Table 1.
Epidemical and clinical comparison of highly pathogenic avian influenza and low pathogenicity avian influenza fatalities and survivors.
| Characteristics | HPAI | L PAI | p3 | p4 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| H5N1 | H5N6 | H7N9 | H9N2 | |||||||||
| Fatalities (N = 293) | Survivors (N = 151) | p1 | Fatalities (N = 11) | Survivors (N = 5) | Fatalities (N = 265) | Survivors (N = 391) | p2 | Fatalities (N = 0) | Survivors (N = 18) | |||
| Epidemical characteristics | ||||||||||||
| CFR [% (No.)] | 66.0 (293/444) | - | 68.75 (11/16) | 40.4 (265/656) | - | 0.0 (0/18) | <0.001 | - | ||||
| Percentage of countries/provinces reporting fatalities [% (No.)] | 87.5 (14/16) | - | 71.43 (5/7) | 95.0 (19/21) | - | 0.0 (0/4) | 0.587 | - | ||||
| Reported onset date of the first fatality | 2003/11/25 | - | 2014/4/23 | 2013/3/3 | - | 1998 | - | - | ||||
| Reported date of last fatality | 2015/1/12 | - | 2016/11/20 | 2015/5/28 | - | - | - | - | ||||
| Peak season | January | February | - | January | December | January | January | - | - | December | - | - |
| Exposure history [% (No.)] | ||||||||||||
| Any exposure to poultry (Total) | 91.25 (73/80) | 95.4 (103/108) | 0.366 | 100 (11/11) | 100 (5/5) | 49.3 (101/205) | 55.1 (140/254) | 0.223 | - | 77.8 (7/9) | <0.001 | <0.001 |
| Males | 93.0 (40/43) | 92.6 (38/41) | 1.0000 | - | - | 37.2 (45/121) | 47.3 (53/112) | 0.1175 | - | - | - | |
| Females | 89.2 (33/37) | 97.0 (65/67) | 0.1828 | - | - | 44.8 (22/49) | 50.0 (26/52) | 0.6078 | - | - | - | |
| Exposure to sick or dead poultry | 37.5 (30/80) | 25.0 (27/108) | 0.196 | 27.3 (3/11) | 0.0 (0/5) | 5.9 (12/205) | 3.9 (10/254) | 0.379 | - | 11.1 (1/9) | <0.001 | <0.001 |
| Backyard poultry | 25.0 (20/80) | 17.6 (19/108) | 0.275 | 0.0 (0/11) | 0.0 (0/5) | 6.8 (14/205) | 9.1 (23/254) | 0.491 | - | 0.0 (0/9) | <0.001 | 0.030 |
| Visited LBM | 7.5 (6/80) | 8.3 (9/108) | 1.000 | 63.64 (7/11) | 60 (3/5) | 62.9 (129/205) | 50.8 (129/254) | 0.011 | - | 44.4 (4/9) | <0.001 | <0.001 |
| Human case contact | 1.25 (1/80) | 0.9 (1/108) | 0.486 | 0.0 (0/11) | 0.0 (0/5) | 3.9 (8/205) | 7.1 (18/254) | 0.160 | - | 0.0 (0/9) | 1.000 | 0.074 |
| Unknown | 1.25 (1/80) | 5.6 (6/108) | - | 9.09 (1/11) | 40 (2/5) | 10.7 (22/205) | 7.9 (20/254) | - | - | 0.0 (0/9) | - | - |
| Comorbidity [% (No.)] | 18.8 (15/80) | 8.33 (9/108) | 0.046 | 36.36 (4/11) | 0.40 (2/5) | 58.6 (156/266) | 34.8 (135/388) | <0.001 | - | 22.2 (2/9) | <0.001 | <0.001 |
| Gender [Male% (No.)] | 43 (126/293) | 42.3 (41/97) | 1.000 | 45.45 (5/11) | 40.00(2/5) | 70.1 (183/261) | 68.8 (267/388) | 0.795 | - | 33.3 (5/15) | <0.001 | <0.001 |
| Median age (Range, Years) | 22.5 (1–75) | 17 (8 months–75 years) | 0.018 | 39 (25–50) | 35 (5.5–65) | 61 (13–91) | 49 (8 months–88 years) | <0.001 | - | 13 (9 months–86 years) | <0.001 | <0.001 |
| Age group [No. (%),(Years)] | ||||||||||||
| 0–9 | 63 (22) | 42 (43) | <0.001 | 0 (0) | 1 (20) | 0 (0) | 38 (10) | <0.001 | - | 11 (79) | <0.001 | <0.001 |
| 10–19 | 65 (22) | 14 (14) | 0 (0) | 1 (20) | 2 (1) | 7 (2) | - | 1 (7) | ||||
| 20–29 | 76 (26) | 10 (10) | 2 (18.18) | 0 (0) | 10 (4) | 20 (5) | - | - | ||||
| 30–39 | 62 (21) | 15 (15) | 2 (18.18) | 1 (20) | 21 (8) | 54 (14) | - | - | ||||
| 40–49 | 17 (6) | 13 (13) | 6 (54.55) | 0 (0) | 21 (8) | 48 (12) | - | 1 (7) | ||||
| 50–59 | 5 (2) | 1 (1) | 1 (9.09) | 1 (20) | 60 (23) | 92 (24) | - | - | ||||
| Over 60 | 5 (2) | 2 (2) | 0 (0) | 1 (20) | 151 (57) | 128 (33) | - | 1 (7) | ||||
| Median number of days | ||||||||||||
| Days from onset to hospitalization | 5.5 (0–20) | 5 (0–31) | 0.023 | 4 (0–7) | 4.5 (3–6) | 5 (0–31) | 5 (0–28) | 0.761 | - | 2 (1–5) | 0.954 | 0.071 |
| Days from onset to confirmation of infection | 13 (6–29) | 6 (2–17) | <0.001 | 13 (5–20) | 15 (10–20) | 10 (1–51) | 8 (1–28) | 0.011 | - | 17 (2–43) | 0.027 | 0.020 |
| Days from onset to antiviral treatment | 6 (0–14) | 5 (0–31) | 0.202 | 9 (1–14) | 7 (0–12) | 7 (0–23) | 6 (0–19) | 0.089 | - | - | <0.001 | 0.020 |
| Days from onset to outcome | 10 (2–27) | 13 (3–33) | 0.019 | 8 (4–10) | 58 | 23 (3–111) | 31 (4–187) | <0.001 | - | - | <0.001 | <0.001 |
| Hospitalization days | 4 (0–26) | 11 (6–27) | 0.001 | 4 (0–10) | 52 | 18 (0–103) | 25 (1–179) | 0.001 | - | - | <0.001 | 0.044 |
Note: p1 value: The comparison of confirmed H5N1 fatalities and survivors. p2 value: The comparison of H7N9 fatalities and survivors. p3 value: The comparison of confirmed H7N9 and H5N1 fatalities. p4 value: The comparison of confirmed H7N9 and H5N1survivors. We used ANOVA analysis to analyze the average age and median days for a four-group comparison and a T-test to analyze the average age and median days for a two-group comparison. Chi-square (χ2) tests were used to compare the distribution of the different variables of qualitative measurements such as gender distribution; a Kruskal-Wallis test was used in the analysis of proportion in the different age groups. The difference is significant between the two groups (p < 0.05). CFR = case fatality rate, HPAI = highly pathogenic avian influenza, LPAI = low pathogenicity avian influenza, LBM = live bird markets. “-” = not available.