Seroprevelance of Bovine Brucellosis in the Nile Delta Region, Egypt: a Preliminary Study
Total Page:16
File Type:pdf, Size:1020Kb
Central Journal of Veterinary Medicine and Research Bringing Excellence in Open Access Research Article *Corresponding author Mayada Gwida, Faculty of Veterinary Medicine, Department of Hygiene and Zoonoses, Mansoura Seroprevelance of Bovine University, Mansoura 35516, Egypt, Tel: 002050 2372592; Fax: 00205023799; E-mail: Submitted: 30 October 2015 Brucellosis in the Nile Delta Accepted: 10, December 2015 Published: 12 December 2015 Region, Egypt: A Preliminary ISSN: 2378-931X Copyright Study © 2015 Gwida et al. OPEN ACCESS Mayada Gwida1*, Maged El-Ashker2, Mohamed El-Diasty3, Falk Melzer4 and Heinrich Neubauer4 Keywords 1Department of Hygiene and Zoonoses, Mansoura University, Egypt • Brucellosis 2Department of Internal Medicine and Infectious Diseases, Mansoura University, Egypt • Nile Delta 3Department of Infectious Diseases, Mansoura Provincial Lab, Egypt • Egypt 4Friedrich-Loeffler-Institute, Institute of Bacterial Infections and Zoonoses Jena, Germany • Serology • Zoonoses Abstract There is currently an obvious discrepancy between the officially reported data for seroprevalence of human and animal Brucellosis in Egypt and the data obtained from scientific reports. The present study gives a preliminary data about the seroprevalence of Brucella infection in dairy cattle herds from three large Egyptian Governorates located in the Nile Delta region. The study population consisted of 2.830 dairy cattle from private farms in Dakahlia, Damietta and Port-Said Governorates. Serum samples were randomly collected from 811 cows (203 animals showed reproductive disorders group 1); while 608 cows were apparently healthy (group 2). The collected sera were tested by Rose Bengal Test (RBT), Enzyme Linked Immunosorbant Assay (ELISA) and Fluorescent Polarization Assay (FPA). The overall seroprevelance among the tested cows in the first group was 52.2% (106/203). ELISA showed the highest number of positive reactors (n = 138; 67.9%) followed by FPA (n = 120; 59.11%) and RBT (n = 109; 53.7%); while in group 2, the number of positive animals were 25 (4.2%), 20 (3.3%) and 11 (1.8%) by using RBT, ELISA and FPA, respectively. It is very likely that brucellosis Could poses a great risk to consumers in the study region and Could be a potential source of infection to animal keepers, veterinarians and slaughterhouse workers. Further studies are warranted to unravel the epidemiological situation of human, animal and environmental brucellosis in other regions of Egypt. INTRODUCTION Egyptian control program, brucellosis remains endemic among ruminants and humans and recent reports suggest that the Brucellosis, caused by Brucella spp., is considered one of incidence of human infection is dramatically increased [6]. Given the most important contagious diseases in animals causing that infected animals are the source of human infection, the unbearable serious impacts due to abortion, premature birth, decreased milk production, and reduced reproduction rate of a similar trend in domestic animals [2]. Several authors have resulting in substantial economic losses [1,2]. It also represents a increasing incidence of human brucellosis is probably a reflection great public health problem in the Mediterranean region, western attributed the limited success of the control program in Egypt to Asia, parts of Africa and Latin America and more than 500,000 improper diagnosis and spreading of the disease at large animals humans get infected with brucellosis every year worldwide [3]. markets where different animal species of unknown health status from different localities intermix. Additionally, small ruminant the island of Malta in the 19th and early 20th centuries. In Egypt, 7]. Brucellosis was first recognized as a disease affecting humans on Other researchers linked the lack of Brucella flocks present in high numbers in Egypt are highly migratory [ endemic in most parts of the country [4]. The annual economic compensation for owners and the emotional attachment of control to insufficient lossesit was reporteddue to brucellosis in 1939 for were the estimated first time andto be is about now considered 60 million owners to their animal’s resulting in slaughtering of only 0.2% of Egyptian pounds yearly in 1995 [5], but actual estimates are seropositive animals [8,9]. Importantly, the failure to get access still missing. Despite almost 30 years of implementation of the to all animals which should be tested according to the control Cite this article: Gwida M, El-Ashker M, El-Diasty M, Melzer F, Neubauer H (2015) Seroprevelance of Bovine Brucellosis in the Nile Delta Region, Egypt: A Preliminary Study. J Vet Med Res 2(5): 1037. Gwida et al. (2015) Email: Central Bringing Excellence in Open Access program is also one reason for the lack of reliable data on animal MATERIALS AND METHODS brucellosis in the country [10]. Study population and selection criteria Brucella melitensis (main hosts are small ruminants) and B. An informed consent for investigation was given by abortus (main hosts are bovids) are the species causing most brucella human cases. Human brucellosis is well documented from all the owners. All procedures were performed in accordance with over Egypt with annual incidence ranging from 64 to 70 per Guidelines 100,000 in Fayoum Governorate [6]. Three and 11% of acute for the Care and Use of Agricultural Animals in Research and the principles and specific guidelines presented in the febrile illness patients in Egypt were positive either by culture or Teaching (3rd ed.; http://www.fass.org/), and those of Mansoura serology, respectively [11]. The vast majority of brucella isolated University Animal Care and approved by its Ethical Committee. from humans was B. melitensis [12]. The disease is spreading During 2012 and 2013, a total of 2.830 Holstein-Friesian mainly due to close contact between farmers and their animals, dairy cattle aged between 2 to 5 years, from farms located at occupational exposure of farmers, veterinarians and butchers to Dakahlia, Damietta, and Port Said Governorates were examined infected animals and through the food-chain via contaminated for Brucella infection according to the practiced routine control milk and dairy products. program (Table 1). The data retrieved from the farm medical Accurate diagnosis of the disease is considered as an elusive records indicated that all cattle investigated were not previously target. Isolation of Brucella species or detection of its DNA by vaccinated with Brucella vaccine. These animals were allocated using PCR is the only method that allows certainty in diagnosis into two groups. Group 1 included 1.920 cattle with various [13]. Despite being the gold standard, bacterial isolation has been reproductive disorders; while group 2 included 910 apparently reported to show poor sensitivity for samples with low-level healthy cattle with no history of reproductive troubles (Table contamination and is impractical for regular screening of large 1). All holdings were chosen because they were known to have populations [14]. Thus, serological tests still have a major role good management practices. They were considered as closed in the routine diagnosis of brucellosis especially in developing epidemiological entities. countries due to their ease in handling, high sensitivity and Sampling low price [15]. In this setting, Buffered Plate Agglutination Blood samples were randomly collected from cows with reproductive disorders (n = 203) and from apparently healthy screeningTest (BPAT), tests Enzyme [16]. RBT,Linked Serum Immunosorbant Agglutination Assay Test (ELISA) (SAT), ones (n = 608). As many cows as possible were sampled on a farm Complementand Fluorescent Fixation Polarization Test (CFT), Assay and (FPA) indirect are still ELISA appropriate (IELISA) have also been applied for the diagnosis of brucella infection [17]. was collected from each animal through jugular vein puncture Although these tests are well-established for the diagnosis of usingto detect plain asymptomatic vacutainer tubes and chronic and needles. cases. Each Briefly, blood ten sample ml of blood was labeled with the respective animal number. The collected blood standards. There is also an obvious discrepancy between the samples were kept overnight at room temperature for clotting. bovine brucellosis in Egypt, they still doBrucella not follow infection the scientific in Egypt On the next day, sera were collected and stored in cryo-tubes at -20°C until further examination. presentofficially study reported was seroprevalenceplanned to provide for a preliminary study on the Serological tests prevalenceand the data of cattleobtained brucellosis from scientific in three large reports. Governorates Therefore, in the Eastern Nile Delta region using different serological tests. All sera were tested by RBT, ELISA and FPA. RBT was Table 1: The numbers and distribution of the cattle investigated (n = 2.830) in the selected regions. Location Number of animals on the farm Number of samples being tested Health status Port said 520 100 Reproductive disorders Damietta 1.400 103 Reproductive disorders Damietta 600 334 Apparently healthy Dakahlia 310 274 Apparently healthy Total 2.830 811 Table 2: Seroprevalence of brucellosis among cattle showed reproductive disorders. Number Serologicaltest of positive Number of animals RBT ELISA FPA Location examined by all animals serological + % - % + % - % + % SUSP % - % test Port said 100 44 44 44 56 56 57 57 43 43 52 52 4 4 44 44 Damietta 103 62 65 63.1 38 36.9 81 78.6 22 21.4 68 66 10 9.7 25 24.3 Total 203 106 109