Los Angeles County Public Health officials say mpox cases are on the rise, with transmission “significantly higher” in 2024 than 2023.
The two-dose JYNNEOS vaccine is available countywide to protect against the virus. Sex workers, people who engage in group sex, and men and transgender people who have sex with men or transgender people are at highest risk for contracting mpox, health officials say.
Here’s what you need to know about mpox:
What is mpox?
Mpox is a zoonotic disease originally transmitted from animals to humans. Mpox is endemic in West and Central African countries and cases are often found near tropical rainforests where animals may carry the virus. These animals include squirrels, rodents such as dormice and the Gambian pouched rat and different species of monkeys, according to the World Health Organization. In humans, mpox causes symptoms similar to but milder than those of smallpox, which was declared eradicated in 1980.
There are two kinds of mpox, clade I and clade II. Clade I is associated with a higher percentage of people developing severe illness, says Dan Uslan, MD, chief infection prevention officer for UCLA Health. All the cases observed in L.A. County and across the country have been clade II. There have been no reported cases of clade I mpox in the United States, according to the U.S. Centers for Disease Control and Prevention.
Is mpox a new virus?
Previously known as monkeypox, mpox is not a new disease, but cases in the U.S. had been associated with travel to West or Central Africa or contact with imported infected animals prior to the 2022 global outbreak.
Mpox isn't the only virus causing some concern in Southern California
How is mpox transmitted?
Mpox in the U.S. and other countries where the virus wasn’t traditionally found is mainly spread through person-to-person contact. Transmission generally occurs through direct contact with skin lesions, bodily fluids or contaminated items, such as sheets or clothing, that have been in contact with fluids or sores. The likelihood of transmission through respiratory droplets is low, according to the CDC.
What are the symptoms of mpox?
The onset of mpox symptoms is typically five to 21 days after exposure. Symptoms often begin with fever, swelling of the lymph nodes, body aches and fatigue. Ultimately, symptoms include a rash of bumps and blisters, which can be painful. The illness typically lasts two to four weeks.
Is there treatment for mpox?
An antiviral medication called tecovirimat is being studied as a treatment for mpox, Dr. Uslan says. UCLA Health is conducting a clinical trial using this medication and can provide it to certain individuals, he says.
Can I get tested for mpox?
Testing requires clinical evaluation. People who think they might have mpox should contact their primary care doctor, who can assess symptoms and possible exposure and refer them for testing. Individuals who don’t have a primary care doctor can call 211, the county help line.
What is the risk of getting mpox?
Despite the ongoing outbreak and recent increase in cases, the risk of contracting mpox remains “very low,” health officials say.
