Brucellosis In Sheep Research Articles

Study of the brucellosis transmission with multi-stage

In this paper, based on characteristics of brucellosis infection in some regions in China, a multi-stage dynamic model is proposed for sheep brucellosis transmission. The birth rate is related to the adult and vaccinated sheep. More realistically, the immigration from other place is also considered. Firstly, the basic reproduction number $ R_{0}$ is determined and the dynamical properties of the model is discussed. It is concluded that the unique endemic equilibrium exists when $ R_{0}>1$. By constructing suitable Lyapunov function, the global stability of the endemic equilibrium is verified. By carrying out sensitivity analysis of the basic reproduction number in term of the parameters, it is concluded that increasing the sheep vaccination rate and elimination rate of infected sheep is important for the control brucellosis.

Molecular epidemiological characterization of Brucella isolates from sheep and yaks in northwest China.

Animal brucellosis is a re-emerging disease in China with high prevalence in the northwest region. A total of 66 isolates of Brucella were recovered from sheep and yaks in the Inner Mongolia, Xinjiang, Qinghai and Gansu provinces of northwest China in 2015 and 2016. Using classical biotyping and the Brucella AMOS PCR assay, all isolates were identified as Brucella melitensis biovar 3 (n=58), B.melitensis biovar 1 (n=1), Brucella abortus (n=5), or Brucella suis biovar 3 (n=2), and B.melitensis biovar 3 was found to be mainly responsible for sheep brucellosis in northwest China. Multilocus variable-number tandem-repeat analysis (MLVA) was used to identify the epidemiological relationships among the isolates and to assess their genetic diversity. Multilocus variable-number tandem-repeat analysis-16 identified 46 genotypes in these populations, including 37 unique and nine shared genotypes. Multilocus variable-number tandem-repeat analysis-11 showed that 71% of the isolates (47 of 66) were genotype 116 (1-5-3-13-2-2-3-2-4-41-8), a characteristic subgroup of the East Mediterranean group, showing that isolates from different geographical areas exhibit similar epidemiological characteristics in different regions and may be epidemiologically linked. Multilocus variable-number tandem-repeat analysis-11 also revealed that an isolate from Inner Mongolia had a novel genotype, 369 (1-5-3-13-2-2-3-2-7-41-8). Multilocus variable-number tandem-repeat analysis-16 genotyping of northwest China Brucella isolates allows a better understanding of the epidemiology of animal brucellosis in this region. This study is the first analysis of B.melitensis in Gansu province, and the results confirmed that in this province, isolates of this species are disorderly and unsystematic.

Comparative evaluation of blood based lateral flow assay for diagnosis of brucellosis in livestock species

Brucellosis is a zoonotic and economically important disease of livestock. Pen side diagnostics are the need of the hour for the rapid diagnosis of brucellosis. The present study aimed to evaluate blood based lateral flow assay (LFA) with serum based LFA and rose bengal plate test (RBPT) for diagnosis of brucellosis. Sera/blood samples [792: cattle, 153; buffalo, 55; sheep, 140; goats, 219; and pigs, 225] were collected from Karnataka, India with history of repeat breeding, retention of placenta and abortion.The seropositivity of brucellosis in cattle, buffalo, sheep, goats and pigs was 7.84, 3.63, 12.85, 2.73 and 39.11% by RBPT; 5.88, 3.63, 8.57, 2.73 and 31.1% by blood-LFA; and 7.18, 3.63, 10.71, 3.19 and 32.88% by serum-LFA. Relative specificity of blood based LFA was between 98.97 to 99.53% and 97.42 to 100% in comparison to serum-LFA and RBPT, respectively in all the species. The relative sensitivity for all the species ranged from 64.29 to 83.33% by blood-LFA and 57.14 to 84.09% by serum-LFA. The diagnostic accuracy of blood-LFA to RBPT and serum- LFA ranged from 91 to 99% among the species studied. It is opined that blood based LFA can serve as diagnostic test in place of serum based LFA for brucellosis screening in multiple livestock species and suggested for adaptation on-farm, slaughter, market, clinical and prepurchase surveillance of brucellosis in the country.

Sero-epidemiological study of brucellosis in small ruminants and associated human beings in district Quetta, Balochistan

Brucellosis is an occupational hazard in animal handlers and medical practitioners. This study was aimed to estimate the sero-prevalence of brucellosis in goats, sheep and butchers (slaughterhouse worker) in Quetta and its suburb. A total of 530 peripheral blood samples were collected randomly from goats (n=250), sheep (n=250) and butchers (n=30). The serum samples were subjected for Rose Bengal Precipitation Test and Slide Agglutination Test, whereas hematological test was performed for (n=30) samples collected from slaughterhouse workers. Butchers were interviewed with the help of a predesigned questionnaire. Results showed that the overall prevalence of brucellosis in the area was about 3.4 % out of 530 serum samples. The antibody titer through SAT for Barbari breed was ranging 1:525 to 1:2625. For Khurasani and Mengali breeds, it was 1:125. In Complete Blood Count leukopenia was detected (WBC<4300/mm3) 21/30 (70 %), anemia 21/30 (70 %) thrombocytopenia (Platelets <150.000/mm3) within samples of butchers. Hemoglobin deficiency (HGB< 12mg/dl) 24/30 (80%) were found. It is concluded that brucellosis is more prevalent in female animals as compared to males. Barbari, Khurasani and Lehri breeds in goats and Mengali, Shinwari and Bibrik in sheep were more affected by brucellosis. Although insignificant association between prevalence of brucellosis in sheep and goat (P <0.05) was observed. Butchers and slaughter house workers are found to be at high risk due to their low immunity level. Keywords: Sero-prevalence; RBPT; SAT; Slaughterhouse; Brucella http://dx.doi.org/10.19045/bspab.2017.60084

Brucellosis in mammals of Costa Rica: An epidemiological survey.

Brucellosis has been an endemic disease of cattle and humans in Costa Rica since the beginning of XX century. However, brucellosis in sheep, goats, pigs, water buffaloes, horses and cetaceans, has not been reported in the country. We have performed a brucellosis survey in these host mammal species, from 1999–2016. In addition, we have documented the number of human brucellosis reported cases, from 2003–2016. The brucellosis seroprevalence in goat and sheep herds was 0.98% and 0.7% respectively, with no Brucella isolation. Antibodies against Brucella were not detected in feral or domestic pigs. Likewise, brucellosis seroprevalence in horse and water buffalo farms was estimated in 6.5% and 21.7%, respectively, with no Brucella isolation. Six cetacean species showed positive reactions against Brucella antigens, and B. ceti was isolated in 70% (n = 29) of striped dolphins (Stenella coeruleoalba). A steady increase in the diagnosis of human brucellosis cases was observed. Taking into account the prevalence of brucellosis in the various host mammals of Costa Rica, different measures are recommended.

Seroprevalence of Brucellosis in Small Ruminants Assayed by The Rose Bengal Test, Al-Jabal Al-Akhdar Libya

This study aimed at determining the prevalence of anti- Brucella antibodies in small ruminants in Al- Jabal Al- Akhdar area, Libya. Nine regions were selected for the investigation (Al- Goba, Al- Wasata, Side Kahled, Lamloda, Al-Hesha, Marawa, Al-Gagab, Gandola and Ain Mara). Seroprevalence was assayed using the Rose – Bengal Plate Test (RBPT). Four hundred blood samples were collected randomly from 247 sheep and 153 goats with a history of abortion and reproductive disorders, during the period from January 2015 to June 2016. Approximately 10 ml blood sample was taken from each animal, in vacutainers. Serum samples were separated and subjected to examination by the RBPT. Samples showing visible agglutination within 4 mins. were regarded as positive for anti- Brucella antibodies. Data were analyzed statistically by the Chi- square test using the SpSS software, at p ≤ 0.05 level of significance. Out of the 400 ovine and caprine sera tested, 125 (38%) were positive for anti – Brucella antibodies by the RBPT (Table 3). The rate of seropositivity was higher in goats (69.3%) than in sheep (18.6%) (Table 2). There were variations in seroreactivity from different regions. For instance, sera from Al- Hesha and Gandola exhibited 100% positivity, whereas those from both species in Al- Gagab were remarkably sero-negative (0%) (Table 3). Striking differences were shown by the sera from Gandola and Ain- Mara. Where all the caprine sera from Gandola were positive for anti – Brucella antibodies, all the 18 sera from Ain- Mara were serologically negative. Serum reactivity from both goats and sheep in other regions ranged between 60 and 83.3% in goats and 11.5 and 23.3% in sheep (Table 3). It can be concluded that the prevalence of anti- Brucella antibodies is high in small ruminants of Al- Jabal Al- Akhdar, Libya and may indicate a possible existence of Brucellosis in goats and sheep.

Comparative Efficacy of Serological Tests for Detection of Brucella Antibodies in Sheep and Goats

Brucellosis is an important zoonosis and a significant cause of reproductive losses in animals. In view of the considerable problems related to direct diagnosis of brucellosis in animals, the present study envisaged the appraisal of seroepidemiology of brucellosis in sheep and goats by detection of brucella specific antibodies, comparison of two serological tests, viz., i-ELISA (Indirect Enzyme Linked Immunosorbent Assay) and RBPT expand for detection of Brucella-specific antibodies. Out of 1012 sheep and goat sera screened, 88 (8.70%) and 75 (7.41%) were detected positive by RBPT and i-ELISA, respectively. Species-wise seroprevalence was detected 12.26% and 10.97% in sheep and 5.67% and 4.39% in goats by RBPT and i-ELISA, respectively. During present investigation, RBPT detected more number of samples positive for brucella antibodies. However, compared to i-ELISA, overall sensitivity and specificity of RBPT were 80.00% and 97.01%, respectively. Species-wise sensitivity of RBPT found was 82.35% in sheep and 75.00% in goat, whereas specificity was 96.38% in sheep and 96.41% in goats.

Sero-diagnosis of brucellosis in Gharbiya governorate, Egypt

A total 1006 animals (300 cattle, 300 buffaloes, and 300 sheep and106 goats) were selected from private farms andsuspected to suffer from brucellosis from different localities in Gharbiya governorate, as well as 50 rats (31Rattus rattus&19 Rattus norvegicus) and 15 stray dogs were collected from the same localities associated with examined animals. Inaddition, 160 persons suffering from fever suspected to be brucellosis were collected (80 workers contact with examinedanimals and 40 from fever hospitals). Serological tests were carried out by using Rose Bengal plate (RBPT), BufferedAcidified plate test (BAPAT), Complement Fixation test (CFT), Tube Agglutination test (TAT) and 2- Mercapto-Ethanoltest (2-MET). The results showed that the percentage of positive reactors were 9%, 7.3%, 9.3% 8.5%, 8% and 0% usingRBPT in cows, buffaloes, sheep, goats, rats and dogs respectively. Meanwhile the percentage of positive reactors usingBAPAT was 9.6%, 8.3%, 10.7%, and 9.6% in cows, buffaloes, sheep and goats and by using CFT the percentage was9.3%, 8%, 10.3% and 10.3% in previously examined animals. Also the result of TAT was 8% in rats and 0.0% in dogs.The occurrence of brucellosis in sheep and goats was higher than cows and buffaloes. Finally, the results in humans were13.1%, 11.3% and 10% by using RBPT, TAT and 2MET respectively. The incidence of brucellosis was higher in males(14.9%) than females (3.8%) and higher in humans aged between 20-30 years

Sero-epidemiological survey of brucellosis in small ruminants in Hamedan province, Iran

Objective: Brucellosis is a highly contagious zoonosis with global distribution. The disease remains endemic in many countries including Iran, while its seroprevalence in endemic area is not well documented. We aimed to determine the seroprevalence of brucellosis in sheep and goats in Hamedan province, west of Iran. Material and methods: A total of 3,250 blood samples from 2,550 sheep and 700 goats were collected randomly. All samples were analyzed for the presence of Brucella antibodies using Rose Bengal, Wright standard tube agglutination and 2-mercaptoethanol agglutination tests. Results: The seroprevalence rate of brucellosis in animals and flock level were found in 4.6% and 13.6% of goats and 3% and 27.9% of sheep, respectively. No evidence of correlation between gender and Brucella infection rate were found in animals ( P >0.05). Statistical significant differences was seen between age groups and infection rate in goats ( P =0.033, OR=2.1); unlike to sheep ( P =0.373). Also, the infection rate in nomads population of sheep was higher than fix location animals ( P =0.003; OR=1.9); unlike to goats ( P =0.195). In animals with history of abortion and vaccination against brucellosis, seroprevalence rate was significantly lower than other ( P <0.05). Conclusion: This is the first report of brucellosis in sheep and goats in Hamedan province. The design of a comprehensive control program including vaccination, screening, and culling of brucellosis-positive animals is recommended. http://doi.org/10.5455/javar.2016.c179

A Sero-epidemiological Survey of Brucellosis, Q-Fever and Leptospirosis in Livestock and Humans and Associated Risk Factors in Kajiado County- Kenya

Animal and human health is inextricably linked. People depend on animals for nutrition, socio-economic development and companionship. A cross-sectional serological study was carried out to determine the seroprevalence of three related zoonotic diseases namely Brucellosis, Q-fever and Leptospirosis in cattle, sheep, goats and humans in three sub counties of Kajiado County. In addition the risk factors associated with sero-positivity in animals and humans were assessed. A total of, 250 (cattle), 167 (sheep), (167) goats and 317 (humans) samples were collected. Serum samples were screened for brucellosis using Rose Bengal Plate Test (RBPT) and thereafter a total of 400 samples from all the four species (all the positive on RBPT and other randomly picked samples) were subjected to cELISA (COMPELISA, VLA, UK) test. Results indicated a low prevalence of brucellosis in humans 1.3% (2/150) but a higher prevalence of Q-fever 26% (24/90). The overall prevalence in livestock was 12.91% (27/209) and 79.3% (249/314) 21.8% (54/248) (in cattle only) for brucellosis, Q-fever and Leptospirosis respectively. The prevalence estimates in cattle, sheep and goats were 21.92% (16/73), 8.6% (6/69) and 7.3% (5/67) for brucellosis respectively and 89.7% (140/156), 57.5% (46/80) and 83.1% (69/83) for Q-fever respectively and 21.8% (54/248) for Leptospirosis in cattle only, indicating a high risk of transmission of the diseases to humans through contact and/or consumption of livestock products such as milk. The study and the data obtained therefore indicates that the two zoonotic diseases brucellosis and Q-fever maybe enzootic in the study area in human, cattle, sheep and goats, while leptospirosis is present in cattle and presents a serious public health problem among the inhabitants of the county and that there is need to create awareness among all concerned on the likely high prevalence of the two diseases to avoid misdiagnosis and suffering of patients. It is recommended that the veterinary personnel in Kajiado County make an effort to investigate all cases of abortions and retained placentas that are included in their disease surveillance reports.

Sensitivity and Specificity of Various Serological Tests for Detection of &amp;lt;i&amp;gt;Brucella spp&amp;lt;/i&amp;gt;. Infection in Male Goats and Sheep

Brucellosis is a zoonosis found throughout the world with major implications both in the field of public health and farming economy. It is most often caused by Brucella abortus and Brucella melitensis. This study aimed for evaluation of the sensitivity and specificity of immunochromatographic assay (ICA) and comparing the results with those obtained from Rose Bengal Plate Test (RBPT) and in direct Enzyme Linked Immunsorbent Assay (ELISA) for serodiagnosis of sheep and goat brucellosis. Out of 41 sera samples (21 ram and 20 male goats) which were examined, antibodies against Brucella were detected in ram 8 (38.09%), 6 (28.57%) and 16 (76.19%) in ram samples, whereas they were detected in 3 (15%), 1 (5%) and 12 (60%) serum sample of goats males by RBPT, (ICA) and iELISA respectively. The kappa value between iELISA and ICA was -0.08 and that between RBPT and ELISA was -0.01 in ram and the kappa value between iELISA and ICA was -0.06 and that between RBPT and ELISA was -0.14 in male goats. The sensitivity for RBPT and ICA were 37.5% and 25% while specificity was 60% and 60% in ram; whereas, in male goats, sensitivity for RBPT was 8.33% and ICA was 8.33% while specificity was 75% and 100% respectively. It can be concluded that the developed ICA is immunodiagnostic assay, and it is rapid, non-expensive, economical and suitable for large-scale screening in developing countries and rural areas.

Epidemiological survey of brucellosis in sheep and goats in selected pastoral and agro-pastoral lowlands of Ethiopia.

An epidemiological survey was conducted in pastoral regions of Ethiopia to investigate the distribution of brucellosis in sheep and goats. Between November 2004 and December 2007, a total of 6,201 serum samples were collected from 67 randomly selected peasant associations, 25 districts and eight pastoral zones of Ethiopia. The Rose Bengal plate test (RBPT) and complement fixation test were used in series. Samples for bacteriology were collected from three export abattoirs, where 285 goats were randomly selected and tested by RBPTthree days before slaughter. Tissue samples were collected from 14 strongly positive goats and cultured in dextrose agar and Brucella agar base. To confirm and subtype the isolates, staining, biochemical tests and polymerase chain reaction were used. The overall standardised seroprevalence of brucellosis was 1.9%, ranging from 0.07% in Jijiga zone to 3.3% in Borena zone. There was statistically significant variation among the studied regions, zones, districts and peasant associations (p < 0.05). Male goats and sheep were twice as likely to test positive as females (relative risk [RRJ: 2.04; 95% confidence interval [CI]:1.7-3.4; x2 = 21.05, p < 0.05). Adults (older than 1.5 years) were three times more likely to test positive than younger animals (RR: 2.76; 95% CI: 1.14-6.73; chi2 = 5.18, p < 0.05). Goats were around four times more likely to be infected than sheep (RR: 3.8; 95% CI: 2.4-6.1; chi2 = 36.99, p < 0.05). Brucella melitensis was isolated from 2 of the 14 samples analysed. The widespread distribution of brucellosis in goats and sheep in these areas justifies the use of control measures to minimise the economic losses and public health hazards.

Seroprevalence and "Knowledge, Attitudes and Practices" (KAPs) survey of endemic ovine brucellosis in Egypt.

BackgroundBetween February and July 2014, a cross-sectional study to estimate the seroprevalence of brucellosis in sheep in the Kafrelsheikh district of Egypt was carried out, together with a survey of knowledge, attitudes and practices (KAPs) among local shepherds. A total of 273 serum samples were collected from 28 sheep flocks in 10 villages within the study area. These samples were analysed by the Rose Bengal Plate test (RBPT) test, with all positive samples being confirmed by complement fixation test (CFT).ResultsTrue seroprevalence was 20 % (95 % CI 15.3–24.7 %) with the prevalence of villages with at least one seropositive sheep estimated at 95.5 % (95 % CI 92.2–100 %); village flock seroprevalence ranged from 0 to 46.8 %. Results of the KAPs survey demonstrated that despite good knowledge regarding brucellosis being potentially present within their flocks, shepherds lacked knowledge regarding routes of livestock to humans disease transmission and the symptoms of brucellosis in humans. This lack of knowledge regarding disease transmission resulted in high-risk practices being widespread—practices such as assisting parturition without protective measures, throwing aborted material into water canals and a reluctance to remove animals that had aborted from the flock.ConclusionsThis study proposes potential measures to reduce seroprevalence of brucellosis in sheep and reduce public health risks from brucellosis such as culling aborted livestock and educational campaigns among shepherds regarding disease risks and modes of transmission.Electronic supplementary materialThe online version of this article (doi:10.1186/s13028-015-0183-2) contains supplementary material, which is available to authorized users.

Brucella suis strain 2 vaccine is safe and protective against heterologous Brucella spp. infections

Brucellosis is a wide spread zoonotic disease that causes abortion and infertility in mammals and leads to debilitating, febrile illness in humans. Brucella abortus, Brucella melitensis and Brucella suis are the major pathogenic species to humans. Vaccination with live attenuated B. suis strain 2 (S2) vaccine is an essential and critical component in the control of brucellosis in China. The S2 vaccine is very effective in preventing brucellosis in goats, sheep, cattle and swine. However, there are still debates outside of China whether the S2 vaccine is able to provide protection against heterologous virulent Brucella species. We investigated the residual virulence, immunogenicity and protective efficacy of the S2 vaccine in BALB/c mice by determining bacteria persistence in spleen, serum antibody response, cellular immune response and protection against a heterologous virulent challenge. The S2 vaccine was of low virulence as there were no bacteria recovered in spleen four weeks post vaccination. The vaccinated mice developed Brucella-specific IgG in 2–3 weeks, and a burst production of IFN-γ at one week as well as a two-fold increase in TNF-α production. The S2 vaccine protected mice from a virulent challenge by B. melitensis M28, B. abortus 2308 and B. suis S1330, and the S2 vaccinated mice did not develop any clinical signs or tissue damage. Our study demonstrated that the S2 vaccine is of low virulence, stimulates good humoral and cellular immunity and protects animals against infection by heterologous, virulent Brucella species.

MLVA as an Epidemiological Tool To Trace Back Brucella melitensis Biovar 1 Re-Emergence in Italy.

Brucellosis is an important zoonosis caused by Brucella spp., still prevalent in most areas of the world. Brucellosis control in animals is the key to protect humans. The knowledge of Brucella spp. prevailing genotypes in a territory represents an important epidemiological tool to formulate policies and strategies for disease control and to trace back the introduction of new strains previously considered as exotic. In the last years, multiple-locus variable number tandem repeat analysis (MLVA) has been proposed as complementary to classical biotyping methods. MLVA may add important information to the classical epidemiological investigation techniques, to help in tracing back sources of infection in brucellosis outbreaks. Sardinia is an Italian region officially free from sheep and goats brucellosis since 1998. In 2011, Brucella melitensis biovar 1, a biotype not reported in Italy since 1995, was isolated in one flock in the region. The genotyping MLVA-16 showed that isolates belonged to a rare American lineage, confirming it was introduced from other countries. The strain was considered as probably originating from Spain, where this lineage is endemic. BrucellaMLVA-16 has been proved to be useful to analyse the epidemiological correlation of strains enabling to trace its geographic origin by comparing their previously reported genetic patterns.

Innocuousness of conjunctival vaccination with Brucella melitensis strain Rev.1 in pregnant Iranian fat-tailed ewes

&lt;em&gt;Brucella&lt;/em&gt; &lt;em&gt;melitensis&lt;/em&gt; strain Rev.1 is the most effective vaccine against brucellosis in sheep and goats. In Iran, mass vaccination is carried out all over the country in which adult animals are immunized by subcutaneous injection of reduced doses of the vaccine. However, due to antibody responses elicited by vaccination, concomitant implementation of test-andslaughter is impossible. To overcome the problem, vaccination through conjunctival route is recommended. In this study, serological responses of six pregnant Iranian fat-tailed ewes to conjunctival vaccination with standard doses of the vaccine were evaluated using modified Rose Bengal test, serum agglutination test and indirect ELISA. Besides, vaccine strain excretion in milk and vaginal discharges was also examined by microbiological culture of milk and vaginal swab samples taken one day post-parturition. Animals were vaccinated during the second half of gestation. As the results, antibody titers of five (83.3%) ewes decreased to the levels not detectable by the tests within three months after vaccination. No vaccine-induced abortions occurred and vaccinated ewes delivered healthy lambs 50.33±15.56 (mean ± standard deviation) days post-vaccination. Vaccine strain was not isolated from milk and vaginal swab samples. Generally, our study shows full doses of &lt;em&gt;B. melitensis&lt;/em&gt; strain Rev.1 can be used conjunctively to vaccinate pregnant Iranian sheep during late pregnancy without abortifacient effects, prolonged antibody responses and vaccine strain excretion in milk and vaginal discharges. Nevertheless, further studies are required to determine safety and immunogenicity of the vaccine in field conditions.

Evaluation Of Immune Response To Brucella Infection In Sheep

Brucellosis in sheep and goats is a zoonotic infection (excluding Brucellaovis) with important effects on both public health and animal health. The disease is widespread in many areas of the world, particularly in some Mediterranean and Middle Easterncountries.Aim of the study: the present study aims to find out the prevalence of brucellosis in sheep in one of the areas of An Najaf El-Ashraf city, and study of the immune response by measuring the levels of and interleukin-10 (IL-10).Methodology: Current study conducted in the Najaf province (Al-Barakyia) during the period between September 2013- March 2014, fulfilled by using Rose Bengal and Enzyme Immunosorbent Assay (ELISA) tests for estimation of brucella antibodies. A total number of 48 serum samples were collected from sheep and stored at -20 C.Results: the frequency of positive sera by Rose Bengal test (RBT) was 20% and by ELISA technique was 25%. The level of interleukin 10 (IL-10) was estimated in all surveyed animals, 12 sera samples were showed an elevated IL-10 levels, all were positive with ELISA serological test.Conclusion: the detection of significant concentration of IL-10 among the seropositive cases may be indicated an active infection of brucella with type 2 cytokine production.Recommendations: the evaluation of immune response of vaccinated sheep with brucella REV1 vaccine, depending on the estimation of IFN-γ and IL-10 ratio that will reflect the cytokines induced during vaccination and consequently, the effective or not immune response.

Modeling sheep brucellosis transmission with a multi-stage model in Changling County of Jilin Province, China

Brucellosis is one of the major public health problems in Jilin Province of China, especially in Changling County of Jilin Province where at least 95 % of the human brucellosis cases are caused by sheep, which attribute to the large number of sheep kept there and the high positive rate of sheep. In this paper, based on the monitoring data and the characteristics of brucellosis infection in Changling County of Jilin Province, a multi-stage dynamic model is proposed for sheep brucellosis transmission, involving young sheep population and adult sheep population. Firstly, the basic reproduction number $$R_0$$ is determined and then the dynamic properties of the model is further discussed. By carrying out sensitivity analysis of the basic reproduction number in terms of some parameters, it concluded that the birth rate of sheep, sheep vaccination rate, and the elimination rate of infectious sheep play an important roles in the transmission of brucellosis. After investigating and comparing the effect of vaccination and culling strategies is completed, the results show that vaccinating sheep and culling infectious sheep are two effective and feasible strategies to control the spread of brucellosis in Changling County of Jilin Province, but the latter is more effective than the former.

Seroprevalence and comparison of different serological tests for brucellosis detection in small ruminants.

Aim:The aim was to study the seroprevalence and efficacy of the different serological tests used for detection of antibody against Brucella species in small ruminants of Banaskantha district of North-Gujarat.Materials and Methods:Total 1000 serum samples comprising of 485 from sheep and 515 from goat tested for detection of antibodies against the Brucella species by three different serological tests viz., Rose bengal plate test (RBPT), Standard tube agglutination test (STAT), and Indirect Enzyme-linked immunosorbent assay (I-ELISA).Results:The seroprevalence of brucellosis in small ruminants was 11.30%, 11.10%, and 8.80% by RBPT, STAT, and I-ELISA, respectively. The seroprevalence of brucellosis was found to be higher in sheep than goats. The sensitivity of RBPT was found slight more than STAT, but the specificity of both tests was same. In this study, the overall agreement of RBPT and STAT with I-ELISA was found 92.50% and 92.30% in small ruminants, respectively.Conclusion:I-ELISA was a better serological test as compared to RBPT and STAT in the sense of sensitivity, specificity, and rapidity and it could be advocated for screening of brucellosis in sheep and goats.

Retrospective analysis of the prevalence of Brucella antibodies in sheep in the Karas Region of Namibia.

In this retrospective study, complete Brucella serology data from the annual national brucellosis testing program and disease investigation for the years 2008-2010 was collated and analyzed to estimate the prevalence of brucellosis in sheep in the Karas Region of Namibia. A total of 22,994 serological results from 762 flocks screened using the Rose Bengal test (RBT) and confirmed using the complement fixation test (CFT) were analyzed. An overall prevalence of 0.14% was recorded over the 3 years. Yearly prevalence was 0.19% (2008), 0.05% (2009), and 0.18% (2010). At district level, brucellosis prevalence was estimated to be between 0 and 0.49%. On positive farms (n = 32), prevalence was between 2.25 and 30%. True prevalence was zero at district level and in all the three study years. We concluded that the prevalence of Brucella antibodies in sheep was low taking into account that some farmers may have vaccinated against the disease. The low prevalence confirms the effectiveness of existing brucellosis control measures implemented by the official veterinary services.