Journal of Nature and Science of Medicine

: 2022  |  Volume : 5  |  Issue : 4  |  Page : 317--318

Monkeypox infection

Abdulkarim F Alhetheel 
 King Saud University Medical City; Department of Pathology, College of Medicine, King Saud University, Riyadh, Saudi Arabia

Correspondence Address:
Abdulkarim F Alhetheel
Department of Pathology, College of Medicine and University Hospitals, King Saud University, 2925, Riyadh 11461
Saudi Arabia

How to cite this article:
Alhetheel AF. Monkeypox infection.J Nat Sci Med 2022;5:317-318

How to cite this URL:
Alhetheel AF. Monkeypox infection. J Nat Sci Med [serial online] 2022 [cited 2023 Mar 23 ];5:317-318
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Electron microscopy image of Monkeypox virus


Monkeypox virus occasionally causes infection and illness in humans through zoonotic transmission.[1],[2] The virus was originally isolated from cynomolgus monkeys in a laboratory in Denmark in 1958[3] and is classified under the Orthopoxvirus genus and the Poxviridae family.[4] Structurally, the virus is similar to other poxviruses (variola, cowpox, and vaccinia viruses),[4],[5] which have a single-molecule double-stranded DNA genome covered by a capsid and an outer lipoprotein envelope [Figure 1].[4] The genome is approximately 197 kbp in size and contains over 190 open reading frames encoding for various viral proteins.[4] Although the virus was first detected in monkeys, it can infect different animals including squirrels, rats, dormice, and dogs.[6] The virus is transmitted through close contact with infected animals and humans, or through contact with contaminated surfaces and materials. It can be acquired through small skin cuts; droplet inhalation of infectious respiratory secretions; or through the mucous membranes of the eye, nose, or mouth.[4],[7] Vertical transmission of the monkeypox virus can also occur between an infected mother and the fetus during pregnancy. Ingestion of undercooked meat and sexual intercourse may also be potential sources of transmission.[4],[8]{Figure 1}

The first reported case of human monkeypox infection was in 1970 for an infant from the Democratic Republic of Congo.[9] Since the discovery of the virus, two monkeypox strains have been endemic and circulating in Africa: The Central African and West African strains. The Central African strain is more transmissible and more severe, with a fatality rate of 10.6% compared to that of the West African strain, which causes less severe symptoms and has a fatality rate of 3.6%.[10] The first monkeypox outbreak reported outside of Africa was in 2003-47 confirmed and suspected cases were reported in the United States (US) due to infected animals imported from Ghana.[6],[8] Since then, several cases have been diagnosed in nonendemic countries between 2018 and 2021, including the UK, Israel, Singapore, and the USA.[4],[6] In May 2022, the World Health Organization announced that there were approximately 120 confirmed and suspected cases of monkeypox in different European countries (the UK, Spain, Italy, Portugal, Belgium, France, Germany, Sweden, the Netherlands, North America (Canada and the US), and Australia).[6] In July 2022, the Centers for Disease Control and Prevention (CDC) reported that over 16,800 monkeypox cases were identified in 74 countries.[7]

Infection with monkeypox can result in asymptomatic and mild illness to severe disease, which could lead to complications and death, especially for people with compromised immunity, pregnant women, and infants. In contrast to smallpox, the vast majority of infections result in mild illness.[4],[8] The most common symptoms associated with monkeypox infection include fever; cervical or inguinal lymphadenopathy; dysphagia; lesions or vesicular-pustule eruption in the face; palms of the hands, and soles of the feet; generalized muscle pain; chills; backache; headache; and cough.[11] Symptoms last for approximately 2–4 weeks and then spontaneously resolve; however, supportive medications can be administered to relieve symptoms such as pain and fever.[4],[11] Recently, antiviral drugs (Tecovirimat) and vaccinia immunoglobulin have been approved to help control this disease.[7] An infected person will remain contagious until the vesicles have become crusted and fallen off.[12]

Infection with monkeypox is confirmed by the detection of viral genetic material from vesicle fluid or skin scraping of the lesions using molecular testing, which applies specific primers for monkeypox virus using the polymerase chain reaction system.[4],[8] Thus, any suspected case with a rash and evidence of traveling to any monkeypox virus-endemic countries, or coming into contact with infected animals, should be screened for monkeypox infection. Other laboratory methods, including inoculation of vesicle fluid in cell culture and serological tests for the detection of IgM and IgG antibodies from serum samples, may aid in the diagnosis of monkeypox infection.[4],[8] To date, no specific vaccine against monkeypox exists; however, reports suggest that the smallpox vaccine could provide up to 85% protection owing to cross-reactive antibodies.[10],[13]

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