Oct 12, 2010
Review: Vaccinating health workers may not lower flu in nursing homes
After poring through more than 1,000 potentially relevant articles, researchers have concluded that studies of the effects of healthcare worker (HCW) vaccination on influenza in elderly residents of long-term care facilities are few and flawed and the data inconclusive. The three scientists, two of whom are affiliated with the Cochrane review system, searched seven electronic databases. They identified only four randomized controlled trials (RCTs, from 1997, 2000, 2006, and 2009) and one observational study (from 2000) that addressed the topic with enough specificity to be included in the review. Pooled data from three of the RCTs showed that HCW vaccination had no effect on serologically proven influenza, pneumonia, or deaths from pneumonia but did show lower all-cause mortality and influenza-like illness (ILI). However, because flu causes less than 10% of all deaths even in epidemic years, the authors questioned the appropriateness of using all-cause mortality as an outcome measure. Also, because flu constitutes less than 25% of ILI and the data did not show a reduction in serologically proven flu, they also questioned whether the reductions in all-cause mortality and ILI were due to confounding.
Oct 10 Vaccine abstract
New antiviral looks good in Asian clinical trial
The new, long-acting influenza drug laninamivir compared well with oseltamivir (Tamiflu) in an international clinical trial involving close to 1,000 participants, according to a report published by Clinical Infectious Diseases. Laninamivir is an inhaled neuraminidase inhibitor that was recently approved in Japan under the name Inavir but has not been licensed in the United States. In the study, researchers from Japan, Taiwan, Korea, and Hong Kong used a double-blind, randomized, controlled design to assess whether laninamivir was noninferior to oseltamivir. They assigned 1,003 adult patients with "febrile influenza symptoms" to receive either one 40-mg dose of laninamivir, one 20-mg dose of laninamivir, or 5 days of oseltamivir treatment (75 mg twice a day). The patients started treatment within 36 hours of onset of illness. The median time to illness alleviation was 73.0 hours for the 40-mg laninamivir group, 85.8 hours for the 20-mg group, and 73.6 hours for the oseltamivir group. The percentage of patients who were shedding virus on day 3 was significantly lower in the 40-mg laninamivir group than in the oseltamivir group. The study was supported financially by Daiichi Sankyo, maker of laninamivir.
Oct 11 Clin Infect Dis study abstract
Adults were hard-hit by HUS in E coli O111 outbreak
An analysis of hemolytic uremic syndrome (HUS) cases linked to a 2008 outbreak of Escherichia coli O111, an unusual strain, found that the attack rate was similar to that for the more common E coli O157:H7, but adults were unusually hard-hit. Researchers from the US Centers for Disease Control and Prevention and the Oklahoma State Department of Health published the findings yesterday in the Archives of Internal Medicine. The outbreak, which struck patrons of a Locust Grove, Okla., restaurant, was the nation's largest involving the E coli O111 strain. The contamination source was never identified. The outbreak sickened 341 people and led to 72 hospitalizations and 1 death. Of the 156 confirmed and probable case-patients, 26 had HUS. Unlike in other E coli outbreaks, which usually hit young children hardest, adults accounted for three quarters of hospitalizations and close to 60% of HUS cases in the Oklahoma outbreak. Signs on hospital admission that were linked to HUS included elevated initial white blood cell count and creatinine levels and vomiting.
Oct 11 Arch Intern Med abstract
WHO official says dengue cases have doubled in past decade
A World Health Organization (WHO) official said global dengue fever cases have doubled in the last 10 years, and the toll is significantly worse this year than it was last year, according to an Oct 10 Xinhua report. Shin Young-soo, the WHO's Western Pacific regional director, made the comments at a press conference in Kuala Lumpur, Malaysia. He said dengue has become the fastest-growing mosquito-borne disease in the world. The reasons for the increasing toll are unknown but may include rising temperatures, increased rainfall, urbanization, and better surveillance for the disease, Shin said. The story said Malaysia's health ministry recorded 37,419 dengue cases from January through Oct 2 of this year, a 17% increase over the same period last year. Meanwhile, the health ministry said it had obtained permission from Malaysia's National Biosafety Board to release genetically modified mosquitoes in an effort to stop the spread of dengue, according to the story. The ministry said offspring of the modified mosquitoes die in the larval stage.
Oct 10 Xinhua report