Utility of the first few100 approach during the 2009 influenza A(H1N1) pandemic in the Netherlands

Table 1 Study schedule of the case–control study in the period before and after the change of notification criteria for influenza A(H1N1) 2009 virus infection at the 15 ^th of August 2009, the Netherlands

		Day 0	Day 5 range [4-6]	Day 10 range [9-11]	Day 30 range [28–35]
Up to 15 August 2009		visit1	visit2	visit3	visit4
case patients	nose- and throat swab^*		X	X
case patients	venipuncture	X^{^}		X	X
control subjects	nose- and throat swab	X
control subjects	venipuncture	X		X	X
From 15 August 2009		GP visit	visit1	visit2	visit3
case patients	nose- and throat swab	X^{^}	X	X
case patients	venipuncture	X^{^ #}	X	X	X
control subjects	nose- and throat swab		X
control subjects	venipuncture		X	X	X

^* The diagnostic nose- and throat swab on which the patients were included in the study was taken by the physician of the municipal health service and is not entered in the schedule.
^ For hospitalised cases the first visits, until the moment of discharge, were scheduled in hospital.
^# The GP took a finger prick instead of a venipuncture.

ISSN: 2047-2994