ADVISORY:  Global Transmission of Clade I Mpox is Increasing – June 2026

Dear Colleagues,

Benton County Health Department is sharing the Oregon Health Authority (OHA) Health Alert Network (HAN) advisory related to the global increase of clade I Mpox transmission. Clade I Mpox may be associated with more severe disease than clade II Mpox. Additional details are available in the full OHA HAN advisory below.

Confirmed, presumptive, and suspect cases of Mpox are reportable in Oregon. If you suspect Mpox in a patient who has traveled internationally or had contact with an international traveler within the past 21 days, please contact the Benton County Health Department Communicable Disease (CD) Program at 541-766-6835 (Press 3 for CD).

Thank you for your continued vigilance and commitment to protecting the health of our community. 

Summary

• Community transmission of clade I mpox is currently increasing in several countries worldwide, including in Western Europe and Central and Eastern Africa.
• Clade I mpox may be associated with more severe disease than clade II mpox, which caused the ongoing global outbreak among gay, bisexual, and other men who have sex with men that started in 2022.
• Mpox should be considered in any individual with clinically compatible symptoms, even if they are vaccinated.
• Providers should continue to recommend vaccination with two doses of JYNNEOS to individuals at increased risk of mpox.
• If mpox is suspected in an individual with a history of international travel or close contact with an international traveler in the past 21 days, please call your local public health department or the Oregon Health Authority Epidemiologist On-call 24/7 at 971-673-1111 to coordinate clade-specific testing and public health investigation.

Epidemiological situation

Mpox has two major clades, clade I and clade II. Clade I has historically been associated with more severe disease than clade II. The global outbreak of mpox among gay, bisexual, and other men who have sex with men that began in 2022 was caused by clade II mpox.

In 2024, an increase in cases of clade I mpox with person-to-person transmission was reported in Central and Eastern Africa. Recently, an increase in cases of clade I mpox among people without a history of international travel has been reported in several Western European countries. These cases have been primarily associated with intimate or sexual contact among men who have sex with men. In 2026, there have been 12 cases of clade I mpox reported in the United States, all in individuals returning from travel to Central and Eastern Africa or Western Europe. Clade II mpox also continues to circulate globally, including in the U.S.

With summer travel and large events approaching, clinicians should consider mpox when evaluating individuals with compatible symptoms and inquire about recent international travel or contact with international travelers. Clinicians should continue to recommend vaccination to individuals at increased risk for mpox.

Clinical signs and symptoms

Mpox lesions are typically firm or rubbery, well-circumscribed, deep-seated, and may be umbilicated. Some individuals develop only a few lesions while others may have disseminated lesions and ulcerations. Internal lesions may present as oral or rectal pain or bleeding. Mpox lesions are non-specific and may resemble other infectious and non-infectious conditions. Testing should be performed if mpox is suspected. Mpox may also cause prodromal symptoms including fever, malaise, headache, sore throat, cough, and lymphadenopathy. Regardless of clade, mpox lesions present similarly; both clades of mpox can be spread, treated, and prevented the same way.

While vaccination significantly reduces the risk of mpox, infections may still occur in vaccinated individuals. Individuals who have previously been vaccinated may have milder disease.

Testing recommendations

If mpox is suspected in a patient with a history of international travel or contact with an international traveler in the past 21 days, call your local health department or the Oregon Health Authority Epidemiologist On-Call at 971-673-1111 to coordinate clade-specific testing free of charge. For suspect cases of mpox without a history of international travel, mpox testing is available through commercial labs. If testing for mpox, consider STI co-infection testing. Testing is still warranted among patients with previous vaccination.

Vaccination

Recommend JYNNEOS vaccine to patients with the following risks:

• Gay, bisexual, and other men who have sex with men; or people who are transgender or nonbinary; and who in the past 6 months have had one of the following: a new diagnosis of ≥1 sexually transmitted disease; more than one sex partner; sex at a commercial sex venue; or sex in association with a large public event in an area where mpox transmission is occurring.
• Travelers to countries with mpox outbreaks who anticipate the following sexual activities (regardless of sexual orientation) during travel: sex with a new partner; sex at a commercial sex venue (e.g., sex club or bathhouse); sex or intimate contact (e.g. massage) in exchange for money, goods, drugs, or other trade; or sex in association with a large public event (e.g., rave, party, or festival).
• Anyone with a sex partner with any of the above risks or who anticipate any of the above scenarios.

JYNNEOS vaccine is licensed as a series of 2 doses administered 28 days apart. If more than 28 days have passed, patients should receive the second dose as soon as possible and do not need to restart the series. JYNNEOS vaccine is expected to be effective against both clades of mpox. For patients who have received two doses, no additional or booster doses are currently recommended. Vaccination is not recommended for patients who have previously recovered from mpox. JYNNEOS vaccine is available to providers commercially. If your clinic does not carry JYNNEOS, it may be available to patients at commercial pharmacies with an appointment. JYNNEOS is FDA approved for patients 18 and older and has Emergency Use Authorization for patients under age 18.

Resources

• Oregon Health Authority Mpox
• Oregon Health Authority Mpox (JYNNEOS) Vaccine Immunization Protocol
• CDC Monkeypox Information for Healthcare Providers

Confirmed, presumptive, and suspect cases of mpox are reportable in Oregon. If you suspect mpox in a patient with a history of international travel or contact with an international traveler in the past 21 days, please call your local public health department or Oregon Health Authority Epidemiologist On-call 24/7 at 971-673-1111.

For questions regarding mpox, please contact Sam Hawkins at the Oregon Health Authority.

This Oregon HAN Notification was sent to the following alert lists: ORCD1 (includes: Tribal and local health administrators and health officers, CD Nurses, hospitals, ICPs, preparedness coordinators, labs, epidemiologists, and members of OHA’s staff and leadership).

If you received this alert from a colleague and would like to receive notifications directly, email HAN.Oregon@ODHSOHA.Oregon.gov

Oregon 24/7 disease reporting: 971-673-1111