ABSTRACT
We describe multiple-aetiology infections involving non-O157 Shiga toxin-producing Escherichia coli (STEC) identified through laboratory-based surveillance in nine FoodNet sites from 2001 to 2010. A multiple-aetiology infection (MEI) was defined as isolation of non-O157 STEC and laboratory evidence of any of the other nine pathogens under surveillance or isolation of >1 non-O157 STEC serogroup from the same person within a 7-day period. We compared exposures of patients with MEI during 2001-2010 with those of patients with single-aetiology non-O157 STEC infections (SEI) during 2008-2009 and with those of the FoodNet population from a survey conducted during 2006-2007. In total, 1870 non-O157 STEC infections were reported; 68 (3.6%) were MEI; 60 included pathogens other than non-O157 STEC; and eight involved >1 serogroup of non-O157 STEC. Of the 68 MEI, 21 (31%) were part of six outbreaks. STEC O111 was isolated in 44% of all MEI. Of patients with MEI, 50% had contact with farm animals compared with 29% (P < 0.01) of persons with SEI; this difference was driven by infections involving STEC O111. More patients with non-outbreak-associated MEI reported drinking well water (62%) than respondents in a population survey (19%) (P < 0.01). Drinking well water and having contact with animals may be important exposures for MEI, especially those involving STEC O111.
Subject(s)
Escherichia coli Infections/epidemiology , Escherichia coli Infections/etiology , Shiga-Toxigenic Escherichia coli , Zoonoses/etiology , Zoonoses/microbiology , Adolescent , Adult , Aged , Aged, 80 and over , Animals , Animals, Domestic/microbiology , Campylobacter Infections/etiology , Child , Child, Preschool , Cryptosporidiosis/etiology , Escherichia coli O157/isolation & purification , Female , Humans , Infant , Male , Middle Aged , Population Surveillance , Risk Factors , Salmonella Infections/etiology , Shiga Toxin/isolation & purification , Shiga-Toxigenic Escherichia coli/isolation & purification , United States/epidemiology , Young Adult , Zoonoses/epidemiologyABSTRACT
Fundamental investigations of the chemical and physical properties of metal beta-diketonate complexes have revealed unusual volatility, as well as solvolytic and thermal stability and solubility in organic solvents. Certain general rules describing the volatility of metal beta-diketonates on the basis of ligand shell character and metal ion size have arisen from extensive gas chromatographic and vapor pressure studies. Several practical applications of volatile beta-diketonates teke advantage of their special properties. In ultratrace metal analysis by gas chromatography, use of these chelates has allowed the detection of smaller amounts of certain metals than can be detected by any other analytic method. Certain rare earth beta-diketonates have been found useful as antiknock additives in gasoline and as catalysts for the removal of carbonaceous deposits from the combustion chambers of internal combustion engines.
