Four people are reported dead and over 100 others have been infected with Legionnaires’ disease in Portugal.

Victims in the Lisbon area include a 66-year-old man and an 81-year-old woman, both of whom were already seriously ill.

Caused by the legionella bacteria, the lung infection cannot be spread directly from person to person but is caught by breathing in small droplets of contaminated water via, for example, air conditioning systems.

The origin of this outbreak is unknown.