Invasive Pneumococcal Disease

Infectious Agent

The bacterium Streptococcus pneumoniae (also referred to as pneumococcus) is a gram-positive diplococcus. To date, 100 different serotypes that have a distinct polysaccharide capsule have been identified [1].

Case Definitions and Notification Criteria

A confirmed case requires laboratory definitive evidence only.

Laboratory definitive evidence:

Isolation of Streptococcus pneumoniae from a normally sterile site by culture

OR

Detection of Streptococcus pneumoniae from a normally sterile site by nucleic acid testing.

Positive cultures or specimens of invasive S. pneumoniae are recommended to be sent to Queensland Public Health Microbiology Reference Laboratory for further typing and surveillance.

Community outbreak criteria:

An increase in the expected number of cases of the same serotype of S. pneumoniae within a defined population, exceeding expected baseline levels.

Notification Procedure

Pathology Laboratories to notify on pathological confirmation, by usual means.

Objectives of surveillance

To monitor the epidemiology of invasive pneumococcal disease (IPD) in Queensland, assess the impact of vaccination programs on disease burden, and inform targeted prevention strategies.

Public Health Significance and Occurrence

S. pneumoniae frequently colonises the nasopharynx and can spread directly via the airway to the lower respiratory tract, causing pneumonia, or to the sinuses or middle ears[11]. Common manifestations of non-invasive pneumococcal disease include middle ear infections, sinusitis and bronchitis[12]. Following nasopharyngeal carriage and contiguous spread of disease to other sites in the respiratory tract, progression to pneumonia requires additional factors (e.g. viral infection, lung injury, impaired host defences etc.)[13].

IPD is defined by the isolation of S. pneumoniae from a usually sterile site; most often from blood, but also from cerebrospinal fluid, pleural fluid or a joint aspirate. Common manifestations of IPD are pneumonia, empyema and/or bacteraemia without focus, and meningitis[14].

In children, bacteraemia without a focus accounts for approximately 70% of IPD, followed by pneumonia with bacteraemia. Meningitis is less common but the most severe manifestation of IPD. Symptoms of pneumococcal meningitis include fever, headache, stiff neck, photophobia, irritability, confusion and seizures[15].

The most common manifestation of IPD in adults is pneumonia with bacteraemia[16]. Streptococcus pneumoniae is the most common cause of community acquired bacterial pneumonia. Pneumococcal pneumonia is frequently preceded by a viral respiratory tract infection and typically presents abruptly with chills and high fever often followed by productive cough and pleuritic pain[16].

Although S. pneumoniae is a frequent cause of non-bacteraemic pneumonia, pneumonia without bacteraemia or empyema is not classified as invasive disease. In low and middle-income countries, non-bacteraemic pneumonia causes the majority of pneumococcal deaths in children[17].

Signs and symptoms of pneumococcal pneumonia includes fever, chills or rigors, coughing, production of mucopurulent sputum, dyspnea, chest pain, tachypnoea, hypoxia, tachycardia, malaise, and weakness. Less commonly, patients may experience nausea, vomiting, and headache.

Complications of pneumococcal pneumonia include empyema, pericarditis, and endobronchial obstruction, with atelectasis and lung abscess formation. Pneumococcal pneumonia has been demonstrated to complicate influenza infection[14].

Fulminant pneumococcal infection presents with a rapidly progressive clinical course and is more common in patients with asplenia or immunocompromise, although it can occur in non-immunocompromised individuals (18). Features of fulminant IPD include sepsis, purpura fulminans, and Waterhouse-Friderichsen syndrome[19].

Reservoir

S. pneumoniae is commonly found in the upper respiratory tract and able to be isolated from the nasopharynx of 5% to 90% of healthy people, depending on the population and setting[20]. Rates of carriage may be higher in school-aged children and military settings[20].

Mode of Transmission

Transmission occurs by direct contact with respiratory droplets when coughing or sneezing or contact with items freshly soiled with respiratory discharges (including hands and tissues)

Person to person transmission of the organisms is common. Invasive illness among contacts is infrequent.

Incubation Period

Typically, 1–3 days.

Period of Communicability

The period of communicability is unknown but presumed to last until secretions no longer contain a significant number of bacteria, or within 24 hours of commencing appropriate antibiotic therapy[16]. Antimicrobial resistance is a growing concern[21].

Susceptibility and Resistance

Susceptibility is general and disease may occur in persons susceptible to the serotype involved. For risk conditions for pneumococcal disease, see: Pneumococcal disease | The Australian Immunisation Handbook

Colonisation with specific serotypes may elicit serotype-specific antibodies. While protection is serotype-specific, cross protection is found in some cases. In addition to anticapsular antibodies (whether acquired naturally or by vaccination), other factors are also involved in eradicating pneumococci, including anatomical barriers, cilia, and other immune processes[13].

Management

Cases

Investigation

Wherever possible, a case report form should be completed for all cases. If capacity within a Public Health Unit is limited, case report forms should be prioritised for children under 5 years of age.

Management

It is recommended that children with IPD are investigated for primary immunodeficiencies as per Children’s Health Queensland Guidelines by the treating clinician (see Invasive pneumococcal disease: Assessment and initial investigation to exclude immune deficiency).

Cases of IPD are at risk of recurrent disease. All cases are recommended to receive further doses of pneumococcal vaccines. For further information, see:

• Pneumococcal disease | The Australian Immunisation Handbook
• Immunisation for people with medical risk conditions | Australian Government | Department of Health Disability and Ageing

Restriction

Cases should be excluded from work, school or childcare until they have received appropriate antibiotic treatment for at least 24 hours and feel well (22).

The importance of standard precautions to minimise the risk of infection should be reinforced in home, community and healthcare settings. Hand hygiene (washing hands with soap and water or using alcohol-based hand rub) should always be performed after coughing, sneezing, or using tissues. Education should be provided about respiratory etiquette, including use of a tissue or the arm when coughing or sneezing. Used tissues should be disposed immediately into the bin and hand hygiene should immediately follow. Education about environmental cleaning of surfaces where respiratory droplets would settle with household cleaning agents should be provided.

In hospital and residential care settings, the infected person should be cared for in a single room using standard and droplet transmission-based precautions for a least 24 hours after commencing appropriate antibiotic treatment. A review of hospitalised cases and local risk assessment should be performed before de-isolation [23,24].

Contacts

Contact Tracing

No.

Because secondary cases of IPD are uncommon, chemoprophylaxis is not indicated for contacts of IPD[20].

Community outbreaks/epidemics

The epidemiology of an outbreak of IPD within a facility or community should be defined, including the implicated serotype. Immunisation is not likely to be useful in acute control but may be considered if the implicated serotype is contained in the available vaccine. Chemoprophylaxis is generally not indicated. Enhanced infection control should form the mainstay of the response to the outbreak.

Preventive Measures

IPD may occur as a result of multiple factors, including genetic factors, comorbidities, overcrowding, hygiene conditions, nutrition, and poverty. Most of these factors are very difficult to change. Immunisation is the most cost-effective way to prevent IPD and to reduce disparities in IPD rates between populations worldwide[25].

Pneumococcal immunisation is the main form of prevention. As pneumococcal disease may occur following viral respiratory illness (including influenza, COVID-19 and Respiratory Syncytial Virus), immunisation to prevent these illnesses is also important.

For pneumococcal immunisation recommendations see the Australian Immunisation Handbook | Pneumococcal disease

It is particularly important that anyone with hyposplenia or asplenia – either functional or anatomical – is adequately immunised against pneumococcal and other invasive bacterial diseases.

Literature and registry data indicate that being on a spleen registry reduces the risk of invasive pneumococcal disease and meningococcal disease by 69% compared to patients not registered[26]. To reduce the risk for people living without a functioning spleen, Queensland Health has engaged Spleen Australia to maintain a registry and provide a range of clinical support services, free of charge, to eligible Queenslanders and their healthcare providers.

For more information, and details of the Spleen Australia Registry, visit Spleen Australia | Queensland Health.

References

1. Ganaie F, Saad JS, McGee L, van Tonder AJ, Bentley SD, Lo SW, et al. A new pneumococcal capsule type, 10D, is the 100th serotype and has a large cps fragment from an oral streptococcus. mBio. 2020 May 19;11(3):e00937-20.
2. Versluys KA, Eurich DT, Marrie TJ, Forgie S, Tyrrell GJ. Invasive pneumococcal disease and long-term outcomes in children: A 20-year population cohort study. Lancet Reg Health - Am. 2022 Aug 8;14:100341.
3. O’Brien KL, Wolfson LJ, Watt JP, Henkle E, Deloria-Knoll M, McCall N, et al. Burden of disease caused by Streptococcus pneumoniae in children younger than 5 years: global estimates. The Lancet. 2009 Sept;374(9693):893–902.
4. Bennett JC, Deloria Knoll M, Kagucia EW, Garcia Quesada M, Zeger SL, Hetrich MK, et al. Global impact of ten-valent and 13-valent pneumococcal conjugate vaccines on invasive pneumococcal disease in all ages (the PSERENADE project): a global surveillance analysis. Lancet Infect Dis. 2025 Apr;25(4):457–70.
5. Hagedoorn NN, Anglemyer A, Gilkison C, Hartley M, Walls T. Comparison of the epidemiology of invasive pneumococcal disease between Australia and New Zealand in 2017–2021: an observational study based on surveillance data. Lancet Reg Health West Pac. 2023 Apr 17;36:100764.
6. Pneumococcal disease in Australia (2025) fact sheet [Internet]. [cited 2025 Nov 12]. Available from: https://www.aihw.gov.au/getmedia/9b5b848f-53c2-483c-881d-7c41b76f3b46/aihw-phe-236_pneumococcal_2025.pdf
7. Australian Government Department of Health and Aged Care. Table: Risk conditions for pneumococcal vaccination and eligibility for NIP funding [Internet]. 2025 [cited 2025 Nov 12]. Available from: https://immunisationhandbook.health.gov.au/resources/tables/table-risk-conditions-for-pneumococcal-vaccination-and-eligibility-for-nip-funding
8. Janoff E, Musher D. Streptococcus pneumoniae. In: Bennett J, Dolin R, Blaser MJ. Mandell, Douglas and Bennett’s Principals and Practice of Infectious Diseases. 8th edition. Philadelphia, PA: Elsevir Saunders; 2015. 2309–2327 p.
9. Cherian T, Steinhoff MC, Harrison LH, Rohn D, McDougal LK, Dick J. A cluster of invasive pneumococcal disease in young children in child care. JAMA. 1994 Mar 2;271(9):695–7.
10. Toms C, de Kluyver R, Enhanced Invasive Pneumococcal Disease Surveillance Working Group for the Communicable Diseases Network Australia. Invasive pneumococcal disease in Australia, 2011 and 2012. Commun Dis Intell Q Rep. 2016 June 30;40(2):E267-284.
11. Dockrell DH, Whyte MKB, Mitchell TJ. Pneumococcal pneumonia. Mechanisms of infection and resolution. Chest. 2012 Aug;142(2):482–91.
12. WHO position paper: Pneumococcal conjugate vaccines in infants and children under 5 years of age [Internet]. [cited 2025 Nov 12]. Available from: https://www.who.int/publications/i/item/10665-310968
13. Lynch JP, Zhanel GG. Streptococcus pneumoniae: epidemiology, risk factors, and strategies for prevention. Semin Respir Crit Care Med. 2009 Apr;30(2):189–209.
14. Gierke R, Wodi P, Kobayashi M. Chapter 17: Pneumococcal Disease. In: Epidemiology and Prevention of Vaccine-Preventable Diseases [Internet]. 2024 [cited 2025 Nov 12]. Available from: https://www.cdc.gov/pinkbook/hcp/table-of-contents/chapter-17-pneumococcal-disease.html
15. Australian Government Department of Health and Aged Care. Pneumococcal disease. In: The Australian Immunisation Handbook [Internet]. [cited 2025 Nov 12]. Available from: https://immunisationhandbook.health.gov.au/contents/vaccine-preventable-diseases/pneumococcal-disease
16. ECDC. Disease information about pneumococcal disease [Internet]. 2023 [cited 2025 Nov 12]. Available from: https://www.ecdc.europa.eu/en/pneumococcal-disease/facts
17. Wahl B, O’Brien KL, Greenbaum A, Majumder A, Liu L, Chu Y, et al. Burden of Streptococcus pneumoniae and Haemophilus influenzae type b disease in children in the era of conjugate vaccines: global, regional, and national estimates for 2000–15. Lancet Glob Health. 2018 June 13;6(7):e744–57.
18. Naito R, Miyazaki T, Kajino K, Daida H. Fulminant pneumococcal infection. BMJ Case Rep. 2014 Aug 22;2014:bcr2014205907.
19. Hale AJ, LaSalvia M, Kirby JE, Kimball A, Baden R. Fatal purpura fulminans and Waterhouse-Friderichsen syndrome from fulminant Streptococcus pneumoniae sepsis in an asplenic young adult. IDCases. 2016 Aug 16;6:1–4.
20. CDC. Pneumococcal Disease. 2025 [cited 2025 Nov 12]. Clinical overview of pneumococcal disease. Available from: https://www.cdc.gov/pneumococcal/hcp/clinical-overview/index.html
21. Higgs C, Kumar LS, Stevens K, Strachan J, Sherry NL, Horan K, et al. Population structure, serotype distribution and antibiotic resistance of Streptococcus pneumoniae causing invasive disease in Victoria, Australia. Microb Genomics. 2023 July 20;9(7):mgen001070.
22. NHMRC. Staying healthy guidelines [Internet]. [cited 2025 Nov 14]. Available from: https://www.nhmrc.gov.au/about-us/publications/staying-healthy-guidelines
23. Abers MS, Musher DM. The Yield of Sputum Culture in Bacteremic Pneumococcal Pneumonia After Initiation of Antibiotics. Clin Infect Dis. 2014 June 15;58(12):1782–3.
24. Harris AM, Bramley AM, Jain S, Arnold SR, Ampofo K, Self WH, et al. Influence of antibiotics on the detection of bacteria by culture-based and culture-independent diagnostic tests in patients hospitalized with community-acquired pneumonia. Open Forum Infect Dis. 2017 Feb 10;4(1):ofx014.
25. Greenberg D, Ben-Shimol S. Editorial commentary: Disparities in invasive pneumococcal disease rates between populations: will the extended pneumococcal conjugate vaccines be a game-changer? Clin Infect Dis Off Publ Infect Dis Soc Am. 2014 May;58(9):1258–9.
26. Arnott A, Jones P, Franklin LJ, Spelman D, Leder K, Cheng AC. A registry for patients with asplenia/hyposplenism reduces the risk of infections with encapsulated organisms. Clin Infect Dis Off Publ Infect Dis Soc Am. 2018 Aug 1;67(4):557–61

Appendices

Appendix 1

List of normally sterile sites

Normally sterile sites include, but are not limited to:

• Blood
• Cerebrospinal fluid (CSF)
• Pleural fluid
• Peritoneal fluid
• Pericardial fluid
• Joint fluid
• Bone including bone marrow
• Internal organs; specimen obtained from surgery or aspirate from one of the following:
  • Lymph node
  • Brain
  • Heart
  • Liver
  • Spleen
  • Vitreous fluid
  • Kidney
  • Pancreas
  • Ovary
  • Vascular tissue

*Lung tissue is not a normally sterile site.

**Interpretation of post-mortem specimens from usually sterile sites should be interpreted with caution, preferably in conjunction with a pathologist and/or clinical microbiologist.

Adapted from NSW Health. Invasive group A streptococcal control guideline [internet]. NSW health; 2025 Sep [cited 2025 Nov 26]. Available from: https://www.health.nsw.gov.au/Infectious/controlguideline/Pages/invasive-group-a-strep.aspx

Appendix 2

Letter to clinician recommending additional pneumococcal immunisations

Dear Doctor,

Queensland Health was notified that the above patient has recently had invasive pneumococcal disease (IPD).

Having a previous episode of IPD is a recognised risk condition for repeat IPD infections. Further pneumococcal vaccines are recommended and funded under the National Immunisation Program (NIP). For those <18 years at diagnosis, screening for underlying primary immunodeficiency is also recommended.

The timing for vaccines/screening and vaccines used is age based, as follows: