Table 3.

Infection of ferrets with H7 influenza viruses

Observation	Result for the following virus:
	MX/7218	gs/NE/11
Days 1–14 p.i.
Weight lossa	7.8 (9–10)	NDf
Feverb	2.9 (7)	ND
Virus in rectal swabc	2/3	0/3
Virus titer at day 3 p.i.d
Nasal turbinates	7.2 ± 0.9	6.4 ± 0.1
Trachea	4.4 ± 2.2 (2/3)	4.4 ± 0.2
Lung	5.0 ± 2.2	3.2 ± 1.2 (2/3)
Olfactory bulb	2.8 ± 0.5	2.7 (1/3)
Brain	2.3 ± 0.2 (2/3)	2.2 (1/3)
Fold induction of cytokine and chemokine transcript in lungs at day 3 p.i.e
IFNα	1.7	1.7
IL-6	49.4	87.6
IL-8	173.2	799.7
IP-10	7.8	6.8

^aPercent mean maximum weight loss. Data in parentheses represent the day(s) p.i. on which the maximum weight loss was detected.

^bMean maximum rise in body temperature in degrees centigrade (baseline body temperature, 38.0 to 38.2°C). Data in parentheses represents the day(s) p.i. on which the maximum rise in temperature was detected.

^cNumber of ferrets with detectable virus in rectal swabs collected on days 3 and 5 p.i./total number of ferrets tested.

^dVirus titers are expressed as the mean log₁₀ EID₅₀/ml ± standard deviation among ferrets with positive virus detection (data are representative of all ferrets examined, unless denoted in parentheses, in which the number of mice with positive virus detection/total number of mice in the group are indicated). The limit of virus detection was 10^1.5 EID₅₀/ml.

^eCytokine and chemokine mRNA expression in lungs of ferrets (n = 3) was measured by RT-PCR and is presented as the mean fold change compared with the values in mock-infected animals. Replicate threshold cycle values for each sample were within 10% of the average.

^fND, not detected.