For the second time this year, the United States has an imported case of monkeypox. A traveler from Maryland who had recently returned from Nigeria has been diagnosed with the dangerous illness, the Centers for Disease Control and Prevention said Wednesday. The unidentified patient is in isolation in Maryland.
The earlier United States case occurred in Texas in July. That patient had also traveled to Nigeria. There were no secondary cases from the Texas patient, though more than 200 people who had contact with the individual were monitored.
The disease can be deadly. In Africa, monkeypox has been fatal in about 1-in-10 cases with severe disease and death more likely among children. In recent years there have been a number of monkeypox cases reported.
Monkeypox is caused by a virus that is related to smallpox; both are Orthopox viruses. Smallpox was declared eradicated in 1980. Routine smallpox vaccination was terminated soon thereafter. The World Health Organization suggests that the risk of contracting monkeypox may be greater in middle-aged and younger people who did not receive the smallpox vaccine as children.
The incubation period for the disease, the time from exposure to the onset of illness, ranges from five to twenty-one days. People who are infected initially develop a mild, flu-like illness, headache, fever, chills, and swollen lymph nodes. But a few days later, a rash will appear, often starting on the face. The rash will typically spread to other parts of the body, though mainly the extremities. Palms of the hands and soles of the feet are frequently affected. Scarring lesions will form in a stage of the disease that can last between two and six weeks.
- The first monkeypox outbreak occurred in 1958 in a colony of research monkeys, hence the name. The primary reservoir of the virus remains unknown, although several African rodent species are known to be susceptible to the virus and have been seen to be involved in its transmission.
- The monkeypox virus appears to be present in a number of countries in West and Central Africa, with locally acquired cases reported from Sierra Leone, Liberia, Côte d’Ivoire, Nigeria, Cameroon, Gabon, Central African Republic, and the Democratic Republic of the Congo.
- The first time monkeypox was reported outside of Africa was in 2003 in the United States. There were 47 confirmed and probable cases reported from six different states. The outbreak was linked to infected exotic pets imported from Ghana, which in turn infected some prairie dogs sold as pets.