PHC SignalTM - Monkeypox

Published: May 19, 2022
Updated: May 25, 2022

PHC Predicts

Based on current information, PHC predicts monkeypox poses low risk to businesses and the general public. We predict global cases from this outbreak will total 500-1,000.

Based on the genetic sequencing available, we believe this outbreak can be attributed to several super-spreading events, as opposed to a significant change in the virus itself (mutation) that allowed it to spread more easily. A high proportion of cases have links to a recent large event in the Canary Islands (one of the superspreader events), however, ongoing person-to-person transmission will likely slow and the outbreak will subside.

As always, an unusual outbreak of a virus that can cause illness or death warrants continued monitoring. For example, if the virus does mutate to transmit more easily, the risk to businesses and the public would increase. See the “PHC Recommendations” section below for basic prevention measures that will help to prevent transmission.


Presentation and clinical outcomes - Monkeypox is a rare but potentially serious viral illness with symptoms similar to smallpox, though less severe. Symptoms typically begin with flu-like illness and swelling of the lymph nodes before progressing to a rash on the face and body. Most infections last 2 to 4 weeks. In some cases the rash may be the initial symptom. The case fatality ratio (CFR) ranges from 1-10%, depending on the strain. Children are at higher risk, and monkeypox during pregnancy may lead to complications. Milder cases of monkeypox may go undetected which means it may increase risk of unknowingly transmitting to others.

Animal exposure -  In parts of central and West Africa where monkeypox typically occurs, people can be exposed through bites or scratches from rodents and small mammals, preparing wild game, or having contact with an infected animal or possibly animal products.

Human transmission - Historically, the virus does not spread easily between people. Transmission can occur through contact with body fluids, especially saliva, monkeypox sores or lesions, items that have been contaminated with fluids or sores (clothing, bedding, etc.), or through respiratory droplets following prolonged contact with an infected person. The incubation period (time between exposure and symptom onset) for monkeypox is usually from 6 to 13 days but can range from 5 to 21 days.

Situation to Date

Since September 2017, Nigeria has routinely reported cases of monkeypox. Ongoing monkeypox transmission in Nigeria has increased the likelihood of sporadic travel-related cases appearing in other countries.

In early May, the UK confirmed monkeypox in a person who recently traveled to Nigeria. Shortly later, over a dozen new cases were identified in the UK, but these individuals had no history of travel and no link to the initial traveler, suggesting monkeypox is spreading locally between people. The majority of the monkeypox patients in the UK identify as men who are gay, bisexual, or men who have sex with men (MSM). Following confirmation of the initial UK case, monkeypox cases have been identified in other countries including in Europe, North America, and Australia, predominantly in men who identify as MSM. It is currently unknown why this population demographic is experiencing the majority of cases, but epidemiological investigations are ongoing.

Some of the recently identified cases were discovered in clinics that specialize in sexually transmitted infections. Even though monkeypox has not historically been regarded as a sexually transmitted infection, that possibility cannot be ruled out. This is because monkeypox can be passed between people by direct contact with skin lesions during sex or close contact, respiratory droplets, or other contact with contaminated clothing or linens. Given the demographics of early cases in this outbreak, monkeypox may be spreading in MSM networks, but not exclusively in them. Any prolonged close contact with an infected person can be an opportunity for transmission.

PHC Recommendations

Although relative risk remains low, PHC recommends businesses in areas with reported cases to reinforce basic prevention measures:

  • Standard household cleaning / disinfectants and hand hygiene will likely remain effective tools to prevent casual transmission of the virus.
  • More frequent laundering of bedding, towels, clothing, or similar materials in areas experiencing outbreaks is advisable. These materials can be washed in a standard washing machine with warm water and detergent. Washing hands with soap and water after touching potentially contaminated surfaces is a good idea.
  • New evidence suggests these recent cases may be driven by close or intimate contact. Providing education and awareness materials to employees may help heighten awareness and inform personal behaviors and risk-assessment, keeping in mind upcoming celebrations such as festivals, events, and concerts where intimate contact may occur.
  • Individuals with monkeypox symptoms should seek medical treatment, which will vary by location. Individuals should contact their local health department or provider directly. The U.S. FDA has approved the use of TPOXX, a prescription antiviral medication.
Data shows the smallpox vaccine is at least 85% effective in preventing monkeypox. Vaccinations can be used in several ways to protect vulnerable populations:
  • Given to healthcare workers as a preventative measure
  • Given to close contacts of known or suspected cases
  • Given to individuals quickly after being exposed

Pressing Questions

Since this is a new outbreak, many questions remain unanswered.
  • Has the virus changed (mutated) to cause this outbreak? 
  • Is the current monkeypox virus more severe than past outbreaks? 
  • Can people without symptoms transmit the virus? 
  • If I had COVID-19, am I more susceptible to monkeypox? 
PHC is actively monitoring numerous sources and networks to provide informed risk assessments.