People with influenza symptoms are often told to stay home from work or school, which is why scientists need to understand how household transmission works and how to control it, not only in responding to H1N1 but also in preparing for future pandemics.
Anne Marie France, PhD, MPH, and her colleagues at the New York City Department of Health and Mental Hygiene and the Centers for Disease Control and Prevention (CDC) surveyed household members of ill students from the New York City high school where the H1N1 outbreak was first documented in April 2009. Because H1N1 was not yet established in the community, secondary cases of influenza-like illness were most likely acquired at home. One-third of the school's students were sick with influenza and told to stay home, and 322 households representing 702 household contacts responded to the survey. Seventy-nine contacts reported influenza-like illness, representing an 11.3 percent secondary attack rate (SAR), with half of the cases occurring within three days and 87 percent within seven days after the initial student reported symptoms.
Having a household discussion about how to prevent transmission was associated with a 40 percent reduction in risk for influenza among others in the household. Providing care for the sick student increased the risk among parents, the researchers found, while watching television and playing video games with the student was a risk factor for siblings.
The finding that a household discussion had a protective effect is especially relevant, given that a vaccine might not be available early in a pandemic. "This is important because it indicates that behavioral changes can be effective in decreasing the risk for secondary illness within a household," Dr. France said. "Understanding the risk and prevention factors that determine household transmission is very important to containing influenza, particularly if the strain of influenza is severe, and it is determined that attempting to contain it is critical to the national management of a pandemic."
The study also found that the risk of acquiring influenza-like illness was most strongly related to age, with the highest SAR (30 percent) among contacts under 5 years of age and the lowest (2.1 percent) in those aged 55 or older. The findings highlight that children can be the principal spreaders of an infection in the early stages of an epidemic, especially in the household, and suggest children should be the focus of preventive measures.
Future studies on household transmission "should attempt to measure the details of interaction between ill and initially non-ill household members," Dr. France noted, such as hand washing and covering coughs, to determine how these behaviors, in addition to minimizing time spent with ill household members, factor into preventing transmission.
In an accompanying editorial, Ruth Lynfield, MD, of the Minnesota Department of Health, agreed and observed that the findings "are useful in reinforcing public health recommendations for infection control within households of infected individuals." When early action is most important at the beginning of a pandemic, Dr. Lynfield wrote, implementation is best reinforced by "data that support simple interventions in the household that are important for infection prevention."
The study also found a protective effect associated with preventive antiviral treatment, or prophylaxis. But the authors and the accompanying editorial highlight reports of the development of antiviral resistance and the need to reserve these drugs for influenza patients most at risk for developing complications, in line with recommendations from the Centers for Disease Control and Prevention (CDC).
- A household discussion about influenza prevention and transmission reduced the risk of family members passing on the virus to each other by 40 percent.
- Transmission of the virus was rapid, with half of secondary influenza cases (in which one family member infected another) occurring within three days and almost 90 percent within one week.
- To help prevent the spread of influenza, cover your nose and mouth when you cough or sneeze. Wash your hands often with soap and water.
Founded in 1904, The Journal of Infectious Diseases is the premier publication in the Western Hemisphere for original research on the pathogenesis, diagnosis, and treatment of infectious diseases; on the microbes that cause them; and on disorders of host immune mechanisms. Articles in JID include research results from microbiology, immunology, epidemiology, and related disciplines. It is published under the auspices of the Infectious Diseases Society of America (IDSA). Based in Arlington, Va., IDSA is a professional society representing more than 9,000 physicians and scientists who specialize in infectious diseases.
John Heys | EurekAlert!
Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel
Oxygen loss in the coastal Baltic Sea is “unprecedentedly severe”
05.07.2018 | European Geosciences Union
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
19.07.2018 | Earth Sciences
19.07.2018 | Power and Electrical Engineering
19.07.2018 | Materials Sciences