Incidental diagnosis of mpox virus infection in patients undergoing sexually transmitted infection screening—findings from a study in France

Abstract

Objectives: This study aimed to investigate the prevalence of mpox virus (MPXV) infections in the general population consulting for routine sexually transmitted infections (STIs) in our Marseille public hospital. In fact, the recent worldwide MPXV outbreak mainly impacted men who have sex with men and the prevalence of MPXV infections in the general population remains poorly defined. Methods: All samples addressed routinely to our microbiological laboratory for STIs between July 1 and October 15, 2022 were screened with MPXV-specific quantitative polymerase chain reaction. Results: A total of 2688 samples from 1896 patients suspected of having STIs were tested and eight (0.4%) patients were incidentally diagnosed with MPXV infection, including six men and two women. MPXV was detected in rectal swabs (n = 2), urine (n = 2), vaginal swabs (n = 2), a urethral swab (n = 1), and a skin swab (n = 1). Conclusions: This study suggests that some MPXV infections are likely to be underdiagnosed because of their non-specific clinical presentation and/or insufficient clinical knowledge of the disease. Our data showed that systematic screening was particularly useful for detecting MPXV in patients without classic lesions or cases of asymptomatic carriage in patients reporting recent high-risk exposure and in patients presenting no obvious risk factor.

Keywords

• Sexually transmitted infection (STI)
• Mpox virus
• Syndromic diagnosis
• Men who have sex with men (MSM)
• qPCR