Mpox (monkeypox)

Strains

• Clade I (Central African) — more severe
• Clade Ia
• Clade Ib (2024 DRC outbreak)
• Clade II (West African)
• Clade IIa
• Clade IIb (2022-2024 global outbreak)

Transmission

• Direct contact with skin lesions, rash, scabs, or body fluids of an infected person
• Prolonged close physical contact, including sexual contact
• Contact with infected animals (zoonotic — rodents, non-human primates)
• Contact with contaminated materials such as bedding or clothing
• Respiratory droplets during prolonged face-to-face contact (less common)

Treatment

Tecovirimat (TPOXX/ST-246) is approved for orthopoxvirus infections including mpox; brincidofovir and cidofovir are used in severe cases. Most clade II cases are self-limiting and resolve in 2-4 weeks with supportive care (pain management, wound care, hydration).

Vaccine status

JYNNEOS (MVA-BN, Imvamune/Imvanex) is approved for both mpox and smallpox; ACAM2000 is also protective but carries more side-effect risk. Recommended as a 2-dose series for at-risk groups. Pre-1980 smallpox vaccination conferred ~85% cross-protection, now waned.

Endemic regions

• Democratic Republic of the Congo — clade I, recurrent outbreaks (2024 clade Ib PHEIC)
• Central Africa (Congo Basin) — clade I reservoir
• West Africa (Nigeria and neighbours) — clade II reservoir
• Global (2022-2024) — clade IIb spread to 100+ countries, twice declared a PHEIC by WHO