Mpox

Skin specimens are preferred due to their much higher sensitivity (85 to 90 per cent) compared to nasopharyngeal/throat (60 to 70 per cent) and blood (40 to 50 per cent). Patients with two to three skin lesions that can be swabbed do not need blood or respiratory specimens collected for mpox. Specimens can be packaged and stored in the fridge for up to three days.

For patients with suspected mpox infection who do not have a rash (e.g., a patient who is a close contact with a confirmed case, or who has a febrile illness but no rash) or whose rash cannot be swabbed (e.g., macular and/or popular rash only), clinicians should submit a nasopharyngeal or throat swab along with a blood sample.

All specimens must be submitted with a Public Health Ontario general test requisition.

Clinicians are strongly encouraged to offer opportunistic STI testing (e.g., chlamydia, gonorrhea, syphilis and HIV testing) to patients when offering mpox testing.

Children with a rash consistent with an enterovirus illness (e.g., hand-foot-and-mouth disease) without epidemiological risk factors (e.g., contact with a confirmed case) do not require mpox testing.

Physicians who suspect that their patient has mpox virus should advise them to self-isolate pending a negative test result.

Patients with confirmed mpox infection should not be directed to community laboratories for any routine laboratory tests until all lesions have crusted over or the patient has been cleared for testing by public health. Patients with possible or suspected mpox who require urgent routine testing of serum or urine samples may be directed to community laboratories. Contact your local community laboratory to find out whether they can accommodate this specimen collection and to arrange an appointment.

Community laboratory couriers will support the transport of specimens collected from possible, suspected or confirmed mpox-infected patients if packaged appropriately by the submitting health-care practitioner. Once verifying the package is appropriate for transport, the courier will affix the TU 0886 certificate to the external package, if not already included by the submitter. Health-care providers are responsible for the packaging of their own samples; couriers are not able to oversee sample packaging.

Trans- or cis-gender individuals who self-identify as belonging to the gay, bisexual and other men who have sex with men community and meet one or more of the following criteria may be eligible for PrEP:

• Have received a diagnosis of bacterial sexually transmitted infection (e.g., chlamydia, gonorrhea, syphilis) in the past two months
• Have visited bathhouses, sex clubs or may be planning to, or work/volunteer in these settings
• Have had anonymous sex or had more than two sexual partners in the last 21 days
• Have engaged in sex work or may be planning to

Individuals who are immunocompromised, pregnant or breastfeeding may be at higher risk for severe disease from a mpox infection and should contact their local public health unit to be considered for PrEP if they are at risk for contracting mpox.

• PEP may be offered to individuals who are a high-risk contact with a confirmed or probable case of mpox
• Intermediate risk contacts may also be offered PEP following assessment by the local public health unit
• A single dose of Imvamune® should be offered ideally within four days of exposure, but up to 14 days
• Imvamune® should not be offered to people with a current mpox infection

The most common side effects include:

• Pain
• Erythema
• Induration
• Swelling
• Fatigue
• Headache
• Myalgia
• Nausea

Due to limited supply and ultra-cold storage requirements, public health units will not store Imvamune® on site. They will order the vaccine from the province once a need is identified.

TPoxx® should be considered for:

• Hospitalized patients with severe disease (e.g., hemorrhagic disease, sepsis, encephalitis, myocarditis or other conditions requiring hospitalization)
• Patients who are severely immunocompromised
• Pediatric populations, particularly children under 10 years of age
• Pregnant or breastfeeding women
• Patients with one or more complications (e.g., secondary bacterial skin infection, gastroenteritis with severe nausea/vomiting, diarrhea or dehydration, bronchopneumonia, concurrent disease or other comorbidities)
• Patients with mpox virus infections with lesions that are leading to significant disability (e.g., proctitis, keratitis or other ocular involvement, pharyngitis/epiglottitis or other breathing/swallowing compromise)

Most common side-effects in adults include:

• Headache and nausea followed by abdominal pain and vomiting

Less common side-effects include:

• Gastrointestinal: dry mouth, chapped lips, dyspepsia, eructation and oral paresthesia
• General pyrexia, pain, chills, malaise and thirst
• Investigations: abnormal electroencephalogram, hematocrit decreased, hemoglobin decreased, heart rate increased and QTc prolongation
• Musculoskeletal and connective tissue: arthralgia and osteoarthritis
• Nervous system: migraine, disturbance in attention, dysgeusia and paresthesia
• Psychiatric: depression, dysphoria, irritability and panic attack
• Respiratory, thoracic and mediastinal disorders: oropharyngeal pain
• Skin and subcutaneous tissue: palpable purpura, rash, pruritic rash, facial redness, facial swelling and pruritus

A limited supply of TPoxx® is available in Ontario for hospitalized patients who are severely ill or disabled due to mpox infection or at high risk for severe disease.

To request TPoxx®, email the Ministry of Health Emergency Operations Centre at EOCoperations.MOH@ontario.ca or call the Healthcare Provider Hotline at 1-866-212-2272.

Read the Q-and-A for mpox (MOH).