Monkey Pox


A ProMED-mail post

The Maryland Department of Health, in collaboration with the US Centers for Disease Control and Prevention (CDC), today [16 Nov 2021] confirmed a single case of monkeypox virus infection in a Maryland resident who recently returned from Nigeria. The individual presented with mild symptoms, is currently recovering in isolation, and is not hospitalized. No special precautions are recommended at this time for the general public. "Public health authorities have identified and continue to follow up with those who may have been in contact with the diagnosed individual"

Monkeypox is in the same family of viruses as smallpox but generally causes a milder infection. It can be spread between people through direct contact with skin lesions or body fluids, or contaminated materials such as clothing or linens. It can also be spread through large respiratory droplets which generally cannot travel more than a few feet, and prolonged face-to-face contact is required.

Illness typically begins with flu-like symptoms and swelling of the lymph nodes, progressing to a widespread rash on the face and body. Most infections last 2-4 weeks. The individuals identified as having been potentially exposed to this case will be monitored for symptoms of monkeypox for 21 days after exposure.

Human monkeypox infections primarily occur in central and western African countries and have only rarely been documented outside of Africa. Although all strains can cause infection, those circulating in western Africa generally cause less severe disease.

Travelers returning from central or western Africa are advised to notify their healthcare provider if they develop symptoms o monkeypox, particularly flu-like illness, swollen lymph nodes, or rash. Clinicians are urged to maintain a high index of suspicion for clinically compatible illness.

This is the 2nd monkeypox case imported into the USA from Nigeria this year (2021). Nigeria is endemic for that virus. The prompt follow up of contacts of the case is prudent. As noted in the previous post, the question remains about the source of these recent infections and the index case above.

Monkeys are not the reservoirs of the virus, despite the name that the virus has received. Studies of prevalence of monkeypox (MPX) virus in populations of rodent hosts are not mentioned in this or in previous reports. The main reservoirs of MPX virus are suspected to be rodents, including rope squirrels (_Funisciurus_ spp., an arboreal rodent) and terrestrial rodents in the genera _Cricetomys_ and _Graphiurus_.

Halting the bushmeat trade and consumption of wild animals to halt MPX virus exposure will be culturally and economically difficult, so continued occurrence of cases can be expected. Even if a vaccine were available for use in Africa, deciding where to mount a campaign in this extensive geographic area where the virus occurs would be a challenge.

Additional information about monkeypox can be accessed from the CDC website at