Be alert for TB in South Australia
24 September 2018
Globally in 2017 there were an estimated 10 million cases of tuberculosis (TB) of which 558,000 were rifampicin/multi-drug resistant. TB is uncommon in Australia with most cases imported by people travelling from high burden countries. See http://www.stoptb.org/countries/tbdata.asp
In South Australia, 52 cases of TB have been notified year to date in 2018, compared to a total of 70 cases in 2017 and 85 cases in 2016. A recent case of extensively drug resistant TB (XDR-TB) in Adelaide, likely related to imported infection, has highlighted the importance of early detection, where early suspicion by the GP and referral to SA TB Services resulted in timely management and minimal public health impact. A delayed diagnosis may result in increased morbidity and mortality in TB cases, and increase the risk of transmission. This is particularly true in drug resistant cases where delayed diagnosis can result in increased disease burden, reduced chance of cure, reduced chance of prevention in newly infected close contacts, and significant increase in cost to the health care system.
Medical practitioners are advised to be aware of the following groups at increased risk of TB:
People with increased risk of exposure to TB
People with increased risk of progression from latent TB infection to active TB disease
• Migrants, refugees or students from high burden countries
• Close contacts of an infectious TB case
• Aboriginal and Torres Strait Islander people
• People born in Australian prior to the 1960s
• Health care workers who have worked in high burden countries
• Infants and children under 5 with a positive tuberculin skin test (TST)
• People with “old healed” TB on CXR
• People with immunosuppressive disorders (e.g. HIV, malignancy) or those requiring prolonged use of corticosteroids or other immunosuppressive agents
• People with solid organ transplants
• People with medical disorders such as diabetes, kidney disease requiring dialysis, or silicosis
Medical practitioners should consider TB in these risk groups when:
- Cough or persistent chest infection is present for more than 2 weeks that does not respond to a standard course of antibiotics and/or,
- Other respiratory symptoms are present – dyspnoea, chest pain, haemoptysis and/or,
- Constitutional symptoms are present – loss of appetite, weight loss, fever, night sweats, fatigue, lymphadenopathy.
Medical practitioners should investigate and manage suspected pulmonary TB by:
- Chest X-ray – atypical findings are common in the immune suppressed and elderly; consider a CT chest if clinical suspicion remains.
- Sputum TB culture and acid-fast bacilli (AFB) smear testing – request 3 sputum specimens collected at least 8 hours apart (e.g. early morning) for AFBs.
- If sputum result is:
- Smear positive – seek urgent advice from SA TB services or nearest tertiary hospital.
- Smear negative – this does not exclude TB as culture confirmation can take 3-6 weeks. Seek specialist advice if high suspicion of TB.
- Note: TST and interferon gamma release assay (IGRA) are NOT recommended for the initial investigation of active TB. A negative result does not exclude the possibility of TB.
For further advice please contact SA TB Services at the Chest Clinic on 8222 4867.
Patient services are provided free of charge.
Dr Louise Flood –Director, Communicable Disease Control Branch
For updated information on notifiable diseases in South Australia visit: www.sahealth.sa.gov.au/NotifiableDiseaseReporting