A novel blood assaying technique requiring only a tiny sample of dried blood could revolutionise patient care in remote locations such as the highlands of Papua New Guinea.
Microbial resistance to antibiotics has grown to be a major global health issue. While the over-administering of antibiotics often takes the blame, there is also the problem of lack of knowledge about the optimal dose to prescribe.
Communities in remote locations are particularly vulnerable, because determining the optimal dosage usually involves the challenge of storing and transporting vials of patients’ blood over vast distances for analysis. It’s also impractical for pregnant women and neonates due to the volume of blood required. Consequently, studies often exclude these vulnerable populations.
Alternative solutions for blood assaying are therefore an increasing focus in pharmacokinetics – a research field central to drug development.
One in ten children in Papua New Guinea die before the age of five. This appalling rate of childhood mortality is in part due to widespread antibiotic resistance, and to the challenges of pharmacokinetic research into these populations.
At Curtin, Professor Kevin Batty has been overseeing studies involving the development of assays for blood samples sent from PNG as ‘dried blood spots’ (DBS). Batty, together with several Western Australian researchers, has used the technique to determine the optimal antibiotic treatment for severe bacterial infections in children in Papua New Guinea, where acute bacterial meningitis and pneumonia are major causes of mortality and neurological damage in children.
“DBS are basically a pin-prick of blood on blotting paper,” he says.
“The method offers an alternative to the logistically challenging and costly process of venous blood collection, where multiple samples of patient blood are drawn and then centrifuged to provide plasma samples for analysis.
“These must then be stored and transported at temperatures below minus 20 degrees Celsius.”
DBS overcomes these challenges and furthermore, Batty explains, it is suitable for pregnant women and neonates.
While DBS was therefore considered innovative, limitations in the sensitivity of analytic equipment has hindered the development and application of assays. At Curtin, however, the availability of mass spectrometry-based technologies, together with the leading analytical skills of Dr Madhu Page-Sharp, have seen Curtin build impressive capabilities in antimicrobial research.
Funded by the National Health and Medical Research Council, the PNG project also involved researchers at the University of Western Australia (UWA), Papua New Guinea Institute of Medical Research and University of Papua New Guinea.
“The key outcome has been to determine the optimal dosage of a frontline antibiotic, ceftriaxone, with our DBS assays using a small fraction of the standard volume of blood for PK studies,” Batty says.
The team’s success has encouraged the School of Pharmacy to strengthen its focus in the area, recently appointing Dr Brioni Moore as Senior Research Fellow. With extensive experience in clinical studies in PNG, she and Page-Sharp are working with their UWA collaborators, as well as teams from WA hospitals and other research organisations, to develop DBS assays for children and neonates with serious infections.
“DBS is now the cornerstone of our pharmacokinetic studies,” Moore confirms. “Expertise in DBS assay development provides a platform for collaborations that will fill many knowledge gaps about drug therapies, particularly for vulnerable sub-populations.”