08/13/2022
What You Need to Know About Monkeypox
Monkeypox is an orthopoxvirus that causes disease in humans like smallpox, although with notably lower mortality.
Monkeypox virus was first isolated and identified in 1958 when monkeys shipped from Singapore to a Denmark research facility fell ill.
Coincident immunity to monkeypox virus was previously achieved with vaccinia vaccination; however, eradicating smallpox and subsequent lack of vaccination efforts paved the way for monkeypox to gain clinical relevance.
Although first identified in captive monkeys, African rodents are the natural reservoir.
Transmission can occur through contact with bodily fluids, skin lesions, or respiratory droplets of infected animals directly or indirectly via contaminated fomites (transmission of infectious diseases by germs left on objects.)
Following viral entry from any route (oropharynx, nasopharynx, or intradermal), the monkeypox virus replicates at the inoculation site then spreads to local lymph nodes. Next, there viral spread and seeding of other organs. This represents the incubation period and typically lasts 7 to 14 days with an upper limit of 21 days.
Initial symptoms include fever, headache, myalgia, fatigue, and lymphadenopathy, a key differentiating feature of monkeypox from smallpox. After 1 to 2 days, mucosal lesions develop in the mouth closely followed by skin lesions of the face and extremities (including palms and soles) and are centrifugally concentrated. The rash may or may not spread to the rest of the body, and the total number of lesions may vary from a small amount to thousands.
Over the following 2 to 4 weeks, the lesions evolve in 1 to 2-day increments through macular, papular, vesicular, and pustular phases. Lesions change synchronously and are characterized as firm, deep-seated, and 2 to 10 mm in size. Lesions remain in the pustular phase for 5 to 7 days before crusts begin to form. Crusts form and desquamate over the subsequent 7 to 14 days, and the condition resolves around 3 to 4 weeks after symptom onset in most cases. Patients are no longer considered infectious after all crusts fall off.
Currently, there are no specific clinically proven treatments for monkeypox infection. As with most viral illnesses, the treatment is supportive symptom management. There are, however, prevention measures that can help prevent an outbreak.
The infected individual should remain in isolation, wear an N95 mask, and keep lesions covered as much as reasonably possible until all lesion crusts have naturally fallen off and a new skin layer has formed. For severe cases, investigational use brincidofovir, tecovirimat, and IVIG have unknown efficacy against the monkeypox virus.
Post-exposure vaccination with JNNYEOS is recommended. Contact between broken skin or mucous membranes and an infected patient’s body fluids, respiratory droplets, or scabs is considered a “high risk” exposure that warrants post-exposure vaccination as soon as possible. According to the CDC, vaccination within four days of exposure may prevent disease onset, and vaccination within 14 days may reduce disease severity.
COMPLICATIONS
• Bacterial superinfection of skin
• Permanent skin scarring
• Hyperpigmentation or hypopigmentation
• Permanent corneal scarring (vision loss)
• Pneumonia
• Dehydration (vomiting, diarrhea, decreased oral intake due to painful oral lesions, and insensible fluid loss from widespread skin disruption)
• Sepsis
• Encephalitis
• Death
