Dutch expert sees parallels with outbreaks of Q fever

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WWhen pathologist Thijs Kuiken looks at what is happening in the US in response to the H5N1 bird flu outbreak in dairy cows, he is reminded of a difficult period in the Netherlands, where he lives, in the late 1990s.

Large goat and sheep farms in the country were hit every year from 2007 to 2010 by outbreaks of what is known as Q fever. The disease, caused by the bacterium Coxiella burnetii, mainly affects ruminants: sheep, goats and cows. But people can also contract it. Some don’t get sick. Some have a flu-like illness and recover. But some develop chronic Q fever syndrome, a debilitating condition. Hundreds of people in the Netherlands still suffer from the condition as a result of the epidemics of 2007-2010.

H5N1 is a virus that scientists fear could one day cause a pandemic; Q fever is a bacterial disease that, if present in an environment, can lead to significant numbers of infections in humans. But the similarity Kuiken sees is that in both cases the initial tendency is to treat these animal events as an economic problem for the agricultural sector, rather than as an agricultural problem that could also have major consequences for human health.

“My general concern about this outbreak is that it is being treated too much as an economic problem and not enough as a public and animal health problem,” says Kuiken, who works in the viroscience department of the Erasmus Medical Center in Rotterdam.

Kuiken is one of the influenza experts STAT spoke to last week for an article analyzing the response to the H5N1 outbreak in cows so far. He and others are concerned about the lack of urgency in the U.S. response and the apparent absence of a comprehensive plan to eradicate the virus from livestock. Secretary of Agriculture Tom Vilsack thinks the answer is this better biosecurity on farms. But as the number of affected farms continues to rise – the figure reached 139 in 12 states at the end of last week, and those are the farms where farmers actually had testing done – there is no point in the tide turning. (The USDA count was 133 as of Friday, not including the two latest detections in Iowa and the four latest in Colorado.)

If H5N1 were to establish itself in cows, the virus would have a chance to adapt to a mammalian species, increasing the risk that it would acquire mutations that would help it spread to and among humans.

The response to the Q fever outbreaks was similar, says Kuiken: “In the beginning it was mainly treated as an economic problem and a problem of the dairy goat sector and handled by the Ministry of Agriculture.”

Infected animals excrete large amounts of bacteria in their milk, urine, feces and placenta; The infections caused “abortion rushes” on farms with pregnant animals, Kuiken said. The bacteria floated in the wind from the farms. “There were people who cycled past these farms and became infected.” But the locations of the affected farms have not been made public for privacy reasons. (Sound familiar?) “So even if people were worried about getting infected and wanted to stay away from these areas, they didn’t know where they were,” he said.

Ultimately, the country’s health minister intervened and demanded that the outbreaks also be treated as a human health problem. “It was a really important lesson for the veterinary and medical authorities,” Kuiken said.

Currently, control of the response during the H5N1 outbreak lies firmly in the hands of the U.S. Department of Agriculture. While there have been numerous reports of sick farmworkers — far more than the three who have tested positive for H5N1 so far in this outbreak — few have been tested. The Centers for Disease Control and Prevention reported Friday that at least 53 people have been tested for the virus since the outbreak was first discovered. At the end of last week that number was 51.

Efforts to get a handle on how many people may have been infected have been hampered as farmers have in many cases refused to allow public health workers onto their properties to talk to and test their workers. But there’s finally a breakthrough on this front: Michigan health authorities are conducting a small serological survey, with the participation of an undisclosed number of farms in that state. Participating workers will complete questionnaires describing their encounters with cows and their daily tasks, and provide a blood sample that will be analyzed for antibodies against the virus. The CDC is working with Michigan on the investigation.

Another study currently underway is part two of a Food and Drug Administration effort to assess the risk of the H5N1 virus to commercial milk production. In early May, the agency reported that of nearly 300 store-bought milk samples, about 1 in 5 contained fragments of bird flu viruses, but that the viruses had been killed by pasteurization. (The FDA and USDA a preprint was released — a study that has not yet been peer-reviewed — showing Friday that commercial pasteurization techniques reduce the virus in milk to undetectable levels.)

Part two of the milk study will focus on some milk products that were not tested in the first version, Don Prater, the FDA’s acting director of the Center for Food Safety and Applied Nutrition, told reporters last week. They include: cream cheese, aged raw milk cheese, butter and ice cream. The results leave much to be desired for several weeks, he said.

Available soon – today actually – USDA will begin submitting applications for an assistance plan to compensate farmers for loss of income due to reduced milk production from H5N1-infected cows. Now that there is actual money on the table to cover the losses, we hope that farmers will finally see a reason to test animals they suspect are infected with the virus.