It Might Not Just Be Flu: Secondary Infections Can Be Dangerous

Each year influenza affects millions of Americans, and while most people recover from the flu without consequences, even young healthy adults can develop life-threatening complications like septic shock and pneumonia. In 2017, Kyler Baughman, a 21-year old fitness buff from Pennsylvania, developed a runny nose and mild cough while visiting at his family over the Christmas holiday.  Several days later he was in the emergency room suffering from flu-related sepsis. Sadly, this completely healthy young man rapidly declined and lost his battle within 24 hours of admission to the hospital.1

Kyler was among the 61,000 Americans who died during the 2017-2018 flu season, the highest flu-related mortality in over a decade. The current 2019-2020 season is on track to be at least as severe, and in fact pediatric deaths have already doubled this year compared to the 2017-2018 season. 2

Influenza infection typically leads to debilitating symptoms such as fever, cough, headache, muscle aches, fatigue, and dehydration.  Most patients improve spontaneously within a couple of weeks, but some will develop more serious complications such as viral pneumonia, myocarditis, encephalitis.  The most severe consequence of the flu is the risk of secondary bacterial infections such as pneumonia and sepsis.  These infections occur 3–7 days after the initial influenza infection and are associated with high mortality.3  Young children, the elderly, and people with chronic illnesses are at highest risk, but as Kyler’s case illustrates even healthy young adults may be affected.  This is because influenza causes excessive inflammation that can lead to life-threatening organ dysfunction and weaken the immune system so that patients are more susceptible to bacterial infections.4,5,6 Interestingly, the deadly flu epidemic of 1918 disproportionately affected young healthy adults and pregnant women, due to both the exaggerated immune response that develops in this population and the resulting bacterial infections like sepsis and pneumonia.7  In fact, one of the most important bacteria responsible for these infections, Haemophilus influenzae, was originally given its name because it was frequently found in people who died of the flu.8

Flu patients may present to the emergency department with severe dehydration or signs of more serious infections.  Adequate and timely fluid resuscitation is critical for these patients, but it is particularly important for those with suspected sepsis.  Repeated studies have demonstrated that earlier fluid resuscitation for patients with septic shock results in better patient outcomes and lower mortality.9,10  Providers may be concerned that since many of these patients also have pneumonia, fluid therapy may increase the risk of respiratory failure.  The opposite is actually true, since earlier fluid resuscitation targeted at reversal of shock and hypotension in patients with sepsis actually reduces the need for endotracheal intubation and the length of ICU stay.10  While conservative fluid management in the ICU does improve outcomes for critically ill patients with pneumonia and ARDS, patients with sepsis-associated ARDS who do not receive adequate fluids in the first hours of care have worse outcomes.10,11

The severity of the current flu season is a reminder of the life-threatening complications that can occur and the need for early recognition and treatment of secondary bacterial infections like sepsis.  For patients with septic shock, quick recognition and early administration of fluids and antibiotics can be lifesaving.

Interested in learning more about rapid, controlled delivery of a fluid bolus with LifeFlow? Contact us.



1.  Bever L. “He was fit and 21. He tried to push through the flu and it killed him.”Washington Post. 11 Jan 2018.

2.  Advisory Board Daily Briefing. 14 January 2020.

3.  Kalil AC, Thomas PG. Influenza virus-related critical illness: pathophysiology and epidemiology. Crit Care. 2019;23(1):258. doi:10.1186/s13054-019-2539-x.

4.  Joyce EA, et al. (2009). Streptococcus pneumoniae nasopharyngeal colonization induces type I interferons and interferon-induced gene expression. BMC Genomics 10:404

5.  Bucasas  KL, et al. (2013). Global gene expression profiling in infants with acute respiratory syncytial virus broncholitis demonstrates systemic activation of interferon signaling networks. Pediatr. Infect. Dis. J. 32, e68–e76.

6.  Kimaro M. S., Peret T. C., Kumar N., Romero-Steiner S., Dunning H. J., Ishmael N., et al. (2013). Transcriptional adaptation of pneumococci and human pharyngeal cells in the presence of a virus infection. BMC Genomics 14:378 10.1186/1471-2164-14-378.

7.  Morris DE, Cleary DW, Clarke SC. Secondary Bacterial Infections Associated with Influenza Pandemics. Front Microbiol. 2017;8:1041. doi:10.3389/fmicb.2017.01041.

8.  Nicola J, High NJ, Fan F, Schwartzman JD. Chapter 97 – Haemophilus influenzae. Molecular Medical Microbiology (2nd Edition). Volume 3, 2015, Pages 1709-1728. doi:10.1016/B978-0-12-397169-2.00097-4.

9.  Kuttab HI, et al. Evaluation and predictors of fluid resuscitation in patients with severe sepsis and septic shock. Crit Care Med. 2019;47(11):1582-1590.

10.  Lee SJ, et al. Increased fluid administration in the first three hours of sepsis resuscitation is associated with reduced mortality: a retrospective cohort study. Chest. 2014;146(4):908-915.

11. Murphy CV, Schramm GE, Doherty JA, et al. The importance of fluid management in acute lung injury secondary to septic shock. Chest. 2009;136(1):102-109.