A US agricultural laborer who contracted avian influenza following interaction with dairy cattle in Texas appears to be the initial documented case of mammal-to-human transmission of the virus, according to a recent study.
The dairy worker sought medical attention in late March upon experiencing painful red, swollen, and weeping eyes with burst blood vessels. Although he did not exhibit fever, his lungs remained clear, as outlined in a letter detailing the case published in the New England Journal of Medicine on Friday.
Despite reporting no direct contact with sick or deceased birds or other animals, the worker had frequent close interaction with dairy cows within the same region as other infected herds.
While the man's illness did not progress severely, its significance lies in confirming the potential for H5N1 transmission to humans through contact with cows. Yet, it also highlights unresolved queries about a virus deemed to possess "pandemic potential," underscoring the challenge of monitoring infections within this vulnerable workforce, where testing positive for a contagious ailment could result in loss of workdays and wages.
"For farmworkers specifically, certainly these are folks that are living in a state of economic desperation, and what they’re not going to do is, they’re not going to test for something if they don’t have paid sick leave, because they cannot afford to be sent home and told to stay home and not work," remarked Elizabeth Strater, director of strategic campaigns for United Farm Workers.
Strater noted rumors of dairy workers falling ill but refraining from testing due to economic constraints, though confirmation of such cases remains elusive.
Health authorities in Texas disclosed testing of other ailing dairy workers, including some with red eyes, all of whom tested negative for bird flu.
"The people tested volunteered to be tested," stated Lara Anton, senior press officer with the Texas Department of State Health Services. "It’s likely there were other people with symptoms who did not want to be tested so we cannot say with absolute certainty that no one else contracted H5N1."
Regarding the infected individual, he received antiviral treatment and recovered fully, with his immediate family receiving precautionary medication as well.
Analysis of swabs from the patient's eyes and lungs revealed an intriguing finding: while his eyes exhibited abundant H5N1 virus, minimal virus was detected in his lungs. This suggests potential infection through ocular exposure rather than respiratory pathways.
The inability to conduct epidemiological investigations at the farm hindered further understanding of the infection's origins and potential spread among workers.
To address these gaps, the CDC seeks farms willing to participate in detailed studies while maintaining vigilance through nationwide flu surveillance.
White House spokesperson Karine Jean-Pierre affirmed the administration's serious approach to monitoring the situation closely.
