Sexually or intimately transmitted infections: A look at the current outbreak of monkeypox in 2022.

Dear Editor,

Intimately or sexually transmitted infections represent one of the most effective ways for pathogen dissemination, taking advantage of a mandated evolutive process in sexually differentiated animals to easily spread amongst a large group of hosts. Although the number of pathogens that spread through this mechanism is limited, it encompasses some of the most successful infectious organisms which have become almost impossible to eradicate. The most recent outbreak of Monkeypox (MPXV) in 2022 has brought new light to the importance of this mechanism in the dissemination of an emerging pathogen.

MPXV is a DNA based Orthopoxvirus that has two clades: West African and the Central Africa (Congo Basin) [1]. The largest number of cases had been confined to the African continent where the pathogen is considered endemic, presenting sporadic but self-contained outbreaks through the years. Cases outside Africa were exclusively confined to travelers staying in endemic areas, who encountered bodily fluids from infected animals [1].

The current outbreak began on May 13, 2022, when the World Health Organization (WHO) reported cases of MPXV in at least 12 countries where the virus is not endemic [2]. However, the common thread of most of these cases was that the affected individuals had no contact with animals or direct travel to Africa. It is thought that this outbreak is due to close contact with secretions on the skin or mucosa of other infected humans, and some have speculated even through the sharing of clothing and bedding sheets. Even though traditional sexual transmission is not known to occur with MPX, several cases have been detected in men who have had sex with men (MSM) that according to the European Center for Disease Prevention and Control became infected with the virus after attending two distinct massive parties (in which sexual intercourse was prevalent) without any other clear epidemiological link [3]. In the United Kingdom there have been cases with no prior history of travel, as only 34 confirmed cases (18%) reported recent travel abroad to several different countries in Europe within 21 days of symptom onset. It has been reported that 86% of cases are residents of London (132 of 153 cases) and only 2 were women. Most cases of monkeypox have occurred in people aged 20–49 years (87%). Of all cases 111 patients identified themselves as MSM [4].

MPXV initially presents few defined symptoms, as the patient may present fever, myalgia, headaches, chills, and asthenia, but as the disease progresses a key feature becomes readily identifiable. Unlike smallpox, the patient afflicted with MPXV develops regional lymphadenopathy which is followed by the characteristic eruption (which is similar but not as severe as that of smallpox). Nevertheless, not all patients who have acquired the disease through close and prolonged contact during sexual intercourse present this typical clinical picture, there have been cases in which the eruption was limited to the rectogenital region. Some cases reported in MSM seek attention at sexual health clinics for genital lesions.

As such, it is important to keep in mind the differential diagnosis of the main infections of the sexual tract (Table 1 ), with close attention to MSM complaining of genital rash [7]. It is important to state that even though MSM have been identified as a particularly at-risk population for this disease, all sexually active individuals should be considered at risk. It must also be pointed out that patients with genital rash must usually be evaluated for any other form of sexually transmitted infection rather than MPXV. The United States (US) Centers for Disease Control and Prevention (CDC) warns that lesions in these patients may be mistaken for syphilis, Varicella/VZV, disseminated Herpes, Molluscum contagiosum, other smallpox viruses, disseminated fungal infections, disseminated gonococcal infection, proctitis, gonorrhea and chalmidiasis (including lymphogranuloma venereum) [5,6]. Non-infectious diseases such as recurrent aphthous stomatitis, Behcet's disease, trauma, squamous cell carcinoma and drug-induced eruptions must also be ruled out [6].

Table 1

Genital Ulcer disease differential diagnosis [7].

Pathogen	Disease	Incubation	Number of lesions	Consistency	Lymph nodes
Treponema pallidum	Syphilis	9–90 days	Single	Hard	Hard, painless bilateral
Haemophilus ducreyi	Chancroid	1–14 days	Multiple	Soft	Painful, suppurative, unilateral
Herpes virus 1 y 2	Genital Herpes	2–7 days	Multiple	N/A	Hard, painful, unilateral
Monkeypox virus	Monkeypox	5–21 days	Single/Multiple	Hard	Painful bilateral
Chlamydia trachomatis	Lymphogranuloma venereum	3 days to 6 weeks	Single	Occasionally hard	Painful, suppurative, unilateral

Adapted from: Bennett, J. E. 1., Dolin, R., & Blaser, M. J. (2020). Mandell, Douglas, and Bennett's principles and practice of infectious diseases (Ninth edition.). Philadelphia, PA: Elsevier.

MPXV represents the most recent in a line of emerging zoonotic diseases that have begun their spread due to the relative ease of mobility of modern human populations [8]. Although the disease to this moment seems to have difficulties in achieving a more effective spread, the possibility of dissemination through intimate or sexual contact should represent an alarm to infectious disease specialists to conduct further studies to ascertain the actual ways of dissemination of this disease to prevent its global dissemination.

Author's contributions

Dr. Gabriela Zambrano and Dr. Jaime Acosta wrote the main body of the manuscript and carried out the main bibliographic research. Dr. Altamirano aided Dr. Acosta in writing his segments of the manuscript. Dr. Mosquera provided additional insight for portions of the manuscript and reviewed the manuscript in its entirety to ensure its grammatical and orthographic correctness.

Funding

There was no economic funding provided by any institution for the redaction of this letter.

Declaration of competing interest

Nothing to declare.