July 16 (UPI) -- The first case of monkeypox in the United States in nearly 20 years was confirmed Friday by officials with the Centers for Disease Control and Prevention and the Texas Department of State Health Services.
The patient, described as a U.S. resident who recently traveled from Nigeria to Texas, is currently hospitalized in Dallas, the CDC said.
The agency is working with the airline and state and local health officials to contact airline passengers and others who may have been in contact with the patient during two flights, the first from Lagos, Nigeria, to Atlanta on July 8, with arrival on July 9 and the second from Atlanta to Dallas on July 9, it said.
"Travelers on these flights were required to wear masks as well as in the U.S. airports due to the ongoing COVID-19 pandemic," the CDC said in a statement.
"Therefore, it's believed the risk of spread of monkeypox via respiratory droplets to others on the planes and in the airports is low," it said.
Monkeypox is a rare but potentially serious viral illness that typically begins with flu-like symptoms and swelling of the lymph nodes and progresses to a widespread rash on the face and body, typically over a period of two to four weeks, according to the CDC.
It is believed that African rodents and small mammals play a part in spreading the virus to people and other forest animals such as monkeys, the CDC said.
People can get monkeypox when they are bitten or scratched by an animal, prepare wild game, or have contact with an infected animal or possibly animal products, it said.
Monkeypox can also spread between people through respiratory droplets, or through contact with body fluids, sores or items that have been contaminated with fluids or sores, such as towels, according to the agency.
Human-to-human transmission is thought to occur primarily through large respiratory droplets following prolonged face-to-face contact, it said.
Although it is in the same family of viruses as smallpox, it causes a milder infection that usually responds to standard respiratory virus treatments, including steroids and intravenous fluids, the agency said.
Though there are no approved treatments for the disease, the smallpox vaccine can help prevent it, according to the agency.
In the case of the patient currently receiving treatment in Dallas, laboratory testing performed by CDC investigators showed the patient is infected with a strain of monkeypox most commonly seen in parts of West Africa, including Nigeria.
Infections with this strain of monkeypox are fatal about 1% of the time, though those with weakened immune systems are at higher risk, according to the CDC.
Most monkeypox outbreaks have occurred in Africa, including in Nigeria and nine other countries in central and western Africa since 1970, the agency said.
Monkeypox also caused a large outbreak in people in the United States in 2003 after the virus spread from imported African rodents to pet prairie dogs, it said.
In that outbreak, up to 47 people were sickened, including 37 who tested positive for the infectious disease, according to the CDC.
Prior to the current case, there have been at least six reported monkeypox cases among travelers returning from Nigeria, in Britain, Israel and Singapore, the agency said.
However, the case in Texas is not related to any of these previous cases, though several people in Britain were infected after having had contact with the traveler to that country, it said.