Point-of-Care Diagnostics - Holographic Sensors - page 2

limited [ 6 , 7 ]. Other trends include increase in healthcare associated infections [ 8 , 9 ],
preservation of the life span of cost-effective drugs [ 10 ], increase in spurious/
counterfeit medicines [ 11 ], and mitigating the epidemic-to-pandemic transitions
of infectious diseases [ 12 ]. In terms of impact, low-cost diagnostics will reach
underserved communities. Low-cost diagnostics that can allow local communities in
developing regions to improve healthcare [ 13 ], environmental safety [ 14 ], animal
health [ 15 , 16 ], and food quality [ 17 ] will play key roles in the United Nation s Post-

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2015 Millennium Development Goals.
In the developing world, medical diagnostics for poverty-related conditions are
outdated. In the absence of the diagnostic equipment, healthcare personnel make
their decisions based on symptoms. WHO s Integrated Management of Childhood

Illness (IMCI) is a diagnosis guideline based on signs and symptoms with minimum
or no instrumentation [ 18 , 19 ]. However, such systematic guidelines have limita-
tions in (i) distinguishing asymptomatic diseases, (ii) detecting multiple infections,
(iii) identifying the disease window period, and (iv) quantifying concentrations of
target analytes. Eventually, the development and delivery of affordable testing
technologies can enable local communities that lack access to technical and human
resources present in urban areas. The de

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ciency in diagnostics and healthcare
resources can have an irreversible negative effect on developing economies. Such
an economic impact is pronounced for non-infectious as well as infectious diseases.
For example, the Ebola virus epidemic in West Africa has overwhelmed the
healthcare systems of Liberia, Sierra Leone, Guinea and their neighbouring coun-
tries since 2013. Such outbreaks have a profound impact on the development of
emerging economies. Currently, it is dif cult to identify Ebola because its symp-

toms such as fever are generic, also seen in commonly occurring diseases such as
malaria and typhoid fever. Existing laboratory techniques are based on transcription
polymerase chain reaction (RT-PCR) and quantitative PCR; however, they are not
portable and affordable in the developing world. Other rapid tests suffer from
sensitivity and selectivity, which may put the entire healthcare system at risk by
misdiagnosing patients. Yet, recent Ebola epidemic is an example of many ongoing
dif

culties in healthcare systems and highlights the dire need for the development
of low-cost rapid diagnostics.
While the main application of rapid tests is in medical diagnostics, such assays
are also necessary for veterinary testing, environmental monitoring and food quality
testing. Low-cost diagnostics would allow farmers and entrepreneurs in the
developing world to assess the quality of their products and mitigate potential risks
due to enterohemorrhagic strain of E. coli (O157:H7) and Salmonella in under-
cooked meat and poultry products [ 17 ]. Low-cost diagnostics are also required in
testing water supplies. Inadequate environmental monitoring capabilities were
highlighted by the cholera epidemic in Haiti after the earthquake in 2010 [ 20 - 24 ].

Although the cholera epidemic took most people by surprise, it wasn it totally

unexpected since Haiti ranked last out of 147 countries surveyed in the 2002 Water
Poverty Index [ 25 ]. Due to globalisation, such epidemics also concern the devel-
oped nations. The development of low-cost, rapid quantitative diagnostics will aid
in screening large regions and populations. For

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the development of rapid