What's Going ’Round Right Now?

CAP No. 21093-30
CLIA No. 45D0927522

Urgent updates about viral activity will be posted here:

7/31/09 Summer Flu Season Continues - Influenza A virus continues to circulate in Houston. Over 96% of influenza A virus detected in our laboratory specimens currently is subtype novel H1 swine. Small numbers of influenza A subtype seasonal H3 have also been detected. We will continue to update you on the circulating influenza types and subtypes through the Summer, Fall and Winter seasons.

4/23/09 - Influenza Update from Diagnostic Virology Laboratory at Texas Children's Hospital - Swine Flu Alert - Twocases of swine influenza H1N1 virus have been confirmed in April 2009 in children from Texas. Another five cases have been confirmed in California. Even though our usual seasonal influenza virus season has declined, please continue to consider influenza in the differential diagnosis of patients with febrile respiratory illness or other influenza-like illnesses or complications that may be associated with influenza in children. It also is very important samples for influenza testing (Rapid Flu A/B and viral culture) be sent on patients who present with influenza-like illnesses. All samples positive for influenza A virus by rapid tests or viral culture will be sent immediately for subtyping. To date, all influenza A H1N1 subtypes have been A/Brisbane/59/2007-like; NO novel swine influenza – like H1N1 subtypes have been reported from Texas Children's patients to this date.

See the news release below provided for more information. Detailed information may also be viewed at www.cdc.gov

Thank you,
Gail J. Demmler-Harrison, M.D.
Director, Diagnostic Virology Laboratory
Texas Childrens Hospital
Dept of Pediatrics
Baylor College of Medicine
gjdemmle@texaschildrenshospital.org

Texas Department of State Health Services

News Release

April 23, 2009 - Two Human Cases of Swine Flu Confirmed in Texas

The Texas Department of State Health Services today announced that swine flu has been confirmed in two 16-year-old boys from Guadalupe County near San Antonio. One became ill on April 10, the other on April 14. Their illnesses were relatively mild. Neither was hospitalized. Both have recovered. Though the boys are friends, it has not been determined how either became infected.

Laboratory test results received today from the U.S. Centers for Disease Control and Prevention indicate that the illnesses were caused by a swine influenza A (H1N1) virus. Preliminary lab data suggests that the virus closely matches the viruses from recent swine flu infections in human cases from Southern California.

State public health officials are investigating to determine if any close contacts of the boys have become ill and are asking hospitals, doctors and others in the area to be especially alert for other possible cases.

DSHS and local public health agencies in Texas were already involved in a CDC-led swine flu investigation because one of the two original cases from Southern California, a 10-year-old boy, traveled to Dallas for an extended visit with relatives. No additional cases connected to the boy have been confirmed.

Initial information from the investigation of the two teenagers' illnesses indicates no recent travel and no connection to the boy who traveled to Dallas from Southern California.

Symptoms of swine flu in people are similar to those of regular or seasonal flu and include fever, lethargy, lack of appetite and coughing Some with swine flu also have reported runny nose, sore throat, nausea, vomiting and diarrhea.

Health officials say the public should follow standard precautions to reduce the spread of any respiratory illness.

• Stay home when you are sick to avoid spreading illness to others.
• Cough or sneeze into the crook of your elbow or a tissue and properly dispose of used tissues.
• Wash hands frequently and thoroughly with soap and warm water or use an alcohol-based hand sanitizer.

GovDelivery, Inc. sending on behalf of the Texas Health and Human Services Commission · 4900 North Lamar Blvd · Austin TX 78751 · 1-800-439-1420

1/20/09 - Flu Update - Results from the first six influenza type B viruses isolated from children evaluated at Texas Children’s during December 2008 show all six were B/OHIO/01/2005-LIKE viruses, members of a Victoria-lineage type B that is NOT in this season’s flu vaccine. All six influenza type B viruses were sensitive to both oseltamivir and zanamivir.

Results from January 2009 influenza A and B viruses we submitted for antigenic and genetic analysis have not yet been reported. Stay tuned for updates as they are received http://www.bcm.edu/web/pediatrics/documents/nws1_2009.pdf

1/13/09 – Flu Update -I have received many inquiries by phone and e-mail about our recent influenza updates, so I have sent this flu update with information on the top four questions I have received.

Question One

What antiviral should we use if we decide to treat a patient with influenza?

Answer – Influenza B – oseltamivir or zanamivir may be appropriate. Influenza A – depends on the subtype. Is it H1N1 or H3N2. The currently circulating H1N1 appears to be resistant to oseltamivir, but sensitive to zanamivir, amantadine and rimtantadine. The currently circulating H3N2 appears to be sensitive to oseltamivir and zanamavir, but resistant to amantadine and rimantadine. If you don’t know the type or sub-type, some experts suggest you consider zanamivir (if appropriate) or combination therapy with oseltamivir and rimantadine/amantadine. The first two Influenza A viruses isolated from children evaluated at Texas Children’s in December 2008, during the early part of the flu season, were sub-typed as H1N1 virus and have now been reported from CDC to be sensitive to the adamantanes (amantadine and rimantadine). They were originally also found to be sensitive to zanamivir and resistant to oseltamivir. So they matched national trends summarized below:

On a national basis, the patterns of antiviral resistance that are being identified and reported by the CDC, based on a small number (less than 200) influenza types and subtype isolated and characterized so far are summarized as follows:

• Type A H1N1 98% resistant to oseltamivir 100% sensitive to zanamivir 100% sensitive to amantadine and rimantadine.
• Type A H3N2 100% sensitive to oseltamivir 100% sensitive to zanamivir 100% resistant to amantadine and rimantadine.
• Type B 100% sensitive to oseltamivir 100% sensitive to zanamivir 100% always resistant to amantadine and rimantadine (intrinsic).

Note -- Flu B is co-circulating with Flu A, and Flu A H1N1 appears to be more common than Flu A H3N2 currently in the early season, but this could change as the season unfolds.

Question Two

Are the circulating influenza viruses covered in the current flu vaccines?

Answer – Each year, the influenza vaccine has two A strains and one B strain. The first two influenza A H1N1 viruses from Texas Children’s Hospital were strains covered in this season’s vaccine. On a national basis, so far, based on just over 100 influenza viruses antigenically characterized:

The good news - Both influenza type A H1N1 and H3N2 viruses appear related to the influenza A H1N1 and H3N2 components of this season’s vaccine.

The other news - Two circulating strains of influenza B viruses have been identified and only one of them appears related to this season’s vaccine.

We have not received final reports from our other influenza A and B viruses sent to CDC at this time. Updates will come as they arrive.

Question Three

Why don’t we have two type B influenza viruses in the flu vaccine each year?

Answer – That’s a good question. I don’t know.

Question Four

Have we had any pediatric deaths yet from influenza?

Answer - No, we have not had any influenza-associated pediatric mortality reported from Texas Children’s, but one influenza-associated pediatric mortality has been reported nationally.

A complete national summary of the 2008-2009 influenza season can be found at the following CDC link: http://www.cdc.gov/flu/weekly/

Staying current on influenza surveillance, including subtypes and antiviral resistance, is now important for patient care. For a quick 30 minute CME on pediatric influenza, co-sponsored by Texas Children's and BCM, see the following BCM CME link: http://www.baylorcme.org/flu

1/8/09 - Flu Update – The first two influenza A viruses isolated from children evaluated at Texas Children’s in the first week of December have now been subtyped as H1N1 and characterized as A/Brisbane/59/2007-like. This same influenza A virus subtype was included in the 2008/2009 Northern Hemisphere and the 2009 Southern Hemisphere influenza vaccines formulations. Also, both of these influenza A viruses were found to be resistant to oseltamivir (Tamiflu) and sensitive to zanamivir (Relenza). Another batch of influenza A and B viruses isolated from children evaluated at Texas Children’s later in December have already been sent to the CDC for analysis and we will update you as new information arrives.

1/5/09 - Both influenza A and influenza B virus have been isolated from children recently evaluated at Texas Children's. Therefore, both types of influenza virus appear to be circulating at this time. In addition, subtyping and antiviral resistance testing on the first two influenza viruses isolated from children s evaluated earlier this season at Texas Children's show that both influenza viruses were type A, subtype H1N1, and both were resistant to oseltamivir (Tamiflu) and both were sensitive to zanamivir (Relenza). We will continue to send all available influenza virus isolates for subtyping and antiviral resistance testing and we will update you as information becomes available.

Please also refer to our current newsletter for monthly summary.

Summary of Rapid Test Results - 2009