2023-03-15-世界卫生组织-Multi-country_outbreak_of_mpox,_External_situation_report_18_-_16_March_2023_22页_1mb

Summary of the Multi-country Outbreak of Mpox

Core Content

The document presents an updated situation report on the global mpox outbreak as of 13 March 2023, highlighting the epidemiological trends, clinical characteristics, and management strategies for severe mpox cases.

Global Overview

• Total Confirmed Cases: 86,496
• Total Deaths: 111
• Countries Affected: 110
• Global Risk Assessment: Moderate

The number of mpox cases has been slowly declining globally, with the Americas reporting the highest number of cases. Transmission and reporting are more continuous in the African region, where there is no clear downward trend. Other regions report sporadic cases and small clusters.

Key Epidemiological Findings

• Case Distribution:
  • 96.4% of cases are men, with a median age of 34 years.
  • 1.1% of cases are children aged 0-17 years, with the majority of pediatric cases in the Americas.
• Transmission Patterns:
  • 82.1% of cases with reported sexual orientation are among gay, bisexual, and other men who have sex with men (MSM).
  • Skin and mucosal contact during sex is the most common mode of transmission (68.9% of all reported transmission events).
  • Party settings with sexual contact are the most common exposure setting (68.2% of all reported exposure settings).
  • In recent months, there has been an increase in household transmission (from ~10% to ~22%).

Mpox Deaths

• Total Deaths: 111
• Case Fatality Ratio (CFR): 0.13%
• Demographics:
  • All deaths with available information occurred among adult males.
  • Most of these males were immunocompromised, primarily due to untreated or uncontrolled HIV infection or other immunocompromising conditions.
  • 72% of deaths were among immunocompromised individuals.
• Geographic Distribution:
  • 10 deaths were reported in the Americas (5 from Peru, 4 from the USA, 1 from Costa Rica).
  • 1 death was reported in the European Region (Belgium).

Clinical Characteristics of Mpox

• Symptoms:
  • Rash is the most common symptom (83.3% of cases).
  • Fever (59.5%), generalized or genital rash (54.2% and 47.1% respectively) are also common.
  • The rash typically appears in sequential stages and may involve the face, palms, soles, and mucous membranes.
• Special Populations:
  • MSM: Majority of cases are among MSM, with severe disease often involving genital or perianal lesions.
  • HIV-positive Individuals: Co-infection with HIV is associated with more severe disease, higher rash burden, and more frequent perianal lesions.
  • Pregnant Individuals: No severe disease or worse outcomes have been reported in pregnant individuals compared to non-pregnant individuals.
  • Children: A small proportion (0.3%) of cases in the US involved children and adolescents, with no critical illness or death reported.

Complications of Mpox

• Common Complications:
  • Severe pain, bacterial superinfections, pneumonia, corneal infections, vomiting, diarrhea, sepsis, encephalitis, and myocarditis.
• Newly Described Complications:
  • Mucosal ulceration, proctitis, colitis, urethritis, and balanitis.
• Long-term Morbidity:
  • Persistent pain, scarring, and mental health issues (e.g., anxiety, depression) are reported in some patients.

Management of Severe Mpox

• Supportive Care:
  • WHO recommends analgesia, skin care, and adequate nutrition.
  • High-quality care for critical illness is essential, including oxygen and ventilation for respiratory issues.
• Therapeutics:
  • Tecovirimat: Under evaluation in several randomized controlled trials (RCTs).
  • It is licensed for use under exceptional circumstances in the EU and USA.
  • Typically well-tolerated and recommended for severe disease by the CDC.
• Passive Immunotherapy:
  • Vaccinia immune globulin intravenous (VIGIV) is considered for ocular infections, though more data are needed for broader recommendations.
• HIV Coinfection:
  • Immune reconstitution is crucial for optimal outcomes in HIV-positive patients.
  • The role of antiretroviral therapy (ART) in clearing MPXV is unclear and requires further study.

Ongoing Research and Trials

• Tecovirimat Trials:
  • ACTG-5418 / STOMP: RCT (2:1) in Brazil, Mexico, South Africa, US, and Puerto Rico (target enrollment: 530, status: open).
  • PALM-007: RCT in DRC (target enrollment: 450, status: open).
  • NCT05534165/PLATINUM+CAN: Canadian feasibility study (target enrollment: 120, status: open).
  • NCT05597735/UNITY: RCT in Brazil and Switzerland (target enrollment: 1,152, status: open).
  • PLATINUM: RCT in the UK and selected European sites (target enrollment: 500, status: open).

Conclusion

The global mpox outbreak, primarily driven by Clade IIb, continues to show a decline in case numbers, though sustained transmission is still observed in the African region. The majority of cases and deaths are among men, particularly MSM and immunocompromised individuals. Severe disease is often associated with complications such as mucosal and ocular involvement, neurological issues, and myocarditis. Supportive care and the use of tecovirimat are currently recommended for severe cases, with ongoing trials aiming to confirm its efficacy. Special attention is required for managing complications, especially in immunocompromised and vulnerable populations.