Atypical Testing in the Viral Era

Study questions routine testing for atypical bacterial co-infection in viral respiratory hospitalizations

Category	Detail
Condition	Viral respiratory infections with potential atypical bacterial co-infections
Key Mechanisms	Low prevalence of atypical bacterial co-infections in hospitalized patients with viral infections
Target Population	Patients hospitalized with COVID-19, influenza A or B, or respiratory syncytial virus
Care Setting	Hospitalized patients in the Central Denmark Region

Confirmed co-infection with atypical bacteria was rare (1% of tested patients)
Empirical clarithromycin therapy was administered to 4% of patients despite low co-infection rates
Most patients with confirmed co-infection did not receive early macrolide therapy
Testing frequency varied by hospital and was associated with disease severity
Routine testing and treatment for atypical co-infections are not supported by current guidelines

Routine testing for atypical bacterial co-infections is not recommended in viral respiratory infections

Empirical treatment with macrolides is not warranted for most patients hospitalized with viral infections

Consider monitoring for atypical bacterial co-infections in severely ill patients or those with abnormal illness courses

Potential overtreatment with antibiotics in patients unlikely to have atypical co-infections

Patients hospitalized with viral respiratory infections

Empirical clarithromycin use was low despite testing; most patients with positive results did not receive early treatment

Avoid routine empirical treatment for atypical pneumonia in viral respiratory infections
Assess individual patient risk factors before considering atypical bacterial testing