Two key animal health groups recently weighed in on recent H7N9 avian flu developments and possible consequences of the detection of highly pathogenic viruses in China, warning that concerted efforts are needed to eliminate the disease in poultry and share the latest information.
In outbreak developments, Croatia reported its first highly pathogenic H5N5 outbreak in poultry, as Taiwan and Vietnam reported more H5N6 events, and several European countries reported more H5N8 in both wild birds and poultry.
H7N9 threat to humans, poultry
In a joint statement on Mar 17, the United Nations Food and Agriculture Organization (FAO) and the World Organization for Animal Health (OIE) said targeted efforts are needed to control H7N9 in Chinese poultry to protect people as well as the poultry trade.
Vincent Martin, DVM, PhD, the FAO's representative in China, said targeted surveillance is needed to detect the disease and clean affected farms and markets, intervening at critical points along the poultry chain, from farm to table. "There should be incentives for everybody involved in poultry production and marketing to enforce disease control."
Matthew Stone, BVSc, MVS, the OIE's deputy director general, credited China with quickly notifying the global community that it had recently detected a change from low to high pathogenicity. "Timely sharing of surveillance results and sequence information with the international community is crucial for pandemic preparedness," he said in the statement. The groups also emphasized the importance of China to share all information from ongoing and intensified surveillance activities.
Though the shift to high pathogenicity might make the disease easier to identify and control in poultry, it raises the risk of severe animal and economic losses for China's poultry sector, the groups noted. They said another concern is the possibility that H7N9 changes might affect the wild bird population, which could turn them into migratory carriers of the virus, possibly posing a threat to Europe, Africa, or the Americas.
Croatia reports H5N5 in poultry
Croatia's first H5N5 outbreaks in poultry occurred at four locations: two farms and two backyard holdings in Krapina-Zagorje County in the north near the border with Croatia, officials said in a Mar 17 report to the OIE. Croatia had previously reported H5N5 in a wild swan found dead in January.
The outbreak started Mar 8 at two neighboring locations, with increased mortality seen in poultry. A local veterinarian said there were two small ponds nearby where wild ducks gather. After tests confirmed H5N5, authorities ordered control measures for 15 other holdings in the area on Mar 14, where birds at two of them tested positive for H5N5.
Among the four locations, the virus killed 42 of 65 susceptible birds.
H5N5 is a reassortment of H5N8 that was first reported by three European countries at the end of 2016. The virus has been found in 11 of the region's countries.
Vietnam reports more H5N6; Taiwan battles 3 strains
Vietnam and Taiwan both reported more H5N6 outbreaks, with the latter also confirming more detections of H5N8 and low-pathogenic H5N2, officials said in separate reports to the OIE.
The latest event in Vietnam involved backyard birds in Quang Tri province in the central part of the country. The virus killed 130 of 200 susceptible birds, and authorities culled the survivors.
Taiwan, after reporting its first H5N6 outbreak in the middle of February, reported one more, this time at a commercial duck farm in Hualien County on the east side of the island. The facility has been placed under quarantine, and all animals on the farm have been stamped out.
In related developments, Taiwan continues its battle against two other strains, with seven more H5N8 outbreaks and 22 more involving low-pathogenic H5N2, according to separate reports to the OIE. The H5N8 outbreaks involved commercial farms on the west side of the island, striking Chiayi, Pingtung, and Yunlin counties, plus the cities of Tainan and Kaohsiung. The start dates ranged from Feb 25 to Mar 6, with H5N8 affecting turkeys, native chickens, and ducks.
Among the seven outbreaks, the virus killed 5,147 of 69,250 birds.
All but 1 of the 22 low-pathogenic H5N2 outbreaks are on commercial farms on the west side of the island; the other is in the northeast. Taken together, the virus killed 21,592 of 242,300 birds, and authorities destroyed the remaining ones as part of response steps.
H5N8 in Europe
In France, where the foie gras production area in the southwest has been especially hit hard by outbreaks involving different strains, officials reported 11 more H5N8 outbreaks, nine at poultry farms and two in wild birds.
In the farm outbreaks, the virus struck farms in two departments: Landes and Pyrenees-Atlantiques. The events started from Mar 1 to Mar 9, killing 27 of 8,966 birds.
The same part of the country was also affected by low-pathogenic strains in an H5N2 outbreak that struck a duck farm in Pyrenees-Atlantiques department on Mar 9 and in an H5N2 outbreak and an H5N1 event detected at a duck farm on Mar 14 in Lot-et-Garonne department.
France's H5N8 detections in wild birds both occurred in the far northeast of the country, affecting three wild geese found dead earlier this month in Haut-Rhin and Bas-Rhin departments.
Four other European countries reported more H5N8 detections:
- Germany confirmed three more outbreaks, all of them striking turkey farms in Lower Saxony state in the northwest. The events began between Mar 11 and Mar 15, sickening 9,100 of 32,051 birds and killing 73 of them.
- Italy notified the OIE of one more outbreak, this time on a commercial game farm in Veneto region in the northeast. The event began on Mar 16, killing 5 of 180 birds.
- Lithuania noted one more detection involving a wild swan found dead on Mar 13 in Klaipeda County in the far eastern part of the country.
- Dutch officials reported three more outbreaks in wild birds found dead from Feb 7 to Mar 6 in two provinces, North Holland and Friesland.
Mar 17 FAO/OIE joint statement on H7N9
Mar 17 OIE report on H5N5 in Croatia
Mar 19 OIE report on H5N6 in Vietnam
Mar 17 OIE report on H5N6 in Taiwan
Mar 18 OIE report on H5N8 in Taiwan
Mar 17 OIE report on H5N2 in Taiwan
Mar 17 OIE report on H5N8 in French poultry
Mar 17 OIE report on low-path H5N2 in France
Mar 17 OIE report on low-path H5N1 in France
Mar 17 OIE report on H5N8 in French wild birds