Nov 28, 2011
Biosecurity panel said to be reviewing another H5N1 transmissions study
An unpublished study by Dutch scientist Ron Fouchier on the transmission of mutant H5N1 virus in ferrets is not the only such experiment currently being scrutinized because of concern that it could be exploited by bioterrorists, according to a recent report in ScienceInsider. A similar study by virologist Yoshihiro Kawaoka of the University of Wisconsin and the University of Tokyo is also being reviewed by the US National Science Advisory Board for Biosecurity (NSABB), according to the story, which cited unnamed scientists as sources. Both papers have been submitted to journals for publication. In the Fouchier study, an H5N1 virus with five known mutations became capable of airborne transmission after it was passed between ferrets 10 times, according to previous reports. The Kawaoka study had "comparable results," according to ScienceInsider. Dr. Paul Keim, NSABB chair, said he couldn't discuss specific studies but predicted that the board would issue a public statement soon and is likely to make additional recommendations about "dual use" research. In an interview, Fouchier told ScienceInsider that the US National Institutes of Health funded his experiment without giving it a special review and has agreed to publication of the findings. Keim said he agrees with those who argue that dual-use studies should be reviewed before they are conducted, not afterward. The NSABB lacks the authority to prevent publication of dual-use research papers, but it could ask journals not to publish, the story said. Another option in such cases is to recommend the omission of key details from the published version, said Michael T. Osterholm, director of the University of Minnesota's Center for Infectious Disease Research and Policy (CIDRAP), who was quoted in the story.
Nov 23 ScienceInsider story
Nov 17 CIDRAP News story
Study finds rapid flu tests have low specificity in older H1N1 patients
Rapid tests showed good sensitivity for detecting pandemic H1N1 in young children, but sensitivity decreased with age., according to a study in Influenza and Other Respiratory Viruses. Investigators analyzed 1,373 specimens received by the New Hampshire Public Health Laboratories from Sep 1 through Dec 31, 2009, 269 of which tested positive for pH1N1 by polymerase chain reaction. They found clinical sensitivity and specificity of RIDTs across all age-groups to be 53.9% and 98.5%, respectively. By age-group, sensitivity was 85.7% in patients 2 years old and younger, 60.3% in patients from 2 to 39 years old, and 33.3% in those 40 or older. (High sensitivity means the test will miss few true-positives.) The authors conclude, "Findings from this study may impact a clinician's interpretation of RIDT test results and ultimately have implications in clinical decision-making."
Nov 24 Influenza Other Respi Viruses abstract
Study: T-cell response common, cross-reactive after 2009 pandemic
Almost 60% of Canadians had CD8 T-cell responses to pH1N1 8 to 10 months after the second pandemic wave, but the responses appeared to be cross-reactive, according to a study by Toronto scientists. They analyzed samples from 105 blood donors using flow cytometry and microneutralization assays and found that 61 (58%) had T-cell responses. The magnitude of response, though, was similar in cases and controls and in the vaccinated and unvaccinated, suggesting the response was transient, according to the authors. Also, similar recall responses to the pH1N1 and a seasonal H1N1 virus were observed. In addition, those who were vaccinated within a few months after infection had the highest persisting antibody titers, suggesting that vaccination shortly after infection may bolster antibody levels. The team also conducted a longitudinal analysis on one 55-year-old patient, which showed a small, transient increase in neutralizing antibody levels after infection but a robust CD8 T-cell response that rose rapidly after symptom onset, peaked at 3 weeks, and then declined gradually to the baseline levels seen in the cohort patients.
Nov 23 PLoS One study
Underlying heart disease, obesity may herald more serious H1N1 with diabetes
Patients with diabetes who contracted pH1N1 flu were more likely to suffer worse outcomes if they had an additional underlying condition, Spanish researchers report in the Journal of Infection. Among 252 people with diabetes and lab-confirmed pH1N1, only 15.9% had no additional underlying medical condition. The team found that 38% of the diabetes cohort were admitted to an intensive care unit (ICU), compared with 27.4% of patients without diabetes. Thirty patients with diabetes and 15 without died (11.9% vs 6%). Multivariate analysis showed that heart disease (odds ratio [OR], 2.28), morbid obesity (OR, 2.08), and antiviral treatment started later than 48 hours after symptom onset (OR, 1.89) were independent risk factors for ICU admission.
Nov 25 J Infect abstract