The US Centers for Disease Control and Prevention and local health officials in both Dallas, Texas, and Atlanta, Georgia, said Friday they are investigating a case of an unusual virus called monkeypox in a traveler coming from Nigeria.

Experts have yet to identify where monkeypox hides in nature, but it is thought that African rodents and small mammals play a part in spreading the virus to people and other forest animals like monkeys. People can get monkeypox when they are bitten or scratched by an animal, prepare wild game, or have contact with an infected animal or possible animal products.

Monkeypox can also spread between people through respiratory droplets, or through contact with body fluids, monkeypox sores, or items that have been contaminated with fluids or sores (clothing, bedding, etc.) While most of the outbreaks have occurred in Africa, there was a large outbreak, infecting 47 people in the United States in 2003 after the virus spread from imported African rodents to pet prairie dogs.

The CDC considers monkeypox is less transmissible and less deadly than smallpox, while health officials in Dallas said that though the infected traveler flew they believe no one else on the flight was affected by the virus.

“The individual is a City of Dallas resident who traveled from Nigeria to Dallas, arriving at Love Field airport on July 9, 2021. The person is hospitalized in Dallas and is in stable condition,” the Dallas County Department of Health and Human Services said in a statement. “We have been working closely with the CDC and DSHS (the Texas Department of State Health Services) and have conducted interviews with the patient and close contacts that were exposed,” said DCHHS Director Dr. Philip Huang.

“We have determined that there is very little risk to the general public.”

The CDC is working to contact airline passengers and others who may have been in contact with the patient during two flights: Lagos, Nigeria, to Atlanta on July 8, with arrival on July 9; and Atlanta to Dallas on July 9.

“Travelers on these flights were required to wear masks as well as in the U.S. airports due to the ongoing COVID-19 pandemic. Therefore, it is believed the risk of spread of monkeypox via respiratory droplets to others on the planes and in the airports is low. Working with airline and state and local health partners, CDC is assessing potential risks to those who may have had close contact with the traveler on the plane and specific settings,” the CDC said. 

Symptoms for monkeypox include fever, headache, muscle aches, and exhaustion, the CDC notes. “The main difference between symptoms of smallpox and monkeypox is that monkeypox causes lymph nodes to swell while smallpox does not. But like smallpox, monkeypox causes skin blisters that eventually scab over.”

The illness typically lasts for 2-4 weeks, and in Africa, has been shown to cause death in as many as 1 in 10 persons who contract the disease.

This number is higher in those who have compromised immune systems.

The strain involved in this week’s startling case is much less deadly, plus the smallpox vaccine can protect people from monkeypox. The global vaccination campaign that eradicated smallpox ended, which means that access to the vaccine is limited.

According to the CDC, a drug called cidofovir can treat monkeypox infection.