Category "Public Health"
March 29, 2006
MidWest Haze Cam
The sky looked really hazy driving in to work today. I was surprised that our local Air Quality Index (AQI) wasn't elevated above "moderate" when I checked the MPCA web site. The AQI is a composite score based on ground-level ozone, sulfur dioxide, carbon monoxide and fine particles (PM2.5).
But I found out at MPCA's site that there's an even better way to get a sense of local air quality -- the MidWest Hazecam. The site has live camera shots and fine particle and ozone data for many big cities in the Upper Midwest/Great Lakes states. You can also link to it through the EPA's AIRNow site, which gives national forecasts for air quality along with several public health resources. And it's got several great maps. Did you know the U.S. Forest Service has air quality images? Here's one for the Boundary Waters.
Category "Public Health"
Category "Science and Policy"
January 25, 2006
Buying organic; BSE in the news
Consumer Reports recently produced a review of organic foods: Organic products: When buying organic pays (and doesn't). The investigators group foods according to how likely it is that a fruit, vegetable, or meat product contains pesticides and other additives. They also consider the price difference between organically- and conventionally-grown foods.
For example, CR suggests purchasing organic varieties of what the Environmental Working Group calls the "dirty dozen": apples, bell peppers, celery, cherries, imported grapes, nectarines, peaches, pears, potatoes, red raspberries, spinach, and strawberries. This is because these foods "consistently carry much higher levels of pesticide residue than others," based on USDA testing.
On the other hand, CR determined that purchasing organic seafood isn't worth it. The USDA has not established organic certification standards for seafood. And organically-produced fish can still contain mercury and PCBs.
It is important to point out that these evaluations are based solely on a comparison of certain contaminants -- what is typically seen on organic foods versus what is typically seen on non-organic foods. There is no consideration of environmental impact, animal production and handling practices, or other conditions that characterize organic farming. But CR does a good job of explaining why a certain organic food is deemed 'worth it' or not in their opinion. It's a good starting point for consumers to assess their own beliefs and value judgements in deciding whether to buy organic or not.
There was one part of the report that popped out at me as especially intriguing. For the most part, all the comparisons were an assessment of chemicals: pesticides, heavy metals, etc. There was no assessment of risks from infectious agents save one: BSE. CR suggests buying organic meat in part because of the reduced "risk of exposure to the agent believed to cause mad cow disease." They also mention that buying organic meat, poultry, and eggs is a good idea because of the antibiotics used in conventional farming and the greater potential for toxins in non-organic feed. I must say that worrying about contracting the human form of BSE, variant CJD, doesn't keep me up at night. But BSE and other prion diseases are definate health concerns.
The BSE point is especially interesting in light of Japan's recent re-instatement of U.S. beef ban just a month after it lifted its initial ban; and the continuing discovery of BSE in Canada, and suspected BSE in UK cattle born after the 1996 feed regulations.
There is interesting debate between Japan and the U.S. over what is considered risky for BSE. The risk of a cow getting BSE increases with age. This is because the BSE infectious agent, the prions, need time to become established in the brain and nervous system tissues and time to replicate and cause damage. (Find out more about BSE here.)
The U.S. argues that there is little or no risk of BSE in very young cows (less than 30 months old). Furthermore, the very small levels that would exist in these young cows would be too small to detect using the clinical tests that are presently available. These beliefs have resulted in two U.S. policy decisions: first, it is not useful to test any cows younger than 30 months old, and second, brain and other risky tissues pose no risk for transmitting BSE. Japan, on the other hand, tests all ages of cattle and prohibits risky tissues (also called specified risk materials or SRMs) from cows of any age to be included in any food product. This last difference is what prompted the ban reinstatement, and the difference is summarized nicely in this posting to ProMed-mail.
Personally, I tend to agree that testing of symptom-less cows less than 30 months old is futile with current technology. But I also think that the current feed bans for cattle in the U.S. are too permissive. I think they should read as the USDA organic standards do: "The producer of an organic operation must not feed mammalian or poultry slaughter by-products to mammals or poultry" (see National Organic Program regulation § 205.237 Livestock feed). I just don't want to eat meat from a herbivore animal that has been fed animal products. The organic rules aren't perfect, but they are a step in the right direction.
Category "Public Health"
December 6, 2005
HHS Pandemic Preparedness Tour
Department of Health & Human Services Secretary Michael Leavitt announced a plan today for a 50-state summit tour on pandemic flu preparedness. He and his fellow federal agency representatives will be traveling to every state and commonwealth to meet with local officials, starting with our own Star of the North. Leavitt will be here next Wednesday, December 14, to jointly chair the preparedness meeting with Governor Tim Pawlenty.
In a news report about the plan, there were some mixed feelings from health officials. States vary widely in their public health resources, and many see this state-by-state approach as bringing focused attention from the federal government to many states that need more help. Other health officials are worried that we've gotten into a rut of one narrowly-focused preparedness plan after another: anthrax, small pox, SARS, and now pandemic flu. And some see the risk of "fatigue" amongst the professionals and the public in response to another health threat.
I'd like to hope that these meetings will forgo hierarchical barriers that exist in public health and allow frank exchange of ideas. This approach will allow Sec. Leavitt to personally take the pulse, so to speak, of each state so that the feds will have direct knowledge -- a direct connection -- to key personnel, key issues, and key strengths across the nation. I can imagine many ways in which this 'face time' may reap true benefits in the coming months, even if a human influenza pandemic doesn't materialize. Will these meetings be a thoughtful exploration or a more heavy-handed approach? I'll keep you posted.
Some random thoughts on the matter:
· I think the most likely danger related to H5N1 to reach our shores isn't a human epidemic but an animal one. Not to dismiss the former, but the later threat is the one I'm hoping will get the attention it deserves. After all, a readily transmissible "highly pathogenic" H5N1 in birds is what we have. And we all know how highly mobile birds are. What will be the economic cost of H5N1 in our chicken and turkey flocks? What about the ecological cost to wild birds? I read a poignant Op-Ed piece in the New York Times a few weeks ago titled Cull of the Wild that got me thinking about this.
· This is the first time I've seen the government create a web site dedicated to a single health threat -- PandemicFlu.gov. Just a little exploration on the site is enough to grasp the immensity of the coordination effort that is being attempted here. You can see the scope of the national and international activities.
· Also on the web site is information from today's "Convening of the States" planning meeting that spearheaded the 50-state summit announcement. I was intrigued by a link titled Pandemic Planning Assumptions. What I found brought joy to this epidemiologist's heart. An explicit list of assumptions! Wow, just what I've always wanted! (I should explain that part of my work focuses on bringing more transparency to public health science and decision making.) These particular assumptions define the parameters of pandemic flu for health preparedness planners, so they have tangible characteristics to mold their plans around. Impressive!
Category "PhD Process"
Category "Public Health"
Category "Science and Policy"
December 2, 2005
Outbreaks, Dissertation work, and Sprouts
An e-mail newsletter in my Inbox today contained links to two stories. The first story described a recent study by the Center for Science in the Public Interest concluding that produce contributed to more illnesses than poultry, eggs, and other animal products. CSPI studied reports of food-related outbreaks and noted the implicated foods that were the source of the disease-causing organisms.
This report comes at a very influential time in the food safety arena and it raises exactly the questions I am tackling in my dissertation work. There's a great interest in these types of attribution studies that seek to learn where foodborne illness cases are coming from. What types of foods are contributing most to the burden of disease?
But what we really want to know isn't just "what" but also "how" and "where." How are these foods becoming contaminated? Where in the food production, transportation, and preparation steps is this contamination occurring?
In outbreak investigations, the point of contamination can sometimes be difficult to discern. Produce may have been contaminated in preparation, often cross-contaminated from other foods in the kitchen. But there are increasing numbers of multi-state outbreaks where cases crop up in multiple places at about the same time. In these instances, it seems most likely that the implicated food was contaminated on the farm or during processing or shipping. This is where our ability to conduct trace-back investigations is key to solving the mystery of exactly where and how, and, hopefully, preventing similar contamination in the future. CSPI is lobbying for better record-keeping and ID tagging of foods to help in these efforts.
Another difficulty is lack of data. This study looked at outbreaks that had both an identified pathogen -- the bacteria, virus, toxin, or parasite was recovered -- and an identified source -- there was conclusive evidence that pointed to a food. But what about the unknown and unidentified? What about the people who become ill and never see a doctor and don't get tested? We don't have great data on the food side, either -- especially produce where no routine testing is done.
My work is to identify the first two of Sec. Donald Rumsfeld's information trilogy -- the known knowns, the known unknowns, and the unknown unknowns -- and give an account of where our knowledge lies in attributing Salmonella cases to foods at the point of production. [Secretary Rumsfeld got a lot of ribbing after that news briefing, but I've found his words very useful in my work and explaining my work to others!]
The other story in that e-mail relates more to a personal joke than the actual news item. The story is about a recent Salmonella outbreak in Ontario from mung bean sprouts. There have been several Salmonella outbreaks from various types of sprouts in the past decade or so. One of the difficulties in preventing these outbreaks is that Salmonella can contaminate the sprout seed itself, as well as during the growing phase.
The joke here is that I'd heard extensive accounts of these sprout-associated outbreaks from one of my major professors, Dr. Craig Hedberg. We'd worked closely on several food safety projects when I first arrived at the U of M. One time when we were on our way to a meeting off campus, we stopped for lunch at a little sandwich shop. I ordered the veggie special but told them to "hold the sprouts." Craig's eyebrow shot up, he gave a wry smile and said, "Don't do that on my account." I gave a snort and replied that if not on his account -- foodborne disease expert, veteran outbreak investigator -- than whose? And I'm not the only one. Our entire department, it seems, is sprout averse from Craig's stories. So, you see why I smiled when I saw that headline today. Craig is now over in Paris for a year, working with French officials on improving their foodborne disease surveillance. I have to wonder if he's sitting in a little French café at this moment, regaling his company with similar stories.
Category "Public Health"
November 8, 2005
Polio in Minnesota
|from the CDC's Public Health Image Library (ID#: 1624)|
There's an excellent N.Y. Times article on the recent polio outbreak here in Minnesota. It elucidates some key points that I hadn't realized. First, the index case is a infant with an immune system deficiency. This probably put her at risk of acquiring the virus in the first place. But it also means that her body can't easily get rid of the virus, so she most likely will continue to produce and shed the virus in her stool. Indeed, it has spread to four other children who live on neighboring farms.
Another good point is that just because the community is Amish doesn't mean the people are necessarily isolated and immobile. "The Amish commonly take buses and trains, and occasionally even planes," the article notes. Members of the infected infant's Amish community recently attended a large wedding in Ontario, Canada. In the realm of public health at least, we are all one community. Surveillance efforts should strive to extend towards all; prevention and protection should strive to support all. Interwoven among these ideas is the question of reconciling individual rights with what is necessary to protect the larger group. All of the varied scientific and ethical issues that the public health community wrestles with are present in this one case.
Lots of weighty concepts. Lots of uncertainty. But for me, I am glad of one thing: if the case had to occur somewhere, I'm glad it happened in Minnesota. Why am I happy it happened in my state? Because we have the best and brightest public health minds working for us. We have one of the most thorough and comprehensive public health infrastructures. We have integrated laboratory surveillance. We go further than other states in tracking down cases and following leads. That's why I'm here in Minnesota getting my Ph.D. at the School of Public Health. That's why so many come here to be a part of this team: the health department, department of agriculture, the board of animal health, the Pollution Control Agency, environmental health, the Veterinary Diagnostic Lab, and on, and on.
The Times article noted the difference in this polio outbreak:
As [the infant's] care became increasingly complex, she was shuttled through four hospitals. At the third, she developed diarrhea. On Aug. 27, doctors sent a stool sample to the hospital's laboratory, which determined that the girl had an intestinal virus. In many states, nothing more would have been done.
But in Minnesota, hospitals send such samples to a sophisticated state laboratory...
I'd like to close with a special thank you to Minnesota residents and public officials. Thank you for paying the taxes and choosing to fund this great work. What you sow will be reaped by so many.