An estimated 1 million people every year are sickened by salmonella found in products such as eggs, cantaloupe and turkey burgers.
A News21 analysis of salmonella reporting practices found that differences across the country put residents of the worst-performing states at risk and undermine national outbreak surveillance.
In large outbreaks, underperforming states prevent efficient responses and rely on the surveillance of other states to catch outbreaks they miss. Some smaller outbreaks elude detection entirely.
“There are multi-state outbreaks out there that we don’t recognize and we don’t know about,” said Tim Jones, state epidemiologist for the Tennessee Health Department.
National outbreak surveillance depends on the collaboration of 2,800 state and local health departments subject to at least 50 different reporting requirements.
Although the CDC coordinates investigations when these multi-state outbreaks occur, it can only “provide guidelines and recommendations” as a non-regulatory agency, said Ian Williams, chief of the CDC’s outbreak response and prevention branch. Without a federal standard, each state has a unique set of disease-reporting requirements and practices.
The speed of response is critical for foodborne illnesses, yet 10 states allow a week to report a case of listeria — the bacteria that caused 15 deaths this year from contaminated cantaloupe — to the health department. Florida is the only state that requires immediate reporting of listeria, while the others fall somewhere in between, with 16 requiring health departments to be notified within one day.
The breakdown between stringent and lax reporting requirements among states holds true for most illnesses, provided that requirements exist at all. The CDC recommends reporting for 20 foodborne illnesses, but fewer than half of the states require reporting for all of them.
Although every state requires reporting for salmonella, 12 states and the District of Columbia do not require the submission of an isolate — a specimen from a stool sample — to the state public health laboratory, which is the way an outbreak can be identified and traced to its source.
For salmonella, E. coli and other bacterial illnesses, specimen test results can be uploaded to a national database known as PulseNet. Health officials can then try to match the genetic “fingerprint” on the samples with those of cases in other states, which will determine whether they were associated with the same outbreak.
In the summer of 2008, one of the biggest and most widespread outbreaks in American history tested surveillance measures in 43 states and exposed weaknesses in the nation’s ability to identify and respond to outbreaks. When it was over, salmonella-tainted jalapeno and serrano peppers left two men dead in Texas, and across the country put 308 people in hospitals and made at least 1,500 others sick enough to seek medical attention.
The News21 analysis found that significant underreporting in Texas, which does not require samples to be submitted, handicapped its ability to identify clusters of illnesses and respond to outbreaks.
The outbreak spread as Texas spent the first weeks of the investigation relying on data from insufficient reporting. By June 2, 2008, Texas had the most cases of the hot-pepper outbreak in the country.
The time between getting sick, seeing a doctor, reporting the illness and testing specimens allowed two weeks to pass for more than half of the illnesses before they were identified as part of the hot-pepper outbreak. From there, the speed of response and success of the investigation depend on a state’s health department.
Minnesota, however, identified its first case of the hot-pepper outbreak on June 23, 2008 and 15 days later it had “unequivocally implicated jalapenos,” according to congressional testimony by Kirk Smith, state epidemiologist in Minnesota.
Texas reported the same results earlier that week — more than a month after its first cases in late May — taking more than twice the time to reach the same conclusion.
Although the outbreak sickened people in Texas much earlier, its investigation faltered until the Texas State Health Services Department acknowledged the need to increase surveillance in early June.
“We sent out a letter to all the clinical labs in the state and we asked them to please submit all salmonella isolates to the state lab,” said Linda Gaul, the foodborne epidemiologist for the Texas State Health Services Department.
By simply asking, Texas received “twice as many isolates” for the rest of the outbreak, Gaul said. Over the next two months, the lab tested more than 1,200 isolates. In all of 2007, the state performed 1,835 of these tests.
State health officials are discussing how to include mandatory specimen submission for salmonella in Texas’ disease reporting requirements, Gaul said.
If the requirement is added, Florida would replace Texas as the most populous state without mandatory isolate submission for salmonella.
Since 1998, the Florida Health Department has received specimens for less than 20 percent of its cases, the lowest percentage in the country and less than half that of Nebraska, the state with the second-lowest submission rate.
With a large population, low specimen submission rate and no specimen submission requirement, Florida’s salmonella surveillance mirrors Texas before the hot-pepper outbreak. While Texas was able to improve its surveillance by asking for specimens, budget constraints limit Florida’s surveillance capacity, said Richard Hopkins, state epidemiologist for the Florida Health Department.
“If somehow, by some magic, Florida hospitals started sending the other 80 percent [of specimens] to the state public health lab, they wouldn’t have the capacity to do the [testing] that they do,” Hopkins said.
Funding issues are not limited to Florida, with health departments hurting across the country, said Williams of the CDC. Without sufficient funding, departments have fewer resources to test samples, conduct interviews and undertake investigations.
Foodborne outbreaks are more likely to go undetected in states lacking those surveillance and response mechanisms. While most of them will be small, localized clusters of illness, some with the scope of the hot-pepper outbreak also will slip through the cracks, said Jones of Tennessee.
“It’s just Russian roulette, waiting for enough bad things to line up,” he said. “And it’ll happen again.”
This report was produced as part of the Knight-Carnegie News21 program, a national university reporting project headquartered at the Walter Cronkite School of Journalism and Mass Communication at Arizona State University. Student reporters worked from the Cronkite School and from the Philip Merrill College of Journalism at the University of Maryland.