Team:Calgary/PoliciesAndPractices/DiagnosticLandscape

From 2014.igem.org

Diagnostic Landscape

Malaria is a highly treatable and very preventable disease. It is estimated that over 200 million people are affected by it every single year (WHO, 2013). The highest burden is in sub-Saharan Africa where one in five childhood deaths can be attributed to the disease (Unicef, 2008).With an increased awareness of treatment and prevention in recent years, we have seen malaria rates decrease dramatically in the last decade. Although this is a promising statistic, the reality is that millions of people are still living under the threat of malaria (Unitaid, 2011).

Malaria presents symptoms very similar to many other febrile illnesses. Indicators such as fever, headache and fatigue are too wide reaching to attribute illnesses symptomatically to malaria. Effective and reliable diagnostic tests are necessary to properly guide treatment. In resource poor areas where existing malaria diagnostic tests are not available, it is customary to assume that most fevers can be attributed to malaria, and to treat accordingly. Also known as clinical diagnosis, this method is leading the overuse of antimalarial medicines as well as neglecting many other diseases that could be causing these symptoms (Allen et. al, 2013).

With increasing diagnostics for malaria as well as declining rates of infection, and constantly developing antibiotic resistances, this method of clinical diagnosis no longer makes sense. The World Health Organization (WHO) who used to recommend this method have since changed their stance stating for the first time that all suspected cases should be confirmed with a diagnostic test before treatment (WHO, 2013).

One of the largest unmet needs defined recently by Unitaid in the area of malaria diagnosis is a diagnostic test that can provide differential diagnosis of fever. The decreasing burden of malaria means a large number of patients will receive a negative diagnosis from a malarial diagnostic. It is thought that this ever-expanding hole in diagnostic technologies is the main obstacle in managing non-malarial fever, and the main force behind the overuse of anti-malarial treatments (Unitaid, 2011).

Common causes of fever in sub-Saharan Africa can vary tremendously (Crump et. al, 2013). Examples of illnesses that can present fever as an initial symptom can include:

  • Typhoid Fever
  • Visceral Leishmaniasis
  • Meningitis
  • Dengue Fever
  • Schistosomiasis

Some experts suggest that what is needed is a multiplexed point-of-care device that can simultaneously detect several common causes of fever at one time (Unitaid, 2011).

This concept contains several obstacles. First, what should be tested for? Second, how can you distinguish so many pathogens in one test? Currently, there does not appear to be any diagnostic platforms that assist with the diagnosis of non-malarial fever currently on the market, or in the later stages of development.