Performance of an Immunochromatographic Test (ICT) in Comparison to Some Commonly Used Serological Tests for the Diagnosis of Brucellosis in Dromedary Camels (Camelus dromedarius)

Abstract

Serological tests may represent an essential tool for the diagnosis of camel brucellosis; however, concerns arise in the scientific community regarding the direct transposition from cattle and small ruminants without adequate validation. The present study was made to compare four serological tests for the diagnosis of brucellosis in dromedary camels (Camelus dromedarius). In terms of sensitivity, our results show that the Immunochromatographic Test (ICT) shows the higher value of sensitivity, 98.67% (95% Confidence Level (C.L): 94.36%–99.99%), followed by the Fluorescence Polarization Assay (FPA) with 95.05% (95% C.L: 88.23%–99.51%), then the Competitive Enzyme-Linked Immunosorbent Assay (c-ELISA) with 94.94% (95% C.L: 88.25%–99.45%) and, finally, the Rose Bengal Test (RBT) with 68.95% (95% C.L: 56.55%–80.69%), which is the only test showing a significantly lower sensitivity compared to the others. On the other hand, our study revealed no significant difference in terms of specificity between all the tests under study, with a range from 99.06% (95% C.L: 98.34%–99.64%) for the ICT to 99.92% (95% C.L: 99.64%–100%) for the RBT. The ICT was found to be comparable in terms of sensitivity and specificity with the most commonly used tests for camel brucellosis. The results of the present study are of paramount importance for designing surveillance and control measures for brucellosis in camel populations.

An Epidemiological Study of Brucellosis in Different Animal Species from the Al-Qassim Region, Saudi Arabia

“…The brucellosis seroprevalence in camels, goats, and sheep was determined using a cross-sectional study design in the selected study sites as well as the associated risk factors [ 2 , 52 ]. The current investigation was conducted in the north, south, east, and west of the Saudi Arabian province of Qassim ( Figure 1 ).…”

“…The ease of performance, field suitability, rapidity, and simplicity of RBT makes it very useful as a herd screening high sensitivity test even in remote places while confirmatory tests such as CFT and ELISA are utilized for Brucella diagnosis [ 7 , 40 ]. The World Organization for Animal Health (OIE) has also prescribed RBT as one of the recommended serological test methods for international animal trade [ 52 ]. Other common confirmatory tests of high specificity such as the indirect enzyme-linked immunosorbent assay (i-ELISA), competitive ELISA (c-ELISA), fluorescence polarization assay (FPA), and standard agglutination test (SAT) are also well known [ 52 , 53 ].…”

“…The World Organization for Animal Health (OIE) has also prescribed RBT as one of the recommended serological test methods for international animal trade [ 52 ]. Other common confirmatory tests of high specificity such as the indirect enzyme-linked immunosorbent assay (i-ELISA), competitive ELISA (c-ELISA), fluorescence polarization assay (FPA), and standard agglutination test (SAT) are also well known [ 52 , 53 ]. The direct demonstrations of the causal organism of brucellosis have also been reported using techniques such as animal inoculation, culture, immunofluorescent antibody, polymerase chain reaction (PCR), and staining [ 54 ].…”

Selected Aspects of Camel Immune System and Immune Responses

“…It may also be considered standard for virus diagnosis [132]. In camel brucellosis, the CFT indicated high seroposivity (98.98%) in detection of the disease [133]. Khan et al (2020) found that the CFT expressed a significant positive rate for detection of anti-Brucella antibodies compared to the ELISA test [134].…”