Deaths Linked to Influenza-MRSA Coinfection

Clinicians are warned to be alert for patients who may be coinfected with methicillin-resistant Staphylococcus aureus and seasonal influenza after 3 deaths were reported among patients with such coinfections. Image: CDC/Janice Haney

The deaths of 3 family members coinfected with seasonal influenza and methicillin-resistant Staphylococcus aureus (MRSA) have prompted public health officials to remind clinicians how serious such infections can be. A report from the US Centers for Disease Control and Prevention (CDC) on the deaths was published today in the agency’s Morbidity and Mortality Weekly Report (MMWR).

Bacterial coinfection with influenza can rapidly lead to death and other serious complications, according to the CDC, which first reported on this suspected cluster of coinfection cases in March. The first patient to die had developed symptoms of an upper respiratory tract infection and died unexpectedly at home, according to today’s report, which is based on an investigation of the deaths by the CDC and local public health authorities. Two relatives, who lived with the first patient, sought treatment 3 days after the death when they developed fever, difficulty breathing, and coughs producing bloody mucus. These individuals later died in the hospital. Testing confirmed that all 3 patients had been infected with seasonal influenza A(H3N2) and that the second 2 were coinfected with MRSA and developed pneumonia and bacteremia.

The report notes that all 3 patients were older than 50 years and that 2 had multiple comorbidities that may have contributed to their vulnerability to infection. For example, one had been taking low-dose corticosteroids for a prolonged period. Two of the patients had been vaccinated against seasonal influenza.

“The cases in this report are a reminder that influenza and S aureus coinfections, although uncommon, can lead to severe outcomes, including death,” the authors stated.

The authors recommend influenza vaccination for all individuals older than 6 months (even though getting a flu shot doesn’t offer 100% protection against infection) and suggest that physicians consider the use of antiviral agents and antibiotics when bacterial coinfection is suspected in patients with influenza.

Categories: Bacterial Infections, Pneumonia, Viral Infections