Minnesota on Wednesday confirmed a second case of monkeypox involving a Twin Cities man who was likely infected during domestic U.S. travel.
The infection is unrelated to Monday's report of Minnesota's first case, which involved an adult male who was infected during travel to Europe, according to the Minnesota Department of Health.
Monkeypox is characterized by its pimple-like rash and is a growing concern because it is spreading beyond the usual pattern of rodents infecting people in Africa. The virus is spreading person-to-person, mostly through close physical contact with infected individuals or materials such as bedding or clothes, and has been found in more than half of U.S. states.
"It takes prolonged contact, so shaking [hands] with somebody is not likely to get you infected unless [infected people] have blisters on their hands and the blisters are weeping and you have breaks in your skin," said Rick Kennedy, co-director of Mayo Clinic's vaccine research group.
The risk to the broader public is considered low, because the virus doesn't spread as quickly or in the same way as those that cause influenza, COVID-19 or the measles. However, clusters of infections have been found worldwide in close-knit social groups, and among groups of men who have sex with other men.
No high-risk contacts have been identified in Minnesota, at least from the first man, who was receiving outpatient treatment for the infection. While some people experience common symptoms such as fever and fatigue, others only experience the rash that often emerges first on the hands, face or genitals.
Minnesota announced the first cases based on testing at its public health lab for the presence of an orthopox virus and medical evidence that the men had monkeypox.
Tests at the Centers for Disease Control and Prevention will confirm the involvement of the monkeypox virus specifically, but state health spokesman Doug Schultz said the preliminary findings were enough to notify the infected individuals and search for high-risk contacts.
"Monkeypox is the only orthopox virus circulating right now and the [epidemiological] evidence for monkeypox is pretty strong and straightforward," he said.
The White House on Tuesday announced that it was expanding access to monkeypox vaccine in high-risk areas of the U.S. and among high-risk groups. While the vaccine is recommended pre-exposure to lab and medical professionals who work with the virus, it also can be provided post-exposure to close contacts of infected individuals.
The post-exposure group includes people who had close physical contact with infected individuals, and men who had sex with multiple partners in venues or areas where monkeypox is spreading.
The World Health Organization so far this year has identified one death related to monkeypox in Nigeria, but the death rate is well below 1% among known cases.
Monkeypox has emerged along with mysterious hepatitis cases in children amid the COVID-19 pandemic, but Kennedy said the only connections are increased international travel.
"Just because the world has been focused on COVID-19 doesn't mean tuberculosis and hepatitis and measles and all of these other diseases went away," he said. "They're still doing what they do."