Are there different mortality rates for various viruses causing hypoxemia?
Hypoxemia (low blood oxygen) can be caused by many viruses, including SARS-CoV-2, influenza, and respiratory syncytial virus (RSV). A large study from 2022–2023 directly compared outcomes among these viruses. The short answer is that mortality rates do differ by virus type, even when hypoxemia rates are similar.
What the research says
A large US cohort study of over 835,000 patients tested for SARS-CoV-2, influenza, and RSV found that the frequency of hypoxemia was similar across viruses: about 8% for SARS-CoV-2, 7.7% for influenza, and 9.3% for RSV 2. However, death rates varied. After adjusting for age and immune-suppressing drugs, the odds of death were about half for influenza (adjusted odds ratio 0.52) compared to SARS-CoV-2, and also lower for RSV (adjusted odds ratio 0.55) 2. This means that among patients who develop hypoxemia, the risk of dying is not the same for every virus.
Other studies have focused on treatments for hypoxemia caused by specific viruses. For example, a randomized trial of the drug fostamatinib in adults hospitalized with COVID-19 and hypoxemia did not show a significant difference in 28-day mortality compared to placebo 7. Another study on Pneumocystis jirovecii pneumonia (a fungal infection, not a virus) found that high-dose steroids did not lower 30-day mortality compared to lower doses in patients with hypoxemia 8. These findings highlight that outcomes depend on the specific cause of hypoxemia.
It is important to note that the large cohort study adjusted for some factors, but other differences between patient groups (such as underlying health conditions) could still affect mortality 2. Also, the study did not include all possible viruses that cause hypoxemia, so data on other viruses are limited.
What to ask your doctor
- If I have hypoxemia, how does the specific virus causing it affect my treatment plan?
- Are there different monitoring or follow-up recommendations for influenza versus COVID-19 or RSV?
- Should I be concerned about higher mortality risk with certain viruses, and what can be done to reduce that risk?
- Do the treatments for hypoxemia differ depending on the virus, or are they generally the same?
- Are there any ongoing studies or new treatments for hypoxemia caused by the virus I have?
This question is drawn from common patient questions about Pulmonology & Critical Care and answered using cited medical research. We do not provide individualized advice.