TWiV 58: Nipah virus in ferrets

twiv-200Hosts: Vincent Racaniello, Dick Despommier, Alan Dove, and Joshua Stillman

In episode 58 of the podcast “This Week in Virology”, Vincent, Dick, and Alan are joined by emergency medicine physician Dr. Joshua Stillman to talk about passive antibody therapy for Nipah infection in ferrets, annual influenza immunization of children, facemasks to prevent influenza, predicting dengue outbreaks by the weather, and the amazing viral communities in an icy Antarctic lake.

Click the arrow above to play, or right-click to download TWiV #58 (52 MB .mp3, 73 minutes)

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Links for this episode:

Weekly Science Picks
Dick Science News article: Enter the Virosphere
Alan WHO H1N1 timeline interactive map
Vincent
Cheap Google accounts storage and How CDC estimates flu cases

Send your virology questions and comments (email or mp3 file) to twiv@microbe.tv or leave voicemail at Skype: twivpodcast. You can also send articles that you would like us to discuss to delicious and tagging them with to:twivpodcast.

TWiV 53: The ends justify the means

twiv-200Hosts: Vincent Racaniello, Dick Despommier, and Alan Dove

In episode #53 of the podcast “This Week in Virology”, Vincent, Dick, and Alan talk about Nobel prizes for telomere research, bacteriophages that protect aphids from wasps, salicylates and pandemic influenza mortality, and hand washing.

Click the arrow above to play, or right-click to download TWiV #53 (45 MB .mp3, 62 minutes)

Subscribe to TWiV in iTunes, by the RSS feed, or by email

Links for this episode:

Weekly Science Picks
Alan scienceline
Dick Younger by Judith Sulzberger MD
Vincent FluView

Send your virology questions and comments (email or mp3 file) to twiv@microbe.tv or leave voicemail at Skype: twivpodcast. You can also send articles that you would like us to discuss to delicious and tagging them with to:twivpodcast.

Spit Shields UP H1N1: EMS Garage Episode 51

ems-garageThis week I had the pleasure of joining Chris Montera and his friends on “EMS Garage”, a weekly podcast for Emergency Medical Services professionals. We discussed basic information about the 2009 pandemic influenza H1N1 strain such as transmission and immunization plans, and what EMS personnel can do to help prevent the spread of infection.

It was a pleasure podcasting with this crew – they are engaging and proud of their work. They are the ones who respond to emergencies, so head on over to EMS Garage to find EMS news, ambulance information, information for paramedics and EMTs, education, and just general fun. Listen to episode #51 to learn why Chris called it “Spit Shields UP H1N1”.

Personal protective equipment and influenza

N95We’ve had several discussions on the value of personal protective equipment (PPE) in preventing influenza infection. CIDRAP has an excellent summary of an Institute of Medicine meeting on this subject. The IOM has been asked to make recommendations about how to protect healthcare workers against swine-origin H1N1 influenza.

An unpublished study of respiratory protection in hospital workers in Beijing compared the effectiveness of surgical masks, fit- and non-fit tested N95 respirators in conferring protection from clinical respiratory illness, influenza-like illness, and laboratory confirmed influenza. Surgical masks were not effective, while those wearing N95 masks had 75% protection against influenza. Whether the N95 was fit-tested or not made no difference.

Also discussed were the findings of a published comparison of surgical masks and P2 respirators (similar to N95) in Australian homes in which a child had respiratory illness. There was a four-fold reduction in clinical illness for individuals wearing either mask. Slides describing the Beijing and Australian findings are available as a pdf.

In another study in Hong Kong, households were divided into three groups. One group was given only basic health education, while the second group was told to practice hand hygiene with soap and an alcohol hand rub. The third group of households used hand hygiene and surgical face masks. The investigator concluded that “substantial and significant benefits of face masks and hand hygiene if implemented within 36 hours of index case symptom onset.” The slides from this presentation are available as a pdf.

Here is information from the Food and Drug Administration on N95 face masks:

An N95 respirator is a respiratory protective device designed to achieve a very close facial fit and very efficient filtration of airborne particles. In addition to blocking splashes, sprays and large droplets, the respirator is also designed to prevent the wearer from breathing in very small particles that may be in the air.

To work as expected, an N95 respirator requires a proper fit to your face. Generally, to check for proper fit, you should put on your respirator and adjust the straps so that the respirator fits tight but comfortably to your face. For information on proper fit, refer to the manufacturer’s instructions.

The ‘N95’ designation means that when subjected to careful testing, the respirator blocks at least 95% of very small test particles. If properly fitted, the filtration capabilities of N95 respirators exceed those of face masks. However, even a properly fitted N95 respirator does not completely eliminate the risk of illness or death.

N95 respirators are not designed for children or people with facial hair. Because a proper fit cannot be achieved on children and people with facial hair, the N95 respirator may not provide full protection.

What does all this mean? If you wear an N95 properly and continuously, it will confer some protection against respiratory infection. But it won’t help if you poke a hole in the N95 to enable cigarette smoking.

MacIntyre, C. (2009). Face Mask Use and Control of Respiratory Virus Transmission in Households Emerging Infectious Diseases, 15 (2), 233-241 DOI: 10.3201/eid1502.081167