Below is an instruction that describes a task. Write a response that appropriately completes the request. ### Instruction: How do you clinically distinguish a Viral Upper Respiratory Tract Illness from a Bacterial one?Medical student here, year 2Well I've been reading about respiratory pathogens and found out that while viruses are the most common cause for these, bacterial infections can have terrible sequelae when not treated (RHD), so how does a doctor clinically determine if the person presenting to them has Viral or bacterial infection so that right measures can be taken?I'm assuming throat swabs for every single person wouldn't be very economical and just or would they be?. ### Response: Usual disclaimer: no one can provide specific medical advice for a person or condition without an in-person interview and physical examination, and a review of the available medical records and recent and past testing. This comment is for general information purposes only, and not intended to provide medical advice. No physician-patient relationship is implied or established.Streptococcal pharyngitis is a fairly distinct clinical syndrome compared to a garden variety viral respiratory infection. Classically, the symptoms are severe sore throat and fever, and the signs are exudative tonsillitis and tender anterior cervical lymphadenopathy. While sore throat is common in viral infection, exudative tonsillitis is less so, and viral syndromes are often accompanied by cough and coryza, which strep infections do not produce.These distinctions are codified in the Modified Centor Criteria, which can give you a pretest probability for the presence of strep throat, and guide your testing and treatment decisions. Here is a link to a calculator that can help you.https://www.mdcalc.com/calc/104/centor-score-modified-mcisaac-strep-pharyngitisBacterial infections of the respiratory tract typically refer to pharyngitis, tracheitis, sinusitis, or pneumonia depending where along the tract you are worried about. Each will have their own physical exam findings, risk factors and severity that over time, you learn to distinguish.Since you're mentioning throat swabs, testing for EBV, flu, RSV, COVID, or Group A Strep can quickly be done with rapid point-of-care testing if they have risk factors (we can use clinical decision making tools like Centor criteria to help us as well)..