Monkeypox Virus: How to Detect, Vaccinate, and Treat?
Due to its rapid spread, circulation, and growth within several non-endemic countries, monkeypox has rapidly become a disease of global public health importance. Especially the emergence and spread of monkeypox in Europe and North America has caused growing concern of an emerging monkeypox pandemic. Indeed, according to Our World in Data, as of August 1, there are 22,782 confirmed monkeypox cases in a total of 88 countries worldwide. Europe (14,773) and North America (6,035) account for most of these cases, with United States (4,898), Spain (4054), Germany (2595), England (2358), France (1955), and Brazil (1066) being the most affected countries. Since the initial outbreaks of monkeypox in multiple non-endemic countries in May 2022, studies to further determine the epidemiology, sources of infection, and transmission routes of monkeypox virus have accelerated. Along with surveillance and contact tracing, and community education efforts, research to develop novel diagnostics, vaccination, and therapeutics for monkeypox is also underway. Read along to learn more about monkeypox, along with currently available options for testing, vaccination, and treatment.
What is monkeypox?
Monkeypox is a viral zoonotic disease caused by the monkeypox virus (MPXV), an enveloped double-stranded DNA virus from the Ortho-poxvirus (OPXV) genus of the Poxviridae family. Monkeypox virus shares the same family as the variola virus which causes smallpox, the vaccinia virus, which was used in the development of smallpox vaccine, along with several others such as cowpox virus, and camel-pox virus. As such, it is known as a less pathogenic sibling of the smallpox virus. Prior to the recent outbreaks, while it has occasionally been imported to non-endemic regions around the world due to international travel and trade, the spread and circulation of the monkeypox virus was largely limited to endemic regions in tropical rain forest of Central and West Africa. Named after its initial detection in monkeys at the Statens Serum Institut in Copenhagen in 1958, the exact reservoir of monkeypox virus has not yet been identified. However, most likely natural hosts of the disease include rope squirrels, tree squirrels, Gambian pouched rats, dormice, and non-human primates.
Monkeypox virus is known to transmit through direct contact with infected animals, humans, or with recently contaminated objects. Contact with the blood, bodily fluids, skin lesions, and respiratory secretions of an infected person or animal can lead to transmission. As the virus enters the body through the respiratory tract, broken skin, or mucous membranes including the eyes, nose, or mouth, monkeypox can spread through the consumption of inadequately cooked meat or other products from infected animals or through wounds inflicted by an infected animal. Monkeypox can also transmit vertically from mother to fetus via the placenta. The upsurge in new monkeypox cases experienced within several non-endemic countries has led experts to investigate whether monkeypox may also be spreading through unknown transmission routes.
Which symptoms should you watch for?
The incubation period between the exposure to the virus and the onset of the symptoms may range from 5 to 21 days. At the early onset of the disease, monkeypox may cause flu-like symptoms such as fever, chills, headaches, myalgia, fatigue, and swollen lymph nodes. After this initial phase, the infected person typically develops a rash which takes several forms before falling off.
The initial lesions, or enanthema, usually develop in the face, mouth, or tongue before spreading to the rest of the body in the form of macules. Next, these lesions start to get raised to form papules. As papules fill with fluid, they become vesicles and pustules before crusting and falling away.
Which testing options are available for monkeypox?
Due to their sensitivity and specificity, the World Health Organization (WHO) has recently recommended the use of polymerase chain reaction (PCR) tests in the detection of monkeypox virus. The agency has reported that confirmation of monkeypox infections could be performed through laboratory methods which enable the detection of monkeypox-unique sequences of viral DNA, including nucleic acid amplification testing (NAAT) based on real-time or conventional polymerase chain reaction (PCR). Alongside PCR tests, Antigen-based and serological test kits are also available for the detection of monkeypox infections. However, due to the cross-reactivity of ortho-poxviruses, these tests do not provide monkeypox-specific confirmation, and thus, are currently seen as of limited use in the differential diagnosis of monkeypox. The optimal diagnostic sample type for the detection of monkeypox are collected from skin lesions. Samples can be collected from the roof or fluid of vesicles, pustules, or crusts. However, sample collection preferably involves two swabs from open lesions from different parts of the body.
With our RapidFor™ Monkeypox Virus Rapid Antigen Test Kit, RapidFor™ Monkeypox Virus Rapid Antibody Test Kit, and RapidFor™ Monkeypox Virus Detection Kit (PCR-Fluorescent Probe), you meet the easy, accurate, and efficient detection for Monkeypox virus infection.
Is there a vaccine against monkeypox?
There is currently no monkeypox-specific vaccine approved for use. However, thanks to the cross-protection afforded for the immune response to ortho-poxviruses, vaccines that have been originally developed for smallpox and other ortho-poxviruses have demonstrated around 85% efficacy against monkeypox. The efficacy of these vaccines has also been proven in animal studies. For instance, investigating the Edghill-Smith et al. (2005) has found that antibodies induced by vaccination by Dryvax were necessary and sufficient to protect Rhesus macaques from a lethal monkeypox virus infection. Accordingly, various vaccines such as JYNNEOS and MVA have been approved for use against smallpox and monkeypox. Moreover, several health agencies including UK Health Security Agency (UKHSA) have recommended pre-exposure and post-exposure vaccination against monkeypox especially for high-risk populations.
Which treatment options are available against monkeypox?
There is currently no approved treatment specific to monkeypox infections. Still, the efficacy of several antiviral agents that have been originally developed for the treatment of other ortho-poxviruses such as smallpox has been demonstrated. Antiviral agents such as tecovirimat, cidofovir, and brincidofovir have been shown to be effective against ortho-poxviruses in in vitro and animal studies. For instance, comparing the effectiveness of post-exposure smallpox vaccination and antiviral treatment based on either cidofovir or a related acyclic nucleoside phosphonate analogue, Stittelaar et al. (2006) has found that these antiviral agents were more effective than post-exposure smallpox vaccination in reducing mortality caused by lethal monkeypox virus infection in cynomolgus monkeys. Alongside antiviral agents, the use of intravenous vaccinia immune globulin (VIGIV) may also be considered for the treatment of patients with severe monkeypox infection.
Edghill-Smith, Y., Golding, H., Manischewitz, J. et al. Smallpox vaccine–induced antibodies are necessary and sufficient for protection against monkeypox virus. Nat Med 11, 740–747 (2005). https://doi.org/10.1038/nm1261
Stittelaar, K., Neyts, J., Naesens, L. et al. Antiviral treatment is more effective than smallpox vaccination upon lethal monkeypox virus infection. Nature 439, 745–748 (2006). https://doi.org/10.1038/nature04295