The Centers for Disease Control and Prevention in the United States said that four farm workers who work at the same poultry farm contracted bird flu on Monday, bringing the total number of cases to eight.
Concurrent with the incidents is a concerning viral outbreak among livestock that has also infected humans.
Although a fifth case is also suspected, confirmation requires more analysis.
For the American public, the risk is still “low,” according to the CDC. In addition to conjunctivitis, the affected workers reported experiencing “flu-like symptoms.”
In the United States, a surprising twist to the bird flu outbreak was discovered in the spring: cows were suddenly contracting the disease, which had previously only affected poultry and birds.
In the state of Texas, the first human infection caused by a cow was declared on April 1.
After then, two more instances were recorded in Michigan, and a third case was discovered in Colorado around the beginning of July.
The disease is currently spreading among poultry and livestock in that western US state.
Despite the rarity of human cases, experts are concerned about the increasing number of afflicted creatures.
They worry that widespread distribution may facilitate the development of a virus mutation that would enable human-to-human transmission.
The CDC is urging workers who come into touch with infected cows or poultry to take extra care.
