Evaluation Of The Diagnostic Performance Of A Rapid Immunochromatographic Test (RDT) Compared To Real-Time PCR (Radione System) In The Context Of The Cholera Epidemic In The Democratic Republic Of Congo

Cesar Christian CARRENARD ODZALI, Dieudonné Mwamba KAZADI, Tatiana BUABA, Declerk KAPAY LEMBUSA, Destin MBONGI MOKE, Boniface KABASELE, Fiston KADIATA, Patricia MBUNZU NDIBAYOLA, Ruphin EPENDA LOKAKAO, Odette KABENA NGANDU, Erick KAMANGU NTAMBWE

Abstract


Introduction : In the Democratic Republic of Congo (DRC), rapid diagnosis of cholera is crucial for epidemic response. This study evaluates the performance of the immunochromatographic rapid diagnostic test (RDT) compared to real-time PCR (RADIOne system).

Materials and Methods : A cross-sectional study was conducted on 264 stool samples initially tested positive by rapid diagnostic tests (RDTs) in the Democratic Republic of Congo (DRC). All samples were analyzed using the RADIOne 5-Plex Diarrhea multiplex panel, capable of simultaneously detecting Vibrio cholerae ( ctxA gene ), Shigella, Salmonella , and E. coli (ETEC/STEC). Positive predictive values (PPVs) and 95% confidence intervals (CIs) were calculated.

Results : PCR confirmed Vibrio cholerae in 210 of the 264 RDT-positive cases, for a positive predictive value (PPV) of 79.55% (95% CI: 74.07%–84.14%). In the 54 unconfirmed cases (20.45%), multiplex PCR revealed high circulation of other enteropathogens : Shigella spp. (45.46%) and ETEC-producing E. coli (32.58%). Overall, 92.42% of the RDT-positive samples contained at least one target pathogen.

Conclusion : Although the rapid diagnostic test (RDT) is an essential screening tool, it presents a significant risk of false positives due to cross-reactions with Shigella and E. coli. The integration of point-of-care PCR is recommended to validate epidemic alerts and optimize differential clinical management in the DRC.


Keywords


Cholera, RDT, PCR RADIOne, Democratic Republic of Congo, Diagnostic performance, Cross-reactions.

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References


. A Ogouyèmi-Hounto · D. Kinde- Gazard · C. Keke · E. Gonçalves · N. Alapini · F. Adjovi · L. Adisso C. Bossou YV Denon · A. Massougbodji (2012). Evaluation of a rapid diagnostic test and a portable fluorescence microscope for the diagnosis of malaria in Cotonou (Benin), Bull. Soc. Pathol . Exot . (2013) 106: 27-31, https://doi.org/10.1007/s13149-012-0264-7

. Alkassoum Salifou Ibrahim, Doutchi Mahamadou, Amadou Harouna, Brah Souleymane, Djibo Issifou, Ibrahim Mahaman Lamine, Lagaré A., Adehossi Eric , Aka Joseph, Mamadou Saidou (2019). Cholera Epidemics in Sub-Saharan Africa: A Literature Review from 2010 to 2016, European Scientific Journal, Vol . 15, No. 24, ISSN: 1857-7881 ( Print ) e-ISSN 1857-7431, URL: http://dx.doi.org/10.19044/esj.2019.v15n24p315

. Altman, DG & Bland, JM (1994a). Diagnostic tests 1: Sensitivity and Specificity , BMJ, 308(6943), 1552.

. Altman, D.G. & Bland, J.M. (1994b). Diagnostic tests 2: Predictive values, BMJ, 309(6947), 102.

. Altman, DG & Bland, JM (1994c). Diagnostic tests 3: Receiver operating characteristic plots, BMJ, 309(6948), 188.

. Anne-Laure Page, Kathryn P. Alberti, Vital Mondonge , Jean Rauzier, Marie-Laure Quilici, Philippe J.Guerin (2012). Evaluation of a Rapid Test for the Diagnosis of Cholera in the Absence of a Gold Standard, PLoSONE7(5 ):e37360.doi :10.1371/journal.pone.0037360

. Ann-Mari Svennerholm (2011). From cholera to enterotoxigenic Escherichia coli (ETEC) vaccine development , Indian J Med Res 133, pp 188-194

. Bonten , J., Miwanda , B., Kuijpers, A., & Muyembe- Tamfum , JJ (2021). Cross- reactivity of rapid diagnostic tests for Vibrio cholerae O1 with other enteropathogens in the Democratic Republic of the Congo. Journal of Clinical Microbiology , 59(4), e02345-20. https://doi.org/10.1128/JCM.02345-20

. Bossuyt, PM, Reitsma, JB, Bruns, DE, Gatsonis , CA, Glasziou , PP, Irwig , L., Lijmer , JG, Moher, D., Rennie, D., de Vet , HC, Kressel, HY, Rifai, N., Golub, RM, Altman, DG, Hooft, L., Tunis, S., & Magid, N. (2015). STARD 2015: An update list of essential items for reporting diagnostic accuracy studies . BMJ ( Clinical research ed .), 351, h5527. https://doi.org/10.1136/bmj.h5527

. Branscum AJ, Gardner IA, Johnson WO (2005) Estimation of the sensitivity and specificity of diagnostic tests by Bayesian modeling. Prev Vet Med 68: 145–163.

. Ching-Ying J. Poh, David R. Greig, Ella V. Rodwell and Claire Jenkins (2026). Public health surveillance of Vibrio cholerae in travelers returning to the United Kingdom, Journal of Medical Microbiology , 75: 002121, https://doi.org/10.1099/jmm.0.002121

. Diallo, AB, Nguefack, J., & Keita, S. (2023). Evaluation of a new multiplex real-time PCR (RADIOne) for the rapid detection of enteric pathogens in resource-limited settings. African Journal of Laboratory Medicine, 12(1), 1890-1898. https://doi.org/10.4102/ajlm.v12i1.1890

. Dick MH, Guillerm M, Moussy F, Chaignat CL (2012). Review of Two Decades of Cholera Diagnostics-How Far Have we Really Come? PLoS Negl Trop Dis 6(10) :e 1845. https://doi.org/10.1371/journal.pntd.0001845

. Gbadoé AD, Djadou KE, Dagnra HAS , Guédénon K, Tongon K, Adjéloh P (2017). Evaluation of the SDFK50 rapid diagnostic test (RDT) for malaria detecting PfHRP2, J Afr Pediatr Genet Med, No. 2; 34-39

. Global Task Force on Cholera Control (GTFCC). (2022). Technical Guidance on the use of PCR for Cholera Surveillance and Outbreak Detection . World Health Organization . https://www.gtfcc.org/resources/technical-guidance-cholera-surveillance/

. High Authority for Health (HAS), 2004. Methodological guide: How to evaluate a priori a screening program, 68p.

. Lahiri A, Agarwal RK, Sanyal SC (1982). Organic similarity of enterotoxins of vibrio cholerae serotypes other than type 1 to cholera toxin and Escherichia coli heat -labile enterotoxin , J Med Microbiol ., 15(4): 429-40. https://doi.org/10.1099/00222615-15-4-429 .

. Limmathurotsakul D, Jamsen K, Arayawichanont A, Simpson JA, White LJ, et al. (2010) Defining true culture sensitivity for melioidosis diagnosis using Bayesian latent class models. PLoS One 5: e12485

. Ministry of Public Health, DRC. (2024). Annual Epidemiological Surveillance Report: Cholera in the Democratic Republic of Congo. National Cholera Elimination Program (PNECH).

. Ministry of Public Health, DRC. (2024). Epidemiological situation report: Cholera outbreak in the eastern provinces. National Cholera Elimination Program (PNECH).

. Moser, W., Gignoux, E., Keita, S., Katende , A., & Azman, AS (2024). Performance of cholera rapid diagnostic tests during an outbreak in Goma, Democratic Republic of the Congo. The Journal of Infectious Diseases , 229(1), 45-53. https://doi.org/10.1093/infdis/jiad412

. Naglaa F, Abd el-latif, Mona H, El-Sayad , Mohamed A, Talal Saaeed , Omar M Hameed and Heba Said Ibrahim (2022). Evaluation of Multiplex Real Time PCR in Detection of enteric Pathogenic Protozoa among diarrhea children , Journal of the Egyptian Society of Parasitology , Vol.52, No. 3:2090-2549 online.

. Oikarinen S, Tauriaimen S, Viskari H, Simell O, Knip M, 2009. PCR inhibition in stool sample in relation to age of infants, Cin. Virol . J, 44:211-21.

. World Health Organization (2011) Cholera, 2010. Weekly Epidemiological Record 86:325–339.

. World Health Organization (WHO). (2023). Fact sheet: Cholera. Accessed 23 April 2026 at https://www.who.int/fr/news-room/fact-sheets/detail/cholera

. Summary report (2023). Study on the positivity rate of rapid diagnostic tests for malaria using DEKI automatic readers in 3 provinces supported by PMI in DRC, US President's Malaria Initiative (PMI), 22p.

. Schrader, C, Schielke, A , Ellerbroek, L, Johne, R, 2012. PCR inhibitors - Occurrence, properties and removal , Appl. Microbiol . J. 113:1014-9.

. Surl CG, Jung BD, Park BK, Kim HC, 2011. Resistance of Cryptosporidium parvum oocysts following commercial bleach treatment, Korean J. Vet Res 51:101-5




DOI: http://dx.doi.org/10.52155/ijpsat.v58.2.8457

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