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Table 1 Clinical signs and replication of H7N9 virus in mice and ferrets

From: The mouse and ferret models for studying the novel avian-origin human influenza A (H7N9) virus

Mouse Time (d.p.i.) Clinical signs   Mean virus titer (Log10TCID50/g of tissue)
   Weight loss (%)a Ruffled furb Mortality   BALFc Lung Brain Heart Liver Spleen Kidney Intestine
  1 3/10 0/10 0/10 (0%)   3.75 (4/6)d 4.15 (4/6) - - - - - -
  2 8/10 0/10 0/10 (0%)   2.31 (5/6) 5.69 (5/6) - - - 1.25 (2/6) 1.88 (4/6) -
  3 9/10 7/10 0/10 (0%)   2.75 (6/6) 4.38 (6/6) - - - - - 0.69 (5/6)
  5 8/10 10/10 0/10 (0%)   3.58 (6/6) 5.38 (6/6) - - 0.58 (2/6) - - -
  7 8/10 10/10 0/10 (0%)   2.31 (6/6) 3.69 (6/6) - - - - - -
Ferret Clinical signs Euthanized time (d.p.i.) Virus titer (Log 10 TCID 50 / tissue)
  Weight Loss (%) Sneezingb Lethalityc   Trachea Lung Brain Heart Liver Spleen Kidney Intestine Olfactory bulb
  9/9 (10.7/9.3)e 9/9 0/9 3 4.92 (2/2)d 2.59 (2/2) - 2.82 (1/2) - - - - 5.41 (2/2)
     7 4.11 (2/2) 2.87 (2/2) - - 2.16 (1/2) - - - -
  1. a The percentage mean maximum weight loss after inoculation.
  2. b Number of animals in which ruffled fur (mouse) or sneezing (ferret) was observed after inoculation.
  3. c Virus titer was calculated as Log10 TCID50/ml of BALF.
  4. d –Numbers of positive animals in total animals.
  5. e 10.7% for animals inoculated with 108 TCID50 of H7N9 virus, and 9.3% for animals inoculated with 106 TCID50 of H7N9 virus.
  6. Mice were anesthetized and inoculated intranasally with 50 μl of 106 TCID50 of A/Anhui/1/2013 (H7N9) virus and were observed daily for signs of disease and mortality up to 14 days. Meanwhile, six mice were selected randomly and euthanized on 1, 2, 3, 5, and 7 d.p.i. respectively for virus dissemination analysis. Ferrets were divided into two groups, and three were inoculated with 108 while other six were inoculated with 106 TCID50 of A/Anhui/1/2013 (H7N9) virus. Two randomly selected animals which were inoculated with 106 TCID50 of virus were euthanized septely on 3 and 7 d.p.i., and used for virus replication in ferret tissues. All nine animals were observed for clinical signs and weighed daily as an indicator of disease. Nasal and throat swabs were collected on 1, 3, 5, 7, and 9 d.p.i. and virus titers were determined by end-point titration in MDCK cells. All data are presented as mean value ± SD.