biology

Respiratory tract infection

Respiratory tract infection is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Respiratory tract infection rather than just read about it. In short: Respiratory tract infections (RTIs) are infectious diseases involving the lower or upper respiratory tract. An infection of this type usually is further classified as an upper respiratory tract infection (URI or URTI) or a lower respiratory tract infection (LRI or LRTI).

Key takeaways

Respiratory tract infection belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Respiratory tract infection to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Respiratory tract infection from memory before moving on to harder problems.

Reference excerpt

Respiratory tract infections (RTIs) are infectious diseases involving the lower or upper respiratory tract. An infection of this type usually is further classified as an upper respiratory tract infection (URI or URTI) or a lower respiratory tract infection (LRI or LRTI). Lower respiratory infections, such as pneumonia, tend to be far more severe than upper respiratory infections, such as the common cold.

Types

Upper respiratory tract infection

The upper respiratory tract is considered the airway above the glottis or vocal cords; sometimes, it is taken as the tract above the cricoid cartilage. This part of the tract includes the nose, sinuses, pharynx, and larynx. Typical infections of the upper respiratory tract include tonsillitis, pharyngitis, laryngitis, sinusitis, otitis media, certain influenza types, and the common cold. Symptoms of URIs can include cough, sore throat, runny nose, nasal congestion, headache, low-grade fever, facial pressure, and sneezing.

Lower respiratory tract infection

The lower respiratory tract consists of the trachea (windpipe), bronchial tubes, bronchioles, and the lungs. Lower respiratory tract infections (LRIs) are generally more severe than upper respiratory infections. LRIs are the leading cause of death among all infectious diseases. The two most common LRIs are bronchitis and pneumonia. Influenza affects both the upper and lower respiratory tracts, but more dangerous strains such as the highly pernicious H5N1 tend to bind to receptors deep in the lungs.

Diagnosis

Pulmonary Function Testing (PFT) allows for the evaluation and assessment of airways, lung function, as well as specific benchmarks to diagnose an array of respiratory tract infections. Methods such as gas dilution techniques and plethysmography help determine the functional residual capacity and total lung capacity. To discover whether or not to perform a set of advanced Pulmonary Function Testing will be based on abnormally high values in previous test results. A 2014 systematic review of clinical trials does not support routine rapid viral testing to decrease antibiotic use for children in emergency departments. It is unclear if rapid viral testing in the emergency department for children with acute febrile respiratory infections reduces the rates of antibiotic use, blood testing, or urine testing. The relative risk reduction of chest x-ray utilization in children screened with rapid viral testing is 77% compared with controls. In 2013 researchers developed a breath tester that can promptly diagnose lung infections.

Treatment

Bacteria are unicellular organisms present on Earth can thrive in various environments, including the human body. Antibiotics are a medicine designed to treat bacterial infections that need a more severe treatment course; antibiotic use is not recommended for common bacterial infections as the immune system will resolve such infections. This medicine does not effectively treat a viral infection like sore throats, influenza, bronchitis, sinusitis and common respiratory tract infections. This is because antibiotics were developed to target features of bacteria that are not present in viruses, and so antibiotics are ineffective as antiviral agents. The CDC has reported that antibiotic prescription is high; 47 million prescriptions in the United States in 2018 were made for infections that do not need antibiotics to be treated with. It is recommended to avoid antibiotic use unless bacterial infections are severe, transmissible, or have a high risk of further complications if left untreated. Unnecessary use of antibiotics could increase antibiotic-resistant infections, affect the digestive system, create allergic reactions, and other intense side effects. A study published in JAMA found that narrow-spectrum antibiotics, such as amoxicillin, are just as effective as broad-spectrum alternatives for treating acute respiratory tract infections in children, but have a lower risk of side effects.

Prevention Despite the superior filtration capability of N95 filtering facepiece respirators measured in vitro, insufficient clinical evidence has been published to determine whether standard surgical masks and N95 filtering facepiece respirators are equivalent to preventing respiratory infections in healthcare workers. Adults in intensive care units (ICU) have a higher risk of acquiring an RTI. A combination of topical and systematic antibiotics taken prophylactically can prevent infection and improve adults' overall mortality in the ICU for adult patients receiving mechanical ventilation for at least 48 hours, and topical antibiotic prophylaxis probably reduces respiratory infections but not mortality. However, the combination of treatments cannot rule out the relevant contribution in the systemic component of the observed reduction of mortality. There is no sufficient evidence to recommend that antibiotics be used to prevent complications from an RTI of unknown cause in children under the age of 5 years old. High-quality clinical research in the form of randomized controlled trials assessed the effectiveness of Vitamin D, another review of poorer quality RCTs addressed the effectiveness of immunostimulants for preventing respiratory tract infections. Despite some uncertainty due to small study sizes, there is some evidence that exercise may reduce severity of symptoms but had no impact on number of episodes or number of symptom days per episode. Viruses that cause RTI are more transmissible at very high or low relative humidity; ideal humidity for indoor spaces is between 40 and 60%. Therefore, relative humidity in this range can help lessen the risk of aerosol transmission.

Epidemiology

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Respiratory tract infection

Start with the simplest possible case. Write down what Respiratory tract infection claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Respiratory tract infection before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Respiratory tract infection ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Respiratory tract infection

In research: Respiratory tract infection appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Respiratory tract infection in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Respiratory tract infection is common in secondary-school and first-year university syllabi. It links to neighbouring topics Infectious diseases, Respiratory diseases, Viral respiratory tract infections, so understanding it makes those chapters shorter.
In everyday life: Look for Respiratory tract infection outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Respiratory tract infection” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Respiratory tract infection in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Respiratory tract infection means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Respiratory tract infection out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Respiratory tract infection in simple terms?

Why does Respiratory tract infection matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Respiratory tract infection?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Respiratory tract infection.