Ordinary Surgical Masks No Worse Than N95 Respirator at Preventing Influenza

2 October 2009 (Reuters Health)—Surgical masks are noninferior to N95 respirators at protecting health care workers with high exposure from contracting influenza, according to North American researchers.

“Given the likelihood that N95 respirators will be in short supply during a pandemic and unavailable in many countries, understanding the relative effectiveness of personal respiratory protective equipment is important,” Dr Mark Loeb, from McMaster University in Hamilton, Ontario, and associates note in a report posted early online in the Journal of the American Medical Association on October 1.

To compare the 2 devices, the research team conducted a noninferiority trial among nurses at 8 hospitals in Ontario who cared for patients with febrile respiratory illnesses during the 2008–2009 influenza season. Of the 446 nurses originally randomized, 24 withdrew. The researchers analyzed results only for the remaining 212 in the regular surgical mask group and 210 in the N95 respirator group.

Fifty nurses in the surgical mask group (23.6%) and 48 in the N95 respirator group (22.9%) contracted laboratory-confirmed influenza, “indicating noninferiority of the surgical mask,” according to the article.

The authors caution that their findings apply to routine health care settings and “should not be generalized to settings where there is a high risk for aerosolization, such as intubation or bronchoscopy, where use of an N95 respirator would be prudent.”

Editor's comment. I have studiously avoided news about journal articles. I am deviating from that practice in this story because of the timeliness of this study and the Institute of Medicine's recent release advocating N95 masks for the routine care of patients with pandemic H1N1 influenza.

There was a recent report from China presented at the American Society for Microbiology meeting in San Francisco. The study, which involved close to 2000 hospital staffers in Beijing, showed that N95 respirators reduced the risk of respiratory illness by a significant 60% and the risk of confirmed influenza by 75%, whereas surgical masks had no effect. The great difference in outcome between the 2 studies may be explained by differences in compliance in wearing masks in China and North America.

Regardless of explanations, there is insufficient evidence at least in North America to recommend N95 masks for routine care of influenza patients, especially considering the discomfort and difficulty in wearing the masks properly and their much greater expense. (D.K.)

H1N1 Flu Taking off in US, Officials Say

9 October 2009 (Reuters Health [Maggie Fox])—The new pandemic of swine flu has killed 76 children in the United States (US) since it emerged in April and is worsening, US health officials said.

But researchers are reporting some good news about vaccines that may smooth efforts to immunize people against the pandemic and seasonal influenza at the same time.

Several studies have shown that most people, including children, who die from swine flu have comorbidities making them more susceptible, but some who are healthy are also dying, the Centers for Disease Control and Prevention (CDC) said.

“We saw a peak of pediatric deaths starting in April, May, June,” the CDC's Dr Anne Schuchat told reporters in a telephone briefing. “It's starting to shoot up again.”

The 76 deaths compare to 68 deaths from seasonal influenza from September 2008 to April 2009, the CDC said. Many of the children who have died had neurological conditions such as muscular dystrophy or cerebral palsy, the CDC said.

The CDC is trying to roll out vaccines against swine flu at the same time as an usually early campaign of vaccinating against seasonal influenza.

Officials predicted some bumps in the road and there have been some, with some counties suspending seasonal vaccination to make room for H1N1 vaccines.

But a new report suggests it may be easier to do this. Trials show that giving an H1N1 vaccine at the same time as a seasonal influenza vaccine causes no problems and people are fully protected, said Dr Anthony Fauci of the US National Institute of Allergy and Infectious Diseases.

Early results from trials of adults show those who received both vaccines at the same time had good immune responses, Dr Fauci told the briefing.

CDC monitoring shows that 6.1% of all deaths in the last week of September were due to pneumonia and influenza—just below the threshold for an epidemic, which is 6.4% of deaths. More than 99% of confirmed flu cases are from the new pandemic H1N1 virus.

New Rule Requires US Airlines to Monitor Water

6 October 2009 (Reuters Health)—United States (US) airlines will be required to regularly disinfect and monitor on-board drinking water systems under a new rule.

The Environmental Protection Agency (EPA) has for the first time tailored existing public water monitoring regulations to commercial aircraft.

The change, 5 years in the making and affecting 63 airlines and 7300 planes, will replace interim systems for monitoring bacteria and other pathogens that could sicken passengers.

The EPA expects the annual cost to the industry to be about $7 million. Airlines have 18 months to develop maintenance plans that comply with the standards.

Regulators found in 2004 that some US airlines were not in compliance with general clean water standards, mainly because existing EPA rules did not specifically cover on-board water systems.

The EPA ordered dozens of carriers to take steps to ensure that drinking water aboard their planes was clean.

Editor's comment. I have always had a great suspicion about airplane drinking water. I have advised travelers not to drink the water, especially when the airplanes were used for international flights to underdeveloped countries where water may have been onloaded. (D.K.)

US Should Watch for Animal Disease, Institute Says

22 September 2009 (Reuters Health [David Morgan])—The United States (US) needs to lead a global effort to protect people from new outbreaks of deadly infectious diseases that originate in animals, such as swine flu, AIDS, and SARS, health experts said.

Air travel, climate change, population growth, and rising demand for meat products from developing countries have accelerated the spread of “zoonotic” diseases, according to a panel set up by the Institute of Medicine and the National Research Council.

Species-jumping pathogens also pose special dangers for people because the human immune system can be ill-equipped to resist them.

But health authorities have no effective system that can stamp out new diseases as they arise among animals and humans.

“At the moment, it's like a wildfire,” said Dr Gerald Keusch of Boston University, who helped lead the committee that wrote the report. “We deal with it as an emergency. It costs huge amounts of resources. It would be a lot cheaper and cost-effective to have a system in place.”

The panel called for a sustainable, integrated surveillance system to monitor animal and human populations worldwide and for moving quickly to contain new outbreaks.

Such a system could have provided early detection for the H1N1 swine flu virus, which became a pandemic weeks after it emerged in North America in March, said the panel's other co-chair, Marguerite Pappaioanou of the Association of American Veterinary Medical Colleges.

“The swine influenza virus basically was circulating for probably about 10 years,” she said. “There also is evidence to suggest that the first opportunity for the swine virus to jump into people was probably during the summer of 2008.”

Severe acute respiratory syndrome, or SARS, which may have come from civets, circulated for months in southern China before it spread globally in 2003, killing 800 people before it was stopped. AIDS, which has killed 25 million people in 25 years, has been traced to chimpanzees.

The report, which was funded by the US Agency for International Development, suggested US Agency for International Development and the State Department lead the international effort to set up a global surveillance system, along with the World Health Organization and the United Nations Food and Agriculture Organization.

A fully integrated global system could cost about $800 million a year to maintain.

This is a relatively small sum compared with the $200 billion in economic losses caused by species-jumping viruses and other pathogens over the past decade, the panel said.

The report found that the US beef industry alone lost $11 billion in the 3 years after bovine spongiform encephalopathy, known commonly as mad cow disease, appeared in a few cattle in the US.

“Early detection of zoonotic disease emergence is essential to rapidly contain outbreaks,” the report emphasized.