The "siloed" structure of U.S. health agencies is hindering efforts to spot and combat animal-to-human afflictions, such as West Nile Virus, New York University sociologist Colin Jerolmack has concluded after conducting an organizational analysis of their operations.

Even though many newly emerging infectious diseases readily spread from one species to another, Jerolmack found that "agency members interpret certain diseases as 'livestock diseases' or 'wildlife diseases,' and they view categories of animals outside their purview as irrelevant to their institutional prerogatives. Consequently, there is little sense of mutual understanding and common goals -- and thus little coordination -- across these various organizations."

Jerolmack's study, which appears in the journal Sociology of Health and Illness, examined the following agencies and departments: a state Department of Health (DOH); the Department of Agriculture (USDA); a state Department of Wildlife; a state Department of Agriculture; and the Centers for Disease Control and Prevention (CDC). Through interviews with agency or departmental personnel, he looked at how the distinct organizational cultures of these agencies produced incompatible or even competing agendas that hampered efforts to respond to zoonoses -- infectious diseases that can be passed between species.

Jerolmack's interviews revealed several instances in which agencies and departments adopted a siloed, rather than cooperative, approach when faced with zoonoses:

* A state Department of Agriculture official who bristled at efforts to remove livestock that may have posed a health risk to residents because, "We're here to support anyone doing farming [and] keeping animals… We want people to continue keeping animals on their property."

* "Strained" relationships between a state's Department of Health and Department of Agriculture "sometimes meant that the DOH did not receive information on circulating diseases in animals that may become a problem for humans later on." A DOH employee, noting that bird flu strains, particularly those found in livestock, can mutate quickly, said such outbreaks should be considered vital public health information -- a view not shared by that state's Department of Agriculture.

* A city public health official, responding to an outbreak of salmonella, did not turn to the state's Department of Agriculture, the USDA, or any other agencies involved in animal health for help or information. Nor did it share information with them. The official "mentioned the need to change residents' cultural practices, but neglected veterinary medicine solutions," Jerolmack recounts.

* The same agency adopted a siloed approach in addressing other zoonoses, such as Lyme disease and West Nile virus: "It did not regularly communicate with animal agencies or analyze surveillance data on disease outbreaks in animals, but instead responded with medical and educational campaigns once one or more people became infected," Jerolmack writes.

Even instances in which agency cooperation has led to medical breakthroughs -- such as the discovery that West Nile Virus may be transmitted from birds to humans -- has not produced reform.

"Though the discovery of West Nile was greeted with alarm and massive pesticide sprays, it did not usher in a sea change regarding zoonotic surveillance and communications across states and agencies," Jerolmack observes, adding that a USDA official told him that following the West Nile outbreak in 1999, agency and departmental practices returned to "business as usual."

Jerolmack notes the CDC has recognized the need to do a better job of building relationships with the veterinary world. In 2006, it created the Geographic Medicine and Health Promotion Branch, which tracks the flows of both humans (as travelers) and animals (as they are imported or exported), and its director, Dr. Nina Marano, is a veterinarian. He adds that during an outbreak of rabies in the 1990s, state agencies worked together to stem the tide of the disease -- a response he views as an "example of the successful alignment of priorities and action among the myriad agencies responsible for human and animal health."

However, his study found these instances to be the exception rather than the norm.

"Although each agency's institutionalized habits of thought and action may have been relatively well-adapted to addressing the diseases that traditionally concerned each organization," Jerolmack writes, "they constrain members from building the inter-organizational and interdisciplinary bridges required to manage the latest 'hybrid' diseases."