LONDON — British officials say a health worker involved in treating a patient with monkeypox has been infected with the rare disease, suggesting possible lapses in the hospital's infection control procedures.

Earlier this month, Public Health England reported two unconnected cases of monkeypox in people who were recently in Nigeria. The disease is related to smallpox and is mostly seen in Africa.

In a statement Wednesday, Public Health England said the latest case was in a health worker in Blackpool who cared for the patient before the monkeypox diagnosis was made. The agency said officials are now tracing possible contacts.

Monkeypox is mostly spread to people from animals — including rats and monkeys — and causes a rash and lesions similar to smallpox. It can spread among people via droplets or close contact.