How is pneumonia different from a chest infection or bronchitis?

Pneumonia is infection of the lung tissue itself — the alveoli and surrounding parenchyma. Acute bronchitis is infection of the airway lining without parenchymal involvement; it shows no infiltrate on chest X-ray and almost always resolves without antibiotics. Pneumonia produces a new infiltrate on chest imaging along with clinical features including fever, productive cough, shortness of breath, pleuritic pain, and focal crackles on examination. This distinction matters clinically: pneumonia requires antibiotics and follow-up imaging, while acute bronchitis does not benefit from antibiotics in most cases.

Why might a chest X-ray be done 6 weeks after pneumonia?

Adults aged 50 or over, those with a smoking history, and those with multilobar or slow-clearing infiltrates should have a repeat chest X-ray approximately 6 weeks after the acute illness. This follow-up is to confirm resolution of the infiltrate and — critically — to exclude an underlying lung cancer that can present with or mimic pneumonia. A persistent or incompletely clearing shadow at 6 weeks warrants urgent respiratory referral and CT imaging. This is a non-negotiable safety net in older and at-risk patients.

When does someone with pneumonia need to go to hospital?

The Australian CORB severity score guides this decision. CORB stands for Confusion (new), Oxygen saturation ≤90%, Respiratory rate ≥30 per minute, and Blood pressure below 90/60 mmHg. A score of 0 — none of these features — supports outpatient management in a well adult with a reliable home situation and a GP review at 48–72 hours. A score of 1 suggests hospital admission. A score of 2 or more means admission with urgent consideration of ICU-level care. Additional factors requiring hospital include inability to tolerate oral medications, frailty, social isolation, and immunocompromise.

Do I need antibiotics if my GP says I have pneumonia?

Yes — if you have confirmed or highly suspected bacterial pneumonia, antibiotics are an important part of treatment. They shorten illness duration, reduce complications, and prevent progression to more severe disease. For most outpatients the recommended course is now 5 days rather than the older 10-day standard, provided you are improving and temperature-free by 48–72 hours. Complete the course and return earlier if you are worsening rather than improving — shortness of breath at rest, confusion, persistent high fever, or coughing blood are all reasons to seek immediate review.

What vaccinations reduce pneumonia risk?

Pneumococcal vaccination significantly reduces the risk of pneumococcal pneumonia. Current ATAGI guidance in Australia recommends Prevenar 20 (20-valent conjugate vaccine) as a single-dose strategy for many adult risk groups, replacing the older sequential 13-valent plus 23-valent schedule. Influenza vaccination annually reduces post-influenza bacterial pneumonia. COVID-19 vaccination reduces severe COVID-19 pneumonia. RSV vaccine is now available on the National Immunisation Program for adults ≥75, and those aged 60–74 with significant chronic disease. Your GP can review your vaccination status and advise which vaccines are funded under the National Immunisation Program.

Community-acquired pneumonia

Community-acquired pneumonia: diagnosis and treatment for Australian GPs

By Dr HB Lo, FACRRM Reviewed 4 June 2026 8 min read

Community-acquired pneumonia (CAP) — acute lung infection acquired outside hospital — causes approximately 70,000 hospitalisations and 3,500 deaths in Australia per year. Severity is stratified using the CORB score; a score of 0 (no confusion, SpO₂ >90%, RR <30, BP normal) supports outpatient management in well adults.

First-line outpatient antibiotic is amoxicillin 1 g three times daily for 5 days, or doxycycline for penicillin allergy or atypical cover. Adults ≥50 with a smoking history need a repeat chest X-ray at 6 weeks to exclude an underlying lung cancer. Optimise pneumococcal, influenza, COVID-19, and RSV vaccinations after recovery.

Community-acquired pneumonia — what every GP needs to know

Community-acquired pneumonia (CAP) is acute infection of pulmonary parenchyma acquired outside hospital or within 48 hours of admission. It remains a leading cause of infectious morbidity and death in Australia, accounting for approximately 70,000 hospitalisations and 3,500 deaths per year per AIHW. Mortality ranges from 1–5% in patients managed as outpatients to 5–15% on general wards and 30–50% in ICU.

Aetiology in Australian general practice: Streptococcus pneumoniae is the most common bacterial cause. Atypical organisms (Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophila) account for a significant proportion, particularly in younger adults and community outbreaks. Haemophilus influenzae is common in people with COPD. Post-influenza Staphylococcus aureus (including MRSA) causes severe necrotising pneumonia. In tropical northern Australia, melioidosis (Burkholderia pseudomallei) must be considered in severe CAP. Thirty to fifty percent of CAP episodes have no organism identified on routine testing.

High-risk groups in Australia include adults over 65, Aboriginal and Torres Strait Islander people (approximately 3 times the general population rate), people with COPD, immunocompromised patients, and residential aged care residents.

A. Core clinical — the AU general-practice framework

Severity scoring — the CORB score

eTG Antibiotic uses the Australian-derived CORB score to guide admission decisions:

Criterion	Definition
C — Confusion	New confusion or altered mental state
O — Oxygen	SpO₂ ≤90% on room air
R — Respiratory rate	≥30 per minute
B — Blood pressure	SBP <90 mmHg OR DBP ≤60 mmHg

CORB score	Recommendation
0	Mild — outpatient management
1	Moderate — hospital admission
≥2	Severe — admit, consider ICU

The SMART-COP score (Charles et al. CID 2008) predicts the need for intensive respiratory or vasopressor support and is used in hospital settings. Clinical judgement should always supplement severity scores — frailty, social isolation, inability to tolerate oral medications, and immunocompromise may each indicate admission even with a CORB score of 0.

History and examination

History: Cough (productive versus dry), dyspnoea, pleuritic chest pain, fever, rigors, sweats, malaise. Onset character: abrupt onset suggests typical bacterial pneumonia; subacute onset over days to weeks raises atypical, viral, or TB aetiology. Note recent URTI or influenza illness (post-viral bacterial pneumonia); dysphagia or aspiration risk factors (stroke, alcohol use disorder, neurological disease); vaccination history; travel or occupational exposure (TB, Legionella from cooling towers, psittacosis from birds, Q fever from livestock, melioidosis from soil/water in northern Australia); recent antibiotic use within 3 months (resistance risk).

Examination: Vital signs are the critical severity measure — respiratory rate, heart rate, blood pressure, temperature, SpO₂. Chest: focal crackles, bronchial breathing, dullness to percussion, pleural rub. Look for signs of sepsis (mottled skin, prolonged capillary refill, oliguria). Distinguish cardiac failure (raised JVP, S3, bilateral dependent crackles).

Investigations

Outpatient CAP (CORB 0):

Chest X-ray PA + lateral (MBS 58503) — confirms infiltrate, excludes mimics (cardiac failure, malignancy, PE). Sensitivity is 60–80% in low-severity CAP; absence of infiltrate does not exclude pneumonia when clinical features are compelling
Pulse oximetry
FBC (65070), UEC (66500), CRP (66503) — selective; not mandatory in well outpatients
Influenza/COVID-19 PCR (69494) — in season or high-risk patients

Moderate-to-severe (admitted patients): Blood cultures ×2, urinary pneumococcal antigen and urinary Legionella antigen (69408), sputum MCS (69300), viral PCR panel, lactate, arterial blood gas. Sputum AFB ×3 (69354) if TB suspicion. HIV antibody if first episode in a young adult or with risk factors.

Differential diagnosis

Condition	Key discriminator
Acute bronchitis	No infiltrate on chest X-ray
Cardiac failure / pulmonary oedema	Bilateral, gravitational, raised JVP, BNP elevated
Pulmonary embolism	Pleuritic pain, hypoxia, tachycardia, risk factors
Lung cancer	Persistent or non-resolving infiltrate; haemoptysis; weight loss
Tuberculosis	Subacute, upper-lobe pattern, night sweats, AFB positive
COVID-19 pneumonia	Bilateral peripheral ground-glass opacity, PCR positive
Aspiration pneumonia	Dependent lobe; aspiration risk factors

B. Empirical antibiotic therapy

Per eTG Antibiotic and AMH:

Outpatient low-severity (CORB 0):

Amoxicillin 1 g orally three times daily × 5 days — first-line; covers Streptococcus pneumoniae
Doxycycline 100 mg orally twice daily × 5 days — preferred for penicillin allergy, atypical cover (Mycoplasma, Chlamydophila), or community-onset pneumonia with insidious onset
Penicillin allergy (non-severe): cefuroxime 500 mg twice daily or doxycycline
Pregnancy: amoxicillin first-line; avoid doxycycline after 20 weeks

The Uranga JAMA Internal Medicine 2016 trial (5 versus 10 days) and the Dinh JAMA Internal Medicine 2021 trial (3 versus 8 days) both confirm shorter courses are non-inferior to longer courses for stable outpatients who are afebrile and clinically improving at 48–72 hours.

Moderate-severity (admitted ward, CORB 1):

Benzylpenicillin 1.2 g IV 6-hourly + doxycycline 100 mg twice daily orally or IV, OR + azithromycin 500 mg once daily
Switch to oral amoxicillin 1 g three times daily + doxycycline when clinically stable (usually 48–72 hours)
Total course 5–7 days; extend for complications (empyema, lung abscess, bacteraemia)

Severe CAP (CORB ≥2 or SMART-COP ≥5):

Ceftriaxone 1–2 g IV daily + azithromycin 500 mg IV daily
Add vancomycin if MRSA or post-influenza Staphylococcus aureus suspected
Add piperacillin-tazobactam if Pseudomonas risk (bronchiectasis, prior Pseudomonas infection, severe COPD on chronic steroids)
In tropical northern Australia (Top End, North Queensland): consider meropenem for melioidosis cover per eTG

Adjuncts: Oxygen to target SpO₂ 92–96% (88–92% in known COPD per BTS Thorax 2017); IV fluid resuscitation (cautious in elderly with cardiac failure); pleural drainage for empyema. Steroids in severe ICU CAP: the REMAP-CAP trial (Dequin NEJM 2023) showed hydrocortisone reduced mortality in ICU-level severe CAP — emerging practice, specialist decision.

C. Follow-up, vaccination, and notification

The 6-week follow-up chest X-ray

Adults aged 50 or over with a smoking history, multilobar pneumonia, or persistent symptoms require a repeat chest X-ray at 6 weeks to confirm infiltrate resolution and exclude underlying lung cancer. This is a non-negotiable safety-net in Australian general practice. A slowly resolving or non-resolving infiltrate warrants urgent respiratory referral and CT chest.

Outpatient review at 48–72 hours is standard — patients should be improving (decreasing fever, improved breathlessness). If not improving, reassess for antibiotic resistance, complication (parapneumonic effusion, empyema), or an alternative diagnosis.

Vaccination — preventing recurrence

The Australian Immunisation Handbook and ATAGI guide vaccination after CAP:

Pneumococcal vaccine: Prevenar 20 (20-valent conjugate, single dose) is the current preferred strategy for many adult risk groups; verify current ATAGI guidance at the time of vaccination
Influenza vaccine: annually for all adults; reduces post-influenza bacterial pneumonia
COVID-19 vaccine: reduces severe COVID-19 pneumonia
RSV vaccine: now on National Immunisation Program for adults ≥75 and those aged 60–74 with chronic disease

The admission for CAP is a powerful opportunity to review and update the entire vaccination record.

Notifiable diseases

The following CAP-associated pathogens require notification to state or territory Department of Health: Legionella species (any), invasive pneumococcal disease, tuberculosis, Q fever (Coxiella burnetii), melioidosis (Burkholderia pseudomallei), psittacosis (Chlamydophila psittaci), COVID-19, and influenza (state-specific). Document notification.

D. Australian operations

MBS items

Standard consults 23/36/44; chest X-ray PA + lateral 58503; single view 58500; FBC 65070, UEC 66500, CRP 66503; sputum MCS 69300; sputum AFB 69354; viral PCR 69494; urinary pneumococcal/Legionella antigen 69408; spirometry 11506 for post-pneumonia COPD assessment; GPCCMP 965/967 for recurrent pneumonia in the context of chronic disease; ATSI health assessment 715; practice nurse 10997; Mental Health Care Plan 2715/2717 for post-ICU PTSD or depression.

PBS antibiotics

Per PBS (verified 2026-06-04): amoxicillin, doxycycline, clarithromycin, azithromycin, cefuroxime — General schedule. Benzylpenicillin, ceftriaxone, vancomycin, piperacillin-tazobactam, meropenem — hospital Section 100 / Schedule 4; not outpatient GP. Oseltamivir — Authority Required (Streamlined) for influenza in high-risk patients. Nirmatrelvir/ritonavir — Authority Required for COVID-19 high-risk per current criteria.

E. Special populations

Older adults and residential aged care: Higher mortality, atypical presentations (confusion, functional decline, falls without fever). Aspiration pneumonia is common with dysphagia; oral hygiene and speech pathology assessment reduce recurrence. Advance care planning conversations — goals of care, ceiling of treatment including intubation and IV antibiotics — should occur at each pneumonia episode in frail, older patients. Consider Code Status documentation.

Aboriginal and Torres Strait Islander patients: Approximately 3 times the general population hospitalisation rate for pneumonia. Underlying risk factors include higher rates of COPD, diabetes, and cardiovascular disease. Proactive vaccination, smoking cessation, and COPD management reduce risk. Culturally safe care and ATSI health assessment (MBS 715) should be incorporated into follow-up.

Pregnancy: Pneumonia in pregnancy carries additional risks for mother and fetus (preterm birth, maternal hypoxia). Amoxicillin is first-line; doxycycline is avoided after 20 weeks. Admission thresholds should be lower. Fetal monitoring and obstetric input are required for moderate-to-severe CAP.

Tropical northern Australia: Melioidosis (Burkholderia pseudomallei) is endemic in the Top End and North Queensland and can present as severe pneumonia, septicaemia, or both. It is acquired from soil and water; risk is highest after the wet season. High clinical suspicion, blood cultures, and meropenem empirical therapy in severe CAP are essential. Melioidosis is notifiable.

When to escalate

Refer to the emergency department urgently when:

Severe CAP (CORB ≥2), septic shock, severe hypoxia, suspected massive effusion or empyema
Immunocompromised patient with severe illness
Suspected TB with respiratory isolation required in an unstable patient
Outpatient CAP not improving or worsening at 48-hour review

Refer to respiratory physician semi-urgently or routinely for:

Persistent infiltrate at 6-week follow-up
Recurrent same-lobe pneumonia (consider post-obstructive cause — endobronchial lesion)
Bronchiectasis or immunodeficiency investigation for recurrent pneumonia at different sites

What this article is and is not

This is general health information based on eTG Antibiotic, AMH, Australian Prescriber 2024, the Australian Immunisation Handbook, and the SMART-COP, REMAP-CAP, and antibiotic duration trials. It does not constitute personal medical advice and does not create a doctor–patient relationship. Antibiotic selection, admission decisions, and vaccination schedules are determined with your treating GP and where relevant with specialist input.

Safety-net: if breathing becomes worse, you develop confusion, fever persists beyond 48 hours on antibiotics, or you cough up blood — seek immediate medical review or call 000.

For Australian consumer resources: HealthDirect — Pneumonia, Lung Foundation Australia, Better Health Channel — Pneumonia.

Sources cited

Frequently asked questions

How is pneumonia different from a chest infection or bronchitis?

Pneumonia is infection of the lung tissue itself — the alveoli and surrounding parenchyma. Acute bronchitis is infection of the airway lining without parenchymal involvement; it shows no infiltrate on chest X-ray and almost always resolves without antibiotics. Pneumonia produces a new infiltrate on chest imaging along with clinical features including fever, productive cough, shortness of breath, pleuritic pain, and focal crackles on examination. This distinction matters clinically: pneumonia requires antibiotics and follow-up imaging, while acute bronchitis does not benefit from antibiotics in most cases.
Why might a chest X-ray be done 6 weeks after pneumonia?

Adults aged 50 or over, those with a smoking history, and those with multilobar or slow-clearing infiltrates should have a repeat chest X-ray approximately 6 weeks after the acute illness. This follow-up is to confirm resolution of the infiltrate and — critically — to exclude an underlying lung cancer that can present with or mimic pneumonia. A persistent or incompletely clearing shadow at 6 weeks warrants urgent respiratory referral and CT imaging. This is a non-negotiable safety net in older and at-risk patients.
When does someone with pneumonia need to go to hospital?

The Australian CORB severity score guides this decision. CORB stands for Confusion (new), Oxygen saturation ≤90%, Respiratory rate ≥30 per minute, and Blood pressure below 90/60 mmHg. A score of 0 — none of these features — supports outpatient management in a well adult with a reliable home situation and a GP review at 48–72 hours. A score of 1 suggests hospital admission. A score of 2 or more means admission with urgent consideration of ICU-level care. Additional factors requiring hospital include inability to tolerate oral medications, frailty, social isolation, and immunocompromise.
Do I need antibiotics if my GP says I have pneumonia?

Yes — if you have confirmed or highly suspected bacterial pneumonia, antibiotics are an important part of treatment. They shorten illness duration, reduce complications, and prevent progression to more severe disease. For most outpatients the recommended course is now 5 days rather than the older 10-day standard, provided you are improving and temperature-free by 48–72 hours. Complete the course and return earlier if you are worsening rather than improving — shortness of breath at rest, confusion, persistent high fever, or coughing blood are all reasons to seek immediate review.
What vaccinations reduce pneumonia risk?

Pneumococcal vaccination significantly reduces the risk of pneumococcal pneumonia. Current ATAGI guidance in Australia recommends Prevenar 20 (20-valent conjugate vaccine) as a single-dose strategy for many adult risk groups, replacing the older sequential 13-valent plus 23-valent schedule. Influenza vaccination annually reduces post-influenza bacterial pneumonia. COVID-19 vaccination reduces severe COVID-19 pneumonia. RSV vaccine is now available on the National Immunisation Program for adults ≥75, and those aged 60–74 with significant chronic disease. Your GP can review your vaccination status and advise which vaccines are funded under the National Immunisation Program.

Source quality

Sources grouped by evidence tier. AU primary tier first; international where AU is silent or lagging; named-author reconstruction where guidelines have not yet caught up. How tiers work.