Seroprevalence of porcine and human influenza A virus antibodies in pigs between 1986 and 1988 in Hassia

1,268 sera collected from slaughtered pigs in Hassia (FRG) from 1986 to 1988 were tested for antibodies against porcine and human influenza A virus strains using the single radial haemolysis test (SRHT). Antibodies against the porcine strains (subtype H1N1) A/Swine/Arnsberg/1/81, A/Swine/Iowa/15/30 and A/New Jersey/7/76 were detected in 411 (32.4%), 318 (25.1%) and 304 (24.0%) of sera, respectively. Up to 1988 a slight increase (10%) in the seroprevalence to A/Swine/Arnsberg/1/81 was noticed, whereas the results obtained with the other strains showed little variation. Antibodies against the human H1N1 strain A/Singapore/6/86 were only found in sera collected 1987 and 1988 in rates of 1.6% and 3.0%. Serological indication of infections with the human H3N2 strains A/Victoria/1/75, A/Hong Kong/1/68 and A/Philippines/2/82 could be shown in 286 (22.6%), 178 (14.4%) and 135 (10.6%) of the serum samples. Within the three year period the rate of sera positive for antibodies against A/Philippines/2/82 increased from 6.5% to 23.0%, whereas no variation in the rates were found using the other H3N2 strains. Antibodies simultaneously against porcine (H1N1) and human (H3N2) virus strains were detected in 9.9% of all sera tested.     

A survey for paramyxoviruses in caged birds, wild birds, and poultry in New Zealand

AIMS: To determine the presence of avian paramyxovirus (APMV) types 1, 2, and 3 in caged and wild birds, and APMV-2 and -3 in poultry in New Zealand. METHODS: Blood samples collected from caged (231) and wild birds (522) from various regions of New Zealand in 1997-99 were tested by haemagglutination inhibition (HI) test for antibodies to APMV types 1, 2, and 3. Blood samples collected from 1778 commercial poultry in 1996-99 were tested for APMV-2 and APMV-3 antibodies and the samples that reacted with APMV-3 antigen were tested for antibodies to APMV-1. Isolation of APMV was attempted from cloacal swabs collected from 116 of the caged birds and 175 of the wild birds sampled. RESULTS: Antibodies to APMV types 1, 2, and 3 were detected in 4.8, 1.7, and 2.6%, respectively, of caged bird samples. The majority of these caged birds were 'exotic' or 'fancy' poultry breeds. Amongst wild birds, 4.2% had titres to APMV-2 and over half of these were passerine birds; 1.7% of the samples had titres to APMV-1 and 0.8% to APMV-3 antigen. No virus was isolated from any of the cloacal swabs tested. Of the 1778 poultry serum samples tested, only 5 reacted with APMV-3 antigen and these were later found to be cross-reactions to APMV-1. No reactions were detected with APMV-2 antigen. CONCLUSIONS: APMV-1 is present in caged birds, wild birds, and poultry of New Zealand. There is no conclusive evidence of the presence of APMV-2 and APMV-3 in poultry or APMV-3 in wild birds. The results do not provide conclusive evidence for the presence of APMV-2 in wild birds in New Zealand.     

Serologic survey for Toxoplasma gondii in wild animals in Florida

Blood samples were collected for serum separation from 114 species of wild animals (25 species of mammals, 82 species of birds, and 7 species of reptiles) in Florida. Each of the 3,471 samples was tested for antibodies to Toxoplasma gondii, using the indirect hemagglutination test. The highest prevalences of T gondii antibodies were 19% in armadillos (Dasypus novemcinctus), 18% in raccoons (Procyon lotor), 13% in black rats (Rattus rattus), and 11% in opossums (Didelphis marsupialis). Antibody prevalences were significantly higher in male than in female raccoons (P less than 0.05) and in adult than in nonadult raccoons and opossums (P less than 0.005). A high proportion of seropositive animals was found in three other mammalian species: 4 of 4 black bears (Ursus americanus), 2 of 3 bobcats (Lynx rufus), and 2 of 8 Norway rats (Rattus norvegicus) tested. Antibodies were found in 8 of the 1,279 avian serums; they were not found in any of the 13 reptilian serums tested. There were no significant geographic variations in antibody prevalence in any species.     

A survey for Toxoplasma gondii antibodies in deer and other wildlife on a sheep range.

Blood samples were obtained from native mammals and birds on a sheep range (Hopland Field Station) in northern California. Serums were tested for antibodies to Toxoplasma gondii by the indirect hemagglutination test. Of 382 deer that were tested from 1964 to 1973, 77 (20%) were seropositive for T gondii. Among 36 serums representing 6 species of wild carnivores (badgers, bobcats, coyotes, foxes, raccoons, and skunks), 18 (50%) were seropositive. All of the 5 bobcats tested were seropositive, with antibody titers ranging from 1:65,536. The testing of 175 serums from small wild mammals indicated antibody prevalence of 8% among jackrabbits, 6% among brush rabbits, and 2% among squirrels. None of the native mice tested was seropositive for T gondii. Of 120 native birds tested, 6 (5%) were seropositive. Of the resident domestic species of animals tested, antibodies were found in 1 of 7 domestic cats, 1 of 5 feral cats, 1 of 2 dogs, and 54 (13%) of 405 sheep.     

Detection of antibodies against Sarcocystis neurona in cerebrospinal fluid from clinically normal neonatal foals

OBJECTIVE: To determine whether antibodies against Sarcocystis neurona could be detected in CSF from clinically normal neonatal (2 to 7 days old) and young (2 to 3 months old) foals. DESIGN: Prospective study. ANIMALS: 15 clinically normal neonatal Thoroughbred foals. PROCEDURE: Serum and CSF samples were obtained from foals at 2 to 7 days of age and tested for antibodies against S. neurona by means of western blotting. Serum samples from the mares were also tested for antibodies against S. neurona. Additional CSF and blood samples were obtained from 5 foals between 13 and 41 days after birth and between 62 and 90 days after birth. RESULTS: Antibodies against S. neurona were detected in serum from 13 mares and their foals; antibodies against S. neurona were detected in CSF from 12 of these 13 foals. Degree of immunoreactivity in serum and CSF decreased over time, and antibodies against S. neurona were no longer detected in CSF from 2 foals 83 and 84 days after birth. However, antibodies could still be detected in CSF from the other 3 foals between 62 and 90 days after birth. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that antibodies against S. neurona can be detected in CSF from clinically normal neonatal (2 to 7 days old) foals born to seropositive mares. This suggests that western blotting of CSF cannot be reliably used to diagnose equine protozoal myeloencephalitis in foals < 3 months of age born to seropositive mares.     

Seroprevalence of OHV-2, BVDV, BHV-1, and BRSV in ranch-raised bison (Bison bison).

Serum samples were collected at slaughter from 226 24-30-month-old American bison (Bison bison) bulls from Kansas, Minnesota, North Dakota, and Manitoba and assayed for antibodies to ovine herpesvirus type-2 (OHV-2), bovine viral diarrhea virus (BVDV), bovine herpesvirus type-1 (BHV-1), and bovine respiratory syncytial virus (BRSV). Antibodies were detected by serum neutralization for BVDV, BHV-1, and BRSV, while antibodies to OHV-2 were detected by competitive inhibition-ELISA (CI-ELISA). Detectable antibodies were found against all viruses: 10 of 226 (4.40%) against OHV-2, 125 of 226 (55.3%) against BVDV, 99 of 226 (43.8%) against BHV-1, and 208 of 226 (92.0%) against BRSV. Titers from 93.6% of the BVDV-positive animals, 79.8% of the BHV-1-positive animals, and 98.1% of the BRSV-positive animals were > or = 1.25. These data indicate that a low percentage of clinically normal bison are seropositive for OHV-2 while a high percentage of bison sampled are seropositive for BVDV, BHV-1, and BRSV.     

Exploratory spatial data analysis of regional seroprevalence of antibodies against epizootic hemorrhagic disease virus in cattle from Illinois and Indiana

OBJECTIVE: To estimate seroprevalence of antibodies against the serogroup of epizootic hemorrhagic disease viruses (EHDVs) and describe spatial distribution of antibodies against EHDV among cattle herds in Illinois and western Indiana. SAMPLE POPULATION: 9,414 serum samples collected from cattle in 60 herds over 3 transmission seasons. PROCEDURES: Serum samples were tested for antibodies against EHDV by use of an ELISA. Seroprevalence for 4 zones covering the length of Illinois and parts of Indiana were estimated. A multivariable mixed-effects logistic regression model with a random effect for herd was used to estimate seropositive risk for zone (1 through 4), age (yearling, adult), herd type (beef, dairy), transmission season (2000 to 2002), and zone by year interaction. Isopleth maps of seroprevalence at the herd level were produced. RESULTS: Antibodies against EHDV were detected in 1,110 (11.8%) samples. Estimated seroprevalence in 2000, 2001, and 2002 was 15.3%, 13.4%, and 5.2%, respectively. Seroprevalence was highest in the southernmost zone and lowest in the northernmost zone, but risk of seropositivity for EHDV among and within zones varied by year. Clusters of high seroprevalence in the south, low seroprevalence in the north, and outliers of high and low seroprevalence were detected. Risk mapping revealed areas of higher seroprevalence extending northward along the western and eastern ends of the study region. CONCLUSIONS: Seroprevalence of antibodies against EHDV in cattle was higher in the south than north; however, local complexities existed that were not observed in a serosurvey of antibodies against bluetongue virus from the same cattle population.     

Cervids as sentinel‐species for tick‐borne encephalitis virus in Norway ‐ A serological study

Tick‐borne encephalitis virus (TBEV) is the causative agent of tick‐borne encephalitis (TBE). TBEV is one of the most important neurological pathogens transmitted by tick bites in Europe. The objectives of this study were to investigate the seroprevalence of TBE antibodies in cervids in Norway and the possible emergence of new foci, and furthermore to evaluate if cervids can function as sentinel animals for the distribution of TBEV in the country. Serum samples from 286 moose, 148 roe deer, 140 red deer and 83 reindeer from all over Norway were collected and screened for TBE immunoglobulin G (IgG) antibodies with a modified commercial enzyme‐linked immunosorbent assay (ELISA) and confirmed by TBEV serum neutralisation test (SNT). The overall seroprevalence against the TBEV complex in the cervid specimens from Norway was 4.6%. The highest number of seropositive cervids was found in south‐eastern Norway, but seropositive cervids were also detected in southern‐ and central Norway. Antibodies against TBEV detected by SNT were present in 9.4% of the moose samples, 1.4% in red deer, 0.7% in roe deer, and nil in reindeer. The majority of the positive samples in our study originated from areas where human cases of TBE have been reported in Norway. The study is the first comprehensive screening of cervid species in Norway for antibodies to TBEV, and shows that cervids are useful sentinel animals to indicate TBEV occurrence, as supplement to studies in ticks. Furthermore, the results indicate that TBEV might be spreading northwards in Norway. This information may be of relevance for public health considerations and supports previous findings of TBEV in ticks in Norway.     

Serological evidence of West Nile virus infection in human populations and domestic birds in the Northwest of Morocco

West Nile virus (WNV) was recently detected in Culex pipiens mosquitoes in Morocco. The aim of this study was to evaluate the seroprevalence of WNV in humans and in domestic birds in two regions of Morocco by the detection of IgG antibodies. Blood samples were obtained from 91 human patients and 92 domestic birds from September to December 2019. All study samples were tested using competitive enzyme-linked immunosorbent assay (cELISA) and WNV neutralization tests (VNT) were performed on positive sera. Of all samples, 4 (4.39 %) humans and 4 (4.34 %) birds were found to be seropositive for flaviviruses by the cELISA test. The VNT revealed that three of the four human samples detected positive by cELISA contained neutralizing antibodies against WNV. Two bird samples were confirmed positive by VNT. These results show a significant seroprevalence of anti-WNV antibodies and therefore suggest the active circulation and exposure of human and bird populations in the northwest of Morocco.     

Seroprevalence of economically important viral pathogens in swine populations of Trinidad and Tobago,West Indies

The objective of this study was to evaluate the seroprevalence and identify the strains of swine influenza virus (SwIV), as well as the seroprevalence of porcine parvovirus (PPV), transmissible gastroenteritis virus (TGEV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine respiratory coronavirus (PRCV), porcine circovirus type 2 (PCV-2), and classical swine fever virus (CSFV) in pigs in Trinidad and Tobago (T&T). Blood samples (309) were randomly collected from pigs at farms throughout T&T. Serum samples were tested for the presence of antibodies to the aforementioned viruses using commercial ELISA kits, and the circulating strains of SwIV were identified by the hemagglutination inhibition test (HIT). Antibodies against SwIV were detected in 114 out of the 309 samples (37%). Out of a total of 26 farms, 14 tested positive for SwIV antibodies. HI testing revealed high titers against the A/sw/Minnesota/593/99 H3N2 strain and the pH1N1 2009 pandemic strain. Antibodies against PPV were detected in 87 out of the 309 samples (28%), with 11 out of 26 farms testing positive for PPV antibodies. Antibodies against PCV-2 were detected in 205 out of the 309 samples tested (66%), with 25 out of the 26 farms testing positive for PCV-2 antibodies. No antibodies were detected in any of the tested pigs to PRRSV, TGEV, PRCV, or CSFV.     

Diagnostic and prognostic potential of antibodies against O-acetylated sialic acids in canine visceral leishmaniasis.

Employing bovine submaxillary mucin (BSM) as the coating agent, an enzyme-linked immunosorbent assay (BSM-ELISA) was developed to detect antibodies directed against O-acetylated sialic acids (O-AcSA) in canine visceral leishmaniasis (CVL). Serum samples were collected from 50 dogs previously screened by a parasite-ELISA to detect anti-leishmanial antibodies and designated as seropositive (n = 30) and seronegative (n = 20). The BSM-ELISA detected anti-O-AcSA antibodies in 29 out of 30 seropositive dogs and was negative in 15 out of 20 seronegative dogs; the sensitivity and specificity of the assay being 96.6% and 75%, respectively. Seven dogs from an endemic area in central Israel were longitudinally monitored for 15 months clinically, serologically and cultured for parasite. The levels of antibodies directed against O-AcSA increased with the appearance of clinical symptoms and/or seropositivity, disappeared when the disease was self-limiting as also with chemotherapeutic response and reappeared with relapse. The BSM-ELISA, therefore, represents a valuable tool for assessment of disease progression.     

Serum antibodies directed against classical swine fever virus and other pestiviruses in wild boar (Sus scrofa) in the Republic of Croatia

The presence of serum antibodies directed against classical swine fever (CSF) virus and other pestiviruses among the wild boar (Sus scrofa) population in Croatia was investigated. During 2003, serum samples from 214 wild boars were collected in 10 hunting areas in the continental part of the country.The sera were examined by enzyme immunoassay (ELISA) and in the virus neutralization test (VNT). Out of 214 sera tested 111 (51.87 %) were positive by ELISA and regarding neutralising antibodies, against CSFV 75 (35.05 %) samples were positive. In the VNT with the C-strain (conventional live vaccine strain China) and the strain Uelzen were used. Samples were also tested for neutralizing antibodies against border disease virus (BDV) using the strain 137/4 and against bovine viral diarrhoea virus (BVDV) using the NADL strain. Neutralizing antibodies against the C-strain were detected in 36 sera (16.82 %), against strain Uelzen in 17 sera (7.94 %) and in 22 sera (10.28 %) against both strains. In five sera (2.33 %) neutralizing antibodies against BVDV and BDV were found.     

Neospora caninum antibodies in wild carnivores from Spain

Serum samples from 251 wild carnivores from different regions of Spain were tested for antibodies to Neospora caninum by the commercial competitive screening enzyme linked immunosorbent assay (c-ELISA) and confirmed by Neospora agglutination test (NAT) and/or by indirect fluorescent antibody test (IFAT). Samples with antibodies detected by at least two serological tests were considered seropositive. Antibodies to N. caninum were found in 3.2% of 95 red foxes (Vulpes vulpes); in 21.4% of 28 wolves (Canis lupus); in 12.0% of 25 Iberian lynx (Lynx pardinus); in 16.7% of 6 European wildcats (Felis silvestris); in 6.4% of 31 Eurasian badgers (Meles meles); in 21.4% of 14 stone martens (Martes foina); in 66.7% of 3 pine martens (M. martes) and in 50% of 2 polecats (Mustela putorius). Antibodies to N. caninum in common genets (Genetta genetta) and Egyptian mongooses (Herpestes ichneumon) were only observed by c-ELISA but were not confirmed by IFAT and/or NAT. No antibodies were detected in 5 Eurasian otters (Lutra lutra) by any technique. Statistically significant differences were observed among species and among geographical areas. The highest seroprevalence of N. caninum infection was observed in the Cantabric Coastal region characterized by high humidity. To our knowledge, this is the first report of antibodies to N. caninum in free ranging wild carnivores, other than wild canids, in Europe. The existence of a possible sylvatic cycle could have important implications in both sylvatic and domestic cycles since they might influence the prevalence of infection in cattle farms in those areas.     

Epidemiological surveillance of bluetongue virus serotypes 1, 4 and 8 in Spanish ibex (Capra pyrenaica hispanica) in southern Spain

A cross-sectional study was carried out to assess the prevalence and circulation of bluetongue virus (BTV) in Spanish ibexes (Capra pyrenaica hispanica). A total of 770 sera samples, 380 blood samples and 34 spleen samples were collected between 2006 and 2009 in Andalusia (southern Spain), a region and time period with a wide circulation of BTV in livestock. Thirty-one out of 770 (4.0%; CI(95%): 2.6-5.4) sera samples analyzed by ELISA showed antibodies against BTV. Twenty-four out of 31 seropositive samples were tested against BTV serotypes 1, 4 and 8 by serum neutralization test (SNT). Neutralizing antibodies against BTV-1 and BTV-4 were detected in seven and ten animals, respectively, four of them showed neutralizing antibodies to both serotypes. The animals seropositive to BTV-4 were sampled between 2006 and 2008, while BTV-1 circulation was confirmed in ibexes sampled between 2007 and 2009. None of the ibexes presented neutralizing antibodies against BTV-8. Statistically significant differences were found among regions and years, which is in coincidence with what occurred in domestic ruminants. There were no statistically significant differences between sexes, age classes and habitats (captivity vs. free-living). BTV RNA was not found in any of the 380 blood samples analyzed. However, BTV-1 RNA was detected from spleen in one Spanish ibex from Málaga province in August 2008. This finding evidences the presence of BTV-1 in Spanish ibex in a municipality where BT outbreaks were not detected in domestic ruminants during that period. Results of the present study show that Spanish ibexes were exposed and responded serologically to both BTV-1 and BTV-4. The low seroprevalence obtained suggests that Spanish ibex is not a relevant species in the dissemination of BT. However, the detection of BTV-1 RNA and the presence of seropositive ibexes in areas where BT outbreaks were not detected in livestock, could not exclude a significant role in the epidemiology of BTV in certain areas.     

Actinobacillus pleuropneumoniae in Thai pig herds. Prevalence of serum antibodies and relation to performance

The aim of the study was to investigate the prevalence of Actinobacillus pleuropneumoniae infections in market weight pigs in Thailand. ELISA systems employing purified lipopolysaccharide antigens were used to detect antibodies in 549 serum samples collected from pigs of 22 herds. Relevant cut-off values were established from three herds defined seronegative. Serum antibodies were detected to all serotypes except serotype 10. Almost 60% of the samples were seropositive to at least one serotype and 45% of the pigs were seropositive to more than one serotype. Antibodies to the cross-reacting serotypes 1, 9 or 11 were found in 29% of the pigs. Other common serotypes included the cross-reacting serotypes 3, 6 or 8 (26% seropositive pigs) and serotype 5a (also 26%). Antibodies to serotypes 2, 5b and 12 were low in prevalence (<10%). Three herds were regarded to be seronegative and six to have a low pathogen load with respect to the prevalence of seropositive pigs. The remaining 13 herds had a high incidence of pigs with antibodies to A. pleuropneumoniae, dominated by serotypes 1-9-11 and 5a (n = 6), serotypes 3-6-8, and 5a (n = 4) or 1-9-11, 3-6-8, 5a and 4-7 (n = 3). A low pathogen load with respect to A. pleuropneumoniae, as well as small herd size and age-segregated rearing, tended to improve the performance of growers.     

Seroprevalence of Toxoplasma gondii antibodies in wild carnivores from Spain

Serum samples from 282 wild carnivores from different regions of Spain were tested for antibodies to Toxoplasma gondii by the modified agglutination test using a cut-off value of 1:25. Antibodies to T. gondii were found in 22 of 27 (81.5%) of Iberian lynx (Lynx pardinus), 3 of 6 European wildcats (Felis silvestris), 66 of 102 (64.7%) red foxes (Vulpes vulpes), 15 of 32 (46.9%) wolves (Canis lupus), 26 of 37 (70.3%) Eurasian badgers (Meles meles), 17 of 20 (85.0%) stone martens (Martes foina), 4 of 4 pine martens (Martes martes), 6 of 6 Eurasian otters (Lutra lutra), 4 of 4 polecats (Mustela putorius), 1 of 1 ferret (Mustela putorius furo), 13 of 21 (61.9%) European genets (Genetta genetta), and 13 of 22 (59.1%) Egyptian mongooses (Herpestes ichneumon). Serological results indicated a widespread exposure to T. gondii among wild carnivores in Spain. The high T. gondii seroprevalence in Iberian lynx and the European wildcat reported here may be of epidemiologic significance because seropositive cats might have shed oocysts.     

Evidence for BTV-4 circulation in free-ranging red deer (Cervus elaphus) in Cabañeros National Park, Spain

Bluetongue (BT) is an infectious disease of wild and domestic ruminants caused by bluetongue virus (BTV). BTV-4 spread through southern Spain from 2004 to 2006, whereas a BTV-1 outbreak that started in southern Spain in 2007 is still ongoing. Vaccination and movement restriction regulations are applied to domestic ruminants to control BT, but the potential reservoir role of wild European ungulates has not been clarified so far. The aim of this study was to describe the epidemiology of BTV in the wild free-ranging red deer (Cervus elaphus) population of Caba?eros National Park (CNP) in central Spain during the BTV-4 and BTV-1 epizootics, assessing the potential role of this deer population as a BTV reservoir. Blood samples from 2885 (2542 adults, 208 calves and 135 undetermined) wild red deer were collected from 2005 to 2010 in CNP and surrounding hunting estates. All sera were tested for antibodies against the BTV VP7 protein by ELISA. Ninety-four of the ELISA-positive samples were analysed by serum neutralization to detect BTV-4 and BTV-1 specific antibodies, and 142 blood samples were analysed by RT-PCR for BTV RNA. A total of 371 (12.9%) out of the 2,885 deer (35/208 calves, 307/2,542 adults, and 29/135 undetermined) were positive for antibodies against BTV. Prevalence increased in adult deer from 2005-2006 to 2008-2009, declining thereafter. No positive samples for BTV-1 were found by serum neutralization, whereas 43 deer (38 adults, four calves and one undetermined) were positive for BTV-4 specific antibodies. No BTV RNA positive deer were found by RT-PCR. Antibody detection throughout the study period suggests a maintained circulation of BTV in red deer. However, the lack of BTV RNA detection suggests a minor transmission risk to livestock.     

Potential application of serological tests on fluids from carcasses: detection of antibodies against Toxoplasma gondii and Sarcoptes scabiei in red foxes (Vulpes vulpes)

Background

Serological surveys for disease investigation of wild animal populations require obtaining blood samples for analysis, which has logistic, ethic and economic difficulties. Applying serological test to fluids collected from dead animals is an alternative. The aim of this study was to assess if antibodies could be detected in two types of fluids collected from 56 carcasses of red foxes (Vulpes vulpes): pleural fluid and lung extract.

Findings

In 22 (39%) foxes antibodies against Sarcoptes scabiei were detected in both fluid types by ELISA and Western blot. In 46 (82%) foxes, antibodies against Toxoplasma gondii were detected in pleural fluid and in 41 (73%) in lung extract applying a Toxo-screen test (DAT). Antibodies were still detectable in the same fluids kept at room temperature for 28 days, although in fewer foxes (16 and 14 foxes tested for T. gondii in lung extract and pleural fluid respectively; and 1 and 4 tested for S. scabiei in lung extract and pleural fluid respectively.

Conclusions

These results indicate the potential utility of using fluids from carcasses for antibody screening of wild animals at the population level.     

Detection of bovine herpesvirus type 4 antibodies and bovine lymphotropic herpesvirus in New Zealand dairy cows

AIM: To detect the presence of bovine herpesvirus (BoHV) type 4 in New Zealand dairy cows with clinical metritis.

METHODS: Serum samples taken from 92 dairy cows with clinical metritis, each from a different farm, were tested for the presence of antibodies against BoHV-4 using a commercially available, indirect ELISA. Peripheral blood mononuclear cells (PBMC) were collected from 10 BoHV-4 seropositive cows, and PBMC were examined by a pan-herpesvirus nested PCR to detect herpesvirus. PCR products were sequenced directly and a proportion of the PCR products were cloned and sequenced to identify the virus present.

RESULTS: Antibodies to BoHV-4 were detected in 23/92 (25%) serum samples. The pan-herpesvirus PCR was positive in 8/10 PBMC samples. Cloning and sequencing identified that all of the eight PCR-positive PBMC contained bovine lymphotropic herpesvirus (BLHV); no BoHV-4 DNA was detected.

CONCLUSIONS: This study reports the finding of the presence of apparent antibodies to BoHV-4, and BLHV DNA in New Zealand dairy cows affected by metritis.

CLINICAL RELEVANCE: Bovine herpesvirus type 4 and BLHV are reported to have the potential to cause reproduction failure in cows. This is the first report of apparent BoHV-4 antibodies, and BLHV in New Zealand. The importance and epidemiology of these viruses in cattle in New Zealand requires further investigation.     

Bovine virus diarrhoea (BVD) control programme in an area in the Rome province (Italy)

A BVD control programme based on the identification and removal of persistently infected (PI) animals is being undertaken in an area in the Rome province, where BVD outbreaks had been previously detected. It involves 174 mainly dairy herds, from which blood samples of all bovines older than 1 year are obtained through the national brucellosis and leukosis eradication programme. Samples sufficient to detect the presence of seropositive animals at a prevalence of 5% or more are initially screened for antibodies against BVD virus (BVDV) using an immunoenzymatic assay. Upon identification of seroreagents additional blood samples are tested from the 6-12-month age category not included in the initial samples. Animals are considered immunotolerant if BVDV is demonstrated twice at a minimum 30-day interval. When no seropositive animals are detected during the first serological screening the herd is declared BVD-free if a second testing, preferably carried on the same animals previously tested, confirms the seronegative status of the herd. At present 147 farms have been tested, of which 63 (42.9%) are negative with respect to antibodies against BVDV. Of the 84 remaining herds in which one or more seropositives are detected, 13 are classified as recently infected. In eight of these recently infected herds, 22 PI animals have been identified.