The Portuguese newspapers have been screaming about this for weeks, the huge outbreak of Marburg Virus in Angola:

LUANDA, Angola, April 8 – The death toll in Angola from an epidemic
caused by an Ebola-like virus rose to 174 Friday as aid workers in one
northern provincial town reported that terrified people had attacked
them and that a number of health workers had fled out of fear of
catching the disease.
International health officials said the epidemic, already the largest
outbreak of Marburg virus ever recorded, showed no signs of abating.
Seven of Angola’s 18 provinces have now reported suspected cases and
several neighboring countries have announced health alerts.

It isn’t just some vague interest in an ex-colony that’s driving the concern….what’s the main contact between Angola and Europe? Yup, Lisbon Airport. Lots of Angolans going back and forth through the city all the time. Not a happy thought really.