Sequential dengue virus infections detected in active and passive surveillance programs in Thailand, 1994–2010

BMC Public Health

Table 4 Time interval between sequential dengue virus infections by clinical category at infection one and two

		Interval between infections (yrs)
Clinical category^a		All data (n = 502)				Cohort extended dataset^c(n = 195)
Infection one	Infection two	N	Mean	Min	Max	N	Mean	Min	Max
Any	Any	502	3.45	0.18	12.57	195	1.85	.27	4.96
Subclinical^b	Subclinical^b	45	1.74	0.78	3.25	45	1.74	0.78	3.25
Subclinical^b	Symptomatic	26	3.03	0.65	12.26	21	1.84	0.65	4.22
Symptomatic	Subclinical^b	23	2.15	0.77	4.96	23	2.15	0.77	4.96
Symptomatic	Symptomatic	323	4.27	0.18	12.57	21	2.35	0.27	4.28

^aClinical category at infection one and two.
^bSubclinical infections were only captured from cohort studies. Symptomatic infections include all symptomatic infections from Bangkok and Kamphaeng Phet. 56 infection one’s and 42 infection two’s were unable to be clinically categorized as symptomatic or subclinical due to occurrence out of the active study surveillance period and not seeking hospital care (listed as ‘Any’ in the table).
^cOnly infections in cohort subjects were included in this subgroup; includes infections detected from non-study hospital-basedpassive surveillance within five years after infection one.

ISSN: 1471-2458