Acute respiratory infection

1. Acute Respiratory Infection

An acute respiratory infection (ARI) is an infection that may interfere with normal breathing. It can affect just the upper respiratory system, which starts at the sinuses and ends at the vocal cords, or just the lower respiratory system, which starts at the vocal cords and ends at the lungs. ARIs are among the most common infectious diseases and can be caused by a variety of pathogens, including viruses, bacteria, and fungi.

Causes

Acute respiratory infections can be caused by a wide range of pathogens. The most common viral causes include:

• Rhinovirus
• Influenza virus
• Respiratory syncytial virus (RSV)
• Coronavirus

Bacterial causes include:

• Streptococcus pneumoniae
• Haemophilus influenzae
• Mycoplasma pneumoniae

Fungal infections are less common but can occur, especially in immunocompromised individuals.

Symptoms

Symptoms of acute respiratory infections can vary depending on the specific pathogen and the part of the respiratory system affected. Common symptoms include:

• Cough
• Sore throat
• Runny or stuffy nose
• Fever
• Fatigue
• Shortness of breath

In severe cases, especially in lower respiratory tract infections, symptoms can include:

• Chest pain
• Wheezing
• Difficulty breathing

Diagnosis

Diagnosis of an acute respiratory infection typically involves a physical examination and a review of symptoms. Additional tests may include:

• Chest X-ray
• Blood tests
• Sputum culture
• PCR tests for specific pathogens

Treatment

Treatment for acute respiratory infections depends on the cause:

• **Viral infections**: Often self-limiting; treatment focuses on relieving symptoms. Antiviral medications may be used in some cases, such as with influenza.
• **Bacterial infections**: Treated with antibiotics.
• **Fungal infections**: Treated with antifungal medications.

Supportive care, such as rest, hydration, and over-the-counter medications, can help alleviate symptoms.

Prevention

Preventive measures include:

• Vaccination (e.g., influenza vaccine, pneumococcal vaccine)
• Good hygiene practices, such as handwashing
• Avoiding close contact with infected individuals
• Wearing masks in high-risk areas

Epidemiology

Acute respiratory infections are a leading cause of morbidity and mortality worldwide, particularly in children under five years of age and in the elderly. They are more prevalent in the winter months in temperate climates.

Also see

• Chronic obstructive pulmonary disease
• Pneumonia
• Bronchitis
• Common cold
• Influenza