Health officials are trying to determine why there's been a dramatic increase in the number of people in Texas each year who contract a food-borne illness that's often linked to produce imported from Mexico and other warmer climes.
Although there have been outbreaks in several states in recent years, including one in 2005 in Florida that sickened nearly 600 people, cyclosporiasis infection rates returned to normal levels after the sources were contained.
But in Texas, the number of cases shot up from 44 in 2012 to 351 in 2013 and has remained in the triple digits ever since, with 200 in 2014, more than 300 last year and more than 100 so far this year, according to the Texas Department of State Health Services.
State and federal health officials say an increasing amount of produce that's imported from tropical and subtropical regions — where the parasite that causes the illness is endemic — is likely contributing to the recent outbreaks. Some in the past few years were traced to tainted produce from Mexico, but officials haven't found a common source for this year's cases in Texas, said Christine Mann, a spokeswoman for the Texas Department of State Health Services.
"It's very challenging for epidemiologists to investigate food-borne outbreaks," Mann said, explaining that investigators must consider myriad factors like the travel itinerary of people who become ill.
She said there are other circumstances that could be driving up the number of cases, such as the outbreaks raising more awareness of the disease, leading to additional testing for it and more diagnoses. And given its long border with Mexico, Texas could be consuming more imported produce than other states, raising the risk of infection, Mann speculated.
There are more than 250 different food-borne diseases, but cyclosporiasis is among the most common that are closely tracked by health agencies. It often spreads when human feces contaminated with the cyclospora parasite come into contact with water or produce. Those sickened can suffer from diarrhea, cramps, fatigue and vomiting. The Food and Drug Administration last year banned imports of some fresh cilantro from Mexico after an investigation found feces and toilet paper in growing fields there.
The cilantro, imported from the Mexican state of Puebla, was linked to 2013 and 2014 outbreaks of stomach illnesses in the U.S., and health authorities also suspected cilantro from the region was responsible for additional cases in Texas and Wisconsin last year.
No other state in recent years is seeing as many cases as Texas. Florida had its 2005 outbreak, which was linked to basil from Peru, but it typically gets a few dozen cases per year. California recorded about two-dozen cases, total, in the past four years, and Arizona has had just five since the start of 2015.
Seattle attorney Bill Marler, who represents people sickened by contaminated foods, said the boom in Texas cyclosporiasis cases is unusual because the parasite isn't commonly found there.
"As we've been importing more food from places like Mexico, Honduras and Guatemala where cyclospora is endemic, we're starting to see more cases in the United States," said Marler, who built his national reputation representing victims of a 1993 E. coli outbreak at Seattle Jack in the Box restaurants.
The federal government estimates that about 52 percent of fresh fruit and 22 percent of fresh vegetables are imported. Food safety advocates question whether regulations in other countries are adequate to protect U.S. consumers and whether U.S. regulators are equipped to deal with the influx.
"There's a widespread concern that the FDA is getting overwhelmed by all the imported food coming in," said Thomas Gremillion, director of food policy at the Consumer Federation of America.
The federal Centers for Disease Control and Prevention found that, aside from E. coli infections, there were no significant changes in food-borne infection rates last year compared to the three previous years. But Gremillion said the "status quo is pretty grim," citing CDC statistics showing that approximately 48 million Americans are sickened by food-borne illnesses each year and 3,000 die.
The FDA in November released rules that will require importers to be more accountable for the safety of food they bring into the U.S. market. For instance, certified inspectors will conduct food-safety audits on foreign food processors.