I belong to the Infectious Diseases Society of America (what a conversation starter that is at a cocktail party?!?!) and find much of their research most interesting. ;-) The Society has just released a couple of intriguing research papers at their national meeting in Philadelphia. I thought they were worth exploring here online.
YOUNGER CHILDREN WITH H1N1 MAY HAVE LONGER VIRAL SHEDDING THAN OLDER CHILDREN & ADULTS
Influenza A (H1N1) virus was detected by a sophisticated lab test (real time reverse transcriptase polymerase chain reaction) in young patients for up to 13 days after onset of fever, according to results presented at the 47th Annual Meeting of the Infectious Diseases Society of America by an Epidemic Intelligence Service Officer from the CDC.
The researchers conducted a telephone survey to identify elementary school students or household contacts of elementary school students with influenza-like illness onset within seven days of the survey. The study was conducted in May – June 2009 in Pennsylvania. Among 36 specimens from students or contacts with influenza-like illness, 26 were identified as having 2009 H1N1 by real-time reverse transcriptase-polymerase chain reaction (PCR) test. Specimens were also tested by viral culture for the presence of H1N1.
Further analysis by real-time PCR determined that the median duration of viral shedding was six days (range 1 to 13 days) after the onset of fever. Further analysis by culture determined that the median duration that viable H1N1 was detected was five days (range 1 to 7 days) after the onset of fever.
Real-time PCR detected virus for a median of three days following the resolution of fever. Virus was detected by culture an average of two days after the resolution of fever.
In the study, younger children were observed to have prolonged viral shedding, as compared to older children and adults, which is consistent with earlier studies of seasonal influenza.. However, the results of the study should be interpreted carefully, because detection of virus may not mean that patients are likely to transmit the virus to others. More research is required to determine that factor.
This is one of the first studies to determine the duration of viral shedding during the current pandemic and one of the first among children.
TIMING OF ANTIVIRAL THERAPY REMAINS UP FOR DEBATE
The recommended 48-hour window in which to initiate antiviral therapy for the treatment of influenza A (H1N1) remains an ongoing source of concern for clinicians, according to opinions expressed at a press conference at the 47th Annual Meeting of the Infectious Diseases Society of America.
Stephen Redd, MD, chief of the Air Pollution and Respiratory Health Branch in the National Center for Environmental Health at CDC, provided an overview of the epidemiology of the disease in the context of this issue; Arnold Monto, MD, professor of epidemiology at the University of Michigan School of Public Health, attempted to clear up misconceptions regarding influenza A (H1N1) treatment.
”] Monto also discussed the 48-hour mark as the recommended time point for whether to administer treatment or not. “The take-home message about when to treat with the current recommendations is that you might be delayed with treatment because the case may look like ordinary H1N1 and not one of the so-called more severe cases,” he said. “But with the shedding data that we now know about, you can still get an effect later on in treatment. So do not stick with the package insert and the two days.”