Seroprevalence of Toxoplasma gondii and Neospora caninum infections in goats in Poland

In 2007 a survey on herd-level seroprevalence of Toxoplasma gondii and Neospora caninum infections in goats in Poland was carried out. Sera were collected from all 49 breeding goat herds, scattered over the entire country, with the vast majority of them located in the western, central and northern provinces. Only adult females (≥12 months of age) were included in the study. A herd was recorded as infected if at least one seropositive female was detected. In each herd, simple random sampling was applied and sample size was determined in a way, which allowed to evaluate serological status of a herd at expected individual-level seroprevalence 10% and level of confidence 95%. In total, 1060 sera were tested using two commercial indirect ELISA kits. Sera positive to N. caninum were subsequently confirmed with IFAT. The true herd-level seroprevalence was 100% for T. gondii and 9.0% for N. caninum infection. Three herds positive to T. gondii infection were randomly selected and all adult goats were tested with an ELISA. Individual-level true seroprevalence in these herds ranged from 30.2% to 100%. This is the first time that antibodies to N. caninum have been detected in goats in Poland.     

Leptospiral antibodies in the breeding goat population of Poland

In 2007, a survey was conducted on the prevalence of antibodies to 19 Leptospira serovars in goats in Poland . Sera were collected from adult females of all 49 breeding goat herds in Poland by applying simple random sampling. In total, 736 sera were tested by the microscopic agglutination test. A herd was considered seropositive if at least one goat with a titre of 100 or more was detected. Herd-level seroprevalence of Leptospira was 89.8 per cent and individual-level seroprevalence varied from less than 1.0 to 85.0 per cent among the herds. Antibodies to Leptospira serovars Zanoni, Bratislava, Autumnalis, Australis and Javanica were most frequently detected. Although 40.3 per cent of seropositive goats had high antibody titres (≥ 400), suggesting recent infection, no relationship with abortions or other clinical manifestation of leptospirosis in goats was detected.     

Risk factors for Brucella seropositivity in goat herds in eastern and western Uganda.

Cross-sectional prevalences and risk factors for Brucella seropositivity in goats in eastern and western Uganda were investigated. Serum was collected from 1518 goats randomly selected from 145 herds which had been identified using multistage sampling. The brucellosis card test (CT) and the Brucella melitensis tube-agglutination test (TAT) were used in parallel to detect antibodies against B. abortus and B. melitensis, respectively. Interviewer-administered questionnaires were used to collect information on goat health and management. This information was used in multivariable logistic-regression models to determine the risk factors for Brucella seropositivity in goat herds. For each analysis, a herd was considered positive if at least one goat in the herd tested positive for antibodies against Brucella and negative if none was positive.Four percent (55/1480) of the goats screened with the CT had antibodies against Brucella. The reactors were distributed in 13% (19/145) of the herds. The most-important herd-level risk factors identified were use of a hired caretaker as the primary manager of the operation compared to owner/family members (adjusted odds ratio (OR)=8.1; 95% CI 1.6, 39.7), keeping sheep in addition to goats (OR=6.0; CI 1.5, 23.7) compared to having no sheep, and free browsing (OR=4.7; 95% CI 1.0, 20.7) when compared to tethering or zero-grazing.Using the TAT, 10% (141/1446) of the goats tested positive. The positives were distributed in 43% (63/145) of the herds. Free browsing (OR=6.7; 95% CI 2.7, 16.9) when compared to tethering or zero-grazing and lack of veterinary care (OR=2.9; CI 1.3, 6.7) were the most-important factors identified in the multivariable model for B. melitensis herd seropositivity.To explore/reduce the risk of misclassification in a secondary analysis, herds were reclassified as positive if at least one goat tested positive on both tests and negative if none of the goats was positive on any of the two tests. Using this classification, 2% (30/1320; 95% CI 2, 3%) of the goats tested positive resulting in 13% (12/93) of the herds being positive. The distribution of the above risk factors by brucellosis herd-status (as defined by the second criterion) is also presented.     

Seroprevalence of Border Disease in Danish sheep and goat herds

A study was conducted in 1994-96 with the aim of assessing the serological prevalence of Border Disease (BD) among sheep and goats in Denmark and to investigate possible relations to herd factors. From each of 1000 herds, 2 blood samples were obtained from animals older than 1 year. The examination for antibodies was performed using a blocking ELISA detecting antibodies to pestivirus. Data from 815 herds were analysed statistically by the maximum likelihood method in a multinomial model. The estimated herd prevalence was 0.083 and the estimated individual prevalence within the positive herds was 0.50. There was no difference between the prevalence in sheep and goat herds. Records for well over half of the herds could be combined with data from the Danish Central Husbandry Register. No association between occurrence of BD and herd size was found. Cattle were registered as contemporarily present on 135 out of 521 herds which was shown to be strongly associated to BD. The estimated herd prevalences of BD among farms with and without contemporary cattle were 0.24 and 0.042, respectively.     

First report of Chlamydophila abortus infection in the dromedary camel (Camelus dromedarius) population in eastern Algeria

Chlamydiosis is caused by an obligate intracellular gram-negative bacterium of the genus Chlamydophila which is a zoonotic pathogen. The objectives of the study were to identify the seroprevalence of antibodies against Chlamydophila abortus in dromedary camel herds from four districts in eastern Algeria, as well as to estimate the association between seroprevalence and certain factors present at the animal and herd levels. Blood samples were collected from a random sample of animals within each of 82 camel herds. Serum samples were subjected to a C. abortus ELISA test, and association between the presence of antibodies and potential risk factors was estimated. Animal and herd seroprevalence were 2.5 % and 15.8 %, respectively, indicating substantial exposure of camels to C. abortus in the four districts studied. Age, breed, and sex did not influence seroprevalence in tested animals. Based on the univariate analysis, contact with sheep and goats, contact with other camel herds, and histories of abortion were major risk factors for infection. By using multivariate analysis, contact of camels with sheep and goats and with others camel herds, through shared grazing or watering points, were important factors for transmission of chlamydiosis with an odds ratio of 3.3 and 9.4, respectively. At the herd level the introduction of purchased animals was the major risk factor. This baseline information will be highly useful for launching C. abortus control programs in the region and potentially elsewhere.     

Investigations concerning the prevalence of Coxiella burnetii and Chlamydia abortus in sheep in correlation with management systems and abortion rate in Lower Saxony in 2004

The intracellular bacteria Coxiella (C) burnetii and Chlamydia (Chl) abortus induce abortion in sheep and also affect humans. While Chl. abortus only infrequently infects humans, C burnetii is the aetiological agent of numerous Q fever outbreaks during the last decades. There is only limited knowledge about the prevalence of both pathogens in sheep, although sheep are involved in almost all Q fever outbreaks in Germany. The aim of our study was to investigate the prevalence of both pathogens in flocks located in Lower Saxony, Germany, in correlation to the management form and abortion rate. Serum samples of 1714 sheep from 95 flocks located in Lower Saxony were investigated by ELISA. 2.7% of these samples were positive, 1.3% showed inconclusive results in the C. burnetii-ELISA. Elevated intra-flock seroprevalences were only detected in three migrating flocks. Chlamydia-specific antibodies could be detected in 15.1% serum samples of mainly shepherded and migrating flocks. In one of these flocks with a high intra-flock seroprevalence for C burnetii (27%) and Chlamydia (44.9%), C burnetii was detected in 21.6% of the placenta samples of normal births and in 12.5% of the colostrum samples by PCR. Aborted fetuses and the corresponding placentas were negative in C burnetii-PCR, but in most of them and also in many other placenta samples Chl. abortus could be detected by PCR and DNA microarray. This survey shows a low overall prevalence of C. burnetii in sheep in Lower Saxony in the year 2004. However, three migrating flocks with a high intra-flock prevalence are localized in the southern parts of Lower Saxony. Spreading of C burnetii could occur, because of the large radius of grazing of all three flocks.     

Report of a serological study of Coxiella burnetii in domestic animals in Albania

The prevalence of Coxiella burnetii antibodies in domestic ruminants in Albania has been investigated. A total of 1656 serum samples taken from sheep, goats, and cattle housed on farms located in 20 different districts were tested by ELISA for the presence of specific antibodies to C. burnetii phase I and II antigens. Specific IgG antibodies were detected in 9.1% of the animals from both lowland and mountainous areas. In total, a slightly higher percentage of antibodies was detected in sheep and goats (9.8%) than in cattle (7.9%).     

Comparative diagnostic potential of three serological tests for abortive Q fever in goat herds

Performances of an ELISA, an immunofluorescence assay (IFA) and a complement fixation test (CFT) were assessed for detecting antibodies against Coxiella burnetii after Q fever abortions in naturally infected goats. The goal of the study was to provide information useful for veterinary serodiagnosis in regard to categories of goats either experiencing Q fever abortion or not, blood sampling times and recommended cut-offs. The study was conducted on eight goat herds with evidence of C. burnetii abortions. In each herd, at least 5 goats that had aborted and 10 goats prior to parturition or at term were monitored 15, 30 and 60 days (D15, D30, D60) after the onset of Q fever abortion. The overall CFT results distribution did not differ between the two groups of goats and showed poor agreement with the ELISA results. In contrast, the ELISA and IFA results revealed comparable significant differences, but overall the ELISA test was slightly more sensitive than the IFA test. Seroprevalence, according to ELISA and IFA respectively, was higher in the aborting (88% and 82%) than in the non-aborting group (60% and 50%). High levels of serum antibodies were detected in goats post-abortion with an average of 114 %OD using ELISA and a log10(titer) of 2.4 using IFA. Strongly positive ELISA (%OD>80) and positive IFA results (log10(titers)>1.9) were significantly associated with abortion. Sampling on D15 gave the best association with ORs of 10 for ELISA and 6 for IFA. The practical interest of these results is discussed.     

Enzyme immunoassay for surveillance of Q fever

An enzyme-linked immunosorbent assay (ELISA) was developed to monitor antibodies against Coxiella burnetii among animal populations used in research and teaching facilities. Various antigenic components of C burnetii prepared from phase I and phase II whole cells and commercially available antigens were evaluated. A trichloroacetic acid extract was selected for routine use. There was a linear relationship between the transformed absorbance readings of the ELISA results and microagglutination (MA) titers. Comparison between positive or negative results of the MA test and ELISA gave 98.6% concordance. Using the MA test as the standard, ELISA results were 97.8% sensitive and 100% specific. The efficacy of ELISA was evaluated by testing ruminants with known histories of C burnetii infection. Antibody prevalence was 0 in 117 sheep with no history of C burnetii infection, 22% in 145 naturally infected sheep used for research, and 53% in 115 sheep used for vaccine field trials. Forty-eight percent of 120 dairy cows and 52% of 79 goats from endemically infected herds were seropositive. These results indicate that ELISA should be the test of choice for mass screening and surveillance of animals when Q fever is a suspected biohazard.     

Occurrence, distribution, and role in abortion of Coxiella burnetii in sheep and goats in Sardinia, Italy

Between 1999 and 2002, 9349 sera and 517 aborted samples (422 foetuses and 95 placenta) were analysed from 675 sheep and 82 goat farms distributed all over the island of Sardinia. After abortion notification, sera collected at random from adult animals were examined to detect antibodies specific to Coxiella burnetii by ELISA, whereas foetuses and placenta were analysed by PCR assay. Specific IgG antibodies were detected in 255 (38%) sheep farms and in 39 (47%) goat herds whereas 40 ovine (10%) and 3 (6%) caprine foetuses were C. burnetii PCR-positive. Although C. burnetii DNA was amplified from different types of tissues, placenta was the tissue with the highest detection rate. Seroprevalence analysis indicates that C. burnetii distribution in sheep and goats is very high, but PCR results demonstrate that C. burnetii has a relatively low role in abortion, especially in goats.     

Multivariate model for the assessment of risk of fetal loss in goat herds

The observational study was carried out in a population of Polish breeding goats in 2007 to determine the prevalence of fetal loss and identify risk factors contributing to its occurrence. The multivariate model allowing to predict the risk of the occurrence of fetal loss in a herd in a study population was developed. Data on the occurrence of fetal loss, as well as of 28 hypothesized risk factors were collected from goat owners using standardized questionnaire during face-to-face reviews on farms. Moreover, data on the herd-level seroprevalence of four abortifacient infections--Chlamydophila abortus, Leptospira spp., BVDV-1 and Neospora caninum--were included in the final analysis. Fetal loss was reported as occurring often in 12 of 49 goat herds (24.5%). The relationship between the hypothesized risk factors and the occurrence of fetal loss was verified in the multivariate logistic regression (alpha=0.05). Final analysis yielded four risk factors: regular veterinary supervision at least twice a year (OR 0.188; CI 95% 0.054 - 0.656), frequent occurrence of injuries and fractures (OR 3.172; CI 95% 1.081 - 9.310), frequent occurrence of respiratory signs in adult goats (OR 4.848; CI 95% 1.353 - 17.377) and presence of antibodies to C. abortus in a herd (OR 58.116; CI 95% 1.369 - 2466.438). The accuracy of the multivariate model was analyzed using receiver operating characteristic (ROC) curve technique. Area under the curve was 0.895 (CI 95% 0.801-0.981). For optimal cut-off value of 0.20-0.35 the multivariate model had sensitivity of 75.00% and specificity of 89.19% in predicting fetal loss in a herd.     

Seroreactivity of Peruvian sheep and goats to small ruminant lentivirus-ovine progressive pneumonia virus

Sera from 3,369 sheep and 1,394 goats in Peru were examined by agar-gel immunodiffusion for antibodies to ovine progressive pneumonia virus (OPPV). The point prevalence rates for antibodies to OPPV in sheep were 1.7% to 40.6% (mean, 19.02%) in the 7 flocks studied, whereas for goats, the point prevalence rates for antibodies that cross-reacted with OPPV in 12 herds were 0.0% to 45.1%. For sheep, a direct association between increasing age and increasing seroreactivity to OPPV was established, and there was evidence to indicate that lambs born to primiparous ewes and raised separated from all other sheep after they were weaned may have been less likely to become infected with OPPV than those lambs born to multiparous ewes and not separated from other sheep after they were weaned. For goats, antibodies to OPPV were detected in 7 of 12 herds studied, the highest infection rate being present within a herd in the Lima department (district).     

Prevalence of antibody to caprine arthritis-encephalitis virus in goats in the United States.

Goats from 28 states were tested for antibodies to caprine arthritis-encephalitis virus. Of 3,790 goats, 1,175 (31%) tested positive, and of 196 herds tested, 143 (73%) had 1 or more seropositive members. This prevalence, based on serum samples from all goats in the participating herds, was lower than most rates reported in other studies. Such studies were based on fewer samples, incomplete sampling of herds, or smaller geographic base. Prevalence was highest in western Pacific and northern plains regions, increased with age to 3 years, was highest among goats on family-owned farms, and was lowest in the Angora breed. Differences in prevalence was not related to gender or size of herd.     

Serological evidence for BVDV-1 infection in goats in Poland - short communication

A serological survey was conducted in 2007 in the breeding goat population in Poland to gain insights into the epidemiology of pestivirus infection. All breeding herds were included in the study and representative serum samples were taken in each herd to evaluate herd-level seroprevalence at 10% expected individual-level prevalence and 95% level of confidence. Altogether 1060 serum samples from 49 herds were tested with blocking ELISA and then the positive and inconclusive results were confirmed in a serum neutralisation test, which also allowed us to determine the pestivirus species responsible for seroconversion. Herd-level seroprevalence proved to be 10.2% and bovine viral diarrhoea virus type 1 (BVDV-1) was responsible for the seroconversion in seven out of eight cases. In the remaining serum sample the causative virus could not be identified due to a pronounced cross-neutralising activity possibly derived from multiple infections. This is the first report on the diagnosis of BVDV-1 infection in Polish goats.     

Prevalence of bovine herpesvirus-1 in the Belgian cattle population

The national bovine herpesvirus 1 (BHV-1) seroprevalence (apparent prevalence) in the Belgian cattle population was determined by a serological survey that was conducted from December 1997 to March 1998. In a random sample of herds (N=556), all cattle (N=28 478) were tested for the presence of antibodies to glycoprotein B of BHV-1. No differentiation could be made between vaccinated and infected animals, because the exclusive use of marker vaccines was imposed by law only in 1997 by the Belgian Veterinary Authorities. Twenty-one percent of the farmers vaccinated continuously against BHV-1.

In the unvaccinated group, the overall herd, individual-animal and median within-herd seroprevalences were estimated to be 67% (95% confidence interval (CI)=62–72), 35.9% (95% CI=35.0–36.8) and 33% (quartiles=14–62), respectively.

Assuming a test sensitivity and specificity of 99 and 99.7%, respectively, the true herd, individual-animal and median within-herd prevalence for the unvaccinated group of herds were estimated to be 65, 36 and 34%, respectively. The true herd prevalence for dairy, mixed and beef herds were respectively, 84, 89 and 53%; the true individual-animal prevalence for those types of herds were, respectively, 35, 43 and 31%; whereas, the true median within-herd prevalences were 36, 29 and 38%.     

Serological evidence of lack of contact with caprine herpesvirus type 1 and bluetongue virus in goat population in Poland

Investigation into herd-level seroprevalence of caprine herpesvirus type 1 (CpHV-1) and bluetongue virus (BTV) was conducted in 2007 in Poland. It involved the entire population of goats covered by a milk recording program in 2007, which included 49 goat herds. The number of goats examined in each herd was determined statistically in order to detect the presence of at least one seropositive animal in a herd with a 95% probability and simple random method of sampling was applied. No antibodies to CpHV-1 or BTV were detected. Further calculations were carried out to determine the herd-level true seroprevalence, taking into account sensitivity and specificity of the test as well as several other factors. It can be concluded that till the middle of 2007 population of Polish goats covered by the milk recording program remained negative with respect to CpHV-1 and BTV.     

Goats may experience reproductive failures and shed Coxiella burnetii at two successive parturitions after a Q fever infection

Q fever is a zoonosis caused by the obligate intracellular bacterium, Coxiella burnetii. Aborting domestic ruminants are the main source of human infection. In January 2003, an abortion episode occurred in a dairy caprine herd where 18/60 (30%) goats experienced reproductive problems: 4/60 (7%) aborted and 14/60 (23%) had stillbirths. Serological screening for abortion-related infectious diseases suggested Q fever. The diagnosis of C. burnetii infection was confirmed with PCR based on the occurrence of C. burnetii shedding into vaginal mucus, faeces and colostrums taken after kidding from the affected animals. The pregnancy following this episode resulted in one abortion and four stillbirths; three of those goats had already experienced reproductive failure during the previous kidding season. The seroprevalence of C. burnetii infection and the bacteria shedding were investigated using both ELISA and PCR assays, respectively, during the course of the initial and subsequent kidding seasons. Serological testing, performed on the whole herd 6 weeks after the abortion episode, showed 48/60 (80%) of ELISA positive goats. PCR assay performed on both vaginal swab and milk samples showed that the bacterium was shed for almost four months after the outbreak. C. burnetii DNA was also amplified from vaginal swab and milk samples taken from goats after the second kidding season. Furthermore, the bacteria were found into 14 vaginal swabs and 12 milk samples taken from infected females at both kidding seasons.     

Occurrence and risk factors of Coxiella burnetii in domestic ruminants in Lebanon

Coxiella burnetii causes diseases in humans (Q fever) and animals, domestic ruminants playing a major role in the epidemiology of the infection. Information on C. burnetii infection in Lebanon is scanty. In order to assess the prevalence of C. burnetii infection in ruminants, a cross-sectional study was undertaken in 2014. A total of 1633 sera from ruminants (865 cattle, 384 sheep and 384 goats) from 429 farms (173 cattle, 128 sheep and 128 goats), in seven provinces of Lebanon were randomly selected and assayed for the presence of antibodies.39.86% of farms (95% CI: 35.23–44.56) resulted positive. The seroprevalence was 30.63% in Cattle-farms, 46.88% in sheep-farms and 45.31% in goat-farms.Milk samples collected from 282 seropositive animals (86 cows, 93 sheep and 103 goats) from 171 positive farms were tested by a high sensitive Real-Time PCR targeted to the IS1111 transposon of C. burnetii. The overall prevalence in farms was estimated to be 14.04%. Cattle-, sheep- and goat farm prevalence rates were 15.09%, 10% and 17.24%, respectively.The findings of the study show that C. burnetii prevalence in Lebanese domestic ruminants is related to animal species and farming practices. Indeed, the mixed herds with sheep (p < 0.01), the presence of common lambing/kidding areas (p < 0.001) in farms where the use of disinfectants was not a routine practice (p < 0.05) were identified as important risk factors.The results of the study provide baseline information for setting up herd management and public health measures for the prevention and control of Q fever in Lebanon.     

Relationships between infection with caprine arthritis encephalitis virus, intramammary bacterial infection and somatic cell counts in dairy goats.

Somatic cell counts, the bacteriological condition of the milk and antibodies against caprine arthritis encephalitis virus (CAEV) were measured monthly throughout lactation in 121 lactating goats of the Murcia-Granada breed in four commercial dairy goat herds. The prevalence of bacterial intramammary infection was 5.6 per cent and the prevalence of CAEV infection was 20.6 per cent. An analysis of variance revealed a significant effect of herd, intramammary infection and the interaction between intramammary infection and CAEV on the somatic cell count. In udder halves free of intramammary infection, the somatic cell counts were significantly lower in seronegative goats than in seropositive goats (P<0.05), but the difference was not significant in udder halves persistently infected by bacteria. There was a significant increase in somatic cell counts due to bacterial intramammary infection (P<0.01) in the seronegative goats, but this effect was not present in the seropositive animals.     

Coxiella burnetii infections and infections with bacteria of the genus Chlamydia in dairy cattle

Comparative studies on the prevalence of infections caused by Coxiella burnetii (C. burnetii) and Chlamydia were carried out with 592 cattle older than 2 years and 234 cattle younger than 2 years. Of these 477 originated from 24 dairy herds with considerable fertility problems (positive herds) and 349 from 14 dairy herds without major fertility problems (control herds). For the direct detection of these pathogens in the genitals capture ELISAs were employed, for the demonstration of antibodies the complement fixation test (CFT). Direct detection of C. burnetii and Chlamydia single as well as mixed infection revealed significant higher values for cattle from positive herds compared with those from the control herds. Animals revealing insemination ratios of > or = 2 showed significantly more frequent excretion of Chlamydia via the genitals and antibodies against C. burnetii than cattle with an insemination ratio of < 2. Investigations of cows which had had an abortion showed no indications of significantly more frequent C. burnetii or chlamydial infections. Inseminated but non-pregnant cows excreted significantly more C. burnetii and Chlamydia than pregnant cows. Clinical signs of endometritis were associated with an enhanced excretion of Chlamydia. Animals younger than 2 years excreted significantly more frequently C. burnetii but not Chlamydia via the genitals than animals older than 2 years. Indirect test showed results vice versa.