As mpox (previously known as monkeypox) cases rise in certain parts of the world, people are becoming increasingly concerned about protecting themselves during outbreaks. The recent uptick in cases in parts of Africa has especially raised concerns about its potential spread beyond traditional boundaries, such as Central or West Africa, to other countries.
The first case of clade I mpox was reported in California on November 16, 2024. Although no additional cases have been reported, the Centers for Disease Control and Prevention (CDC) advises healthcare professionals and adults across the U.S. to be vigilant for signs of mpox, especially in people who have recently traveled to the Democratic Republic of Congo or neighboring countries.
What is Mpox?
Mpox is a viral disease that is closely related to the smallpox virus but is less severe. The infection itself is caused by the monkeypox virus, also called MPXV.
MPXV originated from wild animals in parts of Africa. It now spreads to humans most often through close contact, including sex, with an infected person. It’s also possible to become infected from exposure to objects that are contaminated with the virus, although this is less common.
Different Types of Mpox
There are two types of the mpox virus: clade I and clade II.
In 2022–2023, a global outbreak of mpox was caused by the clade II strain (specifically clade IIb). More recently, there’s been an upsurge of cases in the Democratic Republic of the Congo and other countries caused by the clade I strain. Clade I (specifically clade Ib) has also been detected beyond Africa, which has raised global concern.
Clade I usually causes a higher percentage of people with mpox to get severely sick or die compared to clade II. On August 14, 2024, the World Health Organization declared the clade I outbreak a “Public Health Emergency of International Concern.”
Causes of the Mpox Outbreak
The current mpox outbreak is primarily fueled by human-to-human transmission through close contact. It’s been exacerbated by international travel, making containment challenging.
The virus spreads through:
- Respiratory droplets that are breathed in during prolonged face-to-face contact
- Skin-to-skin contact, such as kissing and sex
- Direct contact with an infected person’s rash, scabs or body fluids
- Touching items like clothing or linens that previously touched the infectious rash or body fluids
- Pregnant people spreading the virus to their fetus
- Being scratched or bitten by an infected animal or eating the meat of an infected animal
Is Mpox Spreading in New York or the United States?
One case of clade I mpox has been reported in the U.S. as of November 2024, according to the CDC. The risk of clade I mpox to the public remains low, the CDC recently confirmed, and there continue to be sporadic clade II mpox cases in the United States.
The CDC recommends that healthcare providers in the U.S. remain vigilant, particularly for patients who have recently traveled from the DRC or neighboring regions and show symptoms consistent with mpox.
The JYNNEOS vaccine, expected to be effective against both clades I and II, is recommended for those with risk factors for mpox, particularly men who have sex with other men.
Signs and Symptoms of Mpox
Early mpox symptoms generally include:
- Fever
- Rash
- Headache
- Muscle aches
- Backache
- Swollen lymph nodes
- Chills
- Exhaustion
While most cases of mpox are mild, serious illness and death can occur, especially among people with immunocompromising conditions like HIV, older adults, young children and pregnant women.
What Does an Mpox Rash Look Like?
Within one to three days after the development of a fever, many mpox patients develop a rash, often beginning on the face and then spreading to other parts of the body like the feet, chest, mouth or genitals. The rash can be very painful and leave permanent scarring.
An mpox rash progresses through several stages, including appearing as scabs, before healing. It can also look like pimples or blisters. The rash and other symptoms typically last for about two to four weeks.
Mpox Vaccine
A vaccine called the JYNNEOS vaccine is available to protect against both types of mpox infections. The vaccine is given in two doses, administered four weeks apart. When administered as directed, studies show the vaccine is about 85 percent effective.
In response to the recent outbreak, public health officials have recognized the importance of vaccination. The CDC 2024 guidelines recommend the mpox vaccine for high-risk groups to prevent the disease’s spread. The vaccine is part of strategic public health efforts to provide immunization to those most likely to be affected, depending on the availability and risk of exposure.
The CDC recommends getting the mpox vaccine if:
- You had known or suspected exposure to someone with mpox
- You had a sex partner in the past 2 weeks who was diagnosed with mpox
- You are a gay, bisexual or other man who has had sex with men or a transgender, nonbinary or gender-diverse person in the past 6 months who have been diagnosed with an STI or has more than one sex partner
- You anticipate experiencing any of the above scenarios
- You are at risk for occupational exposure to orthopoxviruses, for example, if you work in a laboratory or a healthcare facility
You can also get vaccinated if you’ve been exposed to the virus within the last 14 days. It’s most effective to be vaccinated within four days of exposure, which helps either prevent infection or reduce the severity of symptoms.
Treatments for Mpox
Since there are no specific treatments for mpox infections, the goal is to control outbreaks and help manage infected people’s symptoms.
Along with vaccinations, other treatment approaches for mpox include:
- Use of antivirals in severe cases
- Supportive care for managing symptoms, such as hydration, fever control, and pain management, if needed
Prevention Tips
You can help protect yourself against mpox infection by following these steps:
- Practice safe sex, use a condom, and avoid sexual intercourse and social gatherings with people who may have been exposed to the virus
- Choose sexual partners carefully, such as only having sex with vaccinated people
- Consider mutual masturbation without touching others cybersex/webcam sex
- Avoid close contact with people who have a rash that looks like mpox and animals that can carry the virus
- Do not use objects or materials that a person with mpox has used, such as utensils, towels, cups, water bottles, etc.
- Wash your hands often and avoid touching others
For more detailed guidance on whether the mpox vaccine is right for you and on recognizing the signs of mpox, understanding your risk and preventing infection, visit the website for Stony Brook Medicine Advanced Speciality Care- Infectious Diseases. Our experts are at the forefront of managing and researching infectious diseases, including mpox, ensuring the community and patients receive the most current and comprehensive care available.
To learn more about the mpox (JYNNEOS) vaccine and scheduling an appointment at the Edie Windsor Healthcare Center in Hampton Bays, visit our Mpox Vaccine Information page or call (631) 287-5990.
Sharon Nachman, MD, Chief, Division of Pediatric Infectious Disease at Stony Brook Children’s, is joined by Eric Lella, DO, Medical Director and Family Medicine Physician at the Edie Windsor Healthcare Center, and Susan Donelan, MD, FSHEA, Medical Director, Infection Prevention and Control at Stony Brook Medicine, to discuss Monkeypox (Mpox), including causes, signs, symptoms, prevention and more.
