Marcus Chen is Adjunct Professor at the Central Clinical School, Monash University. He is a specialist in sexual health medicine at the Melbourne Sexual Health Centre, Alfred Health. Chen is a Fellow of the Royal College of Physicians and a Fellow of the Australasian Chapter of Sexual Health Medicine. 

Chen’s research has focused on improving the management of sexually transmitted infections (STIs). Since receiving his PhD in 2006, he has published 360 papers in peer reviewed journals, with 240 of these published in the last 10 years. These papers have been cited 15,000 times with citing publications spanning researchers across 120 countries. 

Chen has been an investigator on research grants totalling $30 million. He is currently lead investigator on an NHMRC Partnership Project Grant (2021-2026) which is designing and trialing innovative methods to improve testing and management of syphilis in the context of growing syphilis epidemics in Australia and other countries.

Chen is a member and previous subcommittee chair of the Australian Government Ministerial Advisory Committee on Blood Borne Viruses and Sexually Transmitted Infections. He was a member of the working group for the Australian National Sexually Transmitted Infection Strategy and was chair of the Australasian contact tracing guidelines. Chen has served on several national and state committees responsible for developing guidelines and policy on gonorrhoea and syphilis control. Chen led the development of the web based contact tracing service Let Them Know, which has been used by individuals diagnosed with sexually transmitted infections to contact over half a million partners. He led the establishment of and oversees the hub and spoke network of sexual health services in Victoria after this was recommended by the Victorian Government Review of Sexual Health Services.

Chen has been plenary speaker at several international conferences including the British Association for Sexual Health and HIV Conference 2018 and the European International Union against Sexually Transmitted Infections Conference 2019. In 2011 Chen received the Award for Significant Contribution to Sexual Health Medicine, and in 2019, the Award for Outstanding Contribution to Research in Sexual Health Medicine from the Australasian Chapter for Sexual Health Medicine. He and fellow researchers won the Australian Eureka Prize for Infectious Diseases in 2022. 

Publication highlights:

Review article

Williamson D, Chen M. Emerging and re-emerging sexually transmitted infections. New England Journal of Medicine 2020; 382: 2023-32.

Original research

Towns J...Chen M. Persistence of mpox virus at oral and rectal sites following resolution of cutaneous lesions. Lancet Microbe 2023; 4(4): e210. 

Chen M, Williamson D. Sexually acquired enteric infections in men who have sex with men. Lancet Infectious Diseases (published online). 

Towns J...Chen M. Clinical and laboratory aspects of condylomata lata lesions of syphilis. Sexually Transmitted Infections 2023; 99(3): 162-6.

Chen M, Williamson D. Sexually transmitted outbreaks and genomic surveillance. Lancet Infectious Diseases 2022; 22(10): 1409-11.

Chow E...Chen M. Human papillomavirus antibody levels following vaccination or natural infection among young men who have sex with men. Clinical Infectious Diseases 2022; 75(2): 323-9.

Towns J...Chen M. Anal and oral detection of Treponema pallidum in men who have sex with men with early syphilis infection. Sexually Transmitted Infections 2022; 98: 570-4.

Towns J...Chen M. Timing of primary syphilis treatment and impact on the development of treponemal antibodies: a cross-sectional clinic-based study. Sexually Transmitted Infections 2022; 98(3): 161-5.

Towns J…Chen M. Oral and anal Treponema pallidum detection in lesion and non-lesion sites in men who have sex with men with early infectious syphilis: a prospective cross-sectional study. Lancet Infectious Diseases 2021; 21(9): 1324-31.

Chow E...Chen M. Non-classical pathogens as causative agents of proctitis in men who have sex with men. Open Forum Infectious Diseases 2021; 8(7): ofab137.

Peel J…Chen M. Clinical presentation of incident syphilis among men who have sex with men taking HIV Pre-Exposure Prophylaxis in Melbourne, Australia. Clinical Infectious Diseases 2021; 73(4): e934-7.

Chow E…Chen M. Prevalence of human papillomavirus in young men who have sex with men after the implementation of gender-neutral HPV vaccination: a repeated cross-sectional study. Lancet Infectious Diseases 2021; 21(10): 1448-57.

Tao Y, Chen M...Zhang L. A nationwide spaciotemporal analysis of syphilis over 21 years and implications for prevention and control in China. Clinical Infectious Diseases 2020; 70(1): 136-9.

Chen M…Oldach D. Solithromycin versus ceftriaxone plus azithromycin for the treatment of uncomplicated genital gonorrhoea: a randomised phase 3 non-inferiority trial. Lancet Infectious Diseases 2019; 19: 833-42.

Williamson D…Chen M & Howden B. Bridging of Neisseria gonorrhoeae lineages across sexual networks in the HIV pre-exposure prophylaxis era. Nature Communications 2019; 10: 3988.

Williamson D...Chen M. Risk factors for asymptomatic enteric pathogen detection among men who have sex with men. Open Forum Infectious Diseases 2019; 6(9): 326.

Kwong J...Chen M & Howden B. Whole genome sequencing reveals transmission of gonococcal antibiotic resistance among men who have sex with men: an observational study. Sexually Transmitted Infections 2018; 94(2): 151-7.

Chow E…Chen M. Increased syphilis testing of men who have sex with men: greater detection of asymptomatic early syphilis and relative reduction in secondary syphilis. Clinical Infectious Diseases 2017; 65(3): 389-95.

Machalek DA…Chen M & Tabrizi S. Human papillomavirus prevalence in unvaccinated heterosexual males following a national female vaccination program. Journal of Infectious Diseases 2017; 215: 202-8.

Ong J...Chen M. Asymptomatic and symptomatic urethral gonorrhoea in men who have sex with men attending a sexual health service. Clinical Microbiology and Infection 2017; 23(8): 555-9.

Cornelisse V...Chen M. Increased detection of pharyngeal and rectal gonorrhea in men who have sex with men after transition from culture to nucleic acid amplification testing. Sexually Transmitted Diseases 2017; 44(2): 114-7.

Leeyaphan C…Chen M. Systematic review and meta-analysis of doxycycline efficacy for rectal lymphogranuloma venereum in men who have sex with men. Emerging Infectious Diseases 2016; 22(10): 1778-84.

Towns J...Chen M. Painful and multiple anogenital lesions are common in men with Treponema pallidum PCR-positive primary syphilis without herpes simplex virus co-infection: a cross-sectional clinic-based study. Sexually Transmitted Infections 2016; 92: 110-15.

Bissessor M...Chen M. The contribution of Mycoplasma genitalium to the aetiology of sexually acquired infectious proctitis in men who have sex with men. Clinical Microbiology and Infection 2016; 22: 260-5.

Zou H...Chen M & Fairley C. Site-specific human papillomavirus infection in adolescent men who have sex with men (HYPER): an observational cohort study. Lancet Infectious Diseases 2015; 15(1): 65-73. 

Bissessor M...Chen M. Persistence of Neissseria gonorrhoeae DNA following treatment for pharyngeal and rectal gonorrhea is influenced by antibiotic susceptibility and reinfection. Clinical Infectious Diseases 2015; 60(4): 557-63.

Bissessor M...Chen M. Detection of Neisseria gonorrhoeae from the tonsils and posterior oropharynx. Journal of Clinical Microbiology 2015; 53(11): 3624-6.

Zou H...Chen M. Early acquisition of anogenital human papillomavirus among teenage men who have sex with men. Journal of Infectious Diseases 2014; 209: 642-51.

Chen M...Hogg G. Failure of ceftriaxone 500mg to eradicate pharyngeal gonorrhoea. Journal of Antimicrobial Chemotherapy 2013; 68(6): 1445-7.

Read T...Chen M. Provision of rapid HIV tests within a health service and frequency of HIV testing among men who have sex with men: a randomised controlled trial. BMJ 2013; 347: f5086.

Zou H...Chen M. Automated computer-generated reminders and increased detection of gonorrhoea, chlamydia and syphilis in men who have sex with men. PLOS ONE 2013; 8(4): e61972. 

Bissessor M...Chen M. Differing Neisseria gonorrhoeae bacterial loads in the pharynx and rectum in men who have sex with men: implications for gonococcal detection, transmission and control. Journal of Clinical Microbiology 2011; 49(12): 4304.

Bissessor M...Chen M. Use of a computer alert increases detection of early, asymptomatic syphilis among high risk men who have sex with men. Clinical Infectious Diseases 2011; 53(1): 57-8.

Bissessor M...Chen M. Frequent screening for syphilis as part of HIV monitoring increases the detection of early, asymptomatic syphilis among HIV positive homosexual men. Journal of AIDS 2010; 55(2): 211-16.