Table 2.

Overview of categories into which included studies were divided.

Type of study		Articles		Further detail
Systematic reviews		n=6		Table 3
Primary studies (N=61)
	Close- or household-contact investigations	n=34 (56%)	Multimedia Appendix 3 and Table 4
	Outbreak investigations	n=17 (28%)	Table 5
	Airline contact investigations	n=3 (5%)
	Epidemiological analyses	n=5 (8%)
	Public-private partnership program	n=1 (2%)
	E-registry program	n=1 (2%)