Small outbreaks of monkeypox, a disease rarely seen outside Africa, have now been reported in four Western countries, with a cluster in England predominantly affecting men who have sex with men, health authorities say. 

UK health officials are now advising individuals — particularly those who are gay, bisexual or men who have sex with men (MSM) — to be alert to any unusual rashes or lesions on any part of their body, especially genitalia.

The virus, which is similar to smallpox but usually with milder symptoms, is usually confined to West and Central Africa apart from the odd imported case in travellers.  

Illness usually lasts between two and four weeks, with patients typically developing flu-like symptoms, such as fever, body aches and chills, and a distinctive rash that can lead to formation of vesicles.