Researchers have been studying whether mammals other than poultry can host H5N1. A new study in the Journal of Dairy Science examined mammary gland tissue from pigs, sheep, goats, beef cattle, alpacas and humans. The team included scientists from the ISU College of Veterinary Medicine and the USDA National Animal Disease Center in Ames.
The tissues contained sialic acid receptors, a sugar on cell surfaces that influenza viruses use to attach to and enter cells. Lead author Rahul Nelli said the study aimed to determine whether transmission among these mammals and humans is possible, and the results indicate that it is. A prior study showed dairy cattle udders have high sialic acid levels, which may explain rapid spread among herds.
Only a few infections have been reported so far in the animals tested, but testing is limited. In infected dairy herds, cows can shed virus into raw milk. The USDA is conducting nationwide surveillance of raw cow milk, and pasteurization kills the virus. Study authors call for increased surveillance and steps to limit spread.
Difficult words
- mammary gland tissue — tissue that produces or supports milk in mammals
- sialic acid receptor — molecule on cells that viruses can bindsialic acid receptors
- transmission — the process of a disease passing between individuals
- surveillance — careful monitoring to find disease or problemsnationwide surveillance, increased surveillance
- pasteurization — heating milk to kill harmful germs and viruses
- shed — to release or send out from the body
- udder — the part of a cow that contains the teatsudders
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- What steps could farms take to limit spread of a virus among animals on the farm?
- How would you feel about drinking raw milk if a virus might be present? Explain your reasons.
- Do you think nationwide surveillance of raw milk is important? Why or why not?
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