Table 2.

Respiratory droplet transmission of 1918-avian reassortant H1N1 viruses

VirusInoculated Animals
Contact Animals
Clinical SymptomsNo. with virus detection(peak titer)No. with seroconversion(HI titer range)§No. with virus detection(peak titer)No. with seroconversion(HI titer range)§
No. with weight loss (%)*No. sneezing (onset day)
A/Dk/NY/962/3 (6)1/3 (3)3/3 (6.3)3/3 (1280)0/30/3
Dk/NY/96-DD3/3 (11.1)0/33/3 (6.6)3/3 (320–1,280)0/30/3
1918NA:Dk/NY/96-DD3/3 (10.6)1/3 (3)3/3 (6.3)3/3 (160)0/30/3
1918HANA:Dk/NY/963/3 (9.1)2/3 (4)3/3 (6.5)3/3 (320–640)0/30/3
Dk/NY/96HANA:19183/3 (13.2)0/33/3 (7.4)ND0/3ND
1918HANAPB1PB2PA:Dk/NY/962/3 (6.8)3/33/3 (8.2)3/3 (80–320)2/3 (7.5)2/3 (160–320)
1918HANAPB1PB2:Dk/NY/962/3 (16.2)3/3 (2)3/3 (7.8)3/3 (320–640)3/3 (6.4)3/3 (320–640)
1918HANAPB1:Dk/NY/963/3 (12.4)3/3 (2)3/3 (7.1)3/3 (160–640)0/30/3
1918HANAPB2:Dk/NY/963/3 (12.9)2/3 (4)3/3 (8.1)3/3 (320)3/3 (7.1)3/3 (160/320)
1918HANAPA:Dk/NY/963/3 (17.5)0/33/3 (8.4)3/3 (320–640)0/30/3
Dk/NY/96-PB2:19183/3 (10.4)2/3 (2)3/3 (7.4)3/3 (320–640)1/3 (7.5)1/3 (320)
  • *Number of animals in which weight loss was observed. Values in parentheses indicate percentage mean maximum weight loss observed during the first 9 days p.i.

  • Number of animals in which sneezing was observed during the first 9 days of the experiment. Values in parentheses indicate day of onset.

  • Number of animals in which virus was detected in nasal washes. Values in parentheses indicate nasal wash titers, which are expressed as mean log10 peak virus titer observed within the first 9 days p.i.

  • §Number of animals in which seroconversion was observed. Values in parentheses show HI antibody titers in sera collected at least 18 days p.i. HI titers were determined using the homologous virus as test antigen.

  • ND, not determined.