Salmonella Typhimurium DT 104 is an apparently new strain of the old pathogenic standby. According to Washington State University veterinary epidemiologist Tom Besser, human illness caused by Salmonella Typhimurium DT 104 increased from one percent of Salmonellas in Washington State in 1989 to 42 percent in 1994. And here it was in Yakima jacking up the incidence even further. But doing something was not easy. The cheese was sold through an informal network, often door to door.
Queso fresco is very much a part of Mexican culture.
Things just fell together, says Theo Thomas, Cooperative Extension agent in Yakima County. Val Hillers, a food safety educator at WSU, and Ryan Bell, a graduate student in the University's food science and human nutrition department, started formulating a program from campus. Bell developed a questionnaire. Anna Zarogoza and Frances Herrera, sisters who work for Cooperative Extension's Expanded Family and Nutrition Education Program, started circulating the questionnaire throughout the Yakima Valley. But the key was their mother Julia Herrera's recipe.