PNEUMOCOCCAL DISEASE (INVASIVE)
Public health priority: Routine.
PHU response time: Enter all confirmed cases on NCIMS within 5 working days of notification.
Case management: Responsibility of treating doctor.
Contact management: Responsibility of treating doctor.
Last updated: 01 July 2012
1. Reason for surveillance
- To monitor the epidemiology of the disease and so inform prevention strategies.
2. Case definition
A confirmed case requires laboratory definitive evidence only.
- Isolation of Streptococcus pneumoniae from a normally sterile site by culture, or
- Detection of S. pneumoniae from a normally sterile site by nucleic acid test (NAT).
Factors to be considered in case identification
Streptococcus pneumoniae causes localised infection of the respiratory tract (in particular otitis media and sinusitis) as well as invasive pneumococcal disease (IPD), commonly manifested as bacteraemia, pneumonia or meningitis. Only invasive disease is notifiable. Isolation of S. pneumoniae from a non-sterile site (such as sputum, nasal aspirates and ear discharge) is not notifiable.
Serotyping of the organism, based on the differences in polysaccharide antigens, is currently performed in a few laboratories in Australia. Although it is not required for individual patient management and rarely for investigation of clusters, surveillance of isolates from cases of IPD and serotyping will assist in monitoring changes in serotype distribution following introduction of vaccination programs.
3. Notification criteria and procedure
Invasive pneumococcal disease is to be notified by:
- Laboratories on microbiological confirmation (ideal reporting by routine mail).
Only confirmed cases should be entered onto NCIMS.
4. The disease
The bacterium Streptococcus pneumoniae (pneumococcus). There are 90 known capsular types, some of which are commonly carried in the upper respiratory tract.
Mode of transmission
The organism is transmitted by respiratory droplets, direct oral contact, or indirectly through articles freshly soiled with respiratory discharges.
The typical incubation period is not well determined, probably as short as 1 to 3 days.
The period of communicability is unknown, although it is presumably until discharges from the mouth and nose no longer contain virulent pneumococci in significant numbers. Penicillin will render patients with susceptible strains non-infectious within 24-48 hours.
Pneumococcal pneumonia is the most common clinical presentation of IPD (the organism must be isolated from a blood culture or other sterile site to be counted as IPD). Symptoms are usually sudden in onset and include chills, fever, pleural pain, dyspnoea (breathing difficulties) and productive cough. Symptoms may be less sudden in the elderly. Fever, vomiting and convulsions may be seen in infants and young children. Pneumococcal pneumonia is an important cause of death in infants and the aged. The case fatality rate of pneumococcal pneumonia has fallen to 5-10% with antimicrobial therapy but remains higher in the elderly and immunocompromised people. The case fatality rate for pneumococcal meningitis ranges from 10- 30%.
5. Managing single notifications
Where follow up is undertaken, begin the investigation, of cases aged less than 5 years and 50 years and over, using the Invasive Pneumococcal Disease investigation form, within 5 working days of notification.
Within 5 working days of notification enter confirmed cases on NCIMS.
The investigation of cases aged <5 years and 50 years and over should be completed in collaboration with the case's health carers PHU staff should ensure that action has been taken to:
- Confirm the onset date and symptoms of the illness
- Confirm results of relevant pathology tests
- Find out if the case or relevant care-giver has been told what the diagnosis is before beginning the interview
- Seek the doctor's permission to contact the case or relevant care-giver
- Ensure that the reporting laboratory refers all sterile site isolates to the NSW Pneumococcal reference laboratory at ICPMR, for typing and additional antibiotic susceptibility testing
- Ascertain vaccination status and risk factors for infections and other case details, as indicated on the Invasive Pneumococcal Disease investigation form.
See the latest edition of the Therapeutic Guidelines:Antibiotic.
In general, the medical practitioner should provide information to the case about the nature of the infection and the mode of transmission. A fact sheet is available on the NSW Health website.
Isolation and restriction
Hospitalised patients with antibiotic resistant respiratory disease may be isolated to reduce the risk of transmission to other high-risk patients.
None required for sporadic cases.
Two different types of vaccine are available in Australia: the 23-valent polysaccharide vaccine (for older children and adults) and the 13-valent conjugate vaccine (for children <9 year old).
While these vaccines are very useful in preventing disease, the use in outbreak control is not clear.
None required for sporadic cases.
6. Managing special situations
Generally speaking, in outbreaks in institutions or in other closed population groups, immunisation is not useful in acute control but may be useful for longer term prevention.