Soft Cheese Risks
Soft white cheeses made with raw milk present a health risk, the U.S. Food and Drug Administration has warned. Such cheeses can cause listeriosis, brucellosis, salmonellosis, and tuberculosis, and they pose a particular risk to pregnant women, newborns, older adults, and those with weakened immune systems.
Consumption of queso fresco-style cheeses that were imported from or eaten in Mexico were linked with recent cases of tuberculosis in New York City and found to be contaminated with Mycobacterium bovis, according to the FDA. The cheeses of greatest concern are those originating in Mexico and Central American countries and include queso panela, asadero, blanco, and ranchero. The FDA has warned against consumption of any unripened raw-milk soft cheeses, including those obtained at flea markets or from door-to-door sellers or vendors selling out of their trucks.
TB Trends
The tuberculosis case rate in the United States is declining, but the rate of decline from 2003 to 2004 was the lowest in a decade, and racial disparities remain a concern, according to the Centers for Disease Control and Prevention.
More than 14,500 cases of TB were reported in the United States in 2004, for a case rate of 4.9 per 100,000. This is the lowest rate ever recorded, but the 3.3% decline from 2003 was smaller than the 6.8% average annual decline between 1993 and 2002. In 2004, minority populations had significantly higher TB rates than the overall U.S. average: The case rate was 26.9/100,000 in Asians, 11.1/100,000 in blacks, 10.1/100,000 in Hispanics, and 1.3/100,000 in whites.
Furthermore, foreign-born individuals have a case rate of 22.5/100,000, compared with 2.6/100,000 for U.S.-born persons, and the decline in the TB rate over the last 12 years among foreign-born individuals has been only 34%, compared with 65% among U.S.-born persons.
TB remains a health threat that must be taken seriously, according to the CDC, which is stepping up disease elimination efforts, in part by strengthening global partnerships to address TB among the hardest-hit populations.
HCV and Iron Stores
Hepatitis C virus infection is significantly associated with increased serum levels of ferritin and iron, the third National Health and Nutrition Examination Survey shows.
Among more than 14,400 U.S. residents who participated in NHANES III, nearly 1% had HCV infection. Mean serum levels of ferritin and iron were significantly higher in those with HCV infection, compared with individuals with no liver disease (100 ng/mL vs. 83 ng/mL for ferritin; 229 mcg/dL vs. 101 mcg/dL for iron), reported Ying Shan, M.D., and colleagues at the University of Connecticut, Farmington.
Furthermore, serum levels of ferritin and iron were directly correlated with serum concentrations of ALT, AST, and γ-glutamyl-transpeptidase (Clin. Infect. Dis. 2005;40:834-41).
It remains unclear whether higher iron levels—which have been shown in other studies to be associated with increased risk for persistent viral infection and decreased response to treatment—raise the risk for chronic HCV, or if liver damage increases iron levels, the investigators said. Regardless, it is likely that excess iron contributes to hepatic injury and fibrosis, they concluded, noting that improved understanding of the link between iron levels and liver disease is important for devising strategies to prevent associated morbidity.
Pseudomonas Infections
Health care providers who identify cases of infection with Pseudomonas species in patients with central venous catheters should determine if the patient received a heparin/saline flush recalled earlier this year, and should report cases by calling 800-332-1088 or going to
www.fda.gov/medwatch/report.htm
The flush, preloaded in syringes by IV Flush and distributed by Pinnacle Medical Supply, was initially linked with four cases of P. fluorescens bloodstream infections. The FDA issued an alert, and the company recalled the products.
The syringes had been distributed to locations in as many as 17 states, and in an ongoing investigation, 36 associated cases have been identified.
Infections have occurred up to 1 month after receipt of the product; catheters used infrequently can become colonized, and symptoms may not develop until the catheter is used.
Because susceptibility patterns of isolates from affected patients have varied—with some showing resistance to third-generation cephalosporins and carbapenem antibiotics—treatment of potential patients should include targeted antimicrobial therapy. Catheter removal should be considered as well.