Table 1.

Description of the training and testing data

Bacterial	Cutting	# of viruses	# of viruses	# of
genus	year	before	after the	non-infectious
		cutting year	cutting year	viruses
Bacillus	2012	31	31	1364
Escherichia	2012	141	32	1253
Lactococcus	2013	49	6	1371
Mycobacterium	2013	172	46	1208
Pseudomonas	2013	68	28	1330
Salmonella	2012	32	22	1372
Staphylococcus	2012	43	20	1363
Synechococcus	2012	30	17	1379
Vibrio	2012	39	29	1358

For a specific year, the positive training data set contains viruses infecting the corresponding host identified before the specific year and the positive testing data set contains viruses infecting the corresponding host discovered after the specific year. The negative training data and the negative testing data were chosen randomly without overlaps from the viruses that were not identified to infect the host