The prevalence of camel brucellosis and associated risk factors: a global meta-epidemiological study

Main Article Content

Maryam Dadar
Sharaf S. Omar
Youcef Shahali
Yadolah Fakhri
Jacques Godfroid
Amin Mousavi Khaneghah


meta-epidemiology, brucellosis, camel, Brucella abortus, Brucella melitensis


Camel brucellosis is a widespread and critical zoonotic infection caused by Brucella abortus and Brucella melitensis that negatively impact dairy and meat products. The current meta-analysis covers studies published over a course of 40 years, between 1 January 1980 and 1 April 2021, aiming to investigate the global prevalence of Brucella spp. in camels and related risk factors in different camel-keeping areas. Chi-squared test (I2 index) was applied to evaluate the heterogeneity of studies. A random-effect model (REM) estimated the pooled prevalence among subgroups. The literature search on camel brucellosis was performed among the available databases, including CABI, PubMed, Embase, Web of Science, Cochrane, Scielo, Scopus, and Science Direct. A total of 56 publications, comprising 205 data reports, were evaluated. Our results showed that the overall prevalence of camel brucellosis in the world was 9.23%. The lowest and highest prevalence rates of Brucella spp. infections among camels were reported in Oman (0.34%, 95%CI: 0.18–0.55) and Sudan (37.41%, 95%CI: 25.27–50.31), respectively. According to different risk factors, subgroup analysis showed that the location, sex, herd size, age, and mixed rearing with other animals could be considered the main risk factors impacting the occurrence of brucellosis in camels. The reported Brucella spp. in dromedary camel was Brucella melitensis (Biovar 1, 2, and 3), Brucella abortus (Biovar 3, 5, and 6), and Brucella suis. Our study represented remarkable differences between the prevalence of Brucella spp. in male (6.83% in 41 studies) and female (9.64% among 62 studies) camels. However, the present meta-epidemiological study would help improve control and surveillance approaches to prevent the spread of camel brucellosis among herds.

Abstract 721 | PDF Downloads 580 HTML Downloads 461 XML Downloads 54


Abbas, B. and Agab, H., 2002. A review of camel brucellosis. Preventive Veterinary Medicine 55: 47–56. 10.1016/S0167-5877(02)00055-7

Abdel Hafez, S.M., Ismael, AB; Swelum, AA 2015. Development of a rapid and specific latex agglutination test for the serodiagnosis of camel brucellosis using a Brucella melitensis periplasmic protein antigen. Global Veterinaria 15: 260–267.

Abdelgawad, H.A., 2017. Serological and molecular detection of Brucella species in camels. Benha Veterinary Medical Journal. 33: 314–319.

Abdirahman, D.B., 2020. Camel Brucellosis: sero-prevalence and pathological lesions at slaughterhouses in Garissa County, Kenya. University of Nairobi.

Abebe, G., Worku, Y., Mamo, G., & Nazir, S. 2017. Sero-prevalence and associated risk factors of brucellosis in camel at Akaki Abattoir, Central Ethiopia. Journal of Animal Research, 7(4), 617–622. 10.5958/2277-940X.2017.00094.8

Admasu, P. and Kaynata, G., 2017. Seroprevalence of camel brucellosis in Yabello District of Borena Zone, Southern Ethiopia. Journal of Veterinary Medicine and Research 4: 1115.

Ahmed, M. O., Elmeshri, S. E., Abuzweda, A. R., Blauo, M., Abouzeed, Y. M., Ibrahim, A., ... & Elrais, A. 2010. Seroprevalence of brucellosis in animals and human populations in the western mountains region in Libya, December 2006–January 2008. Eurosurveillance, 15(30), 19625. 10.2807/ese.15.30.19625-en

Ahmad, S., Yaqoob, M., Hashmi, N., Ahmad, S., Zaman, M. A., & Tariq, M. 2010. Economic importance of camel: Unique alternative under crisis. Pakistan Veterinary Journal, 30(4), 191–197.

Al-Busadah, K. A., El-Bahr, S. M., & Khalafalla, A. I. 2017. Serum biochemical profile and molecular detection of pathogens in semen of infertile male dromedary camels (Camelus dromedarius). Animal reproduction science, 180, 58–65. 10.1016/j.anireprosci.2017.03.003

Al-Garadi, M.A., 2015. Bacteriological and serological study on brucellosis infection in camel (Camelus dromedaries), Al-Hodeida governorate, Yemen. International Journal of Advanced Research 3: 786–791.

Al-Khalaf, S. and El-Khaladi, A., 1989. Brucellosis of camels in Kuwait. Comparative Immunology, Microbiology and Infectious Diseases 12: 1–4. 10.1016/0147-9571(89)90002-7

Al-Majali, A.M., 2008. Risk factors associated with camel brucellosis in Jordan. Tropical Animal Health and Production 40: 193–200. 10.1007/s11250-007-9080-7

Al-Majali, A. M., Al-Qudah, K. M., Al-Tarazi, Y. H., & Al-Rawashdeh, O. F. 2008. Risk factors associated with camel brucellosis in Jordan. Tropical Animal Health and Production, 40(3), 193–200.

Alamian, S. and Dadar, M., 2019. Brucella abortus contamination of camel milk in two Iranian regions. Preventive Veterinary Medicine 169: 104708. 10.1016/j.prevetmed.2019.104708

Alatabi, A.C., 2020. Serodiagnosis for brucellosis in camels by rose Bengal and C-ELISA test in Iraq. Annals of Tropical Medicine & Public Health. 23(7): 20–32. 10.36295/ASRO.2020.23719

Alrawahi, A. H., Robertson, I., Hussain, M. H., & Saqib, M. 2019. A cross-sectional seroepidemiological study of camel (Camelus dromedarius) brucellosis and associated risk factors in the Sultanate of Oman. Open Veterinary Journal, 9(2), 133–139. 10.4314/ovj.v9i2.7

Aujla, K. M., Jasra, A. W., & Munir, M. 1998. Socioeconomic profile of camel herders in South-western mountainous areas of Pakistan. In Proceedings of the Third Annual Meeting for Animal Production under Arid Conditions, Al-Ain, United Arab Emirates. Vol. 2, 154–174.

Baumann, M. and Zessin, K., 1992. Productivity and health of camels (Camelus dromedarius) in Somalia: associations with trypanosomosis and brucellosis. Tropical Animal Health and Production 24: 145–156. 10.1007/BF02359606

Bayasgalan, C., 2018. Risk factors of brucellosis seropositivity in Bactrian camels of Mongolia. BMC Veterinary Research 14: 1–11. 10.1186/s12917-018-1664-0

Benfodil, K., 2022. Seroprevalence and associated risk factors for camel brucellosis in south Algeria. Veterinaria 71: 17–26. 10.51607/22331360.2022.71.1.17

Bornstein, S. and Musa, B., 1987. Prevalence of antibodies to some viral pathogens, Brucella abortus and Toxoplasma gondii in serum from camels (Camelus dromedarius) in Sudan. Journal of Veterinary Medicine, Series B 34: 364–370. 10.1111/j.1439-0450.1987.tb00409.x

Chinakwe, E., 2019. Microbial population changes in the rhizo-sphere of tomato Solanum Lycopersicum varieties during early growth in greenhouse. Malaysian Journal of Sustainable Agriculture (MJSA) 3: 23–27. 10.26480/mjsa.01.2019.23.27

Corbel, M.J., 2006. Brucellosis in humans and animals. World Health Organization.

Dadar, M. and Alamian, S., 2020. Isolation of Brucella melitensis from seronegative camel: potential implications in brucellosis control. Preventive Veterinary Medicine 185: 105194. 10.1016/j.prevetmed.2020.105194

Dadar, M., 2020. Contamination of milk and dairy products by Brucella species: a global systematic review and meta-analysis. Food Research International 128: 108775. 10.1016/j.foodres.2019.108775

Damir, H.A., 1989. Isolation of Brucella abortus from experimentally infected dromedary camels in Sudan: a preliminary report. Veterinary Research Communications 13: 403–406. 10.1007/BF00402559

Dawood, H.A., 2008. Brucellosis in Camels (Camelus dromedorius) in the south province of Jordan. American Journal of Agricultural and Biological Sciences 3: 623–626. 10.3844/ajabssp.2008.623.626

De Souza, C., 2021. The occurrence of aflatoxin M1 in industrial and traditional fermented milk: a systematic review study. Italian Journal of Food Science 33: 12–23. 10.15586/ijfs.v33iSP1.1982

Díaz, R., 2011. The rose Bengal test in human brucellosis: a neglected test for the diagnosis of a neglected disease. PLoS Negl Trop Dis. 5: e950. 10.1371/journal.pntd.0000950

El-Sayed, A.M., 2017. Sero-prevalence of camel brucellosis (Camelus dromedarius) and phenotypic characteristics of Brucella melitensis biovar 3 in Shalateen City, Red Sea Governorate, Egypt. African Journal of Microbiology Research 11: 1259–1266. 10.5897/AJMR2017.8629

Fatima, S., 2016. Serological, molecular detection and potential risk factors associated with camel brucellosis in Pakistan. Tropical Animal Health and Production 48: 1711–1718. 10.1007/s11250-016-1148-9

Franck, S.V., Prevalence of brucellosis in camels (camelus dromedarius) in northern Niger.

Gameel, S., 1993. Prevalence of camel brucellosis in Libya. Tropical Animal Health and Production 25: 91–93. 10.1007/BF02236513

Gessese, A., 2014. Seroprevalence of brucellosis in camels (Camelus dromedaries) in South East Ethiopia. Journal of Veterinary Scientific Medical Diagnosis 3: 2.

Ghanem, Y.M., 2009. Seroprevalence of camel brucellosis (Camelus dromedarius) in Somaliland. Tropical Animal Health and Produc tion 41: 1779. 10.1007/s11250-009-9377-9

Ghorbani, A., 2013. Comparison of serology, culture, and PCR for detection of brucellosis in slaughtered camels in Iran. Comparative Clinical Pathology 22: 913–917. 10.1007/s00580-012-1499-1

Gizachew, A., 2014. Review on medicinal and nutritional values of camel milk. Nature and Science 12: 35–41.

Gutema Wegi, F., 2020. Brucellosis in cattle, camel and human: sero-prevalence and associated risk factors in Amibara district of Afar region, Ethiopia. Addis Ababa University.

Gutema, F. and Tesfaye, J., 2019. Review on camel brucellosis: public health importance and status in Ethiopia. Academic Research Journal of Agricultural Science and Research 7: 513–529.

Gwida, M., 2012. Brucellosis in camels. Research in Veterinary Science 92: 351–355. 10.1016/j.rvsc.2011.05.002

Gwida, M.M., 2011. Comparison of diagnostic tests for the detection of Brucella spp. in camel sera. BMC Research Notes 4: 1–7. 10.1186/1756-0500-4-525

Hadush, A., 2013. Sero-epidemiology of camel brucellosis in the Afar region of Northeast Ethiopia. Journal of Veterinary Medicine and Animal Health 5: 269–275.

Hamdy, M.E. and Amin, A., 2002. Detection of Brucella species in the milk of infected cattle, sheep, goats and camels by PCR. The Veterinary Journal 163: 299–305. 10.1053/tvjl.2001.0681

Hanon, B.M., 2017. Seroprevalence of brucellosis and toxoplasmosis in camels of Wasit Province, Iraq. AL-Qadisiyah Journal of Veterinary Medicine Sciences 16: 29–37. 10.29079/vol16iss2art440

Higgins, J.P. and Green, S., 2011. Cochrane handbook for systematic reviews of interventions. John Wiley & Sons.

Higgins, J.P. and Thompson, S., 2002. Quantifying heterogeneity in a meta-analysis. Statistics in Medicine 21: 1539–1558. 10.1002/sim.1186

Hosein, H., 2016. Seroprevalence of camel brucellosis and molecular characterization of Brucella melitensis recovered from dromedary camels in Egypt. Res. J. Vet. Pract. 4: 17–24. 10.14737/journal.rjvp/2016/

Hussein, M.F., 2021. Brucellosis (Brucella abortus and Br. melitensis). In: Infectious diseases of dromedary camels. Springer, pp. 89–94.

Ibrahim, M., 2020. Sero-prevalence of brucellosis, Q-fever and Rift Valley Fever in humans and livestock in Somali region, Ethiopia. bioRxiv. 10.1101/2020.01.31.928374

Ismail, W., 2012. Seroprevalence and associated risk factors of camel (Camelus dromedaries) brucellosis in and around Dire Dawa, Ethiopia. Global Veterinaria 8: 480–483.

Jackson, D., 2015. Approximate confidence intervals for moment-based estimators of the between-study variance in random effects meta-analysis. Research Synthesis Methods 6: 372–382. 10.1002/jrsm.1162

Jasra, A.W. and Mirza, M.A., 2004. Camel production systems in Asia. of the Series: ICAR Technical Series.

Khadjeh, G., 1999. Incidence of brucellosis in one-humped camels of Boushehr, Iran. Archives of Razi Institute 50: 83–86.

Khalafalla, A.I., 2017. A study on some reproductive disorders in dromedary camel herds in Saudi Arabia with special references to uterine infections and abortion. Tropical Animal Health and Production 49: 967–974. 10.1007/s11250-017-1284-x

Khalafalla, A.I., 2020. Preliminary comparative assessment of brucellergene skin test for diagnosis of brucellosis in dromedary camels (Camelus dromedarius). Vector-Borne and Zoonotic Diseases 20: 412–417. 10.1089/vbz.2019.2537

Khamesipour, F., 2015. Molecular study of Brucellosis in camels by the use of TaqMan® real-time PCR. Acta Microbiologica et Immunologica Hungarica 62: 409–421. 10.1556/030.62.2015.4.6

Khan, A.U., 2020. Seroprevalence and molecular identification of Brucella spp. in camels in Egypt. Microorganisms 8: 1035. 10.3390/microorganisms8071035

Kim, J.-Y., 2016. Distinctive phenotypic and molecular characteristics of Brucella abortus strains isolated from Mongolia. Turkish Journal of Veterinary and Animal Sciences 40: 562–568. 10.3906/vet-1511-75

Kudi, A., 1997. Brucellosis in camels. Journal of Arid Environments 37: 413–417. 10.1006/jare.1997.0277

Kula, J.T. and Tegegne, D., 2016. Chemical composition and medicinal values of camel milk. Int J Res Stud Biosci. 4: 13–25.

Liberati, A., 2009. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. PLoS Medicine. 6: 15–25. 10.1371/journal.pmed.1000100

Lu, H., 2021. A critical review on communication mechanism within plant-endophytic fungi interactions to cope with biotic and abiotic stresses. Journal of Fungi 7: 719. 10.3390/jof7090719

Mahyuddin, H.S., 2020. Using soxhlet and supercritical fluid (SFE) methods. Science 4: 9–12. 10.26480/gws.01.2020.09.12

Megersa, B., 2005. Seroprevalence of brucellosis in camels (Camelus dromedarius) in Borena Lowland, Southern Ethiopia Sero-prevalence de la brucellose chez les dromadaires (Camelus dromedarius) dans la plaine de Borena au Sud de l’Ethiopie. Bulletin of Animal Health and Production in Africa 53: 252–257. 10.4314/bahpa.v53i4.32718

Megersa, B., 2011. Seroprevalence of brucellosis and its contribution to abortion in cattle, camel, and goat kept under pastoral management in Borana, Ethiopia. Tropical Animal Health and Production 43: 651–656. 10.1007/s11250-010-9748-2

Moghney, F., 2004. A preliminary study on brucellosis on camels at Behira province. Ass Univ Bull Environ Res. 7: 39–43. 10.21608/auber.2004.150592

Mohammed, M.A. and Shigidy, M.T., 2013. Sero-prevalence and epidemiology of brucellosis in camels, sheep and goats in Abu Dhabi Emirate. International Journal of Animal and Veterinary Advances 5: 82–86. 10.19026/ijava.5.5581

Mokhtar, M.O., 2007. Survey of Brucellosis among sheep, goats, camels and. Journal of Animal and Veterinary Advances 6: 635–637.

Mokhtarian, M., 2020. Aflatoxin B1 in the Iranian pistachio nut and decontamination methods: a systematic review. Quality Assurance and Safety of Crops & Foods 12: 15–25. 10.15586/qas.v12i4.784

Moustafa, T., 1998. Surveillance of Brucella antibodies in camels of the eastern region of Abu Dhabi, United Arab Emirates. Proceedings of the Third Annual Meeting for Animal Production under Arid Conditions 1: 160–166.

Musa, M. and Shigidi, M., 2001. Brucellosis in camels in intensive animal breeding areas of Sudan. Implications in abortion and early-life infection= La brucellose chez les dromadaires en zones d’élevage intensif au Soudan. Implications dans l’avortement et l’infection précoce= Brucelosis en camellos en areas de cria animal intensiva en Sudan: implicaciones para el aborto y las infecciones neonatales. Revue d’élevage et de médecine vétérinaire des pays tropicaux. 54. 10.19182/remvt.9799

Musa, M., 2008. Brucellosis in camels (Camelus dromedarius) in Darfur, western Sudan. Journal of Comparative Pathology 138: 151–155. 10.1016/j.jcpa.2007.10.005

Noor, M., 2020. Prevalence, risk factors associated with Brucellosis and presence of pathogenic bacteria isolated from camel milk in Garissa County, Kenya. South Asian Journal of Research in Microbiology 42–52. 10.9734/sajrm/2020/v6i430158

Omer, M., 2000. Prevalence of antibodies to Brucella spp. in cattle, sheep, goats, horses and camels in the State of Eritrea; influence of husbandry systems. Epidemiology & Infection 125: 447–453. 10.1017/S0950268899004501

Omer, M., 2010. Brucellosis in camels, cattle and humans: associations and evaluation of serological tests used for diagnosis of the disease in certain nomadic localities in Sudan. Revue scientifique et technique (International Office of Epizootics) 29: 663–669. 10.20506/rst.29.3.2003

Pappas, G., 2010. The changing Brucella ecology: novel reservoirs, new threats. International Journal of Antimicrobial Agents 36: S8–S11. 10.1016/j.ijantimicag.2010.06.013

Rabah, I., 2020. Serological and molecular epidemiological study on Brucellosis in camels and human in Matrouh Province. Damanhour Journal of Veterinary Sciences 4: 1–6.

Radwan, A., 1992. Serological and bacteriological study of brucellosis in camels in central Saudi Arabia. Revue Scientifique et Technique-Office International des Epizooties 11: 837–837. 10.20506/rst.11.3.612

Sabrina Mahyuddin, H., 2020. Antibacterial activity of compounds from azolla pinnata extracted using soxhlet and supercritical fluid (SFE) methods. Science Heritage Journal 4(1): 9–12. 10.26480/gws.01.2020.09.12

Salisu, U., 2018. Risk factors and knowledge of Brucella infection in camels, attitudes and practices of camel handlers in Katsina State, Nigeria. Nigerian Veterinary Journal 39: 227–239. 10.4314/nvj.v39i3.6

Shahzad, A., 2017. Seroprevalence and molecular investigation of brucellosis in camels of selected districts of Punjab, Pakistan. The Thai Journal of Veterinary Medicine 47: 207.

Shehzad, A., 2020. Seroprevalence and potential risk factors associated with brucellosis in the Desert Thal of Pakistan. Human and Veterinary Medicine 12: 47–52.

Shome, R., 2013. A report of seroprevalence of camel brucellosis in India. J Camel Pract Res. 20: 183–186.

Solonitsuin, M., 1949. Brucellosis in camels. Veterinarya, Moscow 26: 16–21.

Sprague, L.D., 2012. A review on camel brucellosis: a zoonosis sustained by ignorance and indifference. Pathogens and Global Health 106: 144–149. 10.1179/2047773212Y.0000000020

Stanley, T.D. and Jarrell, S.B., 1989. Meta-regression analysis: a quantitative method of literature surveys. Journal of Economic Surveys 3: 161–170. 10.1111/j.1467-6419.1989.tb00064.x

Teshome, H., 2003. A seroprevalence study of camel brucellosis in three camel-rearing regions of Ethiopia. Tropical Animal Health and Production 35: 381–390. 10.1023/A:1025874310261

Tilahun, B., 2013. Camel brucellosis and management practices in Jijiga and Babile districts, Eastern Ethiopia. Journal of Veterinary Medicine and Animal Health 5: 81–86.

Ullah, S., 2015. Prevalence of brucellosis among camels in district Muzaffargarh Pakistan. J Infec Mol Biol. 3: 52–56. 10.14737/journal.jimb/2015/

Waktole, H., 2022. Seroepidemiology of camel brucellosis in and around Dire Dawa, Eastern Ethiopia. Veterinary Medicine International.

Wardeh, M., 2004. Classification of the dromedary camels. J. Camel Sci. 1: 1–7.

Warsame, I., 2020. Seroprevalence and associated risk factors of camel (Camelus dromedaries) Brucellosis in and around Dire Dawa, Ethiopia.

Wernery, U., 2014. Camelid brucellosis: a review. Rev sci tech. 33: 839–857. 10.20506/rst.33.3.2322

Yawoz, M., 2012. A serological study of brucellosis in camels south of Kirkuk, Iraq. Iraqi Journal of Veterinary Sciences 26: 105–107. 10.33899/ijvs.2012.67484

Zowghi, E. and Ebadi, A., 1989. Brucellosis in Camels in Iran. Archives of Razi Institute 40: 111–115.857. 10.20506/rst.33.3.2322