Solving Puzzles vs. Solving Problems [The ScienceBlogs Book Club]

Liz Borkowski writes: Mark Pendergrast wrote yesterday about how politics plays into the work of the EIS, and it's something that I kept noticing as I read Inside the Outbreaks. As he points out, my post last week highlighted the solution to the Reye's Syndrome puzzle - which was solved by Karen Starko, who's also one of the Book Club bloggers! - but didn't get into the larger issue: there can be a big difference between solving the puzzle and solving the problem. In yesterday's post, Mark writes:

Although Karen's and subsequent CDC studies clearly demonstrated that giving children aspirin caused the vast majority of Reye syndrome cases, the CDC has no regulatory power. The FDA gave in to pressure from the aspirin industry and delayed a warning label on children's medicine containing aspirin for five years, during which nearly 300 more children died of Reye syndrome in the United States.

He follows up the Reye's Syndrome story by asking "Should the CDC have regulatory power?" In considering that question, it's instructive to look at some of the many episodes in the book where EIS officers either were or weren't able to use their discoveries about the source of disease outbreaks to get necessary large-scale changes made.

Because there's such a range of causes of disease outbreaks, I'm going to confine my comments today to food. Food-borne diseases were a constant thread running through the book, and the EIS officers were usually able to identify a source, like a producer or food preparer failing to take proper sanitary precautions or a production facility being contaminated with bacteria. In many cases, an EIS officer to pinpoint a cause that was simple to fix - a food handler putting potato salad in containers that had held raw chicken, for instance. In other cases, as with an entire shipment of toxin-laden smoked whitefish or contaminated canned mushrooms from China, the FDA was able to issue a recall or ban importation. Our overall food safety system would be stronger if we devoted more resources to inspections and surveillance, but my impression when I finished the book was that a lack of regulatory authority isn't the problem in these situations.

In terms of preventing food-borne illnesses, CDC findings on eggs that were described in the book also seemed to translate into policy with relative ease. After a string of mid-1960s salmonellosis cases being traced to products containing eggs, Philip Brachman, head of the Salmonella Surveillance Unit, sent recommendations to state health departments. Following his recommendations, FDA "passed regulations requiring that eggs be inspected (and diverted for pasteurization if cracked), then graded and sanitized on the outside." This policy was based on the knowledge that cracked or soiled eggs could be contaminated with Salmonella-containing chicken feces. In the late 1980s, a multi-state outbreak of Salmonella eteritidis from products from a Rotanelli Foods plant sent EIS officer Mike St. Louis on the Salmonella trail:

EIS officers had made the egg-Salmonella link 25 years before, but past outbreaks had been traced to fecal contamination of cracked or soiled eggs. The modern Rotanelli plant had purchased unblemished large white eggs and then disinfected their exteriors. St. Louis buried himself in poultry research and found a 1944 article in the British Medical Journal stating that S. enteritidis could persist in the ovaries of chickens. Could the hens actually be depositing bacteria inside the intact eggs they laid? He published the suggestion in the Journal of the American Medical Association, raising a storm of protest from the egg industry.

Illinois-based EIS officer Sue Trock incubated whole eggs from an implicated farm, washed and flame-sterilized them, then cracked and cultured them. She found an abundance of S. enteritidis. Until then, eggs had been considered perfectly packaged natural products requiring no refrigeration. Illinois was the first state to demand chilled eggs (to prevent bacterial proliferation), even in transport, and the FDA soon followed suit.

Food on cruise ships is another recurring agent of disease outbreaks. Here's how EIS officers went about tackling that:

In October 1973, 16 recently returned passengers from the S/S Statendam, operated by Holland-American Cruises, had experienced diarrheal illness due to Salmonella bareilly or S. senftenberg, both relatively rare serotypes. On December 19, 1973, the Statendam sailed on a nine-day Caribbean Christmas cruise, during which 55 of the 750 passengers complained of diarrhea. For the next five cruises, a CDC team, including EIS officers Mike Merson and Dale Lawrence, distributed a diarrhea questionnaire to all passengers. On each cruise, between six and ten percent reported a diarrheal illness. Swabs from crew members revealed ten salmonella varieties. Many of the afflicted crew worked in the ship's galley.

Food preparation methods were alarming. Raw and cooked poultry were cut on the same butcher block with the same knives. Food handlers rarely washed their hands. Food was left at room temperature for two or three hours for breakfast and lunch buffets, then returned to the refrigerator. Leftovers were reworked and set out again for a midnight buffet. Once the problems were addressed, the number of Salmonella isolates declined, but on the eighth monitored cruise, there were still two senftenberg rectal isolates, and nine percent of the passengers reported illness.

EIS officers boarded nine other cruise ships at random during January and February 1974, administering questionnaires. The diarrhea rate ranged from 1.9 percent to 10.2 percent of the passengers, averaging 5.7 percent -- not much different from the Statendam's record.

"We recommended that shipboard disease data be made public to put pressure on the cruise companies," Merson recalled. The New York Times and Miami Herald ranked ships by illness records. Swiftly, the ships changed their food preparation and water storage practices, but cruise outbreaks have continued to plague tourists periodically.

This wasn't the only instance in the book where a publicity campaign proved a swift and effective way to get companies whose products were implicated in disease outbreaks to improve their practices.

Between CDC's ability to draw media attention to health problems and its apparently effective working relationship with FDA, it's succeeded in addressing lots of food-related illnesses. However, Inside the Outbreaks includes plenty of examples where CDC wasn't able to translate its findings into prevention, and the case of antibiotic use in livestock is one of those.

In 1983 EIS officer Scott Holmberg found victims in Minnesota and South Dakota to be suffering from a strain of Salmonella that was resistant to several antibiotics. He traced it to a farmer who "told Holmberg that he always threw in a handful of tetracycline per ton of feed to promote growth and prevent disease in his livestock." Holmberg's discovery spurred a push for regulation:

This outbreak was proof that resistant organisms developed in animals fed antimicrobials (primarily to fatten them faster) and then caused disease in humans. Holmberg documented that the fatality rate for people infected with drug-resistant Salmonella was 21 times greater than for regular strains. His investigation spurred FDA hearings and calls for a federal ban on adding antibiotics to animal feed. Although some breeders voluntarily stopped the practice, there is still no regulation in place. "If you want to buy antibiotics for yourself," Holmberg observed, "you need a prescription, but not if you go to the feed store."

More than a decade later, EIS officer Fred Angulo created a surveillance system whose information then spurred FDA action on a single antibiotic used for livestock:

In 1995, the FDA authorized the use of fluoroquinolones (i.e., Cipro) in chickens and turkeys, to promote growth and prevent disease. In response, Angulo created the National Antimicrobial Resistance Monitoring System for Enteric Bacteria (NARMS). Launched in 1996, it documented an alarming increase in fluoroquinolone resistance in the ensuing years. The FDA finally reversed its approval of the drug for poultry, but limiting antibiotic use in U. S. food animals remained a challenge.

When it comes to limiting the use of antibiotics in livestock in order to reduce the risk of antibiotic-resistant infections in humans, FDA probably gets more pressure from livestock producers - and the members of Congress who look after their interests - than from the public health community. FDA has the regulatory authority to withhold or revoke approval of antibiotics for routine use in livestock (as opposed to targeted use to combat actual infections), but the political environment is another matter.

There book contains many other examples of problems that CDC has identified but been unable to solve, for a wide range of reasons. Within CDC itself, a director's reluctance to address sexually transmitted diseases can hobble prevention efforts recommended by agency staff. It may be up to another regulatory agency to ban or recall a product CDC has identified as being dangerous, and the agency may want to avoid the wrath of manufacturers. In some cases, Congress forbids an agency from tackling a particular issue - like refusing to let FDA regulate herbal supplements - or from making recommendations that would upset an interest group, like prohibiting CDC from advocating for gun control.

To return to Mark's question, I doubt that giving CDC regulatory authority would make the agency dramatically more effective at solving the problems it identifies. For all of the examples I can think of, there's another agency that does have the power to regulate the product or practice in question, but political or budgetary pressures keep them from doing so. Would CDC be any less subject to such pressures?


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