Revealing a hidden indicator
The first step to solving public health problems is accurate assessment. The tests that are currently used to assess vitamin A deficiency, however, are expensive and complex—not appropriate in countries where money is tight, training is basic, and cutting-edge laboratory equipment is rare.
The standard way to identify vitamin A deficiency is to measure levels of retinol (pure vitamin A) in the blood. The testing process requires expensive laboratory equipment with skilled staff, both in short supply in countries where vitamin A deficiency is most severe. PATH’s test instead measures retinol-binding protein—an indicator of the amount of vitamin A in the blood that can be measured using simple diagnostic procedures requiring limited technical skill and equipment. Our test, the “RBP-EIA” (retinol-binding protein-enzyme immunoassay):
Can be carried out using standard laboratory equipment.
Requires only a small blood sample of either venous blood or capillary blood, which can be collected through a simple finger stick.
Yields results in less than 40 minutes, vastly reducing the time between collecting samples and getting results.