Household Transmission of Monkeypox

Monkeypox cases are occurring worldwide at an increasingly rapid rate 1. Since January 2022, cases of monkeypox have been reported to the World Health Organization (WHO) by 110 member states—and as of November 2022, over 78,000 laboratory confirmed cases, including 41 deaths, have been documented 2. Data demonstrate that the main mode by which people have been infected with monkeypox is through close contact during sexual activity with lesions of the skin or mucosal surfaces of an individual with monkeypox 3. Some infections have also resulted from injury with a sharp instrument used to sample skin lesions, as well as from tattooing or skin piercing. Though household transmission of monkeypox is possible, the risk can be minimized through proper precautions. 

While monkeypox virus has been identified across a range of household surfaces 4, transmission via contact with contaminated surfaces or objects remains unlikely. No cases of transmission during the current outbreak have been documented as a result of exposure to surfaces, materials, or other objects among individuals who have abided by recommended precautions.  

Monkeypox virus has been detected in anogenital and urethral samples from individuals without any evident signs of rash, lesions, or other signs or symptoms of illness, but no cases of transmission have yet been definitively associated with exposure to such individuals. In other words, asymptomatic individuals appear to have low levels of infectiousness. 

The Centers for Disease Control (CDC) recommend that individuals with monkeypox remain isolated, ideally at home, for the duration of their illness. A certain number of CDC recommendations are further aimed at minimizing the transmission of monkeypox within the household 

One directive is that individuals without an essential need to be in the home should not visit. Close contact should be avoided with others who need to be in the home, as well as with pets or other animals. In as much as possible, an infected individual with monkeypox should change their own bandages and handle their own contaminated linens while wearing disposable gloves, followed by immediate handwashing after removal of the gloves.

However, if close contact with others cannot be avoided, such as for the provision of medical care, the same protocol—gloves and handwashing—should be followed by care takers. Infected individuals should also use well-fitting source control, such as in the form of a medical mask, and all skin rashes should ideally be covered by long sleeves or long pants.  

To reduce the risk of household transmission, monkeypox-infected individuals should also refrain from sharing potentially contaminated items, such as clothing, towels, bed linens, and drinking glasses or eating utensils, and frequently touched items, such as light switches or counters should be cleaned routinely. Should someone come into contact with an infected individual’s rash, clothing, linen, or objects that may have has contact with rash material, hand hygiene—the use of an alcohol-based hand rub or hand washing with soap and water—is essential. Contaminated waste, such as dressings or bandages, should also be contained and carefully disposed of. 

There remains a number of questions to be answered as regards the best procedure for minimizing the transmission of monkeypox, both outside of and within the household. It remains unclear how much monkeypox virus is present in body fluids, including oral and respiratory secretions, urine, feces, and semen, as well as the risk of infection from exposure to different fluids. Another important question is whether individuals with immunosuppression harbor greater viral loads, as is the case with many other infectious diseases 5. 

While knowledge regarding the means by which monkeypox virus spreads is rapidly evolving and subject to change, it is essential in the meantime for everyone to be aware of guidance on how to minimize its transmission.  

References 

1. Thornhill, J. P. et al. Monkeypox Virus Infection in Humans across 16 Countries — April–June 2022. N. Engl. J. Med. 387, 679–691 (2022). doi: 10.1056/NEJMoa2207323
2. 2022 Monkeypox Outbreak: Global Trends. Available at: https://worldhealthorg.shinyapps.io/mpx_global/#1_Overview. (Accessed: 8th November 2022)
3. Science Brief: Detection and Transmission of Monkeypox Virus | Monkeypox | Poxvirus | CDC. Available at: https://www.cdc.gov/poxvirus/monkeypox/about/science-behind-transmission.html. (Accessed: 8th November 2022)
4. Pfeiffer, J. A. et al. High-Contact Object and Surface Contamination in a Household of Persons with Monkeypox Virus Infection — Utah, June 2022. MMWR. Morb. Mortal. Wkly. Rep. 71, 1092–1094 (2022). doi: 10.15585/mmwr.mm7134e1
5. Isolation and Prevention Practices for People with Monkeypox | Monkeypox | Poxvirus | CDC. Available at: https://www.cdc.gov/poxvirus/monkeypox/clinicians/isolation-procedures.html. (Accessed: 8th November 2022)