Table 1. Direct transmission of avian influenza viruses to humans.
| Virus subtype | Year | Location | No. cases (no. deaths) | Clinical features | Notes | Reference(s) |
|---|---|---|---|---|---|---|
| H5N1 | 1997 | Hong Kong | 18 (6) | Associated with outbreak of highly pathogenic AI in poultry in the region | (5,6) | |
| H9N2 | 1999 | Hong Kong | 2 (0) | Mild influenzalike illness | (7) | |
| H9N2 | 1999 | Guangdong Province, China | 5 (0) | Mild influenzalike illness | (8) | |
| H9N2 | 2003 | Hong Kong | 1 (0) | Mild influenzalike illness | (9) | |
| H5N1 | 2003 | Hong Kong | 2 (1) | Primary viral pneumonia, lymphopenia, respiratory distress | 7-year-old girl died in Fujian Province, China, and H5N1 infection was not confirmed. Her 33-year-old father died from confirmed H5N1 influenza infection in Hong Kong, and her 8-year-old brother recovered from H5N1 infection. | (10) |
| H7N7 | 2003 | Netherlands | 89 (1) | Conjunctivitis (78 cases), mild influenzalike symptoms (2 cases) or both (5 cases). In fatal case, pneumonia followed by respiratory distress syndrome | Most cases were in persons involved in handling poultry (86), with 3 family members also affected. | (11) |
| H10N7 | 2004 | Egypt | 2 (0) | Fever and cough | Both cases were in infants, who recovered without complications | (12) |
| H5N1 | 2003–present | Asia (Vietnam, Thailand, Cambodia, Indonesia) | 116 (60)* | Fever, respiratory symptoms, lymphopenia, elevated liver enzymes. Severe cases progess to respiratory failure, multiple organ dysfunction, and death. | Human cases concomitant with unprecedented outbreaks of highly pathogenic H5N1 AI in poultry | WHO,* (13–15) |
*WHO, World Health Organization. As of September 29, 2005. Source: http://www.who.int/csr/disease/avian_influenza/country/en