Table 1.
Characteristics of Study Participants
| ILI Number | Date, Month/ Day/Year | Enrollment Site Type | Gender | Age | Signs and Symptoms | rRT-PCR, Ct value, at ILI evaluation, Day 1/Day 3 | Nab Titer, 12/A/C | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Fever, °C | Cough | Sore Throat | Nasal Wash | Nasal Swab | Swine H1N1 | Swine H3N2 | |||||
| S ILI-15 | 8/11/16 | Unexposed | Female | 38 | 38.5 | - | - | -/NA | -/NA | 1:40/1:20/NA | 1:80/1:80/NA |
| S ILI-16 | 12/21/16 | HH | Male | 53 | - | - | + | 33.16/- | -/NA | 1:320/1:80/1:80 | 1:80/1:40/1:40 |
| S ILI-17 | 12/21/16 | HH | Female | 48 | - | + | - | -/- | NA/NA | 1:160/1:40/1:40 | 1:40/1:40/1:80 |
| S ILI-18 | 12/22/16 | HH | Male | 67 | - | + | - | -/- | -/- | 1:10/1:20/1:320a | 1:40/1:40/1:40 |
| W ILI-19 | 12/26/16 | Abattoir | Female | 30 | - | - | + | -/- | -/- | 1:10/1:20/NA | 1:80/1:40/NA |
| S ILI-19 | 12/28/16 | HH | Female | 41 | - | + | + | -/NA | -/NA | 1:80/1:20/NA | 1:80/1:40/NA |
| W ILI-20 | 12/29/16 | CAFO | Female | 35 | 37.0 | - | + | -/- | -/- | 1:5/1:40/1:20a | 1:40/1:320/1:80 a |
| W ILI-21 | 12/30/16 | Abattoir | Male | 38 | - | + | + | -/- | -/- | 1:40/1:40/1:40 | 1:80/1:160/1:160 |
| W ILI-22 | 12/30/16 | Abattoir | Male | 49 | - | + | - | -/- | -/- | 1:5/1:40/1:10a | 1:40/1:80/1:160a |
| W ILI-23 | 12/30/16 | Abattoir | Male | 48 | - | - | + | -/- | -/- | 1:40/1:40/1:40 | 1:80/1:80/1:80 |
| S ILI-20 | 1/4/17 | Unexposed | Female | 42 | - | - | + | -/- | 37.50/- | 1:5/1:20/1:20 | 1:20/1:40/1:20 |
| S ILI-21 | 1/4/17 | Unexposed | Female | 48 | - | + | + | -/- | -/- | 1:20/1:40/1:40 | 1:80/1:40/1:1280a |
| S ILI-22 | 1/4/17 | Unexposed | Female | 46 | 37.2 | - | + | -/- | 37.39/- | 1:40/1:40/1:20 | 1:320/1:40/1:40 |
| S ILI-23 | 1/4/17 | Unexposed | Male | 40 | 37.8 | - | + | -/34.62 | 36.99/- | 1:10/1:20/1:20 | 1:80/1:80/1:320a |
| W ILI-24 | 1/5/17 | Abattoir | Male | 55 | - | + | - | -/- | -/- | 1:5/1:10/1:20 | 1:20/1:40/1:80a |
Data are from participants experiencing influenza-like illness events between March 2016 and February 2017 and their laboratory results during their acute illness. Participants (n = 400) from the Shandong and Jiangsu provinces of China were asked to report influenza-like illness events between annual follow-up visits at 12 and 24 months. Seroconversion against each virus was defined as a 4-fold rise in titer, relative to any previously gathered sample, and 1 titer value ≥40. A/swine/Guangdong/SS1/2012(H1N1) and A/swine/Guangdong/L22/2010(H3N2) were used for neutralizing antibody (Nab) assays.Abbreviations: +, presence of symptoms; -, absence of symptom or negative result for rRT-PCR; 12/A/C, 12-month/acute/convalescent; CAFO, confined animal feeding operation; Ct, cycle threshold; HH, house-holding swine farm; ILI, influenza-like illness; NA, sample was not collected; rRT-PCR, real-time reverse-transcription polymerase chain reaction; S, enrolled in Shandong; W, enrolled in Wuxi.
aSera groups had a 4-fold rise in titer.