Mpox, a viral zoonotic infection previously known as "monkeypox", is endemic in certain parts of Africa. Human cases outside of Africa had typically been linked to international travel or imported animals. However, since May 2022, there has been a large international outbreak of mpox in nonendemic regions. Most cases have been identified in men who have sex with other men (MSM). Refer to global, national, and local data pages for more information: WHO | CDC | CDPH | LAC.

Mpox is an orthopoxvirus that is in the same genus as variola (causative agent of smallpox) and vaccinia viruses (which is used in the smallpox vaccine). Although the mpox virus is in the same family of viruses as smallpox, it is less transmissible and typically less severe than smallpox.

Healthcare providers are encouraged to visit the CDC Mpox Information for Healthcare Professionals for information on clinical recognition, caring for patients with mpox, infection control, and other guidance.

Providers who need clinical consultation (including for patients who are clinically worsening or hospitalized), access to treatment, or approval for mpox testing at the LAC Public Health Lab can call:

Los Angeles County DPH Acute Communicable Disease Control

• Weekdays 8:30am-5pm: 213-240-7941.
• Weekends and holidays 8:00am-5pm or evenings (urgent situations only): 213-974-1234 and ask for the physician on call.

Healthcare providers must report all mpox or orthopoxvirus infections, hospitalizations, and deaths within 1 working day from identification (Title 17, CCR, §2500). See Reportable Disease List

If hospitalized patients are worsening clinically, such as being admitted to the ICU, providers are asked to please contact the LAC DPH healthcare provider line for clinical consultation and to access additional therapeutic options.

Providers should report all cases, hospitalization, and deaths on-line via the LAC DPH secure mpox reporting portal:

Mpox Confidential Morbidity Report

If providers experience technical difficulties with using the on-line report form, reports may be completed using the standard CMR form and submitted via fax to (888) 397-3778 or (213) 482-5508. Note: provider reporting is not necessary for positive tests conducted by the LAC DPH PHL.

Mpox reporting on the death certificate for all decedents where the disease caused or contributed to death is important to ensure deaths related to mpox are captured.

For more information on how to complete a mpox-related death certificate please see here.

Priority Populations for Mpox Testing at the Public Health Lab (PHL)

To expedite testing, providers with a suspect mpox case in one of the following priority populations are asked to submit specimens to the PHL:

• Persons experiencing homelessness (PEH)
• Pregnant persons
• Children with a history of close, personal contact with someone who has mpox

In addition, providers that do not have access to commercial orthopoxvirus testing may submit specimens to PHL.

Preparation and Collection of Specimens

Collection

Depending on the stage of disease, specimen collection involves vigorous, firm swabbing of lesions (vesicular, pustular, or crusted) with paired sets of DRY synthetic swabs. Swabbing may rupture lesion to release fluid or pus material.

The swab used may be made of flocked or spun synthetic material but should have a shaft that is sturdy enough to enable the lesion to be rubbed vigorously. Do not use a nasopharyngeal (NP) swab as the shaft is too flexible and the tip too small to collect an adequate sample. Do not place swabs in any type of transport media; use an empty sterile screw cap tube or sterile screw cap specimen cup for transport of swab.

Dry swabs are required for orthopoxvirus PCR. Paired sets of swab samples, from the same lesion, are required for testing because mpox specific PCR confirmation and clade differentiation is performed as a send-out test to CDC.

Additionally, scabs or crusts may be removed for collection in a dry, sterile screw cap specimen container.

Serum collected in gold top serum separator vacutainer tube may be collected for serology in selected cases for poxvirus serology.

Consultation for collecting and submitting any additional and/or other specimens (e.g., tissue samples) must be made with PHL Director (562-658-1300). 

Storage

Dry swab specimens should be stored refrigerated and ideally frozen within 1 hour. Serum specimens should be spun and stored refrigerated.

Labelling

Label all specimens with a minimum of two patient identifiers (e.g., full name and date of birth) and completely fill out the LAC Public Health Laboratory test requisition form.

For swabs and scabs/crusts, write in "Orthopoxvirus PCR" in the "Other" box at the bottom of the form.

For serum, write in "Orthopox serology" in the "Other" box at the bottom of the form.

Each specimen needs a separate test requisition form. The Public Health Laboratory test request form can be found here.

For Providers

• CDPH Information for Healthcare Providers
• CDC Information for Healthcare Professionals

For Patients/General Public

• LAC DPH: Refer to Mpox Resources for patient resources in multiple languages.
• CDC Information for the Public
• CDC Mpox Print Materials
• CDPH Mpox