Differentiating between viral and bacterial infections in patients presenting with acute respiratory symptoms can be challenging due to overlapping clinical features NICE NG237. Most acute respiratory tract infections are viral and self-limiting NICE NG237.
Clinical assessment is crucial for differentiation NICE NG237. While many symptoms are common to both, certain indicators may suggest a higher likelihood of a bacterial infection, such as pneumonia NICE NG237,NICE CKS. These include new focal chest signs like crackles or signs of consolidation on examination NICE NG237,NICE CKS. Other indicators that might prompt consideration of a bacterial cause include a high fever, significant shortness of breath, or pleuritic chest pain NICE NG237,NICE CKS. Purulent sputum can be present in both viral and bacterial infections, but its presence alone does not reliably differentiate between them NICE NG237.
Symptoms more commonly associated with viral infections often include a runny nose, sore throat, cough, myalgia, and headache NICE NG237,NICE CKS. However, it is important to note that viral infections can also lead to severe conditions, such as respiratory viral sepsis, highlighting that severity alone does not definitively rule out a viral cause Gu et al. 2020.
In general practice, the decision to prescribe antibiotics is often based on the likelihood of a bacterial infection and the severity of symptoms, rather than definitive differentiation through routine testing NICE NG237.
Key References
- NG237 - Suspected acute respiratory infection in over 16s: assessment at first presentation and initial management
- NG12 - Suspected cancer: recognition and referral
- CKS - Cough - acute with chest signs in children
- CKS - Influenza - seasonal
- CKS - Chest infections - adult
- (Gu et al., 2020): Respiratory viral sepsis: epidemiology, pathophysiology, diagnosis and treatment.