Monkeypox: The Latest Endemic

Quarantine is not recommended, but isolation is.

Monkeypox is endemic in parts of Africa. In May 2022, an outbreak started and is now spreading exponentially. On Aug. 4, 2022, the United States declared monkeypox as a public health emergency (PHE). We weren’t even done with the last PHE!

The illness has been found in 95 countries with over 40,000 cases globally. As usual, we, the United States, are number one with more than one quarter of the cases, over 15,000.

The World Health Organization (WHO) just reclassified the previously named variants of monkeypox, Clade I (clade means descendants of a common ancestor, i.e., a variant) and Clade II, to eliminate stigmatizing the locale of where the illness was discovered. They are looking for a new name to replace “monkeypox,” too.

Monkeypox is one of a group of illnesses caused by a genus of viruses called orthopoxvirus. These illnesses are zoonoses which means they start in animals and spread to humans. Orthopoxviruses include rabbitpox, camelpox, and cowpox. The variety of monkeypox which seems to be spreading is the less severe type (Clade II), and fatalities are rare. Mortality is most common in severely immunocompromised individuals who do not receive antiviral therapy.

The symptoms of monkeypox are typical prodromal viral symptoms such as fever and chills, headache, muscle aches, swollen lymph nodes, and potentially respiratory symptoms like sore throat and cough. A painful rash then develops that runs through the whole gamut of rash appearance: macules (flat spots) to umbilicated papules (raised bumps with depressed centers) to vesicles (blisters with clear fluid) to pustules (blisters filled with pus) to scabbed lesions. Monkeypox are often larger than chickenpox lesions. The incubation period is 3-17 days, and the illness typically lasts 2-4 weeks. A patient is infectious from prodrome until scabs fall off and new intact skin grows.

It spreads through close personal contact with lesions or secretions. Currently, it is being seen most frequently in men who have sex with men and can be contracted during intimate contact due to direct contact with the rash or infected body fluids. It is not, however, a sexually transmitted disease, per se. It is not believed to be transmitted via respiratory secretions or aerosol, but the jury is not completely out on this, so healthcare workers are advised to wear N95 and eye protection when caring for patients with monkeypox.

Patients who are at high risk of having severe disease include patients with immunocompromise (e.g., HIV, lymphoproliferative malignancies, s/p transplant, etc.), pediatric patients under eight years old, pregnant women, and patients with complications such as secondary bacterial skin infections, dehydration, or concurrent disease. Those patients and patients with severe disease (e.g., hemorrhagic disease, confluent lesions, sepsis, or encephalitis) should be considered for treatment with antiviral medications.

There are two vaccines being used against monkeypox. My son was happy to get his first JYNNEOS vaccine last week which is used for prevention of smallpox and monkeypox. This is a live, nonreplicating vaccine which means that it is only effective as long as the viral units are alive since they can’t propagate. A second dose is indicated at four weeks, but at the moment, the CDC and WHO are trying to sort out who should receive doses, how big the doses should be, and how they should be administered. If a patient has been exposed, they can receive post-exposure prophylaxis if they present expeditiously. The other vaccine, ACAM2000 has more side effects and contraindications than JYNNEOS.

At this time, vaccination is indicated for people at higher risk for exposure, such as the patient population noted above and healthcare workers and laboratory personnel who have or are likely to come into contact with specimens or patients with the disease. Quarantine is not recommended, but isolation is, if there is exposure and onset of symptoms. Needless to say, one’s healthcare provider should be looped in if this occurs.

I do not think this is not going to be a pandemic of COVID-19 proportions. First, it is not novel. Second the mode of transmission is very different. We already have treatment and vaccines. Right now, it is primarily in a single patient population, although they do expect it to spread outside that population. The public health system should be primed and ready.

It just underscores that diseases that are found elsewhere in the world can make their way here. We need to be aware and vigilant. The public health community needs to respond promptly and effectively, and we need to work with them.

Programming note: Listen to Dr. Erica Remer today when she cohosts Talk Ten Tuesdays with Chuck Buck at 10 Eastern.