According to the passage, by the 1960s ----.

Europe faces "a serious risk of an uncontrollable
resurgence of malaria", warns the WHO in a new
report. Drainage, drugs and insecticides had
eradicated malaria from the whole of Europe by
the 1960s. Now civil disorder and irrigation
threaten to bring it back unless controls are
stepped up, the report says. It seems that more
European travellers are bringing malaria back
from countries where it is endemic, and the big
fear is that local mosquitoes could acquire the
parasite from such travellers and re-establish a
local chain of transmission. Three recent cases in
Luxembourg and two in New York have fuelled
concern over air travel as a means of
reintroduction. The cases in Luxembourg all
occurred within a few kilometres of the country's
international airport, and were probably caused by
mosquitoes stowing away on aircraft coming in
from the tropics.