MPOX (Monkeypox) and other poxviruses

Authors: Hensley, Lisa; RIMOIN, ANNE - University Of California (UCLA); JOHNSTON, SAMANTHA - Columbia University

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 9/5/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Poxviruses are large, enveloped DNA viruses that infect various species, including man. Most poxviruses are zoonotic, but the Variola virus (VARV), the causative agent of smallpox (SPOX), and muscollum contagiosum virus (MOCV) are unique to humans. Infection occurs through contact with an infected person, animal(s), or contaminated materials. Poxvirus disease is characterized by the appearance of skin lesion(s) that can range from the small pearly papules in muscollum contagiosum (MOC) cases to the firm with well-circumscribed borders, deep-seated, and often develop umbilication observed in cases of SPOX and MPOX. Fever, headache, and other symptoms can also occur. Most poxviruses produce a primary lesion(s) in persons without underlying conditions; the exceptions are MPOX, VARV, and MOC, which may result in systemic disease and generalized lesions. In 1980, the World Health Organization (WHO) declared SPOX eradicated. Before this, not a single facet of society was immune to the effects of this virus. During the 18th century, SPOX likely claimed approximately 400,000 Europeans each year and was responsible for over 300 million deaths during the 20th century alone (Centers for Disease Control) (Behbehani). Outbreaks of the disease influenced wars, destabilized societies, facilitated colonization, and even influenced religious practices, cultural beliefs, and the policies of governments. The eradication of SPOX remains one of medicine's greatest achievements. Following the eradication of SPOX, vaccination efforts were discontinued (SPOX is discussed in more detail in Chapter TBD). Factors contributing to the increase in poxvirus infections include climate change, geopolitical conflicts, decreased SPOX vaccination, animal reservoir species/deforestation exposure, and human-to-human disease transmission. Over the last decade, there have been increasing reports of poxvirus diseases, and today there are at least 11 poxviruses recognized as causing disease in humans VARV, MPOXV, MOCV, vaccinia virus (VACV), cowpox virus (CPXV), Orf virus (ORFV), Camelpox (CMLVX), Yaba monkey tumor virus (YMTV), Tanapox (TPV), Pseudocowpoxvirus (PCPV), and Bovine papular stomatitis virus (BPSV). Other poxviruses may likely infect humans. Ectromelia virus (ECTV), a poxvirus seen in Mus sp, was detected in throat swabs from a patient in China during an erythromelalgia outbreak. The disease severity can vary, with person-to-person transmission a significant risk. The 2022 multi-county outbreak of MPOX reminded clinicians and public health experts that the threat of disease from poxviruses remains and will continue to grow if left unchecked.