The global outbreak of mpox (formerly known as monkeypox) has emerged as a significant public health challenge. The World Health Organization (WHO) Director-General, Dr. Tedros Adhanom Ghebreyesus, declared mpox a “public health emergency of international concern” (PHEIC) twice, first in May 2022 and again in August 2024. As this viral disease continues to spread, understanding its implications, particularly concerning ocular health, is crucial. This article provides a comprehensive overview of mpox, its ocular manifestations, and what eye care professionals and high-risk groups need to know to effectively manage and prevent its spread.
Understanding mpox and High-Risk Groups
Mpox is a viral zoonosis caused by the mpox virus (MPXV), a double-stranded DNA virus of the orthopoxvirus genus. While its natural host remains unknown, various animals can contract the virus. Historically confined to parts of Central and Western Africa, the 2022 outbreak saw cases emerge globally, prompting the WHO to declare it a “public health emergency of international concern.” As the virus continues to spread, it is important to understand its potential impact on various aspects of health, including ocular health, and to identify who is most at risk.
Historical Timeline of mpox
– 1958: Mpox virus first discovered in research monkeys in Denmark.
– 1970: First reported human case in a 9-month-old boy in the Democratic Republic of the Congo (DRC).
– 1980: Eradication of Smallpox and cessation of global Smallpox vaccination.
– 1980s-1990s: Gradual emergence of mpox in central, east, and west Africa.
– 2003: Outbreak in the United States linked to imported wild animals (Clade II).
– 2005-present: Thousands of cases reported annually in the DRC.
– 2017: Re-emergence of mpox in Nigeria, leading to ongoing local transmission and international travel-related cases.
– 2022: Global outbreak, primarily affecting non-endemic countries.
High-Risk Groups for Mpox Transmission
- Men who have sex with men (MSM): Currently the most affected group in the 2022 and 2024 outbreaks, with close skin-to-skin contact during sexual activity being a primary transmission route. Unfortunately, there may be stigma and discrimination against infected individuals because of this.
- Healthcare workers: Especially those in direct contact with mpox patients or handling potentially contaminated materials, including doctors, nurses, laboratory technicians, and cleaning staff in healthcare settings.
- Veterinarians and animal handlers: Those working with animals that may carry the virus, particularly in endemic regions of Africa.
- Close contacts of infected individuals: Family members, roommates, or others in close physical proximity to someone with Mpox.
- Immunocompromised individuals: People with weakened immune systems due to conditions like HIV/AIDS, cancer, or certain medications that cause immune dysfunction. They are at higher risk of severe disease if infected, and deaths have occurred in this group.
- Pregnant women and young children: May be at higher risk of severe disease, though data is limited.
- Individuals who have traveled to endemic areas: Those who have recently been to regions where Mpox is common, particularly parts of Central and West Africa.
- Laboratory workers: Those handling mpox samples or conducting research on the virus.
Prevention strategies should focus on these high-risk groups, including targeted vaccination campaigns, enhanced surveillance, and directed public health messaging. The virus is classified into two distinct genetic “clades”: Clade I (formerly known as the Congo Basin clade) and Clade II (formerly the West African clade). The current global outbreak is primarily associated with Clade II, which is generally considered less severe than Clade I.
Mpox typically presents with fever, intense headache, muscle aches, and a characteristic rash that progresses from macules to papules, vesicles, pustules, and finally scabs. While mpox is generally self-limiting, it can lead to severe complications, particularly in immunocompromised individuals and children.
Ocular Manifestations of Mpox
As mpox continues to spread, it’s becoming increasingly clear that the virus can affect various parts of the body, including the eyes. Understanding these ocular manifestations is important for early detection, proper management, and prevention of vision-threatening complications. Approximately 20-30% of infected individuals will manifest ocular signs and symptoms. Here are the key ocular symptoms associated with mpox:
- Periorbital and Orbital Rash: The most common ocular symptom of mpox is the characteristic rash around the eyes. This can manifest as small, raised bumps or fluid-filled blisters in the periorbital (around the eye) and orbital areas. In some cases, up to 25% of patients with mpox may develop these rashes in the ocular region.
- Eyelid Involvement: MPXV can affect the eyelids, causing swelling, redness, and the formation of small vesicles or pustules on the eyelid margins. This can be uncomfortable and may interfere with normal eyelid function.
- Conjunctivitis: Inflammation of the conjunctiva (the clear membrane covering the white part of the eye and inner surface of the eyelid) is a common ocular manifestation of mpox. Conjunctivitis due to MPXV infection can present in various forms, including conjunctival ulcers, disseminated blistering or papular conjunctival lesions, conjunctival follicular reactions, and pseudomembranous or subconjunctival nodules. Some studies have reported that up to 23% of mpox patients may develop conjunctivitis. Interestingly, patients with conjunctivitis often report more frequent systemic symptoms such as nausea, chills, sweats, mouth ulcers, sore throats, fatigue, and lymphadenopathy.
- Keratitis and Corneal Ulceration: While less common, corneal involvement is arguably the most severe ocular complication of mpox. Keratitis (inflammation of the cornea) and corneal ulceration can lead to permanent vision loss and corneal scarring if not promptly treated. Studies have reported corneal infections in about 3-7% of mpox cases. The severity can range from mild corneal pitting to severe ulceration and potential blindness.
- Other Potential Ocular Complications: While not yet reported in mpox cases, eye care professionals should be aware that other poxviruses have been associated with conditions such as retinitis, chorioretinitis, optic neuritis, and extraocular muscle palsy. These potential complications underscore the importance of comprehensive eye examinations in mpox patients.
Diagnosis and Detection of MPXV in Ocular Secretions
Accurate diagnosis of mpox, especially in cases with ocular involvement, is vital for proper management and prevention of transmission. The gold standard for confirming MPXV infection is polymerase chain reaction (PCR) testing of various specimens, including those from ocular sources. For patients presenting with eye symptoms, ophthalmologists can collect conjunctival swabs or samples of eyelid lesion fluid for PCR testing. This method allows for precise analysis of even small amounts of ocular samples.
Importantly, studies have shown that MPXV can be detected in conjunctival swabs and even isolated in cell culture, indicating the potential for ocular transmission of the virus. One case report described a patient whose viral load in conjunctival and ocular secretions was similar to that in cutaneous lesions. This finding highlights the importance of appropriate personal protective measures for healthcare workers during ophthalmic examinations of suspected or confirmed mpox cases.
Treatment Approaches for Mpox Eye Infections
Currently, there is no standard treatment specifically approved for mpox. Most cases are mild and self-limiting, with management focusing on supportive care and symptom relief. However, for severe cases or in immunocompromised patients, several antiviral treatments, originally developed for Smallpox, may be considered:
- Tecovirimat (Tpoxx): This antiviral drug, developed for smallpox treatment, has shown effectiveness against various orthopoxviruses, including MPXV. It is licensed for use in mpox, smallpox and cowpox by the European Medicines Agency. However, recent evidence on its effectiveness has been ambiguous and the FDA has not yet approved it for treatment of patients. Infected patients may still be able to access it through the STOMP trial.
- Cidofovir and Brincidofovir: These antivirals have shown promise in animal studies and may be considered for severe cases.
- Vaccinia Immune Globulin (VIG): This antibody preparation may be used in certain cases, although it’s contraindicated for isolated vaccinia keratitis.
For ocular symptoms, treatment approaches may include:
– Lubricating eye drops to prevent corneal dryness and promote healing.
– Antibiotic eye drops to prevent secondary bacterial infections (if indicated).
– Careful monitoring of corneal health to detect and manage any ulceration early.
– Topical trifluoridine has been used anecdotally but its efficacy has not been established.
It is important to note that the use of steroid eye drops in mpox patients with ocular involvement is controversial. Some reports suggest that steroids may prolong viral shedding and potentially worsen outcomes. Therefore, their use should be carefully considered and monitored by an eye care professional.
Vaccination and Its Impact on Ocular Mpox
While there’s no specific vaccine for mpox, smallpox vaccines have shown cross-protection against MPXV infection. Two vaccines are currently available for mpox prevention:
- JYNNEOS (also known as MVA-BN, Imvamune, or Imvanex): This is a third generation, modified, attenuated vaccine that has been licensed in the US, Europe, and Canada. It is considered the primary vaccine for Mpox prevention in the current outbreak.
- ACAM2000: This is an older smallpox vaccine that may provide some protection against Mpox but carries a higher risk of side effects.
Vaccination appears to be effective in reducing the risk of ocular complications from mpox. One study found that only 7% of smallpox-vaccinated individuals developed conjunctivitis and blepharitis from mpox, compared to 30% of unvaccinated individuals. Vaccine strains can occasionally cause unintended infections, including ocular complications. Healthcare workers, especially those at high risk of exposure to MPXV, are recommended to consider vaccination.
Preventing Nosocomial Infections in Eye Care Settings
Given the potential for MPXV transmission through close contact and through ocular secretions such as tear fluid, implementing strict infection control measures in eye care settings is important. Here are some key recommendations from the Centers for Disease Control (CDC):
For Patients:
– Practice regular hand hygiene.
– Avoid touching or rubbing eyes, especially if skin lesions are present.
– Discontinue contact lens use during active infection.
For Eye Care Professionals:
– Use appropriate personal protective equipment (PPE), including respiratory protection, when examining suspected or confirmed mpox cases.
– Thoroughly disinfect all reusable ophthalmic equipment (e.g., slit lamps, ophthalmic lenses) according to local infection control guidelines.
– Consider vaccination if at high risk of exposure to MPXV.
For Healthcare Facilities:
– Implement screening protocols to identify potential Mpox cases before they enter the general waiting area.
– Ensure proper isolation procedures for suspected or confirmed cases.
– Provide training to staff on Mpox recognition, PPE use, and infection control measures.
Special Considerations for High-Risk Groups
Each high-risk group requires specific precautions and considerations. For example:
– MSM should be aware of symptoms and consider temporary changes in sexual practices during outbreaks, including the use of condoms. Participate in vaccination programs if eligible.
– Healthcare workers should strictly adhere to infection control protocols, use appropriate PPE, especially when examining patients’ eyes, and consider pre-exposure vaccination.
– Immunocompromised individuals should be extra vigilant about symptoms and seek medical attention early. Discuss preventive strategies with healthcare providers and consider vaccination, weighing potential benefits and risks.
– Pregnant women and young children should exercise caution and avoid close contact with suspected or confirmed cases. Consult healthcare providers about risk mitigation strategies.
– Travelers to endemic areas should be aware of the risk and take preventive measures. Consider vaccination before travel if recommended.
Conclusion
The current mpox outbreak serves as a reminder of the ever-present threat of emerging infectious diseases and their potential impact on various aspects of health, including ocular health.
As eye care professionals and members of the public, staying informed and vigilant is crucial in effectively managing and preventing the spread of mpox. Ongoing research and collaboration between healthcare specialties will be vital in developing more effective prevention, diagnosis, and treatment strategies.
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