Pneumonia, a curable and preventable disease, is the leading cause of infectious death in children worldwide, per the World Health Organization (WHO). Over 740,000 children died from pneumonia in 2019, which accounted for 22% of all deaths of children aged between one and five years old that year.

In India, about 7.5 lakh cases of pneumonia were reported in 2019, out of which 4,157 people succumbed to the disease. In 2018, of all communicable diseases, pneumonia caused the largest share of deaths (30.65%). FactChecker considered data on pneumonia from 2018 and 2019, the years preceding the Covid-19 pandemic, which began in early 2020, to account for the reduced spread of communicable diseases due to stringent lockdowns and the world's second longest Covid-19 related school closure.

Pneumonia is a type of respiratory infection that inflames the air sacs, or alveoli, in one or both lungs, per the WHO. When the alveoli fill up with pus or fluid, this restricts oxygen intake, making breathing difficult. Pneumonia occurs when the host's immunity is overpowered by the organism, which damages the lung and affects lung function. The severity of the disease is influenced by both the organism itself and the immune system's reaction to the organism. There are over 30 different causes of pneumonia, with bacterial, viral or mycoplasma pneumonia being the most common types.

Common symptoms include a cough that may be dry or produce thick yellow, green or blood-stained mucus, high temperature, difficulty breathing, sharp chest pain, sweating and shivering.

Early detection and annual immunisations can help reduce the risk of contracting pneumonia and disease severity, say experts. On the eve of World Pneumonia Day, November 12, FactChecker spoke to pulmonologists to debunk seven common misconceptions about the disease.

Myth #1: Pneumonia is just a severe form of common cold

Fact: Although the symptoms overlap, pneumonia is different from the common cold. "Common cold is a viral infection that affects the upper respiratory tract [nose, sinus, throat], whereas pneumonia is an infection of the lung parenchyma [a large number of thin-walled alveoli which maintain gas exchange]. Besides symptoms of common cold, pneumonia also comes with breathing difficulties, fever with chills and coughing up of phlegm, mucus or blood. The way that pneumonia and common cold are treated also differs," said Dr Vikram M. Rathi, consultant pulmonologist at Rathi Chest Clinic, Nagpur, told FactChecker.

"As common cold tends to affect the upper respiratory tract more than the lungs, oxygen levels in the lungs remain unaffected, and the disease tends to be milder. Pneumonia, on the other hand, can cause death, especially in individuals who have poor immunity," said Dr Lancelot Pinto, consultant pulmonologist and epidemiologist at P.D. Hinduja Hospital, Mumbai.

The symptoms of pneumonia are aggressive and prolonged, compared to the common cold, and a doctor should be consulted in case of prolonged flu-like symptoms, advised Dr Rathi.

Myth #2: Bronchitis and pneumonia are the same disease

Fact: "Bronchitis is the inflammation or swelling of the tubes of the lung (bronchi), while pneumonia affects the tissue of the lungs where oxygen enters the bloodstream. While both can occur simultaneously, they are not the same," said Dr Pinto.

Bronchitis can be acute or chronic and the swelling caused due to bronchitis can be due to allergic or infectious reasons, explained Dr Rathi. The most common complication of bronchitis is pneumonia. Treatments for both the diseases also vary depending upon the cause.

"To distinguish between pneumonia and bronchitis, apart from physical examination by a doctor and blood tests, other medical examinations such as chest X-ray, CT scan and sputum test are conducted to help detect the location of the infection in the lungs and to assess the appearance of the lungs," said Dr Rathi.

Myth #3: Pneumonia is not contagious

Fact: "Though not all types of pneumonia are contagious, pneumonia that is caused by any organism such as bacteria, virus, fungus or any other parasite, is contagious," said Dr Rathi. Viral pneumonias are more easily transmitted and around one-third of all pneumonia cases are caused by viral pneumonia. "Further, more than 90% of pneumonia cases are due to contagious causes as the transmission is through air or droplets," Dr Rathi added.

Most bacterial pneumonias tend to be a reflection of poor host immunity, and therefore, there is a possibility of transmission, explained Dr Pinto. Immunocompromised people, such as those with asthma, HIV/AIDS, diabetes, and chronic diseases like chronic obstructive pulmonary disease, are more likely to transmit pneumonia.

"Non-contagious pneumonias include aspiration pneumonia caused by inhaling food or liquid contents, and chemical pneumonia caused by inhaling toxic fumes," said Dr Rathi.

Myth #4: Pneumonia only affects children

Fact: Pneumonia can be contracted by people of all ages. "Pneumonia is prevalent in young children as well as the elderly. This is possibly because children have a naïve immune system and the elderly have a weakened immune system, often compounded by comorbidities [such as high blood pressure, diabetes and obesity]," said Dr Pinto.

People over the age of 65 who have pneumonia are at a higher risk of complications, hospitalisation and death, explained Dr Rathi.

Myth #5: Pneumonia poses no risk to healthy people

Fact: "A healthy person can contract pneumonia if they are exposed to the pneumonia-causing organism for an extended period of time. However, the incidence of such cases might be less. Whenever a pneumonia-causing organism overpowers a healthy person's immunity, they may develop pneumonia. The severity of pneumonia is less in healthy people which helps in early recovery," said Dr Rathi.

Most people recover from pneumonia within a few weeks, but it can be life-threatening, according to the American Lung Association.

Myth #6: Pneumonia only affects people who reside in cold climates

Fact: "Viruses tend to thrive in cold weather as people often crowd indoors in cold weather. This probably contributes to higher rates of transmission, especially of viruses, but does not necessarily imply that pneumonias only occur in cold weather," said Dr Pinto.

Similarly, Dr Rathi said that the prevalence of pneumonia in people living in cold climates is high because cold, dry air may increase the sensitivity of airways, making people more vulnerable to infection. However, people living in humid climates are equally susceptible to the disease, he elaborated.

Myth #7: Pneumonia cannot be prevented

Fact: "There are effective ways to prevent pneumonia. Flu shots and annual influenza vaccines reduce the incidence of pneumonia. Antibiotics are also prescribed to treat pneumonia," said Dr Rathi.

"The pneumococcal conjugate vaccine (PCV13) followed by the pneumococcal polysaccharide vaccine (PPSV23), when administered to high risk individuals, reduces the risk of severe pneumonia caused by Streptococcus pneumoniae, the organism that is the most common bacterial cause of pneumonia. These vaccines are routinely recommended for children, the elderly, and those who have immunocompromising conditions. Keeping one's comorbidities such as diabetes well-controlled also contributes to reducing the probability of pneumonia," said Dr Pinto.

Thorough handwashing with soap lowers the risk of pneumonia by 50% in children under the age of five, according to a 2005 study in The Lancet medical journal. Maintaining a healthy lifestyle, regular exercise, adequate nutrition, quitting smoking, sufficient sleep and wearing masks in public places all help prevent pneumonia.