Monkeypox is a viral zoonosis that can be transmitted to humans from animals. It has symptoms similar to those seen in smallpox patients, although it is clinically less severe. With the eradication of smallpox in 1980 and the subsequent cessation of smallpox vaccination, monkeypox has emerged as the most important orthopoxvirus for public health. This blog post will discuss the differences between monkeypox and smallpox, including their pathogen, natural host, outbreaks, transmission, signs and symptoms, diagnosis, treatment, and prevention.
Monkeypox virus is an enveloped double-stranded DNA virus that belongs to the Orthopoxvirus genus of the Poxviridae family. There are two distinct genetic clades of the monkeypox virus: the central African (Congo Basin) clade and the west African clade. The Congo Basin clade has historically caused more severe disease and was thought to be more transmissible. The geographical division between the two clades has so far been in Cameroon, the only country where both virus clades have been found.
Smallpox virus is also an enveloped double-stranded DNA virus that belongs to the Orthopoxvirus genus of the Poxviridae family. It is the virus responsible for smallpox, a contagious and often fatal disease that caused epidemics throughout history. Smallpox has been eradicated since 1980 due to a global vaccination campaign.
Natural Host of the Virus
Various animal species have been identified as susceptible to monkeypox virus. This includes rope squirrels, tree squirrels, Gambian pouched rats, dormice, non-human primates, and other species. The natural reservoir of monkeypox virus has not yet been identified, though rodents are the most likely. Eating inadequately cooked meat and other animal products of infected animals is a possible risk factor. People living in or near forested areas may have indirect or low-level exposure to infected animals.
Smallpox was a human disease with no known animal host. It was transmitted from person to person through respiratory droplets or contact with infected skin lesions.
Human monkeypox was first identified in humans in 1970 in the Democratic Republic of the Congo in a region where smallpox had been eliminated in 1968. Since then, most cases have been reported from rural, rainforest regions of the Congo Basin, particularly in the Democratic Republic of the Congo, and human cases have increasingly been reported from across central and west Africa.
Since 1970, human cases of monkeypox have been reported in 11 African countries: Benin, Cameroon, the Central African Republic, the Democratic Republic of the Congo, Gabon, Cote d’Ivoire, Liberia, Nigeria, the Republic of the Congo, Sierra Leone, and South Sudan. The true burden of monkeypox is not known. For example, in 1996–97, an outbreak was reported in the Democratic Republic of the Congo with a lower case fatality ratio and a higher attack rate than usual. A concurrent outbreak of chickenpox (caused by the varicella virus, which is not an orthopoxvirus) and monkeypox was found, which could explain real or apparent changes in transmission dynamics in this case. Since 2017, Nigeria has experienced a large outbreak, with over 500 suspected cases and over 200 confirmed cases and a case fatality ratio of approximately 3%. Cases continue to be reported until today.
Smallpox was eradicated worldwide by a successful vaccination campaign. The last known natural case was in Somalia in 1977. Monkeypox, however, remains a significant public health concern in Africa, and the global community continues to monitor the disease for potential outbreaks and work towards developing effective prevention and treatment measures.
Prevention and Treatment
There is no specific treatment for monkeypox, and management is generally supportive. Antiviral medications may be used, but their effectiveness is uncertain. Vaccination against smallpox has been shown to provide some protection against monkeypox and is recommended for those at high risk of exposure, such as healthcare workers and laboratory personnel working with the virus.
Preventative measures such as hand hygiene, using personal protective equipment (PPE), and avoiding contact with infected animals or people are also important in reducing the risk of infection.
Monkeypox is a zoonotic disease with potentially severe consequences for humans. While outbreaks are relatively rare, they can have significant public health and economic impacts, particularly in regions with limited healthcare resources. Continued surveillance and monitoring, as well as investment in prevention and treatment measures, are essential to controlling the disease and protecting human health.