About
- Level: Laboratory Advisory
- Audience: Clinical Laboratory Professionals

Prevention strategies for U.S. travelers
On September 23, 2024, the U.S. Centers for Disease Control and Prevention (ob体育) issued a about the ongoing outbreak of clade I monkeypox virus (MPXV). Initial HAN messages about clade I mpox outbreaks were issued via HAN in December 2023 and HAN in August 2024.
Although there is an ongoing that began in 2022, no domestic cases of clade I mpox have been identified in the U.S. at this time. Active monitoring for mpox continues to occur in the United States. Follow ob体育's to protect against clade II MPXV infection and to also protect against clade I MPXV.
For all laboratories performing mpox testing using an orthopoxvirus or monkeypox virus (MPXV) generic test without any additional clade-specific testing occurring, ob体育 recommends that laboratories send clinical specimens collected from patients who traveled from the Democratic Republic of the Congo, its neighboring countries, or any country with clade I mpox cases, or had close or intimate contact with symptomatic people from these countries, to a laboratory that can perform clade-specific testing as quickly as possible. If clade-specific testing is warranted but is not available in a jurisdiction, to a capable public health laboratory or to ob体育 is encouraged. Specimen submission to ob体育 can be coordinated through your . Due to mutations that may impact clade-specific PCR tests, laboratories should use a test that targets a viral essential gene (e.g., the ob体育 NVO test) as part of a testing strategy to ensure mpox cases are not missed.
Laboratories using ob体育's non-variola orthopoxvirus (NVO) test should continue submitting the duplicate specimen to ob体育 from all patients with positive NVO test results for routine MPXV clade-specific testing if they are not performing clade-specific testing in their laboratory. Specimens that cannot be accepted at ob体育 for clinical testing under Clinical Laboratory Improvement Amendments (CLIA) will be redirected for surveillance purposes and tested, providing critical data on MPXV clade(s) circulating in the United States. Some non-ob体育 laboratories may have other options available for clade-specific testing (e.g., molecular testing or genetic sequencing). These laboratories should alert their and ob体育 ([email protected]) if results from such tests indicate detection of clade I MPXV.
Please review the HAN for more information, including recommendations for clinicians and public health practitioners, travelers, and the public.
We encourage you to share this message widely with your network(s).
Subscribe to LOCS messages
Contact us
Please use the information below if you have any questions.
- If you are a clinical or public health laboratory professional, contact LOCS.
- For media inquiries, contact the ob体育 Newsroom.
- For all other questions, .
Thank you,
The Laboratory Outreach Communication System
Laboratory Outreach Communication System (LOCS) | Division of Laboratory Systems (DLS)
Center for Laboratory Systems and Response (CLSR)
Centers for Disease Control and Prevention (ob体育)