Background
Mpox is a zoonotic infectious disease caused by the Mpox virus, which belongs to the Orthopoxvirus genus of the Poxviridae family. The virus is divided into two distinct clades: Clade I and Clade II, which are further subdivided into sub-clades Ia, Ib, IIa, and IIb. Historically, Clade I is more contagious and causes more severe disease than Clade II, with a historical case fatality rate of up to 10%, compared to approximately 1% for Clade II. The global outbreak that began in May 2022 has been primarily driven by the Clade IIb strain, which generally causes milder symptoms with a much lower case fatality rate of about 0.3%. In contrast, the newly emerged Clade Ib strain has been circulating in Central Africa (mainly the Democratic Republic of the Congo and neighboring non-endemic areas) since late 2023, with a case fatality rate of 0.1-0.2% in eastern provinces, while the Clade Ia strain in other provinces shows a higher rate of 2.4-2.6%.

Clinically, the disease presents with symptoms similar to smallpox but generally milder. It typically starts with fever, chills, sweating, headache, muscle aches, swollen lymph nodes (such as around the ears, armpits, neck, or groin), and extreme fatigue. Following these initial symptoms, skin lesions appear and progress through stages from macules to papules, vesicles, pustules, and eventually crusts before falling off.
(Case Definition)

Epidemiology
Historically, Mpox has been endemic in parts of Africa since 1970. In May 2022, a global outbreak began, spreading to multiple non-endemic countries across Europe and North America. Due to the severity of the situation, the World Health Organization (WHO) has declared Mpox a Public Health Emergency of International Concern (PHEIC) , the first PHEIC was declared on July 23, 2022, in response to the rapid global spread, and ended on May 11, 2023. The second PHEIC was declared on August 14, 2024, driven by a significant surge of the Clade I (specifically Clade Ib) virus strain in the Democratic Republic of the Congo (DRC) and its spread to neighboring countries; this second PHEIC was recently terminated on September 5, 2025.

Epidemiological data shows that outside the African region, the vast majority of cases are adults (over 18 years old), and over 90% are male, primarily but not exclusively among men who have sex with men (MSM), with approximately 50% of the cases having HIV co-infection. In Taiwan, the first imported case was confirmed in June 2022, and the first indigenous case was reported in February 2023. As the end of 2025, Taiwan has reported a total of 513 confirmed cases (478 indigenous and 35 imported), all of which are associated with the Clade IIb virus strain.

Prevention and Control

1. Avoid close or intimate contact with individuals in the infectious period, reducing visits to high-risk social venues, and practicing safe sex (e.g., using condoms).

• Safe sex:Most cases of STIs can be prevented with consistent and correct condom use in every sexual encounter, paired with water-based lubricants.
• Reduce risky behaviors:Avoid risky behaviors such as having multiple sexual partners or engaging in sexual activities with strangers.
• Avoid substance abuse:Avoid the use of addictive drugs. substance use can impair your judgment or cause a loss of consciousness, leading to unsafe sexual behaviors and significantly increasing the risk of STIs infection.

2. Avoid contact with wild animals (such as rodents and primates) in endemic areas and thoroughly cooking meat before consumption.
3. Get vaccination: In Taiwan, the government provides the JYNNEOS vaccine, an attenuated vaccinia virus (Ankara strain) vaccine approved for the prevention of both smallpox and Mpox.

• Post-exposure prophylaxis(PEP):Recommended for close contacts within 4 days of their last high-risk exposure to an infected person, which can be extended up to 14 days if no symptoms have appeared.
• Pre-exposure prophylaxis(PrEP):Recommended for individuals at high risk of exposure, include laboratory personnel handling orthopoxviruses, individuals engaging in high-risk sexual behaviors (e.g., having multiple sexual partners, engaging in sex work, or having a history of STIs), and healthcare or cleaning staff caring for Mpox patients.

4. To provide comprehensive case management and implement proper infection control measures (standard, contact, and droplet precautions) in healthcare settings.

FAQs
1.How Mpox spreads?
You can get Mpox through close or intimate contact with an infected person's rashes, scabs, or body fluids, which includes oral, anal, or vaginal sex, kissing, and hugging. It can also be spread through prolonged face-to-face contact via respiratory droplets, by touching contaminated objects, or from an infected mother to her fetus during pregnancy. Additionally, it can be transmitted through direct contact with infected animals or consuming contaminated meat.

2.What is the treatment for Mpox?
Most Mpox cases are self-limiting, so treatment primarily relies on supportive care, to relieve symptoms and complications. However, antiviral drugs like Tecovirimat may be used for patients with severe disease, immunocompromised individuals, pregnant women, and children under one year old.

3.Can Mpox be cured?
Yes, most individuals recover completely within a few weeks (typically 2 to 4 weeks) with supportive care. However, severe complications—such as secondary bacterial infections, pneumonia, or sepsis—can occur, particularly in children and immunocompromised individuals. Anyone experiencing suspected symptoms should seek medical attention promptly.

4.Could I receive the "government-funded" Mpox Vaccine?
If you are a Taiwanese citizen or a foreign national with a National Health Insurance (NHI) card or R.O.C. (Taiwan) Resident Certificate, and you engage in risky sexual behavior (including possible risky sexual behavior with unknown people abroad), such as having multiple sexual partners (having sex with more than one person at different times), engaging in sex work, having sex at commercial venues, having a history of sexually transmitted diseases, or having a sexual partner with any of these risks, you are eligible to get the "government-funded" Mpox vaccine.

For information on medical facilities offering Mpox vaccination, please visit the Sites of Mpox Vaccine Service page under the Mpox Vaccination section of the Taiwan CDC website (https://gov.tw/3SG).

If you "do not meet" the above eligibility criteria for the government-funded Mpox vaccine but are assessed by a physician to be at risk of Mpox exposure, you can receive the self-paid Mpox vaccine. This also applies to foreign nationals in Taiwan with risk behaviors who do not have an NHI card or Resident Certificate as well as individuals planning to travel to countries at high risk of Mpox transmission (based on international travel health notices).

More Information

1. WHO - Mpox
2. Taiwan CDC - Mpox Disease Information