Study of asymptomatic rectal carriage of Monkeypox virus in men who have sex with men, and immunological answer to vaccination, followed in Liège University Hospital.

Since the beginning of May 2022, cases of Monkeypox ( MPX) have been reported in many countries in and outside Europe, not related to endemic country. These are mainly but not exclusively infections in men who have sex with men ( MSM).
MPX can be transmitted by an infected animal or person. The virus enters the body through a lesion on the skin (even if not visible), the respiratory tract or mucous membranes.
Person-to-person transmission is not easy, and requires close contact with an infected person:
1) by direct physical contact with skin lesions or body fluids of an infected person or clothing, linens, or objects used by an infected person
2) by respiratory droplets during prolonged face-to-face contact. Other routes of transmission, such as mother-to-child transmission or nosocomial infection have also been described. Transmission by sexual contact (through close skin-to-skin contact or genital secretions) is currently suspected and under investigation.
The University Hospital of Liege wishes to start on 01/10/2022 a screening campaign for Monkeypoxvirus (MPXV) at rectal level by rectal sampling with genomic detection of the virus by RT-PCR (Reverse Transcription- Polymerase Chain Reaction), on an individual voluntary basis.
The purpose of this study is to detect the extent of the current epidemic and to quantify asymptomatic rectal carriage of MPXV and secondary transmission.
In addition, a study of the serological response to vaccination will be conducted to assess immunological and clinical response to the different actual scheme of vaccination.