. 1.

Mpox symptom identification by 2268 participants who had not been diagnosed with mpox. All potential mpox symptoms were presented in random order. Three ‘decoy’ symptoms were included in the survey but are not reported here, e.g. ‘loss of taste or smell’.

Most participants identified prolonged skin-to-skin contact (2124; 93.7%), brief skin-to-skin contact (1860; 82%) and contact with bodily fluids (1692; 74.6%) as potential ways to acquire mpox. Fig. 2 shows knowledge of transmission routes and uncertainty about them (ranging from 5% to 36%). Participants with more than 10 male sexual partners in the previous 6 months were more likely to recognise potential mpox symptoms (and some transmission routes) compared to those with fewer partners (see Appendix 2, Table S5 for all comparisons).

Fig. 2.

Mpox transmission route identification by 2268 participants who had not been diagnosed with mpox. All potential mpox transmission routes were presented in random order.

Acceptability of behavioural changes in response to mpox

Fig. 3 shows the acceptability of different behavioural changes among the 2268 undiagnosed participants. The most acceptable strategies were reducing or avoiding attendance at sex parties (1494; 65.9%) and sex-on-premises venues (1503; 66.4%), and having fewer sexual partners (1466; 64.6%). Multivariable analyses showed that concern about mpox and vaccination since May 2022 were independently associated with greater acceptability of these three strategies (see Appendix 2, Table S6 for multivariable results). The least acceptable strategies were not hugging people (445; 19.6%), avoiding densely populated venues (760; 33.5%), and not kissing people (771; 34%). Most participants were willing to avoid contact with people if diagnosed with mpox (2110/2268; 93%), but fewer participants were confident they could avoid physical contact with people (1660/2268; 73.2%), work from home (1588/2268; 70%), or not share communal living spaces such as a bathroom, kitchen or bedroom (1222/1268; 53.9%). More than half of participants were comfortable with contact tracers disclosing a potential mpox diagnosis to casual sex partners (1377/2268; 60.7%; see Appendix 2, Table S7 for further details).

Fig. 3.

Endorsement of potential mpox risk-reduction strategies by 2268 participants who had not been diagnosed with mpox. *This item was only shown to the 1733 participants who had not received a smallpox/mpox vaccination or been diagnosed with mpox. All items were presented in random order.

Discussion

This was the first national study of knowledge and attitudes to mpox among GBMSM in Australia. Most participants accurately identified common clinical symptoms (skin lesions and/or rash) and transmission routes (skin-to-skin contact), similar to findings from the state of Victoria.²³ Early recognition of symptoms is an important component of public health responses to an infectious disease outbreak.

Nearly one quarter of participants reported a history of smallpox or mpox vaccination. As Australia never had universal smallpox vaccination^24,25 and estimates suggest only 10% of contemporary Australians have been vaccinated against smallpox,²⁶ it is likely that some participants mistakenly believed they had been vaccinated.²⁷ It is unknown whether mistaken beliefs about historical vaccination may deter people from seeking vaccination against mpox, but it may be important for public education campaigns to highlight the limited coverage and protection offered by historical smallpox vaccination.⁷

As we anticipated, almost two thirds of participants were willing to modify their sexual practices to reduce their risk of acquiring mpox (e.g. avoiding sex parties, sex-on-premises venues or having fewer sex partners). However, changes to social practices, such as avoiding hugging or kissing, or avoiding popular venues, were rated as less acceptable. It is possible that changes to social behaviour were perceived as less acceptable after COVID-19 restrictions in Australia (‘pandemic fatigue’)²⁸ and because GBMSM correctly surmised that prolonged skin-to-skin contact represented a greater transmission risk. Previous research has found that GBMSM are unwilling to avoid kissing to reduce the risk of gonorrhoea.²⁹ However, COVID-19 research showed that GBMSM modified their sexual practices to reduce transmission risk, particularly in the absence of vaccine protection,^17,19 gradually increasing levels of sexual activity after they were vaccinated.³⁰ It is difficult for people to sustain behaviour that has a personal or social cost over time,³¹ so public health messages should consider what behaviour change may be achievable and acceptable for GBMSM during mpox outbreaks, in order for messaging to be effective. Ongoing surveillance of sexual behaviour, vaccine uptake, and behaviour change in response to mpox would be useful.

Lastly, we found a very high willingness to receive mpox vaccination, which was higher than that observed in one state-based survey in Australia,²³ but similar to levels observed in European studies.^21,22 Few factors distinguished between participants who were willing to be vaccinated or not, although bisexual participants and people who were less concerned about mpox were less willing, and people with more sexual partners were more willing. In general, this aligns with community-oriented messaging about mpox vaccination, which encouraged more sexually active people to come forward first, when local health authorities prioritised vaccines for those deemed to be at greatest risk of mpox. Our results are consistent with findings from a UK study that found bisexual participants were less willing to accept an mpox vaccine.²² Our results are also consistent with findings from a European study that found mpox concern was strongly associated with vaccine acceptance.²¹ If mpox vaccination continues to be encouraged among sexually active GBMSM, our results suggest that targeted messaging for bisexual men may be warranted, explaining why vaccination is beneficial, and how vaccination may be accessed safely and discreetly. Such messaging may be particularly important to increase mpox vaccination rates to reduce the risk of future outbreaks, given mpox may circulate globally at low levels for the foreseeable future.

Limitations

We acknowledge the limitations of the analysis, which included the study’s non-random and convenience-based sample. As there are limited national data on GBMSM and non-binary people, the representativeness of our sample is unknown. However, the cross-sectional sample comprised a large proportion of people who were at potential risk of acquiring mpox (i.e. participants who reported potential risk behaviours, recent travel and future travel plans). Further, 19 (14.7%) of the 129 people (as of 12 September 2022) who had been diagnosed with mpox in Australia responded to the survey.¹¹ Participants from New South Wales and Victoria, where most mpox cases were reported, were overrepresented in the sample compared to participants from other Australian states and territories.³ Our findings may therefore reflect the experiences of people with greater interest in mpox or those at risk of acquiring mpox in Australia.

Conclusion

Despite the rapid global emergence of mpox in 2022, Australia avoided a large-scale local mpox outbreak.¹⁰ This likely reflects temporary behaviour changes made by GBMSM to reduce risk, vigilance about symptoms, and the uptake of vaccination once it became available. Preventing future outbreaks can be achieved through widespread mpox vaccination of at-risk people, and targeted education and awareness raising among GBMSM to explain the importance of temporary modifications of sexual practices during outbreaks, particularly if they are unvaccinated. Modelling from the US, for example, suggests that vaccination coverage needs to be 50% or greater among GBMSM to prevent or limit future mpox outbreaks,³² and our study and Australian research suggests that coverage was well below that level in 2022.²³ Our survey found high levels of willingness to receive mpox vaccination, but some groups, namely bisexual men and GBMSM with lower numbers of sexual partners, may benefit from encouragement and support to get vaccinated. Our survey indicates that GBMSM are willing to modify some sexual practices to reduce their risk of mpox, but we caution that such behaviour modification may not be sustainable in the longer term, and hence risk reduction messaging must be carefully timed to achieve maximal impact during periods where there is a risk of transmission. Together, our findings suggest many GBMSM seek to protect their own and others’ sexual health, but some groups may need additional support to access health information, vaccination, and health services. While case numbers are currently low, Australia should seize the opportunity to increase vaccination coverage to reduce the chance of future outbreaks.

Supplementary material

Supplementary material is available online.

Data availability

A deidentified dataset may be available from the authors upon reasonable request, subject to ethical oversight being obtained by bona fide researchers. Syntax for the database coding and analysis may be available upon request.

Conflicts of interest

Benjamin Bavinton, Vincent Cornelisse, Martin Holt and Anthony KJ Smith are Associate Editors of Sexual Health. To mitigate this potential conflict of interest they were blinded from the review process.

Declaration of funding

The Centre for Social Research in Health and Kirby Institute receive funding from the Australian Government Department of Health and from state/territory health departments (e.g. NSW Ministry of Health). The funding sources did not have any involvement in the collection, analysis and interpretation of data, or in the writing of this manuscript and decision to submit for publication. No pharmaceutical funding was received for this study.

Author contributions

All authors contributed to the study design, analysis and interpretation of findings. James MacGibbon, Timothy R Broady and Martin Holt oversaw data collection. James MacGibbon drafted the manuscript and conducted the quantitative analyses, supported by Vincent Cornelisse and Martin Holt. All authors reviewed and commented on drafts of the manuscript and agreed with the final version.