The anatomical structures of the human respiratory system are divided into the upper and lower respiratory tract. While the upper respiratory tract comprises the nasal passages, pharynx (throat), larynx (voice box), and trachea (windpipe), the lower respiratory tract consists of the lungs and the bronchial tubes. The lungs, which are paired, sponge-like organs located in the chest cavity, play an extremely important role in the process of respiration. The air that we inhale enters the trachea, from where it is carried to the lungs through the two main branches of the trachea (bronchial tubes). The exchange of carbon dioxide and oxygen takes place in alveoli, which are microscopic sacs that are present in the lungs. Medically referred to as pneumonia, a lung infection occurs when pathogens such as bacteria, viruses, or fungi enter the lungs and multiply. A viral lung infection, as the name suggests, is an infection that is caused by a virus. Viruses that cause common cold or flu are often responsible for causing pneumonia. These viruses can spread to others if they come in contact with the respiratory secretions of the infected individuals or use their personal belongings. Viruses can also be transmitted if a person touches contaminated surfaces.
Viruses that Cause Pneumonia
Viral pneumonia could be caused by the following viruses:Influenza Viruses
Influenza, which is commonly called flu, is a respiratory infection that is caused by any of the strains of Influenza viruses
. The incidence of flu is higher during winter or spring. The onset of the infection is marked by symptoms such as headaches, chills, and cough. The affected individual may experience other symptoms such as fever, loss of appetite, muscle aches, fatigue, runny nose, irritated throat, sneezing, watery eyes, etc. At times, this upper respiratory tract infection can worsen into pneumonia.Parainfluenza VirusesHuman parainfluenza virus type 2
and Human parainfluenza virus type 3
could also cause lower respiratory tract infections. These viruses can cause severe pneumonia in people who are immunocompromised. Infections caused by Human parainfluenza virus type 3
are likely to affect infants.Respiratory Syncytial Virus (RSV)
Respiratory Syncytial Virus (RSV) is associated with lung infections in infants, as well as young children. Since this virus can get transmitted to others through person-to-person contact or inhalation of respiratory secretions, outbreaks are common in schools and daycare centers. It can also affect immunocompromised children and adults.Varicella-zoster virus
and herpes simplex virus
could also cause pneumonia in adults with a weak immune system. Though adenoviruses
usually cause upper respiratory tract infections, these could sometimes cause bronchiolitis or pneumonia in young children.
Symptoms and Diagnosis
The early symptoms of a viral lung infection are very similar to that of flu. This is due to the fact that viruses that cause flu can also cause inflammation of the airways and the lungs. If left untreated, common cold or flu could progress to pneumonia.
Respiratory tract infections are characterized by inflamed airways, that interfere with passage of air. The air sacs in the lungs could also get filled with pus or fluids. This affects the exchange of oxygen from the alveoli to the blood. This causes breathing problems which may be accompanied by other symptoms such as:►
Loss of appetite►
Cough with sputum►
Shortness of breath on exertion
If a person exhibits the aforementioned symptoms, doctors may conduct a physical examination and study the patient's medical history. Certain diagnostic tests may be conducted to ascertain if a person has pneumonia or not. These include:►
Complete Blood Count (CBC)►
Bronchoscopy is another procedure that may be conducted to examine the bronchial tubes. In some cases, pulse oximetry may be done to measure the amount of oxygen in a person's blood.
Treatment and Prevention
The treatment of a viral lung infection involves the use of antiviral drugs. Since common cold and flu can progress to pneumonia, the use of anti-flu drugs such as amantadine, rimantadine, oseltamivir, or zanamivir can certainly prove beneficial. If the causal organism is the RSV, doctors may prescribe ribavirin. Palivizumab is another drug that helps to prevent infections caused by RSV.
Doctors may also prescribe painkillers, non-steroidal anti-inflammatory drugs, or bronchodilators. Doctors may also follow a symptomatic approach and prescribe specific drugs to alleviate the symptoms that are exhibited by the patient. The affected individual is usually asked to take rest and increase his/her intake of fluids.
Viral pneumonia is a milder form, when compared to bacterial pneumonia. More often than not, the symptoms resolve within three weeks. However, hospitalization may be required in severe cases. Oxygen therapy may be required for a person experiencing breathing problems.
The incidence of viral lung infections is likely to be high in case of immunocompromised individuals, which is why steps must be taken by such individuals to prevent the recurrence of pneumonia. These include:►
Inhalation of airborne nasal and respiratory secretions of the infected individual can cause the transmission of the virus. It would be best to avoid physical contact with a person who has cold, flu, or pneumonia. Transmission of the virus can be prevented if the infected individuals cover their mouth and nose while sneezing or coughing.►
Do not use the personal belongings of an infected person.►
Refrain from touching surfaces that may have been touched by the infected person. Wash your hands with an antiseptic handwash frequently.►
Administration of flu vaccines or immunization shots can lower a person's risk of getting affected by flu, or pneumonia that may develop due to flu.
Following the aforementioned measures can lower the risk of respiratory infections. At times, bacterial pneumonia could occur along with viral pneumonia, or may occur after viral pneumonia. Bacterial pneumonia is believed to be a more severe form, which is why medical help must be immediately sought to treat viral pneumonia at the earliest.Disclaimer
: The information provided in this article is solely for educating the reader. It is not intended to be a substitute for the advice of a medical expert.