Monkeypox

Lindee Abe, APRN

Monkeypox drew media attention when an outbreak occurred in 2022, and it was declared a public health emergency of international concern (PHEIC). At that time, two years into the COVID-19 pandemic, the public was paying more attention to public health and emerging diseases. The reality is that monkeypox, or Mpox, has been around for a long time before that. In 2024, we are seeing news again of another monkeypox outbreak and cautioned to be vigilant for patients presenting with symptoms consistent with monkeypox. 

Discovery and Origins

Monkeypox is a zoonotic virus discovered in 1958 in monkeys kept in a laboratory, thus named monkeypox. It should be noted that monkeypox goes against the World Health Organization naming convention for diseases by using an animal in the name. Viruses should also not be named after places or people. The best practice in naming viruses is to prevent prejudice against one animal or species due to the virus. The best practices are important because in the case of monkeypox, while the source of the virus is unknown, it is believed to be rodents and monkeys. 

Even though monkeypox was discovered in 1958, the first human case of monkeypox was documented in Africa in 1970. Following 1970, monkeypox was seen sporadically throughout Africa. In 2003, there was a small outbreak of monkeypox in prairie dogs shipped to the United States, which were the first cases of monkeypox in the United States. 

Two Clades

Monkeypox comes from the same family of viruses as smallpox and cowpox, the poxviridae family. There are two clades of monkeypox, clade I and clade II. Clade I is considered more severe, has a higher mortality rate, and is found in Central Africa. Clade II is less severe and is found in West Africa. The Clade II is the virus responsible for the 2022 declaration of monkeypox as a PHEIC that ended in May 2023. The most recent outbreak that prompted the World Health Organization to declare monkeypox a PHEIC again in 2024 was caused by clade Ib. This has been newly identified and found in African countries that have previously not had reports of monkeypox (i.e., Rwanda, Uganda, Kenya, Burundi).

The concern with the new clade Ib is that it appears to be more virulent than the previous clade II that caused the outbreak in 2022, which could mean the outbreak of the new clade Ib of monkeypox may cause more illness than the 2022 outbreak. This is compounded by recent cases of clade II in Ontario, Canada. There is potential for multiple outbreaks of monkeypox with different clades. 

Signs and Symptoms of Monkeypox Infection

We are concerned about clade Ib of monkeypox spreading because it is more virulent. Still, the symptoms of monkeypox also lend themselves to be more challenging to detect because they can fit so many different disease processes and would be easy to misdiagnose. The average incubation period is around 10-14 days but can be as short as 3 days or as long as 17 days. During the incubation period, the patient is asymptomatic and cannot spread the virus. After the incubation, the prodrome begins. During the prodrome phase, the patient feels generalized symptoms. This is where misdiagnosis can occur.

The prodrome symptoms include fever, headache, pharyngitis, myalgias, fatigue, cough, and lymphadenopathy. These symptoms could easily be misdiagnosed as a viral infection, influenza, or COVID-19. During the prodromal stage, patients may be contagious. During this stage, it is recommended that patients isolate. Patients should always be educated that if they are febrile, they should be isolated, so even if monkeypox may be initially misdiagnosed, the patient should at least be isolated during the stage. 

Distinctive Rash

After the prodrome phase, a rash will follow and begins as a macular rash that later develops into vesicles and pustules. The pustules, similar to other pox viruses, will eventually rupture and scab over. It is not until the vesicles have all scabbed over that the patient is no longer considered contagious. There are several unique features of the monkeypox rash. The monkeypox rash will have all macules develop into vesicles around the same time, unlike chickenpox, where the lesions can be in varying stages. Monkeypox is also a centrifugal rash, which starts on the head and extremities and spreads inward, similar to smallpox. This is also in contrast to the chickenpox rash that is centripetal (i.e., starting on the trunk and spreading outward). The rash can take around 2 weeks for the scabs to fall off and can leave scarring. 

Diagnosis

Testing for monkeypox is done through a PCR test that should be available through your local health department. The specimen should include at least two swabs from each lesion and several lesions. The results typically take 2 to 4 days. Because the testing is done through the health department and takes longer than other tests, the patient should be educated to remain home and isolate during this period. 

Treatment and Vaccination

There is no readily available FDA-approved treatment for monkeypox. Tecovirimat is considered an expanded-access investigational new drug that is available through the Centers for Disease Control and a National Institute of Allergy and Infectious Disease trial. Two drugs are available through the National Strategic Stockpile: brin cidofovir and Vaccinia Immunoglobulin. Cidofovir is more widely available and has the same mechanism of action as brincidofovir, but it is not FDA-approved for the treatment of monkeypox. 

Initially, it was thought that smallpox vaccination would protect against monkeypox, but most people were vaccinated too long ago and would no longer be protected against smallpox. During the 2022 outbreak, JYNNEOS was used as the primary vaccine against smallpox. The Centers for Disease Control recommends the JYNNEOS vaccine for both smallpox and monkeypox. The vaccine can also be used for post-exposure prophylaxis. 

Although monkeypox was often reported as a sexually transmitted infection during the 2022 outbreak, it can be spread through other means. Monkeypox is spread through direct contact, fomites, and bodily fluids. It can also be spread from the mother to the fetus during pregnancy. Monkeypox may also be spread through respiratory droplets, but more research would need to be done to determine to what degree it is transmissible. Patients should be placed in a single-person room, but the Centers for Disease Control does not indicate specific airflow requirements. 

We will continue to monitor the ongoing outbreak of monkeypox for increased transmission. We have seen how quickly COVID-19 spread throughout the world, with international flights being more common now than ever, and we will need to remain vigilant for patients with symptoms that match monkeypox. 

References:

Balocating, T. (2024). Emergence of new monkeypox strain heightens fears of global spread: Here’s what to know. Retrieved from https://nationalpost.com/health/new-mpox-strain-clade-ib-what-to-know 

Centers for Disease Control. (2024). About mpox. Retrieved from https://www.cdc.gov/poxvirus/mpox/about/index.html. 

Centers for Disease Control. (2023). Clinical recognition. Retrieved from https://www.cdc.gov/poxvirus/mpox/clinicians/clinical-recognition.html. 

Centers for Disease Control. (2024). Clinical testing. Retrieved from 

https://www.cdc.gov/poxvirus/mpox/clinicians/clinical-testing.html

Centers for Disease Control. (2024). Mpox in animals and pets. Retrieved from https://www.cdc.gov/poxvirus/mpox/veterinarian/mpox-in-animals.html. 

Centers for Disease Control. (2024). Mpox treatment information for healthcare professionals. Retrieved from https://www.cdc.gov/poxvirus/mpox/clinicians/treatment.html. 

Isaacs, S. N., Mitja, O. Epidemiology, clinical manifestations, and diagnosis of mpox. UpToDate Inc. Accessed August 17,
2024. https://www.uptodate.com/contents/epidemiology-clinical-manifestations- and-diagnosis-of-mpox-monkeypox 

World Health Organization. (2024). WHO Director-General declares public health emergency of international concern. Retrieved from https://www.who.int/news/item/14-08-2024-who-director-general-declares-mpox-outbreak-a-public-health-emergency-of-international-concern. 

Centers for Disease Control. (2024). Interim clinical considerations for use of JYNNEOS vaccine for mpox prevention in the United States. Retrieved from https://www.cdc.gov/poxvirus/mpox/clinicians/vaccines/vaccine-considerations.html 

Lindee Abe, APRN, FNP-C, ENP-C

Lindee earned her Associate of Science Health Science Laboratory Technology from George Washington University in 2006. She earned a Bachelor of Science and Masters of Science in Nursing from the College of Saint Mary in 2009 and 2011, respectively. She was awarded her Post Masters Certificate as a Family Nurse Practitioner from Clarkson College in 2015. She is dual certified as a Family and Emergency Nurse Practitioner through the American Academy of Nurse Practitioners. She serves as the Nebraska state representative for the American Academy of Emergency Nurse Practitioners. She has worked as a contractor for the VA, urgent care, and emergency medicine. She has served in the Army Reserves for 19 years in varying capacities, including lab tech, emergency room nurse, case manager, and nurse practitioner.