World Pneumonia Day is observed every year on November 12 to raise awareness about pneumonia and to advocate for global action to protect against, help prevent and effectively treat the respiratory disease. The day aims to generate action to combat pneumonia. It was established by the Stop Pneumonia Initiative in 2009 to raise awareness about the toll of pneumonia, a leading killer of children around the world. Pneumonia is the world's biggest infectious killer of adults and children, and claimed 2.5 million lives, including 6,72,000 children under five years of age, in 2019. 


Pneumonia is a serious infection of one or both of the lungs caused by bacteria, viruses or fungi, and causes the air sacs to be filled with pus and other liquid. 


Genetic factors can directly or indirectly increase the risk of pneumonia, experts say.


How genetic factors can lead to pneumonia


Host genetic factors can directly or indirectly result in pneumonia either by increasing the risk of infection or increasing the severity, Dr Rohit Kumar Garg, Consultant, Department of Infectious Diseases, Amrita Hospital, Faridabad, told ABP Live. He added that some lung diseases such as cystic fibrosis, asthma, and bronchiectasis are caused due to underlying genetic factors and result in repeated lung infections. Bronchiectasis is a condition in which the airways of the lungs become damaged, making it difficult to clear mucus. Cystic fibrosis is an inherited life-threatening disorder that damages the lungs and digestive system, affecting the cells that produce mucus, sweat and digestive juices.


"Genetic conditions that affect the immune response of the host also increase the risk of infections," Dr Garg added. For instance, the deficiency of complement factors increases the risk of pneumococcal infection. The complement system in the human body is made up of a large number of distinct plasma proteins that induce a series of inflammatory reactions to help the host fight infection. The deficiency of these proteins is responsible for causing community acquired pneumonia (CAP), which occurs in a community setting. 


Genetic diseases such as cystic fibrosis and primary ciliary dyskinesia make a person more prone to contracting pneumonia, Dr Dixit Thakur, Consultant Pulmonology and Critical Care, Artemis Lite Hospital, New Delhi, told ABP Live. 


Pneumonia is one of the serious manifestations of SARS-CoV-2 infection


The symptoms of Covid-19 pneumonia usually start around five to seven days after infection with SARS-CoV-2, Dr Garg said. The symptoms include fever, cough, difficulty breathing and low oxygen saturation, among others.


SARS-CoV-2 causes mild symptoms like throat pain, runny nose and dry cough, but severe infection with the virus affects the lung parenchyma, resulting in pneumonia, Dr Thakur said. 


Different types of pneumonia


The most common and useful way to categorise pneumonia is based on setting, Dr Garg said. Based on the setting, pneumonia can be classified as community acquired pneumonia (CAP) and nosocomial pneumonia (NP). CAP refers to the infection acquired outside hospital settings while NP refers to the infection caused in hospital settings. 


“Other ways to categorise pneumonia include, causative organism (bacteria, viruses, fungi, parasites), immune status (immunocompetent or immunocompromised), and clinico-pathology (bronchopneumonia, lobar or interstitial pneumonia),” Dr Garg added.


“These categorisations help us to decide on management, considering the most likely possibilities,” he explained. 


For instance, the most common causative organisms of CAP include typical bacteria such as Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus, atypical bacteria like Legionella spp., Mycoplasma pneumoniae, and Chlamydia pneumoniae, and viruses like Influenza virus, SARS CoV-2, other coronaviruses, Adenovirus, and respiratory syncytial virus, among others. Atypical bacteria are those which do not get coloured by gram-staining. This means they are neither gram-positive nor gram-negative. 


“The common pathogens for NP include bacteria such as Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas spp., and Acinetobacter spp., among others. In immunocompromised hosts, pneumonia can be caused by tuberculosis, fungal pathogens, Pneumocystis jirovecii, etc. in addition to other common causes,” Dr Garg said. 


Risk factors for pneumonia


Children below five years of age are more prone to pneumonia than others. “The most common risk factors for pneumonia include smoking, comorbidities (diabetes, chronic heart disease, chronic lung disease), immunocompromising conditions (cancer, HIV, steroids use, chemotherapeutic agents), alcohol use, vaccination status (for common preventable infections) and certain special epidemiological exposures to particular organisms (exposure to birds, bat and bird droppings, contaminated water),” Dr Garg said. 


Stroke patients are also prone to pneumonia, Dr Thakur said.


Can pneumonia be completely treated?


Pneumonia can be treated completely, according to experts. “Pneumonia is completely treatable with a course of antimicrobial agents. The principles of managing pneumonia are common for all types of patients. The choice of treatment options depend on the likely (or confirmed) cause, and certain conditions such as severe illness, kidney disease, liver disease and other ongoing medications. Over the last few years, there has been a concerning change in the profile of causative organisms and antibiotic resistance pattern. This change has made it difficult to treat multidrug resistant microbes with available antimicrobial agents,” Dr Garg said.


“Pneumonia can be completely treated, but treating it earlier works best. If someone is experiencing symptoms, they should get tested immediately. If the person reaches a doctor as soon as the symptoms appear, then the chances of getting treated are more. However, in some cases, such as in the case of multidrug resistant bacteria or extreme drug resistant bacteria, there are chances that pneumonia cannot be treated, and can be fatal too,” Dr Thakur said.


Diseases pneumonia can lead to


Pneumonia can lead to several short term and long term complications, Dr Garg said. “These may be due to pneumonia itself, comorbidities, and/or hospitalisation. Some of the short term complications include progression of illness (severe disease, sepsis, respiratory failure, death), other hospital related infections, myocardial infarction, cardiac arrhythmias, heart failure, pulmonary embolism, and stroke. The long term complications include worsening of lung function or lung disease (eg. COPD), risk of recurrent lung infections, and progression/increased risk of conditions such as diabetes, heart disease and stroke,” Dr Garg said.


Foods and lifestyle habits to prevent pneumonia and keep the lungs healthy


One can prevent themselves from diseases like pneumonia through simple measures such as following a healthy lifestyle with a balanced and nutritious diet, and avoiding smoking as well as unhealthy food items. “Some food items, especially those rich in antioxidants (eg apples, berries, tomato based products), or fibres (eg beans, lentils, whole grains) are particularly beneficial for promoting lung health. Besides vaccination, individuals with chronic lung disease (such as COPD) also benefit from pulmonary rehabilitation programs. Lastly, it is very essential that in case of any illness, we seek expert consultation and avoid self antibiotic use (without medical prescription), to prevent emergence of drug resistance,” Dr Garg said. 


Dr Thakur said that one should lead a normal healthy life, consume home-cooked food, and avoid oily and processed foods. People should exercise regularly and perform yoga. Most importantly, children should undergo vaccination on time to prevent pneumonia.