# 4231
While primarily considered a respiratory illness in humans, over the past few years we’ve seen increasing evidence that suggests that Influenza A (and perhaps B) may have a gastrointestinal connection – particularly in children - as well.
Diarrhea and other gastrointestinal manifestations have been reported with some frequency in both the H5N1 virus, and the novel H1N1 pandemic virus.
The CDC, last October, released this guidance on infection control for HCWs (Health Care Workers).
Interim Guidance on Infection Control Measures for 2009 H1N1 Influenza in Healthcare Settings, Including Protection of Healthcare Personnel
October 14, 2009, 2:00 PM ET
EXCERPT
Modes of 2009 H1N1 Influenza Transmission
2009 H1N1 influenza virus appears to be transmitted from person to person through close contact in ways similar to other influenza viruses. Although the relative contribution of each mode is uncertain, influenza virus can potentially be transmitted through:
- Droplet exposure of mucosal surfaces (e.g., nose, mouth, and eyes) by respiratory secretions from coughing or sneezing;
- Contact, usually of hands, with an infectious patient or fomite (a surface that is contaminated with secretions) followed by self-inoculation of virus onto mucosal surfaces such as those of the nose, mouth, and eyes; and
- Small particle aerosols in the vicinity of the infectious individual.
Transmission of influenza through the air over longer distances, such as from one patient room to another, is thought not to occur. All respiratory secretions and bodily fluids, including diarrheal stools, of patients with 2009 H1N1 influenza are considered to be potentially infectious.
Jason Gale of Bloomberg News picks up the story, with news of a new study that appears in the BMC Journal. I’ve a link and excerpts from the abstract following the Bloomberg story.
Diarrhea May Be Source of Influenza Infection, Researchers Say
January 08, 2010, 04:59 AM ESTBy Jason Gale
Jan. 8 (Bloomberg) -- Diarrhea in flu-infected children may harbor the virus, scientists found, pointing to a previously unrecognized source of infection.
Tests on 733 children with influenza-like illness and an upset tummy found a minority of patients had seasonal strains in their stool and live viral particles were retrieved from one case. The finding, published yesterday in the journal BioMed Central, suggests that flu may invade the gastrointestinal tract, potentially acting as a mode of transmission.
The research may help explain why gastric symptoms, including diarrhea and vomiting, afflicts about one in five people with swine flu, the H1N1 strain that emerged last year and touched off the first influenza pandemic in 41 years. The study is believed to be the largest to investigate flu virus detected in the gastrointestinal tract of children with flu-like illness and diarrhea, the authors wrote.
The provisional abstract from BMC Infectious Diseases. A hat tip to Sharon Sanders of FluTrackers for this link.
Research article
Influenza virus infection among pediatric patients reporting diarrhea and influenza-like illness
Charisma Dilantika , Endang R Sedyaningsih , Matthew R Kasper , Magdarina Agtini , Erlin Listiyaningish , Timothy M Uyeki , Timothy H Burgess , Patrick J Blair and Shannon D Putnam
BMC Infectious Diseases 2010, 10:3doi:10.1186/1471-2334-10-3
Published: 7 January 2010
Abstract (provisional)
Background
Influenza is a major cause of morbidity and hospitalization among children. While less often reported in adults, gastrointestinal symptoms have been associated with influenza in children, including abdominal pain, nausea, vomiting, and diarrhea.
Methods
From September 2005 and April 2008, pediatric patients in Indonesia presenting with diarrhea and influenza-like illness were enrolled in a study to determine the frequency of influenza virus infection in young patients presenting with symptoms less commonly associated with an upper respiratory tract infection (UTI). Stool specimens and upper respiratory swabs were assayed for the presence of influenza virus.
Results
Seasonal influenza A or influenza B viral RNA was detected in 85 (11.6%) upper respiratory specimens and 21 (2.9%) of stool specimens. Influenza B virus was isolated from the stool specimen of one case. During the time of this study, human infections with highly pathogenic avian influenza A (H5N1) virus were common in the survey area. However, among 733 enrolled subjects, none had evidence of H5N1 virus infection.
Conclusions
The detection of influenza viral RNA and viable influenza virus from stool suggests that influenza virus may be localized in the gastrointestinal tract of children, may be associated with pediatric diarrhea and may serve as a potential mode of transmission during seasonal and epidemic influenza outbreaks.
The complete article is available as a provisional PDF. The fully formatted PDF and HTML versions are in production.
