Health Advisory: Potential risk for new mpox cases

Mpox, formerly known as monkeypox, remains a threat to communities in Texas and the United States. Healthcare professionals should be on guard for a possible resurgence in cases this summer, and at-risk people should take action to prevent themselves from contracting and spreading the virus that causes mpox by getting vaccinated and taking precautions during sexual activity.

Recently, the Chicago Department of Public Health reported a cluster of cases among men, some of whom had traveled to New York, New Orleans, and Mexico. The Centers for Disease and Prevention (CDC) reports that the virus continues to disproportionately affect gay and bisexual men and other men who have sex with men (MSM).

While some recent cases have been among people who had received two doses of the JYNNEOS vaccine against mpox, vaccination remains one of the most important ways to prevent illness and severe symptoms. New CDC modeling suggests that at-risk populations in multiple large Texas communities have a low level of immunity from vaccination or previous infection, leaving them vulnerable to a significant mpox outbreak.

Additionally, the summer season could lead to a resurgence of mpox as people gather for festivals and large events. People can take precautions to reduce the risk of transmission, including vaccination and efforts to reduce skin-to-skin contact among people who may have been exposed.

The purpose of this health advisory is to inform clinicians and public health agencies about the potential for new clusters or outbreaks of mpox cases, to provide resources on clinical evaluation, treatment, vaccination, and testing, and to encourage clinicians to offer vaccination against mpox for anyone at higher risk of infection.

A global outbreak of mpox began in May 2022. Previous outbreaks in places where mpox is not endemic were mostly related to international travel; however, this outbreak spread rapidly across much of the world through person-to-person contact, disproportionately affecting men who have sex with men (MSM). Most patients with mpox have mild disease, although some, particularly those with advanced or untreated HIV infection, may experience more severe outcomes.

As of May 24, 30,422 cases have been reported in the United States. This outbreak had a peak of about 460 cases per day in August 2022 and gradually declined, likely because of a combination of sexual behavior changes, vaccination, and infection-induced immunity. However, CDC continues to receive reports of new cases and clusters in the United States and internationally.

Approximately 1.2 million JYNNEOS mpox vaccine doses have been administered in the United States since the beginning of the outbreak, yet only 23% of the estimated population at risk for mpox has been fully vaccinated. Vaccine coverage varies widely among states. Within Texas, CDC estimates that about 15% of the population at increased risk of mpox has received at least one dose of the JYNNEOS vaccine and nine percent has received two doses. Without additional vaccination and/or safer sex practices, CDC projects that the risk of another mpox outbreak is greater than 35% in most U.S states and greater than 40% in the five largest Texas counties (Bexar, Dallas, Harris, Tarrant, and Travis).

To help prevent another outbreak during the summer months, DSHS is urging clinicians to be on alert for new cases of mpox, encourage vaccination for people who consider themselves at risk, and test patients for suspected mpox even if they were previously vaccinated or infected. Clinicians should also familiarize themselves with mpox symptoms, specimen collection, laboratory testing procedures, and treatment options.

Conduct a thorough patient history to assess possible mpox exposures or epidemiologic risk factors. Mpox is usually transmitted through close, sustained physical contact and has been almost exclusively associated with sexual contact in the current global outbreak. It is important to take a detailed sexual history for any patient with suspected mpox.

Perform a complete physical examination, including a thorough skin and mucosal (e.g., oral, genital, anal) examination. Doing so can detect lesions that may have previously been undetected. Clinicians evaluating patients for mpox should refer to infection prevention guidelines for guidance on how to safely handle patients in a healthcare setting.

Consider mpox in the differential diagnosis for patients with diffuse or localized rash, even if they were previously infected with mpox or vaccinated against mpox. Other diagnoses that should be considered include herpes simplex virus (HSV) infection, syphilis, herpes zoster (shingles), disseminated varicella-zoster virus infection (chickenpox), molluscum contagiosum, scabies, lymphogranuloma venereum, allergic skin rashes, and drug eruptions. Specimens should be obtained from lesions (including those inside the mouth, anus, or vagina), if accessible, and tested for mpox and other sexually transmitted infections (STI), including HIV, as indicated. The diagnosis of an STI does not exclude mpox, as a concurrent infection may be present.

Patients with mpox benefit from supportive care and pain control. Mpox can commonly cause severe pain and can affect anatomic sites, including the anus, genitals, and oropharynx, which can lead to other complications. Assess pain in all patients with mpox and recognize that substantial pain may exist from mucosal lesions not evident on physical exam. Topical and systemic strategies should be used to manage pain. Pain management strategies should be tailored to the needs and context of an individual patient.

TPOXX (tecovirimat) is an antiviral medication approved by the United States Food and Drug Administration for treatment against smallpox and is available under CDC’s Expanded Access Investigational New Drug (IND) protocol for treatment against mpox. If a clinician intends to prescribe oral tecovirimat, consider seeking access through enrollment in the Study of Tecovirimat for Human Monkeypox Virus (STOMP). Remote enrollment in the STOMP trial is available at selected sites. For patients not eligible for the STOMP trial or who decline to participate, please continue to send requests, along with a case description and shipping information to the local health department. More information about evaluating and treating patients can be found on the CDC mpox Clinical Guidance web pages.

Clinicians should notify their local health department of any suspected or confirmed mpox cases.

Providers should offer the vaccine to people with a high potential for exposure to mpox or who have known or suspected exposure to someone with mpox disease. However, there are no limiting eligibility criteria to receive the JYNNEOS vaccine. Patients should consult with their providers to discuss vaccination. Providers can contact their local health department or use the mpox vaccine finder tool for vaccine sites in their area.

Clinicians who treat patients with a high potential for exposure to mpox should actively and routinely encourage their patients to get vaccinated against mpox. People who previously received only one JYNNEOS vaccine dose should receive a second dose as soon as possible. There is no need to repeat the first dose. JYNNEOS can be given as post-exposure prophylaxis (PEP) both to people with known or presumed exposure to the monkeypox virus. For PEP, the vaccine should be given as soon as possible, ideally within four days of exposure; however, administration four to 14 days after exposure may still provide some protection against mpox.

Either subcutaneous or intradermal JYNNEOS vaccine administration is recommended at this time. The standard regimen for JYNNEOS involves a subcutaneous route of administration with an injection volume of 0.5mL, although an alternative regimen involving intradermal administration with an injection volume of 0.1mL may be used under an Emergency Use Authorization. JYNNEOS vaccine is a two-dose vaccine series given at least 28 days apart; peak immunity is expected 14 days after the second dose. People who are vaccinated should continue to avoid close, skin-to-skin contact with someone who has mpox.

• DSHS Mpox Website
• Clinical Quick Reference
• Vaccination Basics for Healthcare Professionals
• Case Definitions for Use in the 2022 Mpox Response
• Clinical Recognition
• Clinical Considerations for Treatment and Prophylaxis of Mpox Infection in People Who are Immunocompromised
• Treatment Information for Healthcare Professionals
• Disease Reporting Contacts
• Mpox Vaccine Finder Tool