California officials investigate mpox strain following local cases

Two of the four cases have been confirmed as Clade I by the California Department of Public Health, with testing underway to determine the strain of the remaining two. Notably, three of the individuals infected reported no recent international travel, while the travel history of the fourth patient is still under investigation.

This development follows a trend observed since August 2026, when health officials began noticing an increase in mpox cases among individuals without recent overseas travel, suggesting the virus may be circulating domestically. The source of infection for those in Stanislaus County remains unknown.

“While we have identified four cases in our county, we want residents to know that the risk to the general public remains low,” stated Dr. Thea Papasozomenos, Stanislaus County’s public health officer. She encourages awareness of symptoms, vaccination for those at risk, and prompt medical care.

Mpox, previously known as monkeypox, manifests as painful, blister-like sores and flu-like symptoms such as fever, chills, and swollen lymph nodes. Some patients experience lesions without other symptoms, complicating diagnosis. Recovery typically occurs within two to four weeks, though complications can arise.

There are two main types of mpox: Clade I and Clade II, both spread through close contact, including intimate or sexual contact, and exposure to sores or bodily fluids. Transmission can also occur through shared contaminated items like clothing and bedding. However, officials emphasize that the virus doesn’t easily spread through casual encounters.

Health officials are recommending vaccination with JYNNEOS, a two-dose vaccine administered four weeks apart, for individuals at higher risk. Completion of the vaccine series is encouraged for optimal protection. Anyone with unexplained sores or a rash should seek medical evaluation and testing, typically involving a lesion swab. Individuals suspecting mpox should avoid close contact and sharing personal items until receiving medical advice.

Stanislaus County health officials are collaborating with the California Department of Public Health and healthcare providers to monitor the cases and prevent further infections.