Serological diagnosis of human brucellosis in Morocco and prospects for advanced diagnostic techniques
-
Aicha Qasmaoui
,
Samira Natoubi
,
Mehdi Bougharouine
,
Farida Ohmani
,
Karima Halout
,
Jamila Hamamouchi
,
Bouchra Belkadi
,
Reda Charof
Abstract
Background and Objectives: Brucellosis, a contagious infection caused by Brucella spp, remains the most widely reported bacterial zoonosis globally. Since the clinical manifestations are often non-specific, reliable laboratory confirmation, in accordance with World Health Organization recommendations, is essential. This study reports human brucellosis cases between 2017 and 2025 based on serological confirmation; it also discusses approaches to improve diagnostic accuracy for better surveillance, timely treatment, and support public health strategies.
Materials and Methods: A total of 95 serum samples were obtained from patients presenting with clinical manifestations suggestive of brucellosis. Initial screening was performed using the Rose Bengal test, and positive or equivocal samples were further analyzed by Enzyme-Linked Immunosorbent Assay to detect both IgG and IgM antibodies for serological confirmation.
Results: Among the 95 patients investigated, the Rose Bengal test yielded positive results in 69.5% of cases. Serological confirmation by ELISA demonstrated IgM seropositivity in 57.9% of patients and IgG seropositivity in 55.8%. The diagnostic performance of ELISA showed a sensitivity of 83.3% for IgM detection and 80.3% for IgG detection. Regarding patient demographics, the mean age was 37.9 ± 16.4 years, with a slight male predominance (54.7%).
Conclusion: The study reveals a considerable proportion of brucellosis-positive cases, confirming the value of serological testing in endemic regions such as Morocco. Nonetheless, serology should be complemented with advanced diagnostic methods, including PCR to improve both the accuracy and timeliness of diagnosis. These findings support the adoption of integrated diagnostic approaches and the reinforcement of laboratory capacity in high-risk areas.
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12. Díaz R, Casanova A, Ariza J, Moriyón I. The rose bengal test in human brucellosis: A neglected test for the diagnosis of a neglected disease. PLoS Negl Trop Dis 2011; 5(4): e950.
13. Yumuk Z, Afacan G, Çalışkan Ş, Irvem A, Arslan U. Relevance of autoantibody detection to the rapid diagnosis of brucellosis. Diagn Microbiol Infect Dis 2007; 58: 271-273.
14. Jindan RA, Saleem N, Shafi A, Amjad SM. Clinical Interpretation of detection of IgM Anti-Brucella Antibody in the Absence of IgG and vice versa; a diagnostic challenge for clinicians. Pol J Microbiol 2019; 68: 51-57.
15. Lemnouer A, Frikh M, Maleb A, Ahizoune A, Bourazza A, Elouennass M. Brucellosis: A cause of meningitis not to neglect. IDCases 2017; 10: 97-99.
16. Di Bonaventura G, Angeletti S, Ianni A, Petitti T, Gherardi G. Microbiological laboratory diagnosis of human brucellosis: An overview. Pathogens 2021; 10: 1623.
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18. Xu N, Wang W, Chen F, Li W, Wang G. ELISA is superior to bacterial culture and agglutination test in the diagnosis of brucellosis in an endemic area in China. BMC Infect Dis 2020; 20: 11.
19. Abnaroodheleh F, Ansari F, Shahali Y, Dadar M. Diagnostic performance of four serological assays for bovine brucellosis and optimised cutoff thresholds in an endemic region of Iran. Vet Med Sci 2025; 11(5): e70566.
20. Ekiri AB, Kilonzo C, Bird BH, VanWormer E, Wolking DJ, Smith WA, et al. Utility of the rose bengal test as a Point-of-Care test for human brucellosis in endemic african settings: A systematic review. J Trop Med 2020; 2020: 6586182.
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22. Dong S-B, Xiao D, Liu J-Y, Bi H-M, Zheng Z-R, Wang L-D, et al. Fluorescence polarization assay improves the rapid detection of human brucellosis in China. Infect Dis Poverty 2021; 10: 46.
23. Govindasamy K. Human brucellosis in South Africa : a review for medical practitioners. S Afr Med J 2020; 110: 646-651.
24. Alsayed Y, Monem F. Brucellosis laboratory tests in Syria: what are their diagnostic efficacies in different clinical manifestations? J Infect Dev Ctries 2012; 6: 495-500.
25. Xu N, Qu C, Sai L, Wen S, Yang L, Wang S, et al. Evaluating the efficacy of serological testing of clinical specimens collected from patients with suspected brucellosis. PLoS Negl Trop Dis 2023; 17(2): e0011131.
26. Sahu A, Dhanze H, Singh V, Mehta D, Gupta M, Singh M, et al. Development of IgM-ELISA for diagnosis of recent infection of Japanese encephalitis virus in equines. Biologicals 2022; 75: 16-20.
27. Sisirak M, Hukić M. Evaluation and importance of selected microbiological methods in the diagnosis of human brucellosis. Bosn J Basic Med Sci 2009; 9: 198-203.
28. Shakir R. Brucellosis. J Neurol Sci 2021; 420: 117280.
29. Makala R, Majigo MV, Bwire GM, Kibwana U, Mirambo MM, Joachim A. Seroprevalence of Brucella infection and associated factors among pregnant women receiving antenatal care around human, wildlife and livestock interface in Ngorongoro ecosystem, Northern Tanzania. A cross-sectional study. BMC Infect Dis 2020; 20: 152.
30. Memish ZA, Almuneef M, Mah MW, Qassem LA, Osoba AO. Comparison of the brucella standard agglutination test with the ELISA IgG and IgM in patients with brucella bacteremia. Diagn Microbiol Infect Dis 2002; 44: 129-132.
31. Etemadi A, Moniri R, Neubauer H, Dasteh Goli Y, Alamian S. Laboratory diagnostic procedures for human brucellosis: An overview of existing approaches. Jundishapur J Microbiol 2019; 12(5): e91200.
32. De Souza De Matos T, Fernandes ALP, Bison I, Bandeira ASDM, De Lira Bandeira WG, De Castro Nunes J, et al. New area of occurrence of human brucellosis in Brazil: serological and molecular prevalence and risk factors associated with Brucella abortus infection. One Health Outlook 2025; 7: 8.
33. Kumari R, Kalyan RK, Jain A, Kumar P, Gupta KK, Jahan A, et al. Seroprevalence of brucellosis in patients having complained of joint Pain: A case control. Cureus 2023; 15(7): e41378.
34. Batrinou A, Strati IF, Tsantes AG, Papaparaskevas J, Dimou I, Vourvidis D, et al. The importance of complementary PCR analysis in addition to serological testing for the detection of transmission sources of brucella spp. in greek ruminants. Vet Sci 2022; 9: 193.
35. Khan AU, Melzer F, El-Soally SAGE, Elschner MC, Mohamed SA, Sayed Ahmed MA, et al. Serological and molecular identification of brucella spp. in pigs from cairo and giza governorates, Egypt. Pathogens 2019; 8: 248.
36. Dadar M, Al-Khaza’leh J, Fakhri Y, Akar K, Ali S, Shahali Y. Human brucellosis and associated risk factors in the middle east region: A comprehensive systematic review, meta-analysis, and meta-regression. Heliyon 2024; 10(14): e34324.
37. Kolo FB, Adesiyun AA, Fasina FO, Harris BN, Rossouw J, Byaruhanga C, et al. Brucellosis seropositivity using three serological tests and associated risk factors in abattoir workers in gauteng province, South Africa. Pathogens 2024; 13: 64.
38. Havas KA, Ramishvili M, Navdarashvili A, Hill AE, Tsanava S, Imnadze P, et al. Risk factors associated with human brucellosis in the country of Georgia: a case-control study. Epidemiol Infect 2013; 141: 45-53.
2. Madzingira O, Fasina FO, Kalinda C, Van heerden H. Seroprevalence of brucellosis among clinically suspected human cases presenting at health facilities in namibia from 2012 to 2017. Biomed Environ Sci 2021; 34: 232-235.
3. Yagupsky P, Morata P, Colmenero JD. Laboratory diagnosis of human brucellosis. Clin Microbiol Rev 2019; 33(1): e00073-19.
4. Al Jindan R. Scenario of pathogenesis and socioeconomic burden of human brucellosis in Saudi Arabia. Saudi J Biol Sci 2021; 28: 272-279.
5. Franc KA, Krecek RC, Häsler BN, Arenas-Gamboa AM. Brucellosis remains a neglected disease in the developing world: a call for interdisciplinary action. BMC Public Health 2018; 18: 125.
6. Loubet P, Magnan C, Salipante F, Pastre T, Keriel A, O’Callaghan D, et al. Diagnosis of brucellosis: Combining tests to improve performance. PLoS Negl Trop Dis 2024; 18(9): e0012442.
7. Laine CG, Johnson VE, Scott HM, Arenas-Gamboa AM. Global estimate of human brucellosis incidence. Emerg Infect Dis 2023; 29: 1789-1797.
8. Ben Lahlou Y, Benaissa E, Maleb A, Chadli M, Elouennass M. Pancytopenia revealing acute brucellosis. IDCases 2020; 23: e01037.
9. Nawana TB, Ezzine H, Cherkaoui I, Dahbi Z, Bellefquih AM, Rguig A, et al. Brucellosis at the animal-human-environment interface in Morocco, 2002-2019: a descriptive analysis. Pan Afr Med J One Health 2021; 6: 10.11604/pamj-oh.2021.6.13.31685.
10. Sergueev KV, Filippov AA, Nikolich MP. Highly sensitive bacteriophage-Based detection of brucella abortus in mixed culture and spiked blood. Viruses 2017; 9: 144.
11. Freire ML, Machado De Assis TS, Silva SN, Cota G. Diagnosis of human brucellosis: Systematic review and meta-analysis. PLoS Negl Trop Dis 2024; 18(3): e0012030.
12. Díaz R, Casanova A, Ariza J, Moriyón I. The rose bengal test in human brucellosis: A neglected test for the diagnosis of a neglected disease. PLoS Negl Trop Dis 2011; 5(4): e950.
13. Yumuk Z, Afacan G, Çalışkan Ş, Irvem A, Arslan U. Relevance of autoantibody detection to the rapid diagnosis of brucellosis. Diagn Microbiol Infect Dis 2007; 58: 271-273.
14. Jindan RA, Saleem N, Shafi A, Amjad SM. Clinical Interpretation of detection of IgM Anti-Brucella Antibody in the Absence of IgG and vice versa; a diagnostic challenge for clinicians. Pol J Microbiol 2019; 68: 51-57.
15. Lemnouer A, Frikh M, Maleb A, Ahizoune A, Bourazza A, Elouennass M. Brucellosis: A cause of meningitis not to neglect. IDCases 2017; 10: 97-99.
16. Di Bonaventura G, Angeletti S, Ianni A, Petitti T, Gherardi G. Microbiological laboratory diagnosis of human brucellosis: An overview. Pathogens 2021; 10: 1623.
17. Solís García del Pozo J, Lorente Ortuño S, Navarro E, Solera J. Detection of IgM Antibrucella Antibody in the Absence of IgGs: A challenge for the clinical Interpretation of brucella Serology. PLoS Negl Trop Dis 2014; 8(12): e3390.
18. Xu N, Wang W, Chen F, Li W, Wang G. ELISA is superior to bacterial culture and agglutination test in the diagnosis of brucellosis in an endemic area in China. BMC Infect Dis 2020; 20: 11.
19. Abnaroodheleh F, Ansari F, Shahali Y, Dadar M. Diagnostic performance of four serological assays for bovine brucellosis and optimised cutoff thresholds in an endemic region of Iran. Vet Med Sci 2025; 11(5): e70566.
20. Ekiri AB, Kilonzo C, Bird BH, VanWormer E, Wolking DJ, Smith WA, et al. Utility of the rose bengal test as a Point-of-Care test for human brucellosis in endemic african settings: A systematic review. J Trop Med 2020; 2020: 6586182.
21. Mittal D, Grakh K, Kumar M, Jhandai P, Dahiya S, Gupta R, et al. Seroprevalence of Brucellosis in haryana, India: A study using rose bengal plate test and Enzyme-Linked immunosorbent assay. Pathogens 2025; 14: 373.
22. Dong S-B, Xiao D, Liu J-Y, Bi H-M, Zheng Z-R, Wang L-D, et al. Fluorescence polarization assay improves the rapid detection of human brucellosis in China. Infect Dis Poverty 2021; 10: 46.
23. Govindasamy K. Human brucellosis in South Africa : a review for medical practitioners. S Afr Med J 2020; 110: 646-651.
24. Alsayed Y, Monem F. Brucellosis laboratory tests in Syria: what are their diagnostic efficacies in different clinical manifestations? J Infect Dev Ctries 2012; 6: 495-500.
25. Xu N, Qu C, Sai L, Wen S, Yang L, Wang S, et al. Evaluating the efficacy of serological testing of clinical specimens collected from patients with suspected brucellosis. PLoS Negl Trop Dis 2023; 17(2): e0011131.
26. Sahu A, Dhanze H, Singh V, Mehta D, Gupta M, Singh M, et al. Development of IgM-ELISA for diagnosis of recent infection of Japanese encephalitis virus in equines. Biologicals 2022; 75: 16-20.
27. Sisirak M, Hukić M. Evaluation and importance of selected microbiological methods in the diagnosis of human brucellosis. Bosn J Basic Med Sci 2009; 9: 198-203.
28. Shakir R. Brucellosis. J Neurol Sci 2021; 420: 117280.
29. Makala R, Majigo MV, Bwire GM, Kibwana U, Mirambo MM, Joachim A. Seroprevalence of Brucella infection and associated factors among pregnant women receiving antenatal care around human, wildlife and livestock interface in Ngorongoro ecosystem, Northern Tanzania. A cross-sectional study. BMC Infect Dis 2020; 20: 152.
30. Memish ZA, Almuneef M, Mah MW, Qassem LA, Osoba AO. Comparison of the brucella standard agglutination test with the ELISA IgG and IgM in patients with brucella bacteremia. Diagn Microbiol Infect Dis 2002; 44: 129-132.
31. Etemadi A, Moniri R, Neubauer H, Dasteh Goli Y, Alamian S. Laboratory diagnostic procedures for human brucellosis: An overview of existing approaches. Jundishapur J Microbiol 2019; 12(5): e91200.
32. De Souza De Matos T, Fernandes ALP, Bison I, Bandeira ASDM, De Lira Bandeira WG, De Castro Nunes J, et al. New area of occurrence of human brucellosis in Brazil: serological and molecular prevalence and risk factors associated with Brucella abortus infection. One Health Outlook 2025; 7: 8.
33. Kumari R, Kalyan RK, Jain A, Kumar P, Gupta KK, Jahan A, et al. Seroprevalence of brucellosis in patients having complained of joint Pain: A case control. Cureus 2023; 15(7): e41378.
34. Batrinou A, Strati IF, Tsantes AG, Papaparaskevas J, Dimou I, Vourvidis D, et al. The importance of complementary PCR analysis in addition to serological testing for the detection of transmission sources of brucella spp. in greek ruminants. Vet Sci 2022; 9: 193.
35. Khan AU, Melzer F, El-Soally SAGE, Elschner MC, Mohamed SA, Sayed Ahmed MA, et al. Serological and molecular identification of brucella spp. in pigs from cairo and giza governorates, Egypt. Pathogens 2019; 8: 248.
36. Dadar M, Al-Khaza’leh J, Fakhri Y, Akar K, Ali S, Shahali Y. Human brucellosis and associated risk factors in the middle east region: A comprehensive systematic review, meta-analysis, and meta-regression. Heliyon 2024; 10(14): e34324.
37. Kolo FB, Adesiyun AA, Fasina FO, Harris BN, Rossouw J, Byaruhanga C, et al. Brucellosis seropositivity using three serological tests and associated risk factors in abattoir workers in gauteng province, South Africa. Pathogens 2024; 13: 64.
38. Havas KA, Ramishvili M, Navdarashvili A, Hill AE, Tsanava S, Imnadze P, et al. Risk factors associated with human brucellosis in the country of Georgia: a case-control study. Epidemiol Infect 2013; 141: 45-53.
| Files | ||
| Issue | Vol 17 No 5 (2025) | |
| Section | Original Article(s) | |
| DOI | https://doi.org/10.18502/ijm.v17i5.19877 | |
| Keywords | ||
| Diagnostic Brucellosis Enzyme-linked immunosorbent assay Rose bengal Sensitivity Specificity | ||
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How to Cite
1.
Qasmaoui A, Natoubi S, Bougharouine M, Ohmani F, Halout K, Hamamouchi J, Belkadi B, Charof R. Serological diagnosis of human brucellosis in Morocco and prospects for advanced diagnostic techniques. Iran J Microbiol. 2025;17(5):695-701.
