Mpox Information For Healthcare Providers

Mpox is caused by the monkeypox virus (MPXV), which is a member of the Orthopoxvirus genus in the family Poxviridae.

There are two distinct genetic clades of MPXV: clade I (formerly the Central African or Congo Basin clade) and clade II (formerly the West African clade).

Mpox is typically an acute illness, usually with the sudden onset of the following symptoms:

• Fever
• Headache
• Myalgia
• Lymphadenopathy
• Chills
• Malaise
• Respiratory symptoms (such as cough, nasal congestion, and sore throat)

These prodromal symptoms may also occur after the rash, or not at all. Clinically, the disease closely resembles smallpox, but, typically, lymphadenopathy is a more prominent feature in the early stages of mpox.

Following initial symptoms, usually within 1 to 4 days, a rash develops. The rash may appear initially like pimples or blisters and may be painful or itchy. These lesions will progress from macules to papules to vesicles to pustules to scabs or crusts. Lesions are typically deep-seated and well-circumscribed and often have central umbilication.

The differential diagnosis for mpox may include other diseases, such as varicella, shingles, impetigo, molluscum contagiosum, hand, foot, and mouth disease, primary syphilis, herpes, chancroid, lymphogranuloma venereum, or other infectious and non-infectious conditions.

It is important to note that mpox may not always appear the same way for everyone. In some cases, lesions may be the only symptom experienced. In others, the rash may appear before other symptoms.

Although most patients with mpox experience mild disease, some patients, particularly those with advanced or untreated HIV infection (CD4 count <350 cells/mm³ or in the absence of viral suppression) or with other severe immunocompromise (e.g., solid organ transplantation), may experience more severe outcomes. Lesions in these individuals have generally been diffusely distributed, appearing large, necrotic, and fungating (i.e., appearing or progressing like a fungal infection). Clinicians should request a consultation with the Texas Department of State Health Services (DSHS) and the Centers for Disease Control and Prevention (CDC) in cases presenting with severe immunocompromise, diffuse rash, failure to observe improvement when on antiviral treatment, or other indications of a severe infection.

MPXV can spread when a person comes into contact with the virus from an infected person, infected animal, or materials contaminated with the virus. The virus can also cross the placenta from the mother to the fetus.

Person-to-person transmission of mpox is primarily through direct contact with infectious lesions, scabs, or body fluids. However, the virus can also spread after prolonged exposure to an infected person’s respiratory secretions. It is not known at this time if mpox can spread through semen or vaginal fluids, but viral DNA has been detected in semen.

Examples of activities that may spread mpox from one person to another are:

• Wrestling
• Cuddling
• Kissing
• Intimate sexual contact
• Sharing utensils, straws, or cups used by a person with mpox
• Touching fabrics or objects that were used by a person with mpox

Although the risk of transmission in well-resourced healthcare settings is low, healthcare personnel (HCP) can become exposed to monkeypox virus while caring for infected patients. Unprotected contact with a patient’s skin, lesions, or body fluids (e.g., ungloved contact; splashing of patient’s saliva into eyes or mouth) could expose a person to monkeypox virus. Being in a patient’s room or within six feet of a patient during aerosolizing procedures (e.g., shaking used linens; intubation or extubation; contact with oral secretions or skin lesions) without the use of eye protection, a respirator or other personal protective equipment (PPE) can lead to exposure. Correct and consistent use of PPE when caring for a patient with mpox infection is highly protective and prevents transmission to healthcare workers. However, unrecognized errors during the use of PPE (e.g., self-contaminating when removing contaminated PPE) may create opportunities for transmission.

Similarly, animal-to-human transmission can occur from direct contact with infected animals through direct contact with infectious lesions, scabs, or body fluids. MPXV may spread from animals to people through the bite or scratch of an infected animal, preparing undercooked meat, or using or consuming products made from infected animals. It is not currently known which animal maintains the virus in nature, although African rodents are suspected. Evidence of MPXV has been found in rope squirrels, Gambian pouched rats, dormice, different species of monkeys, and others. There is also evidence of sick people infecting animals with MPXV.

Prior to the 2022 outbreak, mpox had been reported in people in several central and western African countries. Previously, almost all mpox cases in people outside of Africa were linked to international travel to countries where the disease commonly occurs or through imported animals.

The incubation period for mpox is usually 3 to 17 days but can range from 2 to 21 days.

In the context of the current worldwide outbreak of mpox, most infections in the United States have been caused by clade IIb MPXV. Clade I MPXV, which is endemic to central Africa, is generally associated with more severe disease and outcomes and is thought to be more transmissible than clade II MPXV. It has been recently reported that clade I MPXV can also be spread by sexual contact.

The Democratic Republic of the Congo (DRC) is currently experiencing the highest number of mpox cases in the country’s history. Since 2023, the DRC has reported more than 27,000 suspected cases and more than 1,200 deaths. Most of these cases have been caused by clade I MPXV. There is evidence that the virus is spreading across the DRC’s borders, including into Uganda, Central African Republic, Republic of Congo, Rwanda, Burundi, and Kenya. On August 14, 2024, the World Health Organization (WHO) declared the outbreak in the DRC a Public Health Emergency of International Concern (PHEIC).

At this time, no cases of clade I mpox have been reported in the United States or Texas. However, clinical suspicion is critical in rapidly identifying any potential clade I mpox cases.

Clinicians should continue to consider mpox when evaluating the cause of rashes in patients. Consideration of mpox should be heightened in patients who have epidemiologic characteristics supportive of mpox. To help rapidly identify potential clade I mpox infections, clinicians should take a detailed travel history. For patients with travel to the DRC or surrounding region within 21 days of illness onset, MPXV clade-specific testing should be conducted. Clade I mpox associated with the current outbreak in DRC has been reported in the following countries: Uganda, Central African Republic, Republic of Congo, Rwanda, Burundi, and Kenya. Providers should contact their local health department to arrange for clade-specific testing.

Laboratory testing for mpox is most often conducted using a real-time polymerase chain reaction (PCR) assay. Two broad categories of these assays include non-variola Orthopoxvirus  and monkeypox virus specific assays. Non-variola Orthopoxvirus tests can detect the genetic material of viruses in the Orthopoxvirus family (other than variola virus, which causes smallpox). Most monkeypox virus specific assays generally detect the genetic material of clade II MPXV. At this time, assays for clade I MPXV are not readily available and testing must be arranged through the local health department and DSHS. Testing specific for clade I MPXV is available through the CDC.

For enhanced public health surveillance, the DSHS Laboratory in Austin can perform sequencing on specimens. It is recommended that specimens not tested with a clade-specific assay should be sent to the DSHS Laboratory for further analysis.

As specimen submission requirements vary amongst laboratories, providers should have established specimen collection procedures for submitting specimens to their laboratory. Laboratory testing is also available at Laboratory Response Network facilities in Texas but submission must be coordinated with the local health department.

Healthcare personnel who evaluate and provide care to patients with mpox and laboratory personnel should continue to follow CDC guidance on infection prevention and control for mpox. These are effective in minimizing transmission.

There are two vaccines that may be used for the prevention of mpox. The most common vaccine, JYNNEOS, is currently available in Texas and may be given to anyone who requests mpox vaccination. Patients should consult with their provider when considering vaccination against mpox. JYNNEOS is believed to protect against both clades of MPXV.

The Advisory Committee on Immunization Practices (ACIP) recommends that people 18 years of age or older with risk factors for mpox be vaccinated, before an exposure, with two doses of the JYNNEOS vaccine 28 days apart unless they were previously infected with mpox or already received two doses. People who have only received one dose of the JYNNEOS vaccine should receive the second dose as soon as possible, regardless of the amount of time that has elapsed since the first dose.

Both subcutaneous (Subcut) and intradermal (ID) administration is recommended routes of administration 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 (EUA). If there is concern about receiving the vaccination intradermally, the vaccine should be administered subcutaneously.

The JYNNEOS vaccine can also be used as post-exposure prophylaxis (PEP) for individuals with a known or presumed exposure to MPXV. For PEP, vaccine should be given as soon as possible, ideally within 4 days of exposure; however, administration 4 to 14 days after exposure may not prevent disease but may reduce the severity of symptoms.

Individuals should discuss vaccination with their healthcare provider or contact their local health department to see where vaccinations are available.

Currently, there is no FDA-approved treatment specifically for mpox. However, Tecovirimat (also known as TPOXX), which is an FDA-approved treatment for smallpox, can be used as a treatment for mpox. TPOXX is most often used as an oral capsule but can also be administered intravenously, when indicated. Oral TPOXX is available through the Study of Tecovirimat for Mpox (STOMP) Trial or through coordination with DSHS and the Strategic National Stockpile (SNS). Brincindofovir and cidofovir have also been used in patients with severe presentation of mpox. Vaccine Immune Globulin Intravenous (VIGIV) has also been used in patients with severe presentation of mpox. Brincidofovir and VIGIV is available to providers through coordination with DSHS and the SNS. TPOXX, brincidofovir, and VIGIV are expected to be effective against both clade I and clade II MPXV infections. Additional information on treatment options and their use can be found on the CDC’s website.

Mpox cases are immediately reportable upon suspicion.

Immediately report persons under investigation, cases of mpox, or laboratory reports to your local health department.

Several Texas laws (Tex. Health & Safety Code, Chapters 81, 84, and 87) require specific information regarding notifiable conditions to be provided to DSHS. Health care providers, hospitals, laboratories, schools, and others are required to report patients who are suspected or confirmed of having a notifiable condition (25 Tex. Admin. Code §97.2).