Study sheds light on childhood TB in Queensland
A new research study shows the rate of tuberculosis (TB) in children diagnosed in Queensland over a 10-year period was about a third of the adult rate.
The study of all 127 children - aged 16 and below - diagnosed with TB in Queensland from 2005 to 2014 showed the rate of TB was around 1.3 cases per 100,000 people each year.
"This is well below the current overall adult TB rate in Queensland of about 3.9 cases per 100,000 people a year," Department of Health TB Medical Advisor Dr Chris Coulter said.
"The Queensland adult rate of TB is itself lower than the current rate for Australia as a whole which is around 5.3 cases per 100,000," he said.
Dr Coulter said the risk to the general public in Queensland, including children, of developing any kind of TB was very low.
"But obviously we'd like that rate to be zero and that's what all health systems work towards," he said.
Dr Coulter is one of five authors of the study: Paediatric TB in Queensland, Australia 2005-2014: Cross-border diagnoses and over-representation of Indigenous children.
He is also Director of the Queensland Mycobacterium Reference Laboratory.
The other authors include Department of Health Communicable Diseases Unit Principal Epidemiologist Ellen Donnan, Cairns TB Control Unit Director Dr Graham Simpson and Lady Cilento Children's Hospital paediatric TB specialists Dr Julia Clark and Associate Professor Clare Nourse.
The research is due to be presented at the International Congress for Tropical Medicine and Malaria 2016 to be held in Brisbane from 18-22 September and submitted for publication to the International Journal of Tuberculosis and Lung Disease.
Dr Coulter said the study also showed only 16 of the 127 paediatric TB cases identified during the period surveyed were Australian-born.
However, Aboriginal and Torres Strait Islander children were significantly over-represented among those 16, comprising 12 of the total.
The remainder of the 127 included 70 PNG children diagnosed at Queensland Health facilities in the Torres Strait Protected Zone and 41 overseas-born residents and visitors to Australia.
"The study shows that Queensland has quite unique challenges in TB diagnosis and control," Dr Coulter said.
"The high proportion of cross-border diagnoses and over-representation of Indigenous children shows that continued vigilance is needed, particularly in communities where recent TB cases have occurred.
"As such, the creation of the new Torres and Cape TB Control Unit based on Thursday Island in January this year will be of major benefit in allowing a more timely public health response when new TB cases occur, as well as improving education and awareness in the region."
Dr Coulter said understanding paediatric TB was important as children with TB typically reflected recent community transmission.
"Our study confirms previous findings that the majority of children diagnosed with TB in Queensland were born overseas and have either immigrated from or visited a TB-endemic country in the preceding 12 months, or come across from PNG," he said.
"However, only four of the 16 Australian-born children in this study reported visiting high endemic countries, which suggests that local transmission is occurring. This merits further study.
"Also of concern is the disproportionately high number of Australian-born children with TB from the Aboriginal and Torres Strait Islander population - 12 out of the 16.
"Rates of TB are higher in Aboriginal and Torres Strait Islander Queenslanders than non-Indigenous Queenslanders right across the general population, including adults.
"Reasons for this may include increased contact with TB and poorer living conditions and nutrition experienced by some Aboriginal and Torres Strait Islander people.
"The geographic proximity of Australian Torres Strait Islands to PNG, and the provision for free movement between the two countries for traditional activities as permitted under the Torres Strait Treaty Act 1984 represents an additional potential risk for TB acquisition for residents within the Torres Strait Protected Zone."
Dr Coulter said 100 per cent of the 16 Australian-born children in the study successfully completed their treatment, along with 97 per cent of the overseas-born residents.
"Continued strengthening of TB control programmes in the Western Province of PNG will likely improve access for diagnosis and management of TB in PNG itself, thereby ensuring better treatment completion and success rates for PNG children in the region," he said.
Dr Coulter said public health control of TB in Queensland - as throughout Australia - depended on early diagnosis of disease, isolation while infectious and successful treatment.
"TB is a legally notifiable condition in Queensland and Australia as a whole," he said.
"This allows for quick and timely intervention by public health authorities.
"For all new diagnoses of TB in Queensland, contact tracing is undertaken to identify people in contact with the new case and to test them for TB depending on their level of contact with the case."It is through these very effective measures delivered by locally controlled hospital and health services and backed by a network of regional TB control units in Metro South, Toowoomba, Rockhampton, Townsville, Cairns and Thursday Island - that TB is managed and controlled within the state."