Shiloh
Editor, Senior Moderator
Source: https://www.cdc.gov/mmwr/volumes/73/wr/mm7340a3.htm
Notes from the Field: Mpox Cluster Caused by Tecovirimat-Resistant Monkeypox Virus — Five States, October 2023–February 2024
Weekly / October 10, 2024 / 73(40);903–905
Crystal M. Gigante, PhD1; Jade Takakuwa, MS1; Daisy McGrath, MS1; Chantal Kling1; Todd G. Smith, PhD1; Mengfei Peng1; Kimberly Wilkins1; Jacob M. Garrigues, PhD2; Taylor Holly, MPH3; Hannah Barbian, PhD4; Alyse Kittner, MPH3; Danielle Haydel5; Emma Ortega, MPHTM5; Gillian Richardson, MPH5; Julie Hand5; Jill K. Hacker, PhD6; Alex Espinosa, MS6; Monica Haw, MPH6; Chantha Kath6; Meilan Bielby, PhD7; Kirstin Short, MPH7; Kimberly Johnson, MS8; Nelson De La Cruz8; Whitni Davidson, MPH1; Christine Hughes, MPH1; Nicole M. Green, PhD2; Nicolle Baird, PhD1; Agam K. Rao, MD1; Christina L. Hutson, PhD1 (View author affiliations)
Summary
What is already known about this topic?
Tecovirimat is the first-line drug for treatment of orthopoxvirus infection (e.g., smallpox and mpox). Viral mutations that render the drug ineffective can develop during treatment.
What is added by this report?
A new cluster of mpox cases caused by tecovirimat-resistant monkeypox virus (MPXV) was detected among persons with no documentation of previous tecovirimat treatment over multiple months in five U.S. states.
What are the implications for public health practice?
Routine sequence surveillance is needed to detect and monitor resistance. To prevent development and spread of resistant MPXV, tecovirimat use outside of clinical trials needs to be consistent with CDC’s Investigational New Drug protocol for tecovirimat use.
The antiviral drug tecovirimat* has been used extensively to treat U.S. mpox cases since the start of a global outbreak in 2022. Mutations in the mpox viral protein target (F13 or VP37) that occur during treatment can result in resistance to tecovirimat† (1,2). CDC and public health partners have conducted genetic surveillance of monkeypox virus (MPXV) for F13 mutations through sequencing and monitoring of public databases. MPXV F13 mutations associated with resistance have been reported since 2022, typically among severely immunocompromised mpox patients who required prolonged courses of tecovirimat (3–5). A majority of patients with infections caused by MPXV with resistant mutations had a history of tecovirimat treatment; however, spread of tecovirimat-resistant MPXV was reported in California during late 2022 to early 2023 among persons with no previous tecovirimat treatment (3). This report describes a second, unrelated cluster of tecovirimat-resistant MPXV among 18 persons with no previous history of tecovirimat treatment in multiple states...
Notes from the Field: Mpox Cluster Caused by Tecovirimat-Resistant Monkeypox Virus — Five States, October 2023–February 2024
Weekly / October 10, 2024 / 73(40);903–905
Crystal M. Gigante, PhD1; Jade Takakuwa, MS1; Daisy McGrath, MS1; Chantal Kling1; Todd G. Smith, PhD1; Mengfei Peng1; Kimberly Wilkins1; Jacob M. Garrigues, PhD2; Taylor Holly, MPH3; Hannah Barbian, PhD4; Alyse Kittner, MPH3; Danielle Haydel5; Emma Ortega, MPHTM5; Gillian Richardson, MPH5; Julie Hand5; Jill K. Hacker, PhD6; Alex Espinosa, MS6; Monica Haw, MPH6; Chantha Kath6; Meilan Bielby, PhD7; Kirstin Short, MPH7; Kimberly Johnson, MS8; Nelson De La Cruz8; Whitni Davidson, MPH1; Christine Hughes, MPH1; Nicole M. Green, PhD2; Nicolle Baird, PhD1; Agam K. Rao, MD1; Christina L. Hutson, PhD1 (View author affiliations)
Summary
What is already known about this topic?
Tecovirimat is the first-line drug for treatment of orthopoxvirus infection (e.g., smallpox and mpox). Viral mutations that render the drug ineffective can develop during treatment.
What is added by this report?
A new cluster of mpox cases caused by tecovirimat-resistant monkeypox virus (MPXV) was detected among persons with no documentation of previous tecovirimat treatment over multiple months in five U.S. states.
What are the implications for public health practice?
Routine sequence surveillance is needed to detect and monitor resistance. To prevent development and spread of resistant MPXV, tecovirimat use outside of clinical trials needs to be consistent with CDC’s Investigational New Drug protocol for tecovirimat use.
The antiviral drug tecovirimat* has been used extensively to treat U.S. mpox cases since the start of a global outbreak in 2022. Mutations in the mpox viral protein target (F13 or VP37) that occur during treatment can result in resistance to tecovirimat† (1,2). CDC and public health partners have conducted genetic surveillance of monkeypox virus (MPXV) for F13 mutations through sequencing and monitoring of public databases. MPXV F13 mutations associated with resistance have been reported since 2022, typically among severely immunocompromised mpox patients who required prolonged courses of tecovirimat (3–5). A majority of patients with infections caused by MPXV with resistant mutations had a history of tecovirimat treatment; however, spread of tecovirimat-resistant MPXV was reported in California during late 2022 to early 2023 among persons with no previous tecovirimat treatment (3). This report describes a second, unrelated cluster of tecovirimat-resistant MPXV among 18 persons with no previous history of tecovirimat treatment in multiple states...