The first San Diego County resident was diagnosed with Clade I mpox by the California Department of Public Health this week, county health officials said Monday.
They likely contracted the virus while traveling internationally to an area where it is circulating. County health officials are monitoring people known to have had contact with the person, with none reporting any symptoms.
While risk to the general public remains very low, county officials said anyone who develops mpox-like symptoms — such as rash, fever, swollen lymph nodes — especially after travel or potential exposure should contact their healthcare provider.
“It is really important for anyone at risk of contracting mpox complete both doses of the vaccine,” County Public Health Officer Dr. Sayone Thihalolipavan said.
“Completing the series offers the best protection against severe illness, including painful blisters that take a month to heal, and in some cases lead to hospitalization.”
According to the county, the two-dose JYNNEOS vaccine provides the strongest protection against both Clade I and II mpox. It is recommended for people at higher risk, those with potential exposure, and travelers who anticipate close or intimate contact while abroad. Both doses are available through healthcare providers and San Diego County Sexual Health Clinics.
The virus spreads through “close physical contact or sharing personal items with someone who is infected,” according to the county. Symptoms can include a painful rash, sores and sometimes flu-like illness.
Risks can be reduced by avoiding contact with people who have rashes or scabs, not sharing personal items and frequent handwashing.
Clade I mpox, linked to Central Africa, has become more common in Eastern Africa and other parts of the world in recent years. Most Clade I cases outside of Africa are associated with travel, though some areas have reported local spread.
Clade I may be more severe than Clade II, which has been present in San Diego County since 2022, the county statement said.
San Diego County has reported 27 cases of Clade II this year, mostly among people who were not fully vaccinated. All cases involve men between 17 and 53 years old.
For mpox updates, text COSD MPOX to 98256. More information on mpox can be found here.
