Table 2. TBEV-specific RT-qPCR and estimated virus prevalence, Northern Zealand, Denmark, 2019.

Sample site	Sampling date (2019)	Tick stage	Number of ticks	Number of pools	Pool size (Number of ticks)	TBEV RT-qPCR	RT-qPCR (ct)	Estimated prevalence (%) (CI 95%)
1	19 September	Nymphs	124	3	40, 41, 43	0/3	No ct	All negative
		Adults	26	2	18a, 8b	0/2	No ct
2	19 September	Nymphs	91	2	45, 46	0/2	No ct	All negative
		Adults	15	2	4a, 11b	0/2	No ct
3	26 September	Nymphs	216	5	40, 41, 44, 45, 46	3/5	17, 20, 35	2.0 (1.0–6.0)
		Adults	33	2	18a, 15b	0/2	No ct
4	26 September	Nymphs	23	1	23	0/1	No ct	All negative
		Adults	2	1	1a	0/1	No ct
5	26 September	Nymphs	172	4	41, 41, 43, 47	1/4	35	1.0 (0.0–29.0)
		Adults	23	2	11a, 12b	0/2	No ct
3A	4 October	Nymphs	112	11	10c, 12	4/11	16, 16, 31, 34	4.0 (1.0–10.0)
		Adults	4	2	1a, 3b	0/2	No ct
3B	4 October	Nymphs	192	19	10c, 12	2/19	34, 39	1.0 (0.0–3.0)
		Adults	15	3	4a, 5b, 6b	0/3	No ct
4A	4 October	Nymphs	44	5	10c, 4	5/5	15, 18, 31, 32, 35	All positive
		Adults	1	1	1a	0/1	No ct
3A and 4A jointly	4 October	Nymphs	156	16	10c, 12, 4	9/16	NA	8.0 (4.0–14.0)

CI: confidence interval; ct: cycle threshold; NA: not applicable; TBEV: tick-borne encephalitis virus.

^a Adult female ticks.

^b Adult male ticks.

^c All pools contained 10 nymphs unless otherwise indicated.