NEWS SCAN: Flu and birth weight, pandemic planning in Asia, listeriosis investigation, flies as Salmonella vectors

Jun 6, 2011

Studies: Pregnant women with flu more likely to bear smaller infants
Two studies appearing in an American Journal of Obstetrics and Gynecology (AJOG) supplement showed that maternal influenza infection leads to lower birth weight in newborns. The first study looked at data from all singleton births in Nova Scotia from 1990 through 2002 and compared outcomes between women with and without hospital admission for respiratory illness during influenza season at any time during their pregnancies. Infants born to the hospitalized mothers were more likely to be small for gestational age (15.3% vs 9.7%) and to have a lower average birth weight by about 5 ounces (3,348 g [7 lb, 4 oz] vs 3,531 kg [7 lb, 9 oz]).
Jun AJOG seasonal flu study
The second study, from Brown University, found that pregnant women with 2009 H1N1 pandemic flu infections gave birth to smaller babies than did those who had influenza-like illness (ILI). Researchers studied 41 pregnant women who received care at Women and Infants' Hospital of Rhode Island, 16 of whom had 2009 H1N1 flu and 25 who tested negative for 2009 H1N1 but had ILI. They found that birth weights in the 2009 H1N1 group were on average 285 grams (10 oz) lower (3,186 g vs 3,471 g). Three of the infants born to H1N1-infected women were admitted to neonatal intensive care.
Jun AJOG pandemic H1N1 study

Report outlines post-H1N1 pandemic planning steps for Asia
Scientists from Singapore, China, Malaysia, South Korea, and Vietnam concluded in a recent report that Asia, despite years of pandemic preparation, was not ready to respond to pandemic 2009 H1N1 flu and that efforts to ensure equitable sharing of limited resources such as antiviral drugs and vaccines fell short. Among the lessons learned, according to the report: (1) An emerging flu pandemic, regardless of severity, places a huge burden on the healthcare system and will expose its weaknesses; (2) containment measures did little to keep the novel virus out of countries; (3) antiviral stockpiles and plans overly relied on one oral form and had poor distribution plans; (4) some countries failed to engage local practitioners; (5) hospitals had suboptimal infection-control practices; and (6) important clinical research was underused.
Jun 2 Respirology abstract

Investigation of Listeria outbreak finds prompt cheese recall was key
Analysis of a 2008-09 multistate outbreak of listeriosis involving almost exclusively pregnant Hispanic women concluded that recalls of contaminated cheese likely prevented further illnesses. Researchers, writing in the Journal of Food Protection, identified eight patients in five states who became ill from October 2008 to March 2009 and had a Listeria monocytogenes isolate matching the outbreak strain on pulsed-field gel electrophoresis (PFGE). Of those, seven were pregnant Hispanic women from 21 to 43 years old who had all consumed Mexican-style cheese in the month before they became sick (the eighth was a 3-year-old Hispanic girl whose case was not included in the study). Cultures of asadero cheese made from pasteurized milk collected at a manufacturer yielded the outbreak strain, leading to a recall of cheeses produced in the plant. The authors conclude, "This investigation highlights the usefulness of routine product sampling for identifying contaminated foods." They also reported that PFGE analysis was useful in detecting multistate outbreaks.
Jun J Food Prot abstract

Flies may be vectors in Salmonella transmitted between farms
Researchers who recovered Salmonella isolates from flies and swine stool samples said their testing showed that flies may be a transmission vector for the pathogen. They collected 144 Salmonella samples from farms in northwestern Taiwan and found 14 serotypes, eight of which were present in samples from both flies and swine stool. A total of 71.5% were resistant to at least three antibiotics, and some multidrug-resistant strains were identified on PFGE as coming from different farms. The authors conclude, "The similarity in PFGE profiles between isolates from swine and flies in different farms indicate the potential of flies to serve as a vector for transmission."
Jun J Food Prot abstract

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