Effects of swab pool size and transport medium on the detection and isolation of avian influenza viruses in ostriches

Table 2 H7N1 LPAI virus detected by RT-rtPCR in 5 vs. 10 swabs/ pool stored in VTM^a

Spiking dose	5 swabs/ pool				10 swabs/ pool				P (p ≤ 0.05)
Spiking dose	Mean virus titre in EID₅₀ equivalentsViral Transport Medium- brain-heart infusion ^b/ ml	Mean Ct value	SD	Positives	Mean virus titre in EID₅₀ equivalents^b/ ml	Mean Ct value	SD	Positives	P (p ≤ 0.05)
High	10^5.1	24.2	0.24	6/6	10^5.5	23.1	0.29	6/6	0.0011^*
Medium	10^2.9	31.4	0.84	6/6	10^3.1	30.8	1.28	6/6	0.3899
Low	10^1.3	36.7	0.57	6/6	10^1.4	36.3	0.43	6/6	0.2228

SD Standard deviation, Ct Cycle threshold
^aViral Transport Medium- brain-heart infusion broth (pH 7.2), 10% (v/v) glycerol and antimicrobials per litre: 100 mg doxycycline, 100 mg enrofloxacin, 1000 mg penicillin-streptomycin, 5 mg Amphotericin B
^bEgg Infectious Dose₅₀ equivalents as determined by RT-rtPCR
^*Statistically significant

ISSN: 1746-6148