The epidemiology of Mpox (previously Monkeypox) continues to evolve with a new outbreak being caused by a different “strain”. Since 2022, person-to-person transmission of Mpox has been sustained in a global outbreak, primarily among men who have sex with men (MSM). The stigma associated with this disease has negatively impacted containment of this virus with only 1 in 4 at-risk persons being immunized.1 Mpox continues to circulate in the U.S. and modeling data suggest that if vaccine coverage does not increase, large outbreaks could be expected in the future.2 This would most certainly result in a percentage of these patients being hospitalized with risk of transmission within the hospitals walls.
About MPox Clades
Clades are groups of genetically linked viruses. Mpox consists of two clades: Mpox Clade II which causes less severe disease and Mpox Clade I which is more transmissible and causes more severe disease with a mortality rate as high as 10%.3 In early December 2023, the Centers for Disease Control and Prevention (CDC) issued a health advisory of a sexually-transmitted Mpox Clade I outbreak in the Democratic Republic of the Congo (DRC).1 Clinicians were alerted to the possibility of Mpox Clade I in travelers who have been in the DRC. To date, no Mpox Clade I cases have been identified in the U.S., however the World Health Organization (WHO) states there is moderate risk of Mpox Clade I further spreading to worldwide.1,4
What Healthcare Professionals Should Know
The good news is that treatment and prevention measures are the same for both Mpox clades.3 At-risk persons should get vaccinated and should seek medical attention if they have symptoms.3 The virus can be spread from person-to-person from contact with Mpox lesions or respiratory secretions and droplets or from contact with contaminated materials, including soft surfaces like bedding or clothing.3 Because Mpox is spread by direct contact, frequent hand hygiene and routine cleaning and disinfection of environmental surfaces is crucial.3,7 Disinfectants for emerging viral pathogens from the Environmental Protection Agency’s (EPA) List Q should be used.8 The EPA has extended the use for List Q disinfectants for mpox through May 2025.9 Learn more here about navigating List Q as it relates to Mpox.
The risk for occupational transmission of Mpox Clade II to healthcare workers (HCWs) is considered to be low — in fact, only a few cases have been reported.10 However, Mpox Clade I is more transmissible so its plausible that the risk to HCWs may be higher. To protect themselves, HCWs should do the following:
- Adhere to standard and transmission-based precautions, including appropriate PPE.7
- Perform frequent hand hygiene.
- Frequently clean and disinfect high-touch surfaces in mpox patient rooms.
- Avoid dry dusting, sweeping, or vacuuming which can aerosolize the virus.7
- Perform aerosol-generating procedures in a negative pressure room.7
- Never shake or handle soiled linens in a manner that may disperse infectious material.7
- Handle waste in accordance with federal, state, and local regulations. Mpox Clade I is Category A Waste, while Mpox Clade II is Category B Waste.6
The epidemiology of mpox continues to evolve with a substantial increase in the more pathogenic strain of mpox (Clade I) in the DRC.1 Healthcare workers should continue to be vigilant and consider mpox when evaluating the cause of rashes.1 For more information, see our Mpox Pathogen Education Sheet.
References
1. Centers for Disease Control and Prevention (CDC). HAN Alert: Mpox Caused by Human-to-Human Transmission of Monkeypox Virus with Geographic Spread in the Democratic Republic of the Congo; Dec 7, 2023 [Internet]. [cited 2023 Dec 31]. Available from https://emergency.cdc.gov/han/2023/han00501.asp
2. Centers for Disease Control and Prevention (CDC). Mpox Updates for Clinicians, Dec 20, 2023 [Internet]. [cited 2023 Dec 31]. Available from https://www.cdc.gov/nchhstp/dear_colleague/2023/dcl-122023-mpox-updates.html
3. World Health Organization (WHO). Mpox: What we know; Dec 1, 2023 [Internet]. [cited 2023 Dec 31]. Available from https://www.who.int/multi-media/details/mpox-what-we-know
4. World Health Organization (WHO). Multi-country outbreak of mpox; Dec 22, 2023 [Internet]. [cited 2023 Dec 31]. Available from https://www.who.int/publications/m/item/multi-country-outbreak-of-mpox–external-situation-report-31—22-december-2023
5. Centers for Disease Control and Prevention (CDC). About Mpox [Internet]. [cited 2024 Jan 1]. Available from https://www.cdc.gov/poxvirus/mpox/about/index.html
6. U.S. Department of Transportation. Transporting Infectious Substances Overview [Internet]. [cited 2024 Jan 1]. Available from https://www.phmsa.dot.gov/transporting-infectious-substances/transporting-infectious-substances-overview
7. Centers for Disease Control and Prevention (CDC). Mpox: Infection Prevention and Control of Mpox in Healthcare Settings [Internet]. [cited 2023 Dec 31]. Available from https://www.cdc.gov/poxvirus/mpox/clinicians/infection-control-healthcare.html#anchor_1653508940308
8. US Environmental Protection Agency (EPA). Selected EPA-Registered Disinfectants [Internet]. [cited 2023 Dec 31]. Available from https://www.epa.gov/pesticide-registration/selected-epa-registered-disinfectants
9. US Environmental Protection Agency (EPA). Emerging Viral Pathogen Guidance and Status for Antimicrobial Pesticides [Internet]. [cited 2023 Dec 31]. Available from https://www.epa.gov/pesticide-registration/emerging-viral-pathogen-guidance-and-status-antimicrobial-pesticides
10. Alarcón J, Kim M, Balanji N, Davis A, Mata F, Karan A, et al. Occupational Monkeypox Virus Transmission to Healthcare Worker, California, USA, 2022. Emerg Infect Dis. 2023;29(2):435-437. https://doi.org/10.3201/eid2902.221750
