USA: H5N1 in dairy herds, a field epidemiologic summaries
Questionnaires revealed potential risk factors and transmission routes for infections in dairy cattle.
Animal movement
>20% of farms received cattle within 30 days of clinical signs; and >60% of farms continued to move animals off the farm after onset of clinical signs.
Shared transportation vehicles
>50% of farms used trucks and trailers that are shared with other farms to transport livestock within 30 days prior to onset of clinical signs; and >50% of farms that used shared vehicles do not clean vehicles prior to use.
Shared transportation vehicles
>50% of farms used trucks and trailers that are shared with other farms to transport livestock within 30 days prior to onset of clinical signs; and >50% of farms that used shared vehicles do not clean vehicles prior to use.
Other species present on dairy farms
>80% of farms have cats present>50% of farms with cats observed sick or dead cats; and >20% of farms have chickens or poultry present. Nearly all farms with poultry observed sick or dead poultry.
People: Shared Personnel
>20% of dairies’ employees visit other dairies within 30 days of onset of clinical signs; >20% of dairies’ employees own livestock or poultry at their personal residence; >30% of dairies’ employees work at another farm with livestock; most of these employees work on another dairy; and 20% of dairies’ employees have family members who work at another farm with livestock.
People: Support Services >60% affected farms have regular visitors who have contact with cattle; and
- Veterinarians
- Nutritionists/feed consultants
- Contract haulers
- Hoof trimmers
>40% of farms use renderers and breeding technicians.
- Frequent visitors
- Most have contact with cattle
In conclusion, there is a lack of biosecurity in dairy herds in the USA.
