Serological survey for bovine immunodeficiency virus in dairy cattle from Poland

A seroprevalence study of bovine immunodeficiency virus (BIV) was undertaken on 1,541 serum samples from Holstein cattle from 23 herds, located in different geographical regions of Poland. The analysis was performed using ELISA, with recombinant Gag protein of BIV as antigen. The average BIV prevalence was 4.9% in individual cattle, while the percentage of herds harboring at least one seropositive animal, was 82.6%. To demonstrate the correlation of BIV and bovine leukemia virus infection, all sera were analysed for BLV antibodies and there was only a slight association between both infections. Overall, these results show that BIV infection is present in dairy cattle in Poland at a prevalence rate found in other European countries.     

Survey for antibodies to leukemia (C-type) virus in cattle.

Serums from 4,394 dairy cattle in 100 herds and from 2,794 beef cattle in 50 herds were tested for antibody to the bovine (C-type) leukemia virus (BLV), using the agar gel immunodiffusion test. Reactors were found in 66% of the dairy herds (10.2% of the cattle) and in 14% of the beef herds (1.2% of the cattle). The prevalence of reactors was examined with respect to age, herd size, and sex. Few of the reactors were less than 2 years old. There was a high percentage of reactors in small dairy herds (less than 50 cattle). In 22 dairy herds (1,354 cows and 96 bulls), the rate of infection in cows was compared with that in bulls. In those herds, 13.5% of the cows and 10.4% of the bulls were reactors.     

Detection of multiple retroviral infections in cattle and cross-reactivity of bovine immunodeficiency-like virus and human immunodeficiency virus type 1 proteins using bovine and human sera in a western blot assay.

Bovine antibovine immunodeficiency-like virus (BIV) antibodies were detected by Western blot analysis (WBA) using a chemiluminescence protocol. Bovine sera with anti-BIV activity, obtained from cows in two dairy herds, had antibodies directed against a variety of BIV-specific antigens indicating chronic infections. These sera were also tested for serological reactivity against bovine leukemia virus (BLV) and bovine syncytial virus (BSV). Cows most commonly had anti-BSV antibodies (12 of 39). Evidence for infection with BSV and BIV or BSV and BLV occurred with almost equal frequency (5 of 39 and 4 of 39, respectively) while only one instance of BIV and BLV coseropositivity was detected. The high prevalence of BSV seropositivity is consistent with a relatively infectious virus, which, as is known, may be transferred congenitally. Similar rates of coseropositivity of BIV or BLV with BSV in this population suggest that BIV is no more infectious than BLV and probably requires prolonged close contact for transmission. Seven of nine cows with anti-BIV antibodies detected primarily human immunodeficiency virus type 1 (HIV-1) p51 and p63 antigens by WBA using an alkaline phosphatase detection system, suggesting that HIV-1 proteins have potential usefulness in screening cattle for BIV seropositivity. Six human sera that showed strong reactivity against multiple HIV-1 proteins and the serum from one of three patients considered to be an "indeterminate" HIV-1 reactor, cross-reacted primarily with BIV p26. This is the first report of human sera with antibody to BIV-specific proteins.(ABSTRACT TRUNCATED AT 250 WORDS)     

Seroprevalence of bovine immunodeficiency virus in dairy and beef cattle herds in Korea.

Infection of bovine immunodeficiency virus (BIV), a lentivirus, is thought to sporadically occur throughout the world, but seroepidemiological surveys concerning the incidence of BIV are limited and have not been undertaken in Korea. A total of 266 sera from different twenty dairy (Holstein) and twenty-six Korean native beef (Hanwoo) farms of the south-western part of Korea was analyzed for the presence of anti-BIV antibodies by Western blotting. Thirty five percent and 33% of dairy and beef cattle, respectively, were BIV-seropositive. By nested polymerase chain reaction, it was confirmed that these seropositive cows had provirus in the peripheral blood mononuclear cells. To demonstrate the correlation with BIV and bovine leukemia virus (BLV) infection, these sera were also analyzed for anti-BLV antibodies by immunodiffusion test, resulting in high prevalence of BLV infection but relatively a few dual infections. We report herein the first serological detection of antibodies to BIV in Korea.     

Neospora caninum and bovine virus diarrhoea virus infections in Swedish dairy cows in relation to abortion

The protozoan parasite Neospora caninum and bovine virus diarrhoea virus (BVDV) are recognized as important causes of bovine abortion and congenital disease worldwide. In this study, serological investigations were performed to estimate the prevalence of N. caninum infection in Swedish dairy cattle, to assess to what extent it may affect abortion rates, and to determine possible effects of coinfection with BVDV. The overall N. caninum seroprevalence in Swedish dairy cows was estimated at 2% (16/780), and the BVDV seroprevalence was 32% (249/780). Among aborting cows from herds with abortion problems, 7% (26/378) had antibodies to N. caninum and 42% (153/378) to BVDV. Seventeen of the N. caninum positive animals also had antibodies to BVDV. There was a statistically significant (P = 0.013) association between presence of antibodies to N. caninum and BVDV. In a case-control study comprising sera from cows in herds without recognized abortion problems, 6% (5/89) and 1% (1/89) of sera from aborting and non-aborting cows, respectively, had antibodies to N. caninum. Two of the N. caninum seropositive aborting cows also had antibodies to BVDV. These results confirm that N. caninum infection is associated with bovine abortion in Sweden and also indicate that there might be concurrent effects of N. caninum and BVDV. It is concluded that Swedish dairy cows have a low prevalence of N. caninum infection which is favourable in relation to possible future control programmes.     

Natural changes in the spread of bovine viral diarrhoea virus (BVDV) among Estonian cattle

The results of a survey conducted during 1993-2000 to study the spread of bovine viral diarrhoeal virus (BVDV) among Estonian cattle are presented. The BVDV infection status of a representative random sample of cattle herds housing 20 or more dairy cows was established to estimate the prevalence of herds with active BVDV infection [potentially having persistently infected (PI) cattle--suspect PI herds]. The herds investigated comprised approximately 70% of all Estonian dairy cows. The BVDV infection status was established in 315-350 herds (making the sampling fraction about 20%) during three sampling periods: 1993-95, 1997-98, 1999-2000. BVDV antibodies were detected in herd bulk milk samples and/or sera from young stock by a liquid-phase-blocking enzyme-linked immunosorbent assay developed in the Danish Veterinary Institute for Virus Research. The results of the survey demonstrate the reduction in the prevalence of herds with active BVDV infection in the studied fraction of the Estonian cattle population. During the first sampling period (1993-95) a prevalence of 46% (+/- 5%) for suspect PI herds was observed, during the second sampling period this prevalence was 16% (+/- 3%) and in the third period it was 18% (+/- 3%). As there is no control programme for BVDV in Estonia, the observed changes reflect the natural course of the infection in the study population. A possible cause for these changes is the decreased trade in breeding animals as a result of the economic difficulties present in cattle farming during the study period. The farming practices (most large herds are managed as closed herds) and the low density of cattle farms have obviously facilitated the self-clearance of herds from the BVDV infection, diminishing the new introduction of infection into the herds.     

Winter dysentery in dairy herds: electron microscopic and serological evidence for an association with coronavirus infection.

Faeces and, or, paired sera were collected from cows in six dairy herds with classical winter dysentery. Similar samples were collected from cows in three other dairy herds experiencing non-haemorrhagic diarrhoea during the survey period. Coronavirus was the only enteric pathogen identified by immune electron microscopy (IEM) in all six outbreaks, occurring in 26 of 29 (90 per cent) of the affected cows and in one of 11 normal cows from the same herds. Nineteen of 26 affected cows (73 per cent) developed greater than four-fold increases in neutralising antibody titres to the Mebus strain of bovine coronavirus, compared with two of eight normal cows in the same herds. No cows showed greater than four-fold increases in antibody titres to bovine virus diarrhoea virus. None of the cows from the three herds with non-haemorrhagic diarrhoea shed coronavirus in faeces detectable by IEM or developed greater than two-fold rises in coronavirus antibody titres in paired sera. No enteric pathogens were identified in two of the herds. However, two cows in the third herd shed a group B rotavirus detected by IEM. These findings provide additional evidence for a possible role for bovine coronavirus in the aetiology of winter dysentery. Furthermore, this is the first report of a group B rotavirus associated with diarrhoea in adult cattle.     

Effects of crossbreed pregnancies on the abortion risk of Neospora caninum-infected dairy cows

Previous studies have shown that the use of beef bull semen significantly reduces the rate of abortions due to Neospora caninum in artificially inseminated (AI) seropositive dairy cows. In addition, certain beef breeds could be more resistant to N. caninum infection and abortion than others. The aim of the present study was to determine whether different crossbreed pregnancies, those derived from Limousin, Charolais, Piedmontese or Belgian Blue semen, carry different risks of abortion in Neospora-infected dairy cows. The effects of possible interactions between maternal levels of N. caninum antibodies and the different breed crosses were also evaluated. The study was performed on five commercial Holstein–Friesian dairy herds in Northeast Spain with previously confirmed diagnoses of N. caninum infection in aborted foetuses. The study population was comprised of 1115 pregnancies: 633 pregnancies recorded after AI using Holstein–Friesian semen from 18 bulls and 482 after AI using beef semen from 27 bulls (304 inseminations using semen from Limousin bulls, 191 from Belgian Blue bulls, 89 from Piedmontese bulls and 49 from Charolais bulls). Abortion rates were 32.2% (155/482) and 15.2% (96/633) for seropositive cows inseminated with Holstein–Friesian and beef breed semen, respectively. Logistic regression analysis revealed the herd and the interaction between maternal N. caninum antibody titre and the different crossbreeds as significant factors affecting the abortion rate. Lowest abortion rates, similar to that shown by seronegative animals in the analysed herds (3.2%, 239/7432), were observed in dams AI using Limousin semen that had low (<30 relative index (RI) units) N. caninum antibody titres (2.1% abortion, 3/145) and these cows were used as reference. Compared to the cows used as reference, cows with low N. caninum antibody titres (<30 RI units) showed a similar risk of abortion when inseminated with Piedmontese or Charolais bull semen, but higher risk of abortion when inseminated with Holstein (17.9 times) or Belgian Blue (7.2 times) bull semen. All cows with high N. caninum antibody titres (≥30 RI units) had a higher risk of abortion, ranging from 8.9 times (cows inseminated with Limousine semen) to 37.8 times (cows inseminated with Piedmontese semen), compared to the cows used as reference. In conclusion, different crossbreed pregnancies carried different abortion risks in Neospora-infected dairy cows. The use of beef bull semen dramatically reduced the risk of abortion in dairy cows, especially if Limousin breed semen was used. Moreover, this reduction was found to be dependent on the N. caninum antibody titre such that the lowest incidence of abortions was recorded in Limousin semen inseminated cows with low antibody titres. Insemination of Neospora-seropositive cows with beef bull semen could both reduce the risk of abortion and avoid breeding replacements for infected cattle.     

Evidence of bovine immunodeficiency virus (BIV) infection: serological survey in Argentina

This is the first report of serological evidence for bovine immunodeficiency virus (BIV) infection in Argentina. The analysis was performed in 589 dairy bovine sera samples, applying indirect enzyme-linked immunosorbent assay (I-ELISA) using a synthetic antigen (transmembrane peptide, TM) and Immunofluorescent assay (IFA). In this study, 9 dairy herds from 4 Argentinian provinces were evaluated and 12% of the animals tested positive for BIV. Seven of the 9 herds tested were BIV seropositive and the percentage of BIV seropositive animals in the herds ranged from 2% to 42%. Direct detection of BIV provirus applying nested PCR was not conclusive. Antibody detection against bovine leukemia virus (BLV) in all sera was also performed applying immunodiffusion (ID) assay and 59% resulted seropositive. Statistical analysis of the results was carried out and possible evidence of association between BIV and BLV infection was considered. Future studies should be performed including local field isolates strains of BIV.     

Seroprevalence of bovine immunodeficiency virus and bovine leukemia virus in dairy and beef cattle in hokkaido

Serological survey of bovine immunodeficiency virus (BIV) and bovine leukemia virus (BLV) infection was conducted in dairy cattle from 10 different regions of Hokkaido, Japan. Among 390 cattle, 11.0% of cattle were BIV-seropositive and 3.3% were BLV-seropositive. Moreover, in two dairy farms, where bovine leukosis has been reported, prevalence of BIV infections were 6.4 and 9.1%, respectively. In contrast, among 150 beef cattle, 16.6% were BIV-seropositive while none was BLV-seropositive. Dual infections with BLV and BIV in dairy cattle were tested by using 107 BLV-seropositive sera, and 20 sera were found BIV-positive (18.7%). These results indicate that BIV infection was widespread in Hokkaido.     

Seroprevalence and association with abortion of leptospirosis in cattle in Ontario.

Sera were collected using a systematic random sampling from 348 cattle herds in Ontario, in proportion to the cattle population in different areas. One cow in five from 296 dairy herds and one in three from 52 beef herds were sampled. The sera were analyzed for prevalence of antibodies to Leptospira interrogans serovar grippotyphosa, hardjo, icterohaemorhagiae and pomona using the microscopic agglutination test. Herd seroprevalence (one or more animals with titer greater than or equal to 80) in beef and dairy herds combined was grippotyphosa 2%, hardjo 13.8%, icterohaemorrhagiae 10.1% and pomona 25.8%; 39% of all herds showed evidence of leptospiral infection with one or more serovars; 44.2% of 52 beef herds had serological evidence of infection with serovar hardjo compared to 8.4% of 296 dairy herds (P less than 0.0001). Seroprevalence of other serovars was not significantly different between beef and dairy herds. The proportion of beef animals seropositive for hardjo and for pomona increased with age, particularly for hardjo; 26.5% of beef animals aged nine years or over were seropositive for hardjo. Dairy animals showed a significant rise of hardjo but not pomona titers with age. The seroprevalence of pomona infection was significantly higher in dairy cattle in eastern Ontario than in other regions. Thirty-four (6.1%) of 553 aborted bovine fetuses had leptospires detected by immunofluorescence techniques. Sixty-five percent of these fetuses were from submissions made between November and January. Leptospires were identified as serovar hardjo by specific immunofluorescence. There appeared, however, to be a paradoxical serological response in that eight aborting cows had antibody titers to pomona rather than hardjo.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evidence of bovine immunodeficiency virus in cattle in Turkey

A seroepidemiological study of bovine immunodeficiency virus (BIV) and bovine leukemia virus (BLV) infections was conducted in four different cattle herds in Turkey. A total of 300 blood samples were analyzed and 12.3% were found to be positive for anti-BIV p26 antibodies by Western blot analysis and 1.6% positive for anti-BLV gp51 antibodies by an immunodiffusion test. BIV infection was confirmed with the detection of BIV-provirus DNA using the nested polymerase chain reaction. This is the first evidence for the presence of BIV in cattle in Turkey.     

Evidence for bovine immunodeficiency virus infection in cattle in Zambia

We report herein on the first evidence for the presence of bovine immunodeficiency virus (BIV) in Zambia. Serological surveillance of BIV and bovine leukemia virus (BLV) was conducted in traditional cattle herds in Zambia. Out of a total of 262 sera analyzed, 11.4% were found positive for anti-BIV p26 antibodies as determined by Western blot analysis, while 5.0% were positive for anti-BLV gp51 antibodies as detected by immunodiffusion test. Peripheral blood mononuclear cells from BIV seropositive cattle were found to have BIV-provirus DNA, as detected by nested polymerase chain reaction. A nucleotide sequence corresponding to a 298 bp fragment of the BIV pol gene was also analyzed. Amino acid sequences of these Zambian pol gene products showed 98.0 to 100% homology to the American strain BIV R29, 97.0 to 99.0% to Japanese BIV isolates, and divergence ranged from 0.0 to 2.0% among Zambian BIV isolates.     

Evaluation of enzyme-linked immunosorbent assay using milk samples as a potential screening test of bovine tuberculosis of dairy cows in Korea

An enzyme-linked immunosorbent assay (ELISA) using bulk tank milk samples was evaluated as a screening test for bovine tuberculosis (TB), a contagious chronic disease of cattle. An ELISA with MPB70, a major antigen of Mycobacterium bovis was performed using paired sets of milk and sera samples from 33 tuberculin-positive and 43 tuberculin-negative cattle. Anti-MPB70 antibodies were detected in milk samples and there was a significant correlation between seroreactivities of milk and sera samples (R² = 0.83). Using the tuberculin skin test as the reference test, the sensitivities of ELISA using milk and sera samples were 87.8% and 81.8%, respectively, and the specificities were 97.7% and 100%, respectively.In the screening test using bulk tank milk samples from 931 dairy herds in Whasung, Gyeonggi-do, Korea, the positive rate for anti-MPB70 antibody was 4.5% (42/931) and the tuberculin-positive rate was 2.8% (26/931). Individual milk samples (n = 253) were collected from randomly selected 8 problematic and 3 negative herds (positive and negative in the screening test by MPB70 ELISA using bulk tank milk samples, respectively) and tested by MPB70 milk ELISA. In the problematic herds, positive rates were 10.5% (20/190) for anti-MPB70 antibodies in milk ELISA and 2.1% (4/190) in the tuberculin skin test. More than one dairy cows were positive by milk ELISA among the problematic herds, and all tuberculin-positive dairy cows were positive in the milk ELISA. Further, no positive cows were detected in negative herds both by milk ELISA and tuberculin skin test. These results suggest that an ELISA, using bulk tank milk samples, might be a potential efficient screening test for bovine TB of dairy cows.     

Seroprevalence and molecular evidence for the presence of bovine immunodeficiency virus in Brazilian cattle

Data on the worldwide distribution of bovine immunodeficiency virus (BIV) and bovine leukemia virus (BLV) is limited. A prevalence study of antibodies to BIV and BLV was conducted in six different cattle herds in Brazil. Out of a total of 238 sera analyzed, 11.7% were found positive for anti-BIV p26 antibodies as determined by Western blot analysis, 2.1% were positive for anti-BLV gp51 antibodies as detected by immunodiffusion test. Peripheral blood mononuclear cells from BIV seropositive cattle were found to have BIV-provirus DNA, as detected by nested polymerase chain reaction. A nucleotide sequence corresponding to a 298 bp fragment of the BIV pol gene was also analyzed. Amino acid sequences of these Brazilian pol gene products showed 98.0 to 100% homology to the American strain BIV R29, 97.0 to 99.0% to Japanese BIV isolates, and divergence ranged from 0 to 4.0% among Brazilian BIV isolates. This evidence of the presence of BIV and BLV infections in Brazil should be considered a health risk to Brazilian cattle populations and a potential causative agent of chronic disease in cattle.     

Risk factors for Brucella spp. infection In dairy cattle farms in Asmara, State of Eritrea

A cross-sectional study was conducted to identify risk factors for herd infection by Brucella spp. in dairy cattle in the suburbs of Asmara, Eritrea. Data were collected from 64 herds, randomly selected from a total of 99 herds with a minimum herd size of 9 cows. A questionnaire was used to gather data on management, hygiene and herd structure. Serum samples collected from all pregnant heifers, cows and bulls, were screened for Brucella infection by the Rose Bengal test (RBT), and all RBT-positive sera re-tested with the complement-fixation test (CFT) for confirmation. A seropositive herd was defined as one in which at least one animal tested positive in the CFT. There were 23 (36%) positive herds among the 64 studied. Both multiple logistic and multiple betabinomial regression modeling were used to analyze the data. Mixed-breed herds, compared to single (exotic)-breed herds, were found to be independently associated with increased herd seroprevalence (OR=5.2, 95% confidence interval 1.4–18.7) in the multiple logistic model with the herd infection status as the dependent variable. The importance of this variable was supported by the multiple betabinomial regression model (OR=3.3, 1.4–7.6) with animal-level prevalence within herd as the outcome variable. Both models also revealed the presence of a negative association between seropositivity and cattle stocking density.     

Herd-level risk factors associated with Leptospira spp. seroprevalence in dairy and beef cattle in Spain.

Our aim in this cross-sectional study was to investigate the seroprevalence of Leptospira spp. infection in herds and cattle and the relationships between seroprevalence and beef versus dairy, size, replacement policy and grazing management in a representative area of beef- and dairy-cattle production in Spain. Herds were the initial sampling unit. Blood samples were collected from 762 dairy cattle belonging to 81 herds and 1238 beef cattle from 134 herds; sera were tested for antibodies against 11 serovars of Leptospira (autumnalis, ballum, bratislava, canicola, castellonis, copenhagheni, grippotyphosa, hardjo, louisiana, pomona and tarassovi) using the microagglutination test. Forty-three percent (36.2-49.5%) of the herds and 8% (6.4-8.8%) of the individuals were seropositive against one or more of the serovars studied. Bratislava was the most-prevalent serovar (24% of the herds and 4% of the individuals) followed by hardjo (11 and 1%, respectively). Grippotyphosa, copenhagheni and tarassovi were more prevalent in dairy than in beef herds (P<0.001, P<0.05, P<0.05, respectively) -- but no significant association was found between herd-size and Leptospira seroprevalence for any of the serovars considered.     

Prevalence of Neospora caninum and bovine viral diarrhoea virus in dairy cows in Southern Vietnam

The main purpose of this study was to investigate the prevalence of Neospora caninum and bovine viral diarrhoea virus (BVDV) in some dairy herds in Southern Vietnam, and to ascertain whether there were differences in seroprevalences between herds with imported and locally bred cows. Serum samples collected on five state farms and 97 smallholder herds were analysed for the presence of antibodies to N. caninum and BVDV. All BVDV antibody-negative sera were further tested by antigen-ELISA in order to identify persistently infected individuals. The N. caninum prevalence varied between 16% and 53% in the state herds, and was higher in the four herds that had imported cows than in the herd that only had locally bred cows. Nineteen percent of the samples collected on smallholder farms, which all had only locally bred cows, had antibodies to N. caninum. The BVDV seroprevalence varied between 58% and 93% on the state farms. In smallholder herds, the prevalence of BVDV among the sampled cows was 18% and even lower on the state farms. Despite the high seroprevalence for BVDV in the state herds, no persistently BVDV infected cows were found. Given the high prevalence for Neospora and BVDV among herds with imported cows, it seems advisable to test for both infections before cattle are imported into the country.     

Neosporosis as a cause of abortion in dairy cattle in Rio Grande do Sul, southern Brazil.

Forty-six aborted bovine fetuses submitted to the Faculty of Veterinary, Department of Clinical Pathology, Universidade Federal do Rio Grande do Sul, were examined histopathologically. Non-suppurative inflammation was observed mainly in the brain and heart of 22 fetuses. Brain lesions consisted primarily of mononuclear inflammatory cell infiltrates with occasional foci of necrosis. Protozoa that reacted with Neospora caninum antisera were seen in 18 of the 22 (81.8%) brain specimens from fetuses with encephalitis. Blood samples collected from 223 Holstein cows on five dairy herds were tested for N. caninum antibodies by an immunofluorescent antibody technique. These samples were obtained from aborting cattle and normally calving cattle (control group). Overall, 11.2% of cows sampled had N. caninum antibodies at a dilution of 1:200. Seroprevalence was higher (P = 0.0053) in aborting (23.3%) than in non-aborting cows (8.3%). Association between seropositivity to N. caninum and abortion was found, with seropositive cows being 3.3 times more likely to abort than seronegative cows (OR = 3.33; 95% CI: 1.38, 8.062). Additionally, N. caninum antibodies were detected in sera from seven cows that had aborted fetuses with lesions suggestive of protozoal infection. These results suggest that N. caninum is an important cause of abortion in dairy cattle in Rio Grande do Sul State, Brazil.     

Investigation of bovine venereal campyloacteriosis in beef cow herds in New Zealand

AIMS: To determine regional prevalences of beef cow herds in New Zealand positive for Campylobacter fetus subsp venerealis antibodies in samples of vaginal mucus tested using an immunoglobulin (Ig) A enzyme-linked immunosorbent assay (ELISA), and to examine the suitability of the IgA ELISA for detecting infection with C. fetus subsp venerealis under field conditions in New Zealand. METHODS: Vaginal mucus samples (n=1,230) collected from beef cow herds (n=125) throughout New Zealand (approximately 10 samples/herd) were tested for antibodies to C. fetus subsp venerealis using an IgA ELISA. Test results were compared between herds classified as having low, medium and high fertility based on pregnancy test results interpreted in relation to the duration of the mating period used. In addition, a small number of samples were collected from dairy cows that were mated using artificial insemination (AI) and had no contact with breeding bulls. The influence of putative risk factors for the spread of venereal disease and the effect of sample quality on the status of herds according to test results was assessed using multivariate logistical regression. Preputial washings from 54 bulls from nine herds classified as low fertility in which mucus samples from > or =3 cows were IgA antibody-positive were cultured for the presence of Campylobacter spp, and isolates of C. fetus subspecies were characterised using a polymerase chain reaction (PCR) test. RESULTS: One or more mucus samples was positive to the IgA ELISA in 70% of all herds tested. The prevalence of IgA antibody- positive individuals was >20% in most regions of New Zealand and did not differ significantly for cows from herds classified as high, medium or low fertility (28%, 26% and 23%, respectively; p=0.39). No relationship was found between mucus antibody status and age of breeding group, herd size, herd fertility, number of herds that female replacements or breeding bulls were sourced from, whether a serving ability test (SAT) was used to assess bulls, or the quality of samples submitted to the laboratory. Campylobacter fetus subsp venerealis was not cultured from any of the 54 bulls sampled. Four other species of Campylobacter and related organisms were cultured, viz Arcobacter cryaerophilus, Campylobacter jejuni, Campylobacter fetus subsp fetus and Helicobacter cinaedi. CONCLUSIONS: The specificity of the IgA ELISA as a diagnostic test for C. fetus subsp venerealis was found to be unsatisfactory under New Zealand conditions. It is possible that an immunological response by cows to Campylobacter species other than C. fetus subsp venerealis caused cross-reactivity in the IgA ELISA. The results do not support the hypothesis that C. fetus subsp venerealis is widespread in New Zealand.