Relevance of Rapid Diagnostic Tests for Plague in the Field Settings: a Review

Plague has resurfaced in India. Delay in its diagnosis led to spread of disease in 2002 Himachal Pradesh outbreak. There is a need to improve its rapid diagnosis in field situations. There are an array of diagnostic tests for the detection of plague but none of them has been found to be suitable in the field settings. This review article is an attempt to compare various diagnostic tests for detection of plague in field settings, and to explore the potential of introducing a Rapid Diagnostic Test (RDT) for plague in India. A thorough search was made through internet, Institute library and snow-balling technique for articles/studies related to plague diagnosis. The information was collated and catalogued. The literature review revealed a battery of tests for diagnosis of plague like bacteriological culturing, PHA, ELISA, PCR and RDT. Although bacteriology (culture) is considered as the “gold standard” for confirmation of Y. pestis, quick diagnosis of the disease is affected because the technique is not available in the field primarily because of high cost, sophistication and set-up required. The Polymerase Chain Reaction (PCR) method is said to be very specific but not as sensitive as culture or the F1 Ag detection method. Further, it may also not be possible to do PCR in field settings. Cost-effective, easy to use, and reliable, the RDT can be considered as a good tool in early diagnosis of plague. It has proven to be rapid and easy to use at the bedside with 83–93% specificity and sensitivity. Therefore, RDT is a valid and reliable test in field settings, however, it needs testing in different conditions before being used in field settings across India.