A recent University of Guadalajara study has revealed that quesos frescos (fresh cheeses) such as panela, adobera and cotija sold in tianguis (street markets) could contain as much as 100 bacteria of salmonella per gram.

Many rustically produced traditional Mexican cheeses are made from unpasteurized milk and are prepared in “deplorable hygienic conditions,” Maria Refugio Torres, the coordinator of the investigation told Spanish-language daily Mural this week. Even though the cheese may look good and be fresh and nutritious, it can be a potential health hazard if it was not prepared or stored properly. Even storing cheeses in the refrigerator may not be enough to kill salmonella bacteria, she noted.

About 120,000 people were taken ill by salmonella in Mexico last year, according to Mexican health authorities – three times the number reported in the United States. The total figure of people poisoned in both countries, however, is likely to be many times higher. The U.S. Center for Disease Control admits that because many milder cases are not diagnosed or reported (sufferers often tough out the sickness), the actual number of infections may be 30 or more times greater.  If that is the case, the number of people stricken by salmonellosis in Mexico each year may be as high as four or five million.

Disease-causing Salmonella species are classified into a single species, Salmonella enterica, which can cause diarrhea, fever and abdominal cramps lasting four to seven days. Some strains, such as Typhi, which can cause typhoid fever, require antibiotics and often hospitalization.

Under pressure after the recent tomato scare, Mexican Health Secretary Jose Angel Cordova Villalobos has played down the salmonella issue in Mexico. He said authorities here have not identified the salmonella Saintpaul strain that by July 13 had caused at least 1,146 cases of salmonellosis food poisoning in 43 U.S. states. However, Enrique Sanchez Cruz, director of Mexico’s Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria, told the website The Packer En Español that six cases with this particular serovar linked to meat had been detected.

Jalisco was one of three Mexican states U.S. authorities identified as being potential sources of the recent salmonellosis outbreak. According to the Associated Press, the U.S. Food and Drug Administration sent inspectors to check Bonanza 2001, a tomato growing operation in Autlan, Jalisco, that exports 12,000 tons of tomatoes a year to the United Sates.  With this week’s all-clear notice, Bonanza  tomatoes that were being held in warehouses on the U.S. border can now be moved to their final destinations, although some of the produce may no longer be fit for consumption.

U.S. CENTER FOR DISEASE CONTROL GUIDELINES ON PREVENTING SALMONELLOSIs:

• Cook poultry, ground beef and eggs thoroughly. Do not eat or drink foods containing raw eggs, or raw (unpasteurized) milk.
• If you are served undercooked meat, poultry or eggs in a restaurant, don’t hesitate to send it back to the kitchen for further cooking.
• Wash hands, kitchen work surfaces, and utensils with soap and water immediately after they have been in contact with raw meat or poultry.
• Be particularly careful with foods prepared for infants, the elderly, and the immunocompromised.
• Wash hands with soap after handling reptiles, birds, or baby chicks, and after contact with pet feces.
• Avoid direct or even indirect contact between reptiles (turtles, iguanas, other lizards, snakes) and infants or immunocompromised persons.
• Don’t work with raw poultry or meat, and an infant (e.g., feed, change diaper) at the same time.