Mpox: what sexual health physicians need to know?

IJIR: Your Sexual Medicine Journal www.nature.com/ijir REVIEW ARTICLE Mpox: what sexual health physicians need to know? Ahmet Çağkan İnkaya 1✉ © The Author(s), under exclusive licence to Springer Nature Limited 2024 1234567890();,: Monkeypox virus (MPXV) is another zoonotic virus spilled over to the man and resulted in pandemic. World Health Organization declared it as a ‘Public Health Emergency of International Concern (PHEIC) on July 22, 2022. Mpox affected over 95226 individuals among them claimed the lives of 185. Despite the fact that Mpox is generally mild and self-limited, immunocompromised people with low CD4 counts may experience severe disease course. Management of Mpox patients has three pillars. First symptomatic approach includes pain management, prophylaxis for secondary infections and when needed effective treatment of superinfections. Second, vaccines developed against smallpox can be used in preexposure or postexposure prophylaxis strategies against Mpox. Third, current antiviral options include tecovirimat, cidofovir and birincidofovir all of which have been recommended relying on experience from animal studies, clinical case reports or case series. Results of well-planned randomized control trials are not available. Occupational exposure to MPXV is especially a manageable risk for health care workers. Prevention of Mpox also requires risk communication with vulnerable population and their involvement in mitigation efforts. IJIR: Your Sexual Medicine Journal (2024) 36:556–561; https://doi.org/10.1038/s41443-024-00964-w INTRODUCTION We are living in the era of pandemics and another primarily zoonotic virus is now affecting human population. Monkeypox virus (MPXV) has been named after its first detection in captive Asiatic monkeys then first human cases were described in Zaire (now Republic of Congo) [1, 2]. Since then, endemic monkeypox was described in Congo, Nigeria and spread to other African countries [3]. Subsequently, human monkeypox cases were defined outside of Africa after 2003 [4–6]. To avert the risk of stigmatization the term is replaced by ‘Mpox’. Recent outbreak of Mpox disease was first reported at the end of May 2022. WHO closely followed and evaluated the current outbreak and declared a Public Health Emergency of International Concern (PHEIC) on July 22, 2022. As of April 30, 2024, a total of 95226 cases were reported from 117 countries among them over 100 reported Mpox for the first time in the respective country’s history [7]. Most of the recently reported cases were young male people identifying themselves men who have sex with men (MSM). Unlike the previous outbreaks patients refuse direct animal or wild life exposure but confirmed close personal contact. Another distinguishing feature of this current outbreak is it manifests with genital lesions suggesting a close humanitarian contact [8]. BASIC VIROLOGY AND IMMUNOLOGY MPXV is a double-stranded DNA virus belonging to the genus of Orthopoxviruses. Large and brick Orthopoxvirus virions range in length from 220 to 450 nm in width [9]. To the best of our knowledge, 2 MPXV clades have been characterized: West African & Central African clades. There are 4 Orthopoxvirus species which are pathogenic for humans: Variola major virus (eradicated agent of smallpox), variola minor virus, cowpox virus and MPXV [10]. Pox virions include a complete RNA polymerase for primary transcription of up to 200 potential virus encoded proteins [11]. Pox virus genome consists of covalently closed 130–375 kp DNA located within a nucleoprotein complex. This is a sylvatic virus transmitted by droplet exposure or by direct close contact with skin lesions and/or contagious material. The natural animal reservoir remained obscure despite enormous efforts. Existing data shows that African rodents including Gambian marsupial, tree squirrel and rope squirrel, as well as, sooty mangabey monkeys may harbor and transmit MPXV [9]. It looks like rodents and non-human primates are natural reservoirs and incidental hosts [11]. MPXV viral morphogenesis occurs in the cytoplasm and virions are released from cytoplasmic membrane. Some MPXV proteins can counteract intracellular defense systems and modify intracellular restriction [12]. Counteracting intracellular restriction is the main route for MPXV survival in the host. Pox virus infection triggers serial activation of innate and adaptive immune responses. Complement system, interferons, natural killer cells constitute the early response to infection followed by virus-specific humoral and cellular responses [13]. MPXV Clade 1 inhibits the complement activation stronger than Clade 2 which may confer high mortality among patients infected with Clade 1 MPXV [11]. It has been shown smallpox vaccination may confer to Mpox immunity up to 48 years after vaccination [14, 15]. Eradication of variola major as result of comprehensive vaccination program was one of the key achievements in the whole history of medicine. Ever since vaccination against variola discontinued herd immunity against Orthopoxviruses waned over time which, in turn, led to the increase of susceptible unvaccinated individuals [10]. HOW MPXV BECAME A GLOBAL HEALTH PROBLEM? First, eradication of smallpox and discontinuation of smallpox vaccination after 1980s resulted in susceptible population. Second MPXV mutated extensively after 2003 to fit into human population. Hacettepe University Faculty of Medicine, Department of Infectious Diseases, Sihhiye, Ankara 06230, Turkey. ✉email: 1 Received: 31 July 2023 Revised: 9 August 2024 Accepted: 9 August 2024 Published online: 17 August 2024 A. Ç. İnkaya 557 The main driver of the extensive mutation rate was attributed to intracellular restriction factor ‘APOBEC3’. Third, MPXV entered into a human population in an extensive sexual network [11]. Fourth reason why MPVX became a global health problem lies within the concept of ‘one health’. It is apparent that human health is inevitably linked to the health of our precious planet and its non-human residents [16]. TRANSMISSION Mode of transmission of MPXV is still under debate. Animal-tohuman transmission usually occurs through bites and scratches of animals. Consumption and/or handling of bush meat may also lead to transmission [17]. MPXV is present in respiratory secretions and can be transmitted with droplets. Moreover, aerosol transmission between animals have been reported which also been implicated in the nosocomial outbreak in Central African Republic [10, 18]. However, aerosol transmission has not been demonstrated in several settings which generates aerosols procedures [19]. Humanto-human transmission has remained limited in the endemic settings whereas concurrent spillover from different reservoirs once deemed as the main mode of transmission [10]. Direct skin-to-skin contact as well as indirect contact via fomites (i.e, linens, clothing) Fig. 1 Summary of Mpox for sexual health physicians. IJIR: Your Sexual (...truncated)