FLU NEWS SCAN: H1N1 in babies, vaccination in pregnant women, H5N1 in Bhutan, estimating pandemic mortality

Apr 20, 2012

RSV infections more serious than pandemic H1N1 in French infants
A group of French researchers seeking to determine whether the 2009 H1N1 flu was as severe as had been anticipated in infants found that respiratory syncytial virus (RSV) infections were more problematic, according to a study published online Apr 18 in the Pediatric Infectious Disease Journal. All infants under 24 months of age who presented to the pediatric emergency department of the University Hospital of Caen, France, with respiratory symptoms from Nov 1, 2009, to Apr 15, 2010, were included in the study, whether inpatient or outpatient management resulted. Nasal swabs were obtained and specimens tested for a number of viruses including influenza A and B, RSV, adenoviruses, and parainfluenza viruses. A total of 1,021 swabs from 921 infants were obtained; the rate of virus detection was high (81.7%). The most common virus was RSV (34.3% of all samples), followed by rhinoviruses (23.9%), coronaviruses (9.3%), and 2009 H1N1 (7.7%). The overall hospitalization rate was 33.79%. RSV infections were much more likely to be severe than the other infections (odds ratio, 7.85), while the risks of severe illness and hospitalization were lower for pandemic H1N1 cases than for the other viruses. The authors comment that although other studies have found increased hospitalization rates and intensive care unit admissions in 2009 H1N1 cases, these studies have not focused on infants.
Apr 18 Pediatr Infect Dis J abstract

Study finds improved pregnancy outcomes with H1N1 vaccination
H1N1 vaccination in second- or third-term expectant mothers during the 2009 flu pandemic resulted in better fetal and neonatal outcomes, according to a Canadian study published online Apr 19 in the American Journal of Public Health. The study examined a population-based perinatal database in Ontario comprising 55,570 mothers with singleton births to identify preterm births (less than 32 weeks' gestation), small-for-gestational-age (SGA) births, 5-minute Apgar scores below 7, and fetal deaths. A total of 23,340 mothers (42%) had received an H1N1 vaccination during pregnancy. The authors found significant reductions in the risk of SGA babies (10% reduction), preterm babies (27%), and fetal deaths (34%) in the vaccinated mothers. But they said the findings need to be confirmed by further studies with designs that can better overcome concerns about biased estimates of vaccine efficacy.
Apr 19 Am J Public Health abstract

Bhutan reports H5N1 in backyard poultry
Livestock officials in Bhutan today reported that lab tests have detected H5N1 avian influenza in backyard poultry in Mongar district, according to a report from the World Organization for Animal Health (OIE). An outbreak killed 70 of 265 susceptible free-ranging chickens in Yangbari and Patong villages. Samples from one carcass tested positive for H5N1 in real-time polymerase chain reaction testing, but samples from 16 other birds were negative, according to the report. Since surveillance showed no other cases within 3 kilometers, officials said the event "could be a suspected H5N1 outbreak." The source of the virus is unknown. Mongar district is located in eastern Bhutan.
Apr 20 OIE report

WHO reports progress on H1N1 pandemic mortality estimates
The World Health Organization (WHO) is working on a preliminary global mortality estimate for the 2009 H1N1 pandemic, and it recently posted an update on the work of a technical expert group that is in the early stages of gauging the impact. Two teams are working with the WHO to produce independent estimates with different methods, one from the US Centers for Disease Control and Prevention and one from the Netherlands Institute for Health Services Research. A technical committee that is overseeing the groups' work met in late October to review preliminary results and give feedback on the modeling processes. The WHO has said the number of confirmed 2009 H1N1 pandemic deaths is a gross underestimate, for several reasons. It said better estimates of the cases and deaths are needed to better understand the impact of the pandemic and how it measures up historically. "While the data for a definitive estimate of mortality will likely not exist for several years, and will never exist for some parts of the world, a preliminary estimate would be useful in the short term, and would serve to give a more realistic understanding of the true impact of the event than currently available reported mortality figures," the WHO said. Initial work presented at the October meeting was based on limited data from industrialized countries. As the next step, more countries, including some middle- and low-income countries, will provide data for the project this year, which should help the two groups further refine their estimates by the end of the year.
Apr 18 WHO statement

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