Flu Patients at Risk of Developing Sepsis

“First of all, sepsis can be caused by any sort of infection, including influenza. Sepsis can be viewed as an inappropriate response to an infection. So, viral infections can lead to sepsis as much as bacterial infections, fungal infections, or even parasitic infections. There also is a secondary connection that occurs. It is relatively common for people who get severely ill with influenza to also be at higher risk of developing a secondary infection with a bacteria—in particular, bacterial pneumonia. So, patients may end up with influenza and particularly influenza pneumonia, then subsequently develop a bacterial infection that can lead to sepsis,” he says.

Sepsis is the cause of death for many influenza patients, O’Brien says. “Annually, there about 200,000 hospitalizations that are associated with influenza, and there are around 40,000 deaths. If you look within those deaths, there is a significant number of patients who end up dying of sepsis, either associated with the influenza or a bacterial infection.”

It can be difficult to diagnose sepsis in influenza patients, he says.

“The good news with influenza is we have good diagnostics for determining whether someone has influenza. The challenge that we have is isolating the people who feel terrible with influenza versus someone who subsequently develops organ failure and sepsis, where they are at higher risk of dying. It gets tough when people ask, ‘When should I know to go see a doctor?’ We talk about having an elevated temperature due to sepsis, but influenza can result in a temperature of 103 in adults. A high temperature does not necessarily mean you are developing sepsis. Generally, we talk about if patients are feeling the worst they have ever felt; but for young and healthy people, those symptoms can be driven by influenza.”

Changes of cognitive status in influenza patients can indicate the development of sepsis, O’Brien says. “One of the big triggers in influenza patients that indicates the development of sepsis is if someone’s brain is not working the way it should be working. You may not be able to wake the patient. They may be confused. Those are real warning signs of someone who has developed complications beyond just feeling terrible with influenza, and they should seek help.”

There also are risk factors for sepsis in influenza patients, he says.

“Extremes of age are a risk factor—children under 5 and adults over 65. Those extremes are at much higher risk for influenza complications, including sepsis. The farther you get to the age extremes, the higher the risk of sepsis. So, children less than 2 are at greater risk than children less than 5, and adults over 80 are at greater risk than adults over 65. Pregnant women with influenza are at risk of developing sepsis—there are certain races and ethnicities of pregnant women who are at higher risk of developing sepsis. It appears that Native Americans and Alaskan Natives are at higher risk of complications from influenza such as sepsis compared to White populations. Influenza patients with chronic medical conditions such as diseases that affect the immune system are at higher risk for sepsis. People who live in long-term nursing facilities or skilled nursing facilities are other people that we worry about.”

The best way to prevent sepsis in the context of influenza is to get a flu shot, O’Brien says. “Flu shots are not perfect, but they are the best form of protection against severe disease from influenza, including sepsis. If you look at patients who progress enough that they need to be on a ventilator, people who did not get vaccinated are six times more likely to be on a ventilator from influenza than those people who got vaccinated. So, flu shots are the first line of defense.”

Taking measures that prevent the spread of infection are also important to avoid sepsis developing from influenza, he says. “Washing hands frequently is helpful. Covering our mouths when we sneeze or cough is helpful. If we are sick, not being around other people is helpful. Those measures work.”

The Sepsis Alliance offers resources on influenza and sepsis, including a sepsis and flu webpage that features infographics and information guides as well as a free webinar for healthcare professionals.