Monkeypox in humans: a new outbreak

Abstract

Infection caused by Monkeypox Virus (MPVX) has small rodents as its natural reservoir and both monkeys and humans are occasional hosts. The causative agent is an Orthopoxvirus (MPVX) that was isolated in monkeys in 1958 and proved capable of passing to humans in 1970. It remained contained in Africa, causing isolated episodes of infection, until 2003 when an outbreak occurred in the United States following importation of animals from that continent. Since then, anecdotal cases have continued to be reported outside Africa, usually very clearly linked to travelers to those countries, but in May 2022, a broad outbreak of this disease has begun, now affecting several continents, with the emergence of human cases of MPVX (H-MPVX) infection mainly among Men that have Sex with Men (MSM). The disease has an incubation time ranging from 5 to 15 days and is characterized by the presence of pustules, fever, malaise and headache. The presence of significant regional lymphadenopathy is a differential feature with episodes of classical smallpox. Proctitis and pharyngitis, with minimal skin lesions, may be another form of presentation. Diagnosis can be confirmed by PCR testing of lesions or by demonstration of MPVX in other body fluids or tissues, although in the appropriate epidemiologic setting the clinical picture is highly suggestive of the disease. Effective drug treatment has been developed as part of programs to protect against potential bioterrorist agents and smallpox vaccinees are known to have high protection against monkeypox. New vaccines are available, but neither the drugs nor the vaccines are yet freely available on the market. The prognosis of the disease appears, at least in adults in developed countries, to be good, with very low mortality figures and much less aggressive behavior than that described in classical smallpox. Isolation measures, essential for the control of the outbreak, have been published by the health authorities.

Differential Diagnosis, Prevention, and Treatment of mpox (Monkeypox): A Review for Dermatologists

“…Such complications may include confluent and necrotic skin lesions, fatigue, sore throat, headache [26], secondary bacterial sepsis, ocular infection leading to keratitis, encephalitis, and myocarditis. The mortality rate of mpox infection has been estimated to be between 0 and 11% in the general population of African countries [27], with the highest mortality rate being observed in young children [27]. As of 25 March 2023, the fatality rate of the current 2022 outbreak was approximately 0.13% (112/86,646) [6].…”

“…As of 25 March 2023, the fatality rate of the current 2022 outbreak was approximately 0.13% (112/86,646) [6]. Moreover, individuals under 40-50 years of age may be more susceptible to mpox infection due to the discontinuation of routine smallpox immunization in the early 1980s following smallpox worldwide eradication [27].…”

Infectious proctitis: what every gastroenterologist needs to know

“…Clinical manifestations usually appear after an incubation period of 5-24 days, characterized by biphasic pattern with a prodromal phase of fever, lethargy, myalgias, headache and lymphadenopathy, followed by skin eruption 2-4 days later. Skin lesions follow a typical pattern of evolution, starting as macules and progressing into papules, vesicles, pustules and ulcers [ 36 , 37 ]. New clinical presentations of monkeypox infection have been identified, including perianal lesions, severe rectal pain, proctitis, pharyngitis, and penile edema [ 37 ].…”

“…The incidence of proctitis and/or proctalgia in patients with monkeypox in different series ranged from 22-37% [ 34 - 36 ]. In a recent prospective observational study that included 181 patients with Monkeypox virus (MPXV) infection, 78% had lesions in the anogenital region and 43% in the oral and perioral region.…”

An assessment of rates and covariates of mpox diagnosis and vaccination provides evidence to refine eligibility criteria for mpox vaccination among gay, bisexual and other men who have sex with men in the Netherlands

“…Observational studies suggest that smallpox vaccination attenuates mpox disease severity and acquisition risk [2,3,11], and WHO recommends primary prevention vaccination of individuals at high risk, notably GBMSM with multiple sexual partners [12]. However, as in other countries [13], the vaccine for mpox prevention is part of the strategic stockpile and was previously not available to the public in the Netherlands. This limited supply of vaccine necessitates the prioritization of vaccination to population groups at highest risk [14].…”