( CNN ) -- I started to see influenza-like illnesses starting roughly around mid-December , and within a week knew that 2013 was going to be a bad year . In my 12 years of practice in Chicago , this flu season definitely ranks as one of the worst I 've seen . However , I also see no reason to be alarmed that we have a public health threat . What we are dealing with is a well-known virus . This outbreak is worse than average due to , more than anything , poor timing . There are three main factors to consider in evaluating the intense flu activity across the country . One is the virus itself . Both the medical community and the general public alike worry someday we will encounter a `` superbug . '' We fear a virus that is extremely potent at causing disease , replicating , resisting our treatment and killing the host . Though the predominant strain this year may be slightly more potent than average based on the number of cases we are seeing , there is no indication that this virus is markedly different from what we 've seen in other years . Opinion : Next time , get vaccinated earlier . The percentage of influenza-related deaths is not higher than in previous outbreaks . The CDC also has found no viral strains this season that are resistant to neuraminidase inhibitors , the drugs that we use to treat patients once they develop the flu . So , we need not worry too much about the virus . The second factor to consider is the effectiveness of the flu shot . This year 's flu vaccine is well matched to the strains of flu that have been circulating . According to the CDC , more than 90 % of the identified viral types are covered by the current vaccine . In other words , we can not blame an ineffective vaccine for the bad outbreak . Finally , we need to look at environmental factors . The unusually warm weather this winter should not be contributing to the severity of the outbreak . Why ? Because last year , it was also unusually warm , and at the time we hypothesized the weather was partly responsible for a milder than normal flu season . Clearly , warm weather ca n't both enhance and suppress the spread of influenza . Instead , we must focus on what 's different from previous years . Unlike last year , when the flu showed up late , this flu season came early . Most importantly , the peak incidence of illness happened to coincide almost exactly with the onset of the holiday season , which is critical to take into account . If someone were trying to develop a way to disseminate an illness , he would first devise a way to weaken the population 's immune system , and then bring people together to spread the disease . In essence , that is what the holiday season does . Opinion : America flunks its health exam . Because of holiday preparations and parties , people tolerate less sleep . Stress around the holidays generally goes up . Combine those with poor eating habits and overindulgences that are typical in festive times , and the immune system gets weakened . Once a person contracts the flu virus , he or she is contagious approximately 12 to 24 hours before the peak onset of symptoms , and is often contagious up to 24 hours after resolution of fever . During this very social time of year , many of these sick people are either tolerating their symptoms to join big groups of friends or family , or coming together honestly unaware that they are contagious . As a result , we have the perfect storm for the spread of influenza . In sum , our flu season this year is simply a product of poor timing . Health : Your top flu questions answered . The peak onset of the flu just happened to coincide with a period when we have weakened our immune system and congregated in large gatherings to , among other things , disseminate disease . There is no supervirus . The flu strains have been well anticipated and carry no resistance to our treatment . We have no reason to panic . I recommend that everyone de-stress from the holiday stresses , wash their hands , eat healthy , exercise and get plenty of sleep . Stay home if you are sick . And in good time , this too shall pass . The opinions expressed in this commentary are solely those of David Zich .
: ) : This flu season definitely ranks as one of the worst I ' ve seen . Zich : This outbreak is worse than average due to , more than anything , poor timing . He says the time period was the perfect storm for the spread of influenza . Zich : The peak onset of the flu coincided with a time when our immunity was down .