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

Table 1 H5N8 HPAI 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 equivalents^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	10^6.0	22.9	0.12	6/6	10^6.1	22.4	0.48	6/6	0.0556
Medium	10^3.9	30.3	0.29	6/6	10^4.2	29.4	0.66	6/6	0.0293^*
Low	10^2.2	36.5	0.25	6/6	10^2.8	34.3	0.46	6/6	0.0006^*

Ct cycle threshold, SD Standard deviation
^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 Dose ₅₀ equivalents as determined by RT-rtPCR
^*Statistically significant

ISSN: 1746-6148