Evaluation of the General Organization of Veterinary Services control program of animal brucellosis in Egypt: An outbreak investigation of brucellosis in buffalo

Abstract

Background and Aim:Brucellosis is a major constraint to livestock production in Egypt as well as many developing countries worldwide. Bovine brucellosis is an economically important disease with reproductive failure as a principal manifestation resulting in abortion, premature birth and decreased milk production in females, and orchitis and epididymitis in males. In spite of the efforts of Egyptian veterinary services to overcome brucellosis, the disease is still prevalent in both animals and humans and represents one of the most important public health hazards in Egypt. The aim of the present work was to investigate the efficacy of the control program implemented by the General Organization of Veterinary Services in Brucella infected buffalo farm on serological, molecular, cultural, and histopathological basis. Brucella melitensis biovar 3 was recovered from 6 buffalo-cows.Materials and Methods:Blood samples were collected from a total of 750 non-vaccinated lactating buffalo-cows. These animals were proved positive for Brucella by the Egyptian brucellosis national program. Sera were tested using buffered acidified plate antigen test and rose Bengal test as screening tests and complement fixation test as a confirmatory test. Positive animals were separated for slaughtering under the supervision of the Egyptian veterinary authorities. Remaining animals were tested every 3 weeks with slaughtering of positive cases and this continued until the remaining animals revealed three successive negative serological tests. Different lymph nodes (prescapular, prefemoral, mediastinal, retropharyngeal, and supramammary) were collected from 11 Brucella seropositive buffalo-cows slaughtered after being confirmed serologically as Brucella infected cases. Samples were collected and processed for bacterial isolation and nucleic acid detection using polymerase chain reaction (PCR). Parts of these specimens were fixed in 10% neutral buffered formalin for 48 h then processed by paraffin embedding technique.Results:“Test and slaughter” policy was applied on Brucella infected dairy buffalo farm. The program continued for 6 months with slaughtering of positive cases until the herd was proved Brucella free. B. melitensis biovar 3 could be recovered from six buffalo-cows. Universal PCR confirmed Brucella on genus level and Bruce-ladder multiplex, PCR confirmed the presence of B. melitensis on the species level. Histopathological examination of Brucella-infected lymph nodes revealed massive rarified and depleted lymphoid areas of both sub-capsular and deep cortical lymphoid follicles, macrophage cells granulomatous reaction, as well as fat, infiltrates, and chronic vasculitis. The chronic nature of Brucella lesions has been confirmed in this study as indicated by the chronic vasculitis and collagen deposition.Conclusion:Freedom status from brucellosis in this study required 6 months which are considered long time allowing the spread of infection to other localities especially under unhygienic conditions, husbandry system favoring mixed popul...

Comparative Assessment of Sensitivity and Specificity of some Diagnostic Procedures of Brucellosis using Different Approaches

“…Detection of B. melitensis biovar 3 in lactating cattle highlights the substantial danger to public health. Isolation of B. melitensis biovar 3 comes in agreement with several previous reports that described this species as the most prevalent in Egypt (Samaha et al, 2008;Menshawy et al, 2014;Hosein et al, 2017;Hosein et al, 2018).…”

Serological and Molecular Identification of Brucella spp. in Pigs from Cairo and Giza Governorates, Egypt

“…Brucellosis is one of the major livestock production constraints in Egypt [4]. It is likely that it has been endemic in Egypt for thousands of years [5,6].…”

Conventional, Serological and Molecular Characterization of Brucella Species Isolated from Different Governorates in Egypt

“…It is mainly caused by B. abortus (cattle and buffaloes), B. melitensis (sheep and goats), and B. suis (pigs) (Bhat et al, 2012). Brucellosis is endemic among ruminants and humans in Egypt despite the presence of control programs (Hosein et al 2018). The annual incidence of human brucellosis is estimated to be 5 to 12.5 million cases in Egypt (Hull and Schumaker 2018).…”