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Updated: Dec 29, 2025
Field Postmortem Rabies Rapid Immunochromatographic Diagnostic Test for Resource-Limited Settings with Further Molecular Applications
Published on: June 29, 2020
Performance of plague rapid diagnostic test compared to bacteriology: a retrospective analysis of the data collected
Minoarisoa Rajerison1, Marie Melocco2, Voahangy Andrianaivoarimanana3
1Plague Unit, Institut Pasteur de Madagascar, Antananarivo, 101, Madagascar. mino@pasteur.mg.
Background:
Plague is a highly fatal disease caused by Yersinia pestis. Late diagnosis hampers disease outcome and effectiveness of control measures, induces death and disease spread. Advance on its diagnosis was the use of lateral flow rapid diagnostic test (RDT).
Methods:
We assessed the performance of the plague RDT based on Y. pestis F1 antigen detection more than 15 years after its deployment in Madagascar. We compared the RDT with bacteriological culture results, using data from plague notified cases collected during the periods for which both tests were performed independently and systematically.
Results:
Used with bubonic plague (BP) patient samples, RDTs had a sensitivity of 100% (95% CI: 99.7-100%), a specificity of 67% (95% CI: 64-70%) with a good agreement between bacteriology and RDT results (86%; κ = 0.70, 95% CI 0.67-0.73). For pneumonic plague (PP), RDT had a sensitivity of 100% (95% CI: 91-100%) and a specificity of 59% (95% CI: 49-68%) and concordance between the bacteriological and plague RDT results was moderate (70%; κ = 0.43, 95% CI 0.32-0.55). Analysis focusing on the 2017-2018 plague season including the unprecedented epidemic of PP showed that RDT used on BP samples still had a sensitivity of 100% (95% CI: 85-100%) and a specificity of 82% (95% CI: 48-98%) with a very good agreement with bacteriology 94% (κ = 0.86, 95% CI 0.67-1); for PP samples, concordance between the bacteriological and plague RDT results was poor (61%; κ = - 0.03, 95% CI -0.17 - 0.10).
Conclusions:
RDT performance appeared to be similar for the diagnosis of BP and PP except during the 2017 PP epidemic where RDT performance was low. This RDT, with its good sensitivity on both plague clinical forms during a normal plague season, remained a potential test for alert. Particularly for BP, it may be of great value in the decision process for the initiation of therapy. However, for PP, RDT may deliver false negative results due to inconsistent sample quality. Plague diagnosis could be improved through the development of next generation of RDTs.
Insights
The plague rapid diagnostic test (RDT) shows high sensitivity for detecting bubonic and pneumonic plague, aiding early diagnosis. However, its specificity varies, particularly for pneumonic plague during epidemics, suggesting a need for improved diagnostic tools.
Area of Science:
- Medical Microbiology
- Infectious Diseases
- Diagnostic Technologies
Background:
- Plague, a severe disease caused by Yersinia pestis, requires timely diagnosis for effective treatment and control.
- Delayed diagnosis of plague leads to increased mortality and facilitates disease spread.
- Lateral flow rapid diagnostic tests (RDTs) have been developed to expedite plague diagnosis.
Purpose of the Study:
- To evaluate the long-term performance of a plague RDT detecting Yersinia pestis F1 antigen.
- To compare RDT results with bacteriological cultures for both bubonic plague (BP) and pneumonic plague (PP).
- To assess RDT accuracy over 15 years post-deployment in Madagascar.
Main Methods:
- Performance assessment of plague RDTs using samples from notified plague cases in Madagascar.
- Comparison of RDT results against gold-standard bacteriological culture.
- Data analysis stratified by plague clinical form (BP and PP) and epidemic periods.
Main Results:
- RDT demonstrated 100% sensitivity for BP and PP in typical seasons, with good agreement with bacteriology for BP (86%) and moderate for PP (70%).
- During the 2017-2018 pneumonic plague epidemic, RDT sensitivity for BP remained high (100%), but specificity for PP was low with poor concordance (61%).
- RDTs showed high sensitivity for bubonic plague, suggesting value in guiding therapy initiation.
Conclusions:
- The plague RDT is a valuable alert tool, especially for bubonic plague, due to its consistent high sensitivity.
- RDT performance for pneumonic plague can be compromised by sample quality, leading to potential false negatives.
- Development of next-generation RDTs is recommended to enhance plague diagnostic accuracy, particularly for pneumonic forms.
