Flu Season: Northern Hemisphere Update

Tuesday Jan. 24, 2017

Flu Season: Northern Hemisphere Update

Flu season has begun in the Northern Hemisphere, which typically peaks between December and March. Some regions are reporting an increase in cases earlier than anticipated, while influenza activity in other regions remains consistent with past flu season trends. Cases will likely continue to increase in coming weeks across the Northern Hemisphere.

Seasonal influenza can be prevented by receiving the annual influenza vaccine, which protects against three strains of influenza: one strain each of A(H1N1), A(H3N2), and an influenza B strain. Quadrivalent vaccination, offering protection against an additional influenza B strain, is also available in some regions.

Download the iJET Health Intelligence preparedness infographic, Top 6 Tips for Workplace Wellness this Flu Season.



Influenza cases in Europe began increasing mid-November, which is earlier than in recent years. Cases typically increase in the region between the beginning to mid-December. According to the European Center for Disease Prevention and Control (ECDC), the intensity of influenza activity Jan. 2-8, 2017 was high in Finland, France, Greece, Malta, Sweden, and the Ukraine, while both Macedonia and Albania reported very high intensity levels (map, seasonal flu activity in Europe). The influenza A strain has been predominant in confirmed cases, accounting for over 95-percent of influenza activity in Europe. Influenza cases across Europe have primarily been found in adults over the age of 65 years.

As of Jan. 11, health authorities in France have reported more than 6,000 seasonal influenza cases since Oct. 12. This number of cases compares to fewer than 300 cases reported during the same period in the previous season. According to French health officials, all provinces in France have surpassed epidemic thresholds.

In Spain, more than 700 cases have been confirmed as seasonal influenza as of Jan. 8, 2017 since the start of the of the 2016-2017 flu season in mid-October. Spanish health officials report the incidence rate of influenza is 174.5 cases per 100,000 people and activity has been reported countrywide; however, the risk of infection has been highest in Asturias Region. According to media reports, many local hospitals are overwhelmed by the high number of patients seeking treatment, resulting in longer wait times prior to evaluation. While hospital administrators are ordering additional beds to meet the demand, a few weeks may elapse before hospitals are fully equipped to handle the current flu season.

North America


Influenza season activity in North America began to cross baselines in Canada and the US in late December, while cases in Mexico remain low. The most common strain in North America is also influenza A, accounting for 98-percent of cases in Canada, over 70-percent in Mexico, and over 95-percent of cases in the US. Cases continue to increase throughout the region.

In Canada, nearly 9,000 confirmed influenza cases were reported between mid-October and Jan. 7. According to Canadian health officials, influenza season began earlier when compared to the 2015-2016 season. Officials further stated that Canada is likely already approaching the peak of the influenza season.

As of Jan. 7, over 6,000 confirmed cases of influenza have been reported in the US since Oct. 2, 2016, compared to only 1,237 confirmed cases reported during the same period in the previous season. Influenza activity is widespread in 21 states and Puerto Rico (map, U.S. 2016-2017 flu activity), according to the US CDC.

In both the US and Canada, many hospitals have implemented restricted visitor policies to reduce the number of people capable of spreading influenza in a healthcare setting. Some hospitals have gone a step further and asked the public to only seek medical attention in emergency rooms if the patients symptoms are severe.

Influenza activity in Mexico is currently lower than the past five years between October to Jan. 12. Only 381 confirmed cases of influenza have been reported in Mexico this season, while in the same period during the 2015-2016 season over 550 confirmed cases were reported and nearly 1,800 confirmed cases were reported during the 2014-2015 season. Disease activity in Mexico typically begins to increase steadily in December, before peaking in March. It is highly likely that activity during 2016-2017 will increase in the coming weeks as the influenza season progresses, though cases may fluctuate weekly.


The risk of contracting seasonal influenza in the northern hemisphere is increasing. Like all respiratory diseases, individuals can reduce their risk of influenza infection by taking strict respiratory hygiene precautions: washing hands regularly and avoiding large crowds or apparently sick individuals. However, because influenza can be spread before symptoms are apparent, these measures are only partially effective. All individuals, unless medically contraindicated, should be vaccinated. These immunizations protect against influenza infection within 2-3 weeks of immunization.

Influenza does not need to reach pandemic status to affect business continuity; seasonal influenza accounts for USD billions per year in economic losses in the US alone. With the influenza activity expected to continue for the coming weeks, it's not too late to implement preventative measures. Has your office properly prepared for the flu season? Check out our blog post Is Your Workplace Prepared for Cold & Flu Season? to see how your preparations measure up!

Catie Comer joined iJET International in 2015 as a Response Coordinator and became a Health Intelligence Analyst in 2016. She obtained her bachelor’s degree from Shepherd University where she also attended Paramedic School. Catie went on to volunteer with the Fairfax County Fire and Rescue Department for seven years. Prior to working at iJET, Catie was a 9-1-1 dispatcher for Fairfax County for seven years.


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