A large analysis looked at hospital-attended patients with laboratory-confirmed influenza infection. The researchers examined over 111,889 individuals to understand how often bacteria infect these patients alongside the flu virus. They also looked at how often doctors prescribe antibiotics and which specific bacteria are most common.
The study found that 17.3% of these patients had a microbiologically confirmed bacterial co-infection. Antibiotics were prescribed to 88.1% of the patients overall. The risk of bacterial co-infection was higher in intensive care units at 28.3% compared to 13.6% in other hospital areas. Antibiotic use was also more common in adults than children and more frequent in ICU patients.
The most frequently identified bacteria were Streptococcus pneumoniae and Staphylococcus aureus. The researchers noted that diagnostic variability and differences between studies limit how clearly these results can be interpreted. These findings suggest a need for better diagnostic tools and careful antibiotic use to manage suspected cases of bacterial co-infection during flu seasons.