Project #198:
Identify risk factors associated with disparities for resistant bloodstream infections, before, during and after the global COVID-19 pandemic; a national case-control and cohort study

Antibiotics are vital medicines that treat bacterial infections and save lives. However, over time, some bacteria have become resistant to these drugs. These resistant bacteria, sometimes called “superbugs”, can cause infections that are difficult to treat. One serious example is a bloodstream infection where the bacteria do not respond to standard antibiotics. These infections often lead to longer hospital stays, more complications, and in some cases, can be life-threatening.

Before the COVID-19 pandemic, the NHS was already working to reduce antibiotic-resistant infections. But the pandemic placed enormous pressure on healthcare services. Many COVID-19 patients were seriously ill, and doctors, acting with caution, often gave antibiotics to prevent or treat possible secondary infections—even when it wasn’t clear if bacteria were involved. At the same time, routine infection control procedures may have been disrupted, and many people delayed seeking care for other health issues.These changes could have created the conditions for resistant bacteria to spread more easily. Early evidence suggests that hospital infections increased during the pandemic, and some of these were caused by bacteria resistant to antibiotics. We do not yet know how big this problem became or who was most affected.

This study will examine NHS health records from 2017 to 2025. This will allow us to compare how often resistant bloodstream infections occurred before, during, and after the pandemic. We will also look at which groups of people were most affected. For example, did older adults, people with existing health conditions, or people living in deprived areas face a greater risk? Our aim is to understand whether the pandemic led to a rise in resistant infections and whether it increased existing health inequalities.

Understanding the impact of COVID-19 on antibiotic resistance will help the NHS plan future services. If some groups are more at risk, targeted support can be provided. If infection control practices were affected, they can be reviewed and improved. And if some pandemic-era measures helped reduce infections, these could be kept in place. This research will provide important lessons to protect patients in the future. It will support safer, more equal healthcare, and help prevent serious infections that are increasingly difficult to treat.