CLINICAL MATTERS

The news spread like wildfire. Or, perhaps more appropriately, it went viral. Barbie Hsu, the Taiwanese superstar well-known to Filipino audiences as the actress from the 2018 megahit drama series Meteor Garden had just succumbed to complications of influenza. She was only 48 years old. Reports stated that she was not in the best of health and had comorbid conditions. She contracted the flu while traveling with her family in Japan. She did seek medical attention and some reports say she or her family requested discharge despite medical advice for hospitalization. Unfortunately, she got worse and eventually died. 

How can someone die from the flu? While most people recover from a bout of influenza, some develop a bad pneumonia that requires hospitalization and antiviral treatment. If Barbie Hsu, may she rest in peace, did have other comorbid conditions, especially a chronic lung illness like asthma, she would have had a higher risk of developing severe viral pneumonia. Most people who are infected with influenza only have the virus replicating in their upper airways – the mouth, nose and throat. While this can cause fever, muscle aches, coughing, and a runny nose, it usually clears up with only symptomatic treatment. Occasionally, the virus can infect the lower airways and the lungs and this can cause unchecked inflammation and hypoxia as white blood cells and mucus flood the air sacs and impede oxygen exchange. This process results in viral pneumonia. Once pneumonia occurs, things can get worse really quickly and progress to a condition known as acute respiratory distress syndrome or ARDS. ARDS is what killed many of the severe cases of Covid-19 during the pandemic. Even with proper care, a significant number of people still die from ARDS.

Even if the flu virus doesn't end up causing viral pneumonia, post-viral bacterial pneumonia can occur because the immune system and lungs get beaten up badly by the virus. One particularly bad bacteria that can cause post-viral pneumonia is Staphylococcus aureus, especially a drug-resistant strain called Methicillin-Resistant Staphylococcus aureus or MRSA for short. Patients who get MRSA pneumonia can deteriorate very quickly because MRSA is a very aggressive pathogen once it establishes itself in the lungs. MRSA can then cross over to the bloodstream and cause sepsis and septic shock which have a very high mortality.

Based on the different timelines reported in the media, it sounds like Hsu could have had either severe viral pneumonia or she may have had a post-viral bacterial infection on top of the flu. Some reports stated that she initially felt well enough to ask to be discharged from a clinic but ended up getting readmitted and then quickly deteriorated and died. This is consistent with post-viral bacterial pneumonia because the improvement would have meant she didn’t have viral pneumonia initially. This is also consistent with a later report that she died of septic shock. Other reports state that she wasn’t getting better but she declined an offer to transfer to a hospital and continued to deteriorate in her hotel, prompting her family to rush her to a nearby clinic. This would be more consistent with primarily viral pneumonia. Both processes can be deadly and can progress very fast. Unfortunately, Hsu died despite being admitted to a medical facility. Either way, whether directly or indirectly, she died because of influenza.

Elderly people, those with comorbid conditions, and immunocompromised individuals are at higher risk for severe pneumonia from influenza, whether it is viral or post-viral bacterial pneumonia. For these patient populations, the flu can be a life-threatening illness, just like Covid-19 and RSV (respiratory syncytial virus). As we get older, our immune systems start to decline, a phenomenon known as immune senescence. In addition, our body accumulates damage over time which leads to an increase in inflammation as we age. This phenomenon, known as “inflammaging,” further weakens the immune system and diminishes our body’s ability to fight off infection. This is why severe infections from respiratory viruses are more common in the aging population.

How does one lower the risk of dying from the flu? Getting an annual flu shot is recommended for everyone. It doesn't always prevent the flu but it substantially decreases the risk of severe pneumonia and the risk of ending up in the ICU or worse, especially for those in the high-risk populations. Wearing a medical-grade mask or better, especially during flu season can give significant protection from infection. Proper cough and cold etiquette as well as frequent hand-washing can help decrease the risk of transmitting the virus to others. Ensuring good ventilation in closed and crowded areas likewise helps reduce the spread of respiratory viruses. Even those who aren't immunocompromised or elderly are advised to get the vaccine anyway because it decreases the probability of transmitting the virus to someone who is at higher risk. It also decreases the risk of being absent from work or school because flu symptoms can be quite debilitating even if they aren’t deadly most of the time. Vaccines and masking up aren't 100% effective, but both significantly decrease the risk of severe disease and may be the difference between life and death in high-risk populations.

While seasonal flu strains are well adapted to the human body and have relatively low mortality, we know that the influenza virus, especially influenza A, is always mutating and can give rise to the next pandemic. Hsu’s unfortunate death is just a reminder that the threat of an influenza outbreak with a more deadly strain such as avian influenza can kill a lot of people. The OG pandemic virus remains the flu, and the OG pandemic influenza is the 1918 Spanish Flu which killed up to 100 million people. With the erosion of vaccine confidence from antivaxxer disinformation, the defunding of critical government agencies such as the US CDC which monitors outbreaks of influenza, and the overall denigration of public health standards, the risk of a new influenza outbreak getting out of control is very real. If that happens again and millions of people die, no one will ever make the mistake of saying that it’s just the flu.