ABSTRACT
@#Abstract: Objective To study the characteristics and diagnostic efficacy of Rose-Bengal plate agglutination test (RBPT), standard-tube agglutination test (SAT) and enzyme-linked immunosorbent assay (ELISA) in the diagnosis of brucellosis. Methods A total of 489 suspected brucellosis patients with complete records, who admitted to Xing'anmeng People's Hospital from March 2020 to May 2021, were selected as the subjects. The diagnostic value of SAT, RBPT and ELISA for brucellosis was analyzed with exposure history + clinical symptoms + serological test/brucellosis isolation and culture as the gold standard. Results Of the 489 suspected patients, 183 (37.42%) were diagnosed with brucellosis, while 234 (47.85%), 148 (30.27%) and 195 (39.88%) were positive by RBPT, ELISA and SAT, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of RBPT in the diagnosis of brucellosis were 95.08%, 80.39%, 74.36%, 96.47%, and 85.89%, respectively; the values of the above parameters for ELISA were 78.69%, 98.69%, 97.30%, 88.56%, and 91.21%, respectively; those values of SAT were 98.36%, 95.10%, 92.31%, 98.98%, and 96.32%, respectively. The sensitivity of RBPT was significantly higher than ELISA, but the specificity and accuracy were significantly lower than ELISA (all P<0.05). The sensitivity and accuracy of SAT diagnosis were significantly higher than ELISA, but the specificity was significantly lower than ELISA (all P<0.05). There was no significant difference between SAT and RBPT in the sensitivity of diagnosis, but the specificity and accuracy were significantly higher than those of RBPT (P<0.05). Conclusion RBPT and SAT have high sensitivity in diagnosis of brucellosis, while ELISA has high specificity in diagnosis. RBPT with high sensitivity and convenient operation can be used for primary screening in field detection, and then the other two methods can be used for rechecking, so as to further improve the efficiency and accuracy of diagnosis of brucellosis.
ABSTRACT
@#Human brucellosis is a neglected zoonotic problem worldwide with a high degree of morbidity in humans and is mostly overlooked due to other febrile conditions. The aim of this study was to evaluate the sero-prevalence and risk factors of human brucellosis among subjects living in Punjab, Pakistan. In this cross-sectional study, human blood samples were collected from seven districts of Punjab, Pakistan. Information regarding personal data, demographic data and potential risk factors was collected through a structured questionnaire. Detection of anti-Brucella antibodies was done through Rose Bengal Plate Test (RBPT) and Enzyme Linked Immunosorbent Assay (ELISA). Descriptive analysis, Chi square test and Odds ratio was applied using STATA software version 12. The sero-prevalence of human brucellosis was 13.13% with significantly higher percentage in males 17.23% and age group 25-40 years 16.50% (P=< 0.001). The demographic factors positively associated with human brucellosis were lack of education (P = 0.003; OR = 1.85) and farming as an occupation (P =<0.001; OR = 2.50) Similarly, among the risk factors studied, keeping animals at home (P =<0.001; OR = 2.03), slaughtering of animals (P =<0.001; OR = 15.87) and consuming raw milk (P =<0.001; OR = 5.42) were the factors strongly connected with human brucellosis. A massive awareness should be given to livestock farmers and individuals directly linked to animals regarding risk factors and transmission of brucellosis. Consumption of unpasteurized milk and its products should be condemned to curtail this neglected disease.
ABSTRACT
Brucellosis is highly infectious zoonotic disease that causes huge economic losses to livestock farmers by affecting the reproductive potential of animals causing last trimester abortions and infertility. In the present study evaluation of different serological tests to diagnose the seroprevalence of brucellosis in bovines with history of abortion using various serological tests [Rose Bengal Plate Test (RBPT), modified rose bengal plate test (mRBPT), microtitre plate agglutination test (MAT) and indirect enzyme linked immunosorbent assay (i-ELISA)] was carried out. A total of 134 blood samples of cattle and buffalo with history of abortion were collected from organized and unorganized farms. Seroprevalence by mRBPT, RBPT, MAT and i-ELISA was 75.37%, 67.91%, 72.38% and 72.38%, respectively. In organized farms, prevalence of 78.12%, 81.25%, 78.12% and 81.25% while in unorganized farms prevalence of 64.70%, 73.52%, 70.58% and 69.60% was reported by RBPT, mRBPT, MAT and i-ELISA, respectively. The sensitivity and specificity of serological tests by keeping i-ELISA as gold standard were also calculated and the results revealed that sensitivities of RBPT, mRBPT and MAT were 91.75%, 97.94% and 96.91%, respectively, whereas specificities were 94.59%, 83.78% and 91.89%, respectively.
ABSTRACT
Agglutination is the clumping of antigenic particles by antibodies. Several diagnostic kits for infectious diseases of animals and humans, based on slide agglutination/plate agglutination tests like the Rose Bengal Plate Test (RBPT) for diagnosis of brucellosis are used worldwide. False negative and false positive results are commonly encountered in these conventional agglutination tests. Simple, cost effective modifications can help in circumventing these problems. The novel Superagglutination Test reported here is a modified slide / plate agglutination test. False negative results due to smaller clumps formed by low titer of antibodies in serum are minimized by the addition of biotinylated antiglobulin followed by Avidin which forms easily detectable larger clumps. Similarly, prior staining of serum antibodies with a dye helps in differentiating a specific agglutinate formed by both antigen and antibody, from a non-specific aggregate of antigen alone that leads to false positive results. Superagglutination is more sensitive than the current agglutination tests and agglutination based diagnostic kits. The modification steps are easy to perform and give a more accurate diagnosis without much increase in the cost of the test. The economic losses to livestock industry caused by the spread of infectious diseases like brucellosis due to false negative diagnosis and culling/slaughtering of productive animals due to false positive diagnosis can be avoided by employing the new test.