Table 1.
Multivariable meta-regression for change in seroprevalence of antibodies to highly pathogenic avian influenza A(H5N1) virus by different factors
| Study characteristics | All studies (β coefficient¶, 95% CI) | All studies excluding reports related to A(H5N1) outbreaks in Hong Kong in 1997 (β coefficient, 95% CI) |
|---|---|---|
| Year of study | ||
| 1997–2002 | 1.0 | – |
| 2003–2017 | − 1.7 (− 3.2, − 0.2)* | – |
| Epidemic region | ||
| Southeast Asiaa | 1.0 | 1.0 |
| Hong Kong, China | 1.8 (− 0.0, 3.7) | – |
| Mainland China | − 0.4 (− 1.2, 0.4) | − 0.8 (− 1.5, − 0.1)* |
| Middle East and Africab | − 0.4 (− 1.4, 0.6) | − 0.6 (− 1.6, 0.4) |
| Other countriesc | − 0.7 (− 1.7, 0.3) | − 1.0 (− 2.0, − 0.1)* |
| A(H5N1) outbreaks in poultry | ||
| No | 1.0 | 1.0 |
| Yes | 0.2 (− 0.5, 0.8) | − 0.1 (− 0.7, 0.5) |
| Virus clade | ||
| Clade 0 | 1.0 | 1.0 |
| Clade 1 | 0.2 (− 0.8, 1.1) | − 0.0 (− 0.9, 0.9) |
| Clade 2 | 0.2 (− 0.6, 1.1) | 0.0 (− 0.8, 0.8) |
| Study quality | ||
| Category B | 1.0 | 1.0 |
| Category C | − 0.2 (− 0.9, 0.6) | − 0.1 (− 0.8, 0.6) |
| Category D | 0.1 (− 1.1, 1.4) | 0.2 (− 1.0, 1.4) |
| Level of exposure | ||
| Without any exposure | 1.0 | 1.0 |
| Human case contact only | − 0.1 (− 1.5, 1.3) | − 0.3 (− 1.7, 1.1) |
| Both poultry exposure and human case contact | 0.5 (− 0.4, 1.5) | 0.2 (− 0.8, 1.2) |
| Poultry exposure only | 0.6 (0.0, 1.2)* | 0.5 (− 0.0, 1.1) |
*p < 0.05
¶The regression coefficient β refers to the change in the seroprevalence of A(H5N1) virus-specific antibodies. A negative sign for the coefficient β corresponds to a reduction in the seroprevalence of A(H5N1) virus-specific antibodies for given changes in the covariate, while a positive sign corresponds to an increase in the seroprevalence of A(H5N1) virus-specific antibodies
aIncluding Vietnam, Indonesia, Cambodia, Thailand, and Bangladesh
bIncluding Egypt, Turkey, Pakistan, and Nigeria
cIncluding Romania, Russia, South Korea, the USA, England, and Germany