Mpox, formerly known as monkeypox, is a viral disease that continues to pose a global health threat. Caused by the monkeypox virus, it’s crucial to understand what mpox is, how it spreads, and how to protect yourself and your community. This comprehensive guide provides key information about mpox, drawing from the latest scientific understanding and recommendations from global health organizations.
Mpox: Key Facts You Need to Know
Mpox is caused by the monkeypox virus, belonging to the Orthopoxvirus genus. This genus also includes viruses like variola (which causes smallpox) and vaccinia (used in the smallpox vaccine). There are two main clades of the monkeypox virus: clade I and clade II, each with further subclades. The global outbreak in 2022-2023 was primarily driven by the clade IIb strain.
Despite the global outbreak being declared over, mpox remains a concern. Recent surges in cases, particularly in the Democratic Republic of Congo and other regions, caused by clades Ia and Ib, highlight the ongoing threat.
Fortunately, vaccines are available for mpox, offering a critical tool for prevention alongside other public health measures.
The typical symptoms of mpox include a distinctive skin rash or lesions on mucosal surfaces, which can last for 2 to 4 weeks. These skin manifestations are often accompanied by systemic symptoms such as fever, headache, muscle aches, back pain, fatigue, and swollen lymph nodes.
Mpox is transmitted through various routes: close contact with an infected individual, contact with contaminated materials, or through infected animals. Vertical transmission, from a pregnant person to their fetus or newborn, is also possible.
Treatment for mpox primarily focuses on supportive care to alleviate symptoms like pain and fever. This includes ensuring adequate nutrition and hydration, maintaining skin care, preventing secondary bacterial infections, and managing any co-infections, such as HIV.
Overview of Mpox
Mpox is an infectious disease characterized by a range of symptoms, most notably a painful rash. Other common symptoms include enlarged lymph nodes, fever, headache, muscle aches, back pain, and a significant decrease in energy levels. While most individuals recover fully from mpox, some can experience severe illness.
The causative agent is the monkeypox virus (MPXV), a double-stranded DNA virus with an envelope. It belongs to the Orthopoxvirus genus within the Poxviridae family. As mentioned, the virus is classified into two main clades: clade I (subclades Ia and Ib) and clade II (subclades IIa and IIb).
The 2022 global outbreak was attributed to clade IIb. Ongoing outbreaks of clades Ia and Ib are also occurring, particularly in the Democratic Republic of Congo and other African nations. Clade Ib has also been detected outside of Africa as of August 2024, indicating the potential for wider spread.
The natural reservoir of the monkeypox virus remains unidentified. However, various small mammals, including squirrels and monkeys, are known to be susceptible to infection, suggesting their potential role in the virus’s ecology.
How Mpox Spreads: Understanding Transmission
Mpox primarily spreads through close person-to-person contact. This includes:
- Direct skin-to-skin contact: Touching, sexual contact.
- Mouth-to-mouth or mouth-to-skin contact: Kissing.
- Close face-to-face interaction: Talking or breathing in close proximity, potentially generating infectious respiratory particles.
Individuals with multiple sexual partners are considered to be at a higher risk of mpox infection due to increased potential for close contact with infected individuals.
Transmission can also occur indirectly through contaminated objects (fomites). This includes contact with contaminated clothing, bedding, or linens. Needle-stick injuries in healthcare settings or community environments like tattoo parlors also represent a potential transmission route.
Vertical transmission is another concern. The virus can pass from a pregnant person to the fetus during pregnancy or to the newborn during or after birth. Mpox infection during pregnancy can lead to serious complications, including pregnancy loss, stillbirth, newborn death, or health issues for the parent.
Animal-to-human transmission is possible through bites or scratches from infected animals. It can also occur during activities like hunting, skinning animals, trapping, cooking, handling carcasses, or consuming infected animals. The specific animal reservoir of the monkeypox virus is still under investigation.
Further research is essential to fully understand mpox transmission dynamics in various settings and conditions, particularly during outbreaks.
Signs and Symptoms of Mpox
Mpox symptoms typically appear within one week of exposure, but the incubation period can range from 1 to 21 days. Symptoms generally last for 2 to 4 weeks, although they may persist longer in individuals with weakened immune systems.
Common mpox symptoms include:
- Rash: The hallmark symptom of mpox.
- Fever
- Sore throat
- Headache
- Muscle aches
- Back pain
- Low energy (fatigue)
- Swollen lymph nodes (lymphadenopathy)
For some individuals, the rash may be the first symptom, while others may initially experience fever, muscle aches, or sore throat.
The mpox rash often starts on the face and then spreads to other parts of the body, including the palms of the hands and soles of the feet. It can also appear in areas of initial contact, such as the genitals. The rash progresses through distinct stages: from flat spots (macules) to raised bumps (papules), then to fluid-filled blisters (vesicles and pustules), which may be itchy or painful. As the rash heals, the lesions dry up, form crusts, and eventually fall off.
The number of lesions can vary significantly, from a single lesion to hundreds across the body. Lesions can appear on:
- Palms of hands and soles of feet
- Face, mouth, and throat
- Groin and genital areas
- Anus
Some individuals may also experience painful rectal swelling (proctitis), pain or difficulty urinating (dysuria), or pain when swallowing.
Individuals with mpox are contagious until all lesions have healed and a new layer of skin has formed. Asymptomatic infection (infection without symptoms) has been reported, but the frequency and transmissibility of asymptomatic cases are still being investigated.
Certain populations are at higher risk for severe mpox illness and complications, including children, pregnant individuals, and people with weakened immune systems, such as those with uncontrolled HIV.
Severe complications of mpox can include bacterial skin infections leading to abscesses or extensive skin damage, pneumonia, corneal infection with vision loss, swallowing difficulties, vomiting and diarrhea causing dehydration and malnutrition, and infections of the blood (sepsis), brain (encephalitis), heart (myocarditis), rectum (proctitis), genital organs (balanitis), or urinary passages (urethritis). In some cases, mpox can be fatal.
Diagnosis of Mpox
Diagnosing mpox can be challenging as its symptoms can resemble those of other infections and conditions. It is crucial to differentiate mpox from chickenpox, measles, bacterial skin infections, scabies, herpes, syphilis, other sexually transmitted infections, and medication-related allergies. Co-infections are also possible; for instance, an individual with mpox may also have syphilis or herpes, or a child with suspected mpox might actually have chickenpox. Therefore, laboratory testing is essential for accurate diagnosis, prompt care, prevention of severe illness, and control of further spread.
The primary laboratory test for mpox is polymerase chain reaction (PCR) to detect viral DNA. The preferred specimens for testing are samples taken directly from the rash, including skin, lesion fluid, or crusts, collected through vigorous swabbing. In the absence of skin lesions, throat or anal swabs can be used. Blood testing is not recommended for routine diagnosis. Antibody detection tests are generally not helpful as they cannot distinguish between different orthopoxviruses.
HIV testing is recommended for adults diagnosed with mpox and for children as appropriate. Testing for other conditions, such as varicella-zoster virus (VZV), syphilis, and herpes, should also be considered to rule out or confirm co-infections or alternative diagnoses.
Mpox Treatment and Vaccination
The primary goals of mpox treatment are to manage the rash, control pain, and prevent complications. Early and supportive care is vital for managing symptoms and minimizing potential problems.
Vaccination is a key preventive measure against mpox. Pre-exposure prophylaxis (PrEP) vaccination is recommended for individuals at high risk of mpox exposure, especially during outbreaks.
Groups considered at high risk for mpox include:
- Healthcare and laboratory workers at risk of occupational exposure.
- Household contacts and close community contacts of individuals with mpox, including children.
- Individuals with multiple sexual partners, including men who have sex with men.
- Sex workers of any gender and their clients.
Vaccination can also be administered post-exposure prophylaxis (PEP) to individuals who have had contact with someone with mpox. For PEP to be most effective, the vaccine should be given within 4 days of exposure. Vaccination up to 14 days post-exposure may still offer benefit if the person has not yet developed symptoms.
While some antiviral medications have received emergency use authorization in certain countries and are being evaluated in clinical trials, there is currently no proven, universally effective antiviral treatment specifically for mpox. Ongoing research and clinical trials are crucial to identify and evaluate potential therapeutic options. Optimizing supportive care remains a primary focus of mpox management.
Individuals with both HIV and mpox should continue their antiretroviral therapy (ART). For those newly diagnosed with HIV, ART initiation within 7 days of HIV diagnosis is recommended.
Self-Care and Prevention Strategies for Mpox
Most people with mpox recover fully within 2 to 4 weeks. To manage symptoms and prevent mpox transmission to others, consider the following recommendations:
Do:
- Seek medical advice: Contact your healthcare provider for guidance and care.
- Isolate at home: Stay home in a well-ventilated room if possible to minimize contact with others.
- Practice hand hygiene: Wash hands frequently with soap and water or use hand sanitizer, especially after touching sores.
- Respiratory etiquette and lesion covering: Wear a mask and cover lesions when around other people until the rash has completely healed.
- Promote skin dryness and air exposure: Keep skin dry and uncovered unless you are in a shared room with someone else.
- Disinfect shared spaces: Avoid touching items in shared areas and disinfect shared surfaces frequently.
- Oral hygiene: Use saltwater rinses for mouth sores to provide relief.
- Soothe body sores: Take warm baths with baking soda or Epsom salts to alleviate discomfort from body sores.
- Pain management: Use over-the-counter pain relievers like acetaminophen (paracetamol) or ibuprofen for pain relief.
Do Not:
- Pop blisters or scratch sores: This can slow healing, spread the rash, and increase the risk of secondary bacterial infections.
- Shave areas with sores: Avoid shaving areas with sores until scabs have healed and new skin has formed, as shaving can spread the rash.
To prevent the spread of mpox to others, individuals with mpox should isolate at home, following healthcare provider recommendations, or in a hospital if necessary, for the entire infectious period. This period extends from the onset of symptoms until all lesions have healed, and scabs have fallen off. Covering lesions and wearing a well-fitting mask when in the presence of others can significantly reduce transmission.
While condoms during sexual activity can reduce the risk of mpox transmission, they do not completely prevent spread from skin-to-skin or mouth-to-skin contact. As a precaution, consider using condoms for 12 weeks (approximately 3 months) after recovering from mpox if you are sexually active.
Temporarily reducing sexual activity with new partners during periods of increased mpox transmission can lower the risk of infection. Individuals who have had contact with someone with mpox should monitor themselves for signs and symptoms for 21 days (3 weeks) and take preventive measures, including avoiding sexual activity during this period.
Healthcare workers should strictly adhere to infection prevention and control measures when caring for patients with mpox. This includes using appropriate personal protective equipment (PPE) such as gloves, gowns, eye protection, and respirators, and following established protocols for safely swabbing lesions for diagnostic testing and handling sharps like needles.
Mpox Outbreaks: A History and Current Situation
The monkeypox virus was first discovered in 1958 in monkeys kept for research in Denmark. The first human case of mpox was reported in 1970 in a nine-month-old boy in the Democratic Republic of the Congo. Following the global eradication of smallpox in 1980 and the cessation of routine smallpox vaccination, mpox gradually emerged as a public health concern in central, east, and west Africa. Since then, sporadic cases have been reported in central and east Africa (clade I) and west Africa (clade II). In 2003, an outbreak in the United States was linked to imported wild animals (clade II). Since 2005, the Democratic Republic of Congo has reported thousands of cases annually. In 2017, mpox re-emerged in Nigeria and has continued to spread both within the country and internationally through travelers.
Data on suspected and confirmed cases reported up to 2021 are available here, and data on laboratory-confirmed cases from 2022 to the present are available here.
In May 2022, a significant mpox outbreak emerged and rapidly spread across Europe, the Americas, and all six WHO regions. This global outbreak disproportionately affected gay, bisexual, and other men who have sex with men, spreading primarily through sexual networks. More information on the 2022 global outbreak is available here, including resources on community responses to control the outbreak here.
In 2022, clade I mpox outbreaks occurred in refugee camps in the Republic of Sudan.
Since 2022, the Democratic Republic of Congo has experienced a surge in mpox cases and deaths. A new offshoot of clade I, called clade Ib, has been spreading person-to-person in some areas of the country. As of mid-2024, clade Ib has also been reported in other countries.
Between January 2022 and August 2024, over 120 countries have reported mpox, with over 100,000 laboratory-confirmed cases and over 220 deaths among confirmed cases globally.
Addressing Stigma and Discrimination Related to Mpox
Stigma and discrimination associated with any disease are unacceptable and harmful. Stigma related to mpox can undermine public health efforts and prolong outbreaks by discouraging individuals from seeking testing, care, and treatment. Unfortunately, stigma, discrimination, and racism related to mpox have disproportionately affected communities initially most impacted by the disease, particularly men who have sex with men, transgender people, and gender-diverse communities. It is crucial to combat stigma through accurate information and compassionate communication.
WHO’s Response to Mpox
The World Health Organization (WHO) is actively working with member states and partners to prevent and respond to mpox outbreaks globally. This includes coordinating research on mpox vaccines and treatments, strengthening healthcare systems in affected countries, and promoting equitable access to vaccines, therapeutics, diagnostics, and other essential tools.
The WHO Director-General, Dr. Tedros Adhanom Ghebreyesus, has declared mpox a Public Health Emergency of International Concern (PHEIC) twice: first in May 2022 and again in August 2024, underscoring the ongoing global health significance of mpox.
