Monkeypox: Re-Emerging Zoonotic Threat

Abstract

Monkeypox (MPX) is a relatively unknown and minor resurgent viral zoonotic disease caused by the monkeypox virus (MPXV). The disease can spread from person to person or from animal to person. The disease is most prevalent in the tropical rainforests of West and Central Africa. The first MPXV outbreak was recorded in a monkey during 1958 as a small pox-like disease causing flu-like symptoms, such as chills and fever, as well as a rash, and the first MPXV case in a human was in a 9-month-old child in the Democratic Republic of the Congo on 1 September 1970. There were 16,016 laboratory confirmed cases of MPXV infection and five deaths reported in 75 countries/territories/areas across all six WHO Regions as of 22 July 2022. MPXV has a wide host range, including humans, squirrels, mice, rabbits, hamsters, porcupines, non-human primates (orangutans, chimps, sooty mangabeys, cynomolgus monkeys), black-tailed prairie dogs, African brush-tailed porcupines, rats, and shrews. MPXV replicates at the site of inoculation, the respiratory or oropharyngeal mucosa, and spreads to other organs, such as the skin, lungs, and gastrointestinal tract, where clinical signs and symptoms of the disease manifest. Before the rash appears, most patients have prominent lymphadenopathy, which distinguishes human MPX from small pox. This is followed by macules, papules, vesicles, pustules, umbilication, scabbing, and desquamation. Laboratory tools, such as virus isolation, PCR-based assays, haemagglutination inhibition assays, electron microscopy, ELISA, Western blotting, or immunohistochemistry, have been used to confirm diagnoses. Following a confirmatory diagnosis, tecovirimat, an FDA-approved antiviral drug, is currently available to treat severe cases of MPXV infection, along with symptomatic and supportive therapies. Physical and close contact activities, such as sleeping in the same room or on the same bed as the infected person, intimate contact with an infected partner, living in the same house as infected people, and sharing the same cups and plates, must be avoided to prevent the spread of the disease. Vaccination with vaccinia virus against monkeypox is approximately 85% effective and may protect against MPXV infection if administered within 4 days and up to 14 days (without showing any symptoms) after initial contact with a confirmed monkeypox case.