Introduction

Microorganisms that cannot be detected using traditional gram staining or culture procedures cause atypical pneumonia. This illness differs from ordinary bacterial pneumonia regarding clinical and radiological characteristics.¹ Pneumonia severity can vary from moderate to life-threatening, with uncomplicated infections resolving with outpatient antibiotics and complex cases leading to septic shock, acute respiratory distress syndrome (ARDS), and death.²

Epidemiology of atypical pneumonia in young adults

Atypical bacterial germs cause 7% to 20% of community-acquired pneumonia. Since they are intracellular, they are difficult to culture and invisible on gram stains. As a result, the real number of cases is unclear. The preference is for younger people.²

Risk factors of atypical pneumonia in young adults

Lifestyle factors

Smoking

Smoking is a recognized and modifiable risk factor for pneumonia, causing inflammation in the airways and inhibiting immunological responses, particularly mucociliary clearance, both of which increase the risk of pneumonia.^1,2

Smoking cessation is a crucial method to prevent pneumonia and other health concerns.³

Alcohol consumption

Alcohol is the most commonly abused substance in the world, leading to pneumonia morbidity and death and posing a serious public health concern.⁴

Poor diet

It usually happens when the body is weakened in some manner, such as by disease, poor nutrition, or a lack of immunity, and the germs can enter the lungs.⁵

Occupational exposure

Mycoplasma pneumonia spreads when an infected person comes into close contact with others for an extended time. It is particularly common among school-aged children and young adults. The illness, known as "walking pneumonia," is often mild and observed in an outpatient environment.⁶

Legionnaires disease, which is a serious illness, is caused by Legionella pneumophila. It is contracted by inhaling contaminated water droplets. Outbreaks are frequently observed in hotels, offices, and cruise ships, where people are exposed to infected droplets from cooling towers and evaporative condensers. Outbreaks have also been documented in people who have visited whirlpools and saunas.⁶

Travel history

M. pneumonia infections have increased worldwide, particularly in the United Kingdom, Europe, China, and North America. 

Underlying health conditions

Asthma increases the risk of a wide range of infectious diseases, including respiratory (e.g., pneumonia and pertussis), non-respiratory (e.g., zoster and appendicitis), and inflammatory (e.g., coeliac disease and myocardial infarction [MI]), implying that asthma is a systemic disease with consequences beyond the airways.⁷

HIV-infected people are more vulnerable to respiratory tract infections from various infectious agents (viruses, bacteria, parasites, and fungi) as their disease develops into acquired immunodeficiency syndrome.⁸

Social and environmental factors

Most people develop pneumonia after contracting an illness from someone else in their neighbourhood. If you stay in a crowded environment, such as a military barracks, prison, homeless shelter, or nursing home, you are more likely to develop pneumonia.

Certain microorganisms that cause pneumonia can infect birds and other animals. You are most likely to come into contact with these germs if you work in a poultry, pet store, or veterinary clinic. Your risk increases if you often inhale air pollution or harmful odours.⁹

Close contact with infected individuals

M. pneumonia is largely transmitted from person to person via aerosolised respiratory droplets produced during coughing or sneezing.¹⁰

Specific pathogen-related risks

Mycoplasma pneumonia

Mycoplasma pneumonia causes the vast majority of atypical respiratory infections.

However, only approximately 10% of patients with mycoplasma develop pneumonia. The virus can spread throughout the year and epidemics in local areas are typical (for example, schools and residences). The organism is passed from person to person and the illness spreads slowly.²

Chlamydophila pneumonia

Chlamydia pneumonia is a prevalent cause of lung infection. The bacterium is obtained through the inhalation of infected aerosolised droplets. However, the incubation time is lengthy and symptoms are typically minor. The bacteria causes a sore throat, cough, and headache that might persist for several weeks or months. The chest x-ray may reveal a minor infiltrative process. Although death is uncommon, it can occur in people with comorbidities.²

Legionella pneumophila

Legionella pneumonia is the most harmful atypical bacteria that causes lung infections. There are several serotypes and infection most commonly occurs in close quarters. Most cases are caused by inhaling the infection from water systems such as humidifiers, whirlpools, respiratory therapy equipment, water faucets, and air conditioners, rather than spreading from other persons. Places where water stagnates help the organism to multiply. Individuals at risk for legionella may have diabetes, cancer, renal or liver disease, or have recently had plumbing work done in their home. Once acquired, the patient may exhibit altered mental status, cough, fever, and respiratory distress. At least 20–40% of patients get diarrhoea.²

Preventive measures

Vaccination

Pharmacists should educate the patient about medication adherence and the need to receive the annual flu vaccine.²

Hygiene practices

Avoid those who are unwell. If you are sick, stay away from others as much as possible to avoid infecting them.

To help prevent respiratory infections, you can:

• Wash your hands regularly.
• Cleaning and disinfecting frequently touched surfaces.
• Coughing or sneezing through a tissue, elbow, or sleeve.

Lifestyle changes

Population-level interventions targeted at early diagnosis, vaccination promotion, and infection prevention, as well as reductions in smoking, environmental pollutants, physical inactivity, obesity, and malnutrition, may enhance the number of healthy life years. People with atypical pneumonia should drink plenty of fluids to help loosen respiratory secretions and get a lot of rest.¹¹

FAQs

What is atypical pneumonia?

Atypical pneumonia is a lung infection caused by bacteria, viruses, or fungi, undetected by traditional gram staining or culture methods. Unlike typical pneumonia, it often has milder symptoms and may develop gradually. Common pathogens include Mycoplasma pneumonia, Chlamydophila pneumonia, and Legionella pneumophila.

How is atypical pneumonia different from typical pneumonia?

Atypical pneumonia tends to have less severe symptoms compared to typical bacterial pneumonia. Patients may experience a lingering cough, mild fever, and fatigue. Unlike typical pneumonia, which shows clear signs on chest X-rays, atypical pneumonia may present with milder or less obvious radiological findings.

What are the main risk factors for atypical pneumonia in young adults?

Key risk factors include smoking, alcohol consumption, poor diet, occupational exposure to infectious droplets (such as in schools or crowded workplaces), asthma, HIV, and living in densely populated areas. Contact with infected individuals and environmental conditions increase risk.

How is atypical pneumonia transmitted?

Atypical pneumonia is transmitted by inhaling an infected person's airborne respiratory droplets. It spreads from contaminated water systems, such as those in cooling towers, humidifiers, or whirlpools.

What are the symptoms of atypical pneumonia?

Atypical pneumonia symptoms include persistent dry cough, slight fever, sore throat, headaches, muscle aches, and exhaustion. Some individuals may develop shortness of breath, chest pain, and, in more severe situations, gastrointestinal problems such as diarrhoea.

How is atypical pneumonia treated?

Atypical pneumonia requires antibiotics that target the specific pathogen causing the infection, such as macrolides for Mycoplasma pneumonia. Supportive care, such as rest, hydration, and over-the-counter medications for fever and pain, is also recommended.

How can I prevent atypical pneumonia?

Preventive measures include quitting smoking, moderating alcohol consumption, maintaining a healthy diet, and practising good hygiene, such as washing hands regularly and avoiding contact with sick individuals. Vaccination, particularly against the flu, can also help reduce the risk of respiratory infections that may lead to pneumonia.

Is atypical pneumonia contagious?

Yes, atypical pneumonia is contagious if caused by *Mycoplasma pneumonia* or *Chlamydophila pneumonia*. It spreads through close contact with infected individuals via respiratory droplets from coughing or sneezing.

Can young adults with underlying health issues be at a higher risk?

Yes, young adults with underlying health conditions like asthma, HIV, or weakened immune systems are at a higher risk for developing atypical pneumonia. These individuals must take preventive measures and seek early medical care if symptoms arise.

When should I consult a doctor about atypical pneumonia?

Consult a doctor if you develop symptoms that last longer than a week, such as a cough, fever, difficulty breathing, or chest pain. Early identification and treatment are critical to avoiding problems.

Summary

Atypical pneumonia occurs in young people due to lifestyle, occupational, social, and environmental factors. Smoking, alcohol consumption, a poor diet, and intimate contact with infected people are all significant risk factors, as are occupational exposures and underlying health disorders such as asthma and HIV. Pathogens such as Mycoplasma pneumonia, Chlamydophila pneumonia, and Legionella pneumophila pose unique hazards, especially in conditions that promote their spread.

Early detection and prevention are critical for lowering the incidence of atypical pneumonia. Raising awareness of these risk factors and advocating measures such as smoking cessation, vaccination, and good cleanliness can help to reduce the disease's impact. Furthermore, concerted initiatives to improve overall lifestyle and health conditions, particularly in crowded or high-exposure environments, can considerably lower the prevalence of pneumonia in young adults.