Jan 6, 2011
Study: Thermal scanners aren't good flu finders
In a trial of thermal scanners in an airport setting, the devices were moderately successful at detecting fever but didn't perform well at flagging passengers with influenza, New Zealand researcher report in Public Library of Science (PLoS) One. They conducted the study during part of the 2008 Southern Hemisphere flu season (Aug 21 through Sep 12). The dominant strain was influenza B, which is less likely to cause febrile illness than influenza A strains. The study included 1,275 airline passengers who were flying from Australia to Christchurch, New Zealand. Passengers underwent thermal scanning and agreed to tympanic temperature measurement and respiratory sampling. Researchers found 0.5% were febrile and that the positive predictive value (PPV) of thermal screening was 1.5%. They identified influenza in 30 of the travelers, but none of them had fever upon tympanic measurement, and only 3 were symptomatic. The PPV of thermal scanning for flu was 2.8%. The researchers concluded that thermal scanning is not likely to be effective for detecting flu in travelers, even when influenza A is more common, and probably won't help stop infected travelers from entering a country.
Jan 5 PLoS One abstract
Salmonella outbreak from sprouts grows to 112
Eighteen more patients have been sickened in a Salmonella I 4,,12:i:- outbreak linked to an Illinois company's alfalfa sprouts, raising the total to 112, the US Centers for Disease Control and Prevention (CDC) said today. Two more states, Colorado and Kentucky, reported their first cases, raising the number of affected states to 18, plus the District of Columbia. The latest illness onset date is Dec 24, and the hospitalization rate for patients for whom information is available is 24%, the same as in the CDC's last update on Dec 28. No deaths have been reported. About half of the cases are from Illinois, and many of the sick people ate sandwiches containing sprouts at Jimmy John's outlets. An investigation into the source of contamination is ongoing.
Jan 6 CDC outbreak update
Simple screen ID's salmonellosis from consumer complaints
Researchers from the University of Minnesota and the Minnesota Department of Health have developed a tool for screening consumer complaints to identify likely cases of salmonellosis, according to a study in the current issue of the Journal of Food Protection. They examined previous illness complaints in which the causative agent had been identified and developed a predictive model for Salmonella. They then tested variations that maximized sensitivity, specificity, and predictive ability, with the three versions providing sensitivities and specificities of 32% and 96%, 100% and 54%, and 89% and 72%, respectively. The screen that provided the best predictive ability for Salmonella was a caller reporting diarrhea and fever with no vomiting, and five or fewer people sick. They write, "Screening calls for etiology would help identify complaints for further follow-up and result in identifying Salmonella cases that would otherwise go unconfirmed; in turn, this could lead to the identification of more outbreaks." The team published in November 2010 in the same journal a report on a statewide consumer complaint surveillance system that uncovered 79% of foodborne outbreaks in Minnesota in the study period, including 25% of salmonellosis outbreaks.
Jan J Food Prot abstract
Nov 2010 J Food Prot abstract