Preliminary tests identified the source of the outbreak as the highly contagious norovirus, which had struck several guests just before they boarded the cruise Nov. 3 in Rome, Carnival officials said.
The outbreak could have been avoided if people washed their hands more.
( z1 possible :ARG1 ( z2 avoid :ARG1 ( z3 outbreak ) :condition ( z4 wash :ARG0 ( z5 person ) :ARG1 ( z6 hand :part-of z5 ) :ARG1-of ( z7 have-quant :ARG3 ( z8 more ) ) ) ) )