You can pretty much put a mark in your calendar for when the annual flu epidemic begins. Using 20,000 virus samples and weather statistics, researchers have now discovered more details about how outdoor temperature and flu outbreaks are linked.
“According to our calculations, a cold week with an average temperature below zero degree Celsius precedes the start of the flu epidemic” says Nicklas Sundell, a researcher at Sahlgrenska Academy and infectious diseases specialist at Sahlgrenska University Hospital.
The study comprised three seasons and 20,000 virus samples taken with nasal swabs from people who sought medical care in the Gothenburg area. The incidence of respiratory viruses was then compared over time with weather data from the Swedish Meteorological and Hydrological Institute (SMHI) and the results are clear: Flu outbreaks seem to be activated about one week after the first really cold period with low outdoor temperatures and low humidity.
Kickstarting the epidemic
“We believe that this sudden drop in temperature contributes to “kickstart” the epidemic. Once the epidemic has started, it continues even if temperatures rise. Once people are sick and contagious, many more may become infected,” says Nicklas Sundell.
The study supports the theory that aerosol particles containing virus and liquid are more able to spread in cold and dry weather. If the surrounding air is dry, it absorbs moisture and the aerosol particles shrink and can remain airborne.
Of interest, according to the researchers, is the predictable timing with the flu outbreak each studied season starting the week after a cold snap.
Nicklas Sundell says that, at least at our latitudes, this is probably a more important factor for the flu epidemics than indoor crowding during poor weather wintertime.
Other viruses too
“Cold and dry weather and small aerosol particles are important perquisites for the flu epidemic to take off. But cold weather isn’t the only contributing factor. The virus has to be present among the population and there have to be enough people susceptible to the infection,” he says.
The study shows that weather conditions are not only important for the seasonal flu (Influenza A), but also for a number of other common viruses that cause respiratory tract infections, such as RS-virus and coronavirus. These viruses seem to have the same behavior with a significant increase of incidence during cold and dry weather. On the other hand some viruses such as rhinovirus, that are a common cause of cold, are independent of weather factors and is present all year around.
“If you can predict the start of the annual epidemics of the flu and other respiratory viruses, you can use this knowledge to promote campaigns for the flu vaccine and prepare emergency wards and hospital staff in advance for an increased number of patients seeking care. The recommendations are the same as previous years: vaccination of risk groups, cough and sneeze into your elbow, and remember to wash your hands,” says Nicklas Sundell.
Link to the study: https://www.ncbi.nlm.nih.gov/pubmed/27723525
Principal investigator: Nicklas Sundell +46 (0)709 581 504, +46 (0)31-343 43 31; firstname.lastname@example.org
Press contact: Margareta Gustafsson Kubista +46 (0)705 301 980; email@example.com
Thomas Melin | idw - Informationsdienst Wissenschaft
New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)
Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy