Supplement Presents Studies on Importance of Simpler Diagnostics for Infectious Diseases

The Diagnostics Modelling Consortium (DMC) and the Gates Foundation have published a supplement of papers on their latest research outcomes across a range of infectious diseases that affect developing world countries, emphasizing that improved, well-considered field diagnostics could support elimination of multiple diseases. Studies included the use of mathematical modeling to predict impact of new diagnostic tools.

One of the studies, led by researchers from Imperial College London (London, UK), found that wider use of the pulse oximeter (the finger-clip device that measures blood oxygen and pulse) could prevent 148,000 pneumonia deaths in the under-fives in countries where the disease is most prominent. "This is a very simple tool that could have a very big impact," said paper senior author Prof. Azra Ghani, Imperial's School of Public Health and director of the DMC.

Routinely used in hospitals, pulse oximetry is a simple, noninvasive technology that can help diagnose conditions, such as pneumonia, that trigger low oxygen levels. The device is not routinely available in community settings, where pneumonia is often diagnosed via counting the number of breaths per minute, and observing whether a child is sucking their chest under the rib cage, suggesting a struggle to breathe. The researchers argue that pulse oximetry could allow children to be more quickly diagnosed and sent to hospital for life-saving oxygen and antibiotics. However, they caution, improvement also depends on having access to a nearby hospital or medical facility.

In another paper, researchers call for investment to improve diagnostic screening tools for detection of people who are infected but asymptomatic. For example, current tests for malaria, which involve blood finger-prick sampling, can identify only about 50% of carriers, from whom infection can be transmitted further. Detecting a 10-fold lower density of parasites in blood could increase detection rate to over 80%. “Increasing the sensitivity of these tests could improve the prospect of malaria elimination,” said Dr. Hannah Slater, Imperial’s School of Public Health and lead author of one of the malaria papers. With recent investment from the UK government and the Bill and Melinda Gates Foundation it is hoped that malaria could be eradicated in the next 30 years.

Another paper calls for expanded use and improvement of rapid diagnostic tests for Ebola. In the recent outbreak, Ebola testing took 2–7 days, during which patients remained in a holding area where infected and uninfected patients stayed together until their results came in, increasing the risk of contracting Ebola and taking up limited bed capacity. The authors calculated that if rapid tests had been available and used from the start, the scale of the outbreak could have reduced by a third. “The availability of a rapid diagnostic test could have had a dramatic impact on the epidemic and is therefore a priority for future investment, said lead author Dr. Pierre Nouvellet, Imperial’s School of Public Health.

Other papers in the supplement explore similar issues for HIV, TB, or neglected tropical diseases. "Developing effective tests to diagnose disease is critical to guide use of other interventions, such as drugs and vaccines," said Prof. Ghani, “They therefore have the potential to save lives by directing resources to those most in need.”

The supplement was published December 3, 2015, in the journal Nature under contractual agreement with and funding by the Bill and Melinda Gates Foundation and. Content was not written or reviewed by Nature editors.

Related Links:
Imperial College London
Supplement: Infectious disease control and elimination - Modelling the impact of improved diagnostics