Evaluation of two commercial, rapid, ELISA kits testing for scrapie in retro-pharyngeal lymph nodes in sheep.

AIMS: To estimate the number of cases of scrapie that would occur in sheep of different prion protein (PrP) genotypes if scrapie was to become established in New Zealand, and to compare the performance of two commercially available, rapid ELISA kits using ovine retro-pharyngeal lymph nodes (RLN) from non-infected and infected sheep of different PrP genotypes. METHODS: Using published data on the distribution of PrP genotypes within the New Zealand sheep flock and the prevalence of cases of scrapie in these genotypes in the United Kingdom, the annual expected number of cases of scrapie per genotype was estimated, should scrapie become established in New Zealand, assuming a total population of 28 million sheep. A non-infected panel of RLN was collected from 737 sheep from New Zealand that had been culled, found in extremis or died. Brain stem samples were also collected from 131 of these sheep. A second panel of infected samples comprised 218 and 117 RLN from confirmed scrapie cases that had originated in Europe and the United States of America, respectively. All samples were screened using two commercial, rapid, transmissible spongiform encephalopathy ELISA kits: Bio-Rad TeSeE ELISA (ELISA-BR), and IDEXX HerdChek BSE-Scrapie AG Test (ELISA-ID). RESULTS: If scrapie became established in New Zealand, an estimated 596 cases would occur per year; of these 234 (39%) and 271 (46%) would be in sheep carrying ARQ/ARQ and ARQ/VRQ PrP genotypes, respectively. For the non-infected samples from New Zealand the diagnostic specificity of both ELISA kits was 100%. When considering all infected samples, the diagnostic sensitivity was 70.4 (95% CI=65.3-75.3)% for ELISA-BR and 91.6 (95% CI=88.2-94.4)% for ELISA-ID. For the ARQ/ARQ genotype (n=195), sensitivity was 66.2% for ELISA-BR and 90.8% for ELISA-ID, and for the ARQ/VRQ genotype (n=107), sensitivity was 81.3% for ELISA-BR and 98.1% for ELISA-ID. CONCLUSIONS: In this study, the ELISA-ID kit demonstrated a higher diagnostic sensitivity for detecting scrapie in samples of RLN from sheep carrying scrapie-susceptible PrP genotypes than the ELISA-BR kit at comparable diagnostic specificity. CLINICAL RELEVANCE: The diagnostic performance of the ELISA-ID kit using ovine RLN merits the consideration of including this assay in the national scrapie surveillance programme in New Zealand.

A cross-sectional survey of influenza A infection and management practices in small rural backyard poultry flocks in New Zealand.

AIM: To obtain baseline data on the management of small non-commercial backyard poultry flocks, in two rural regions of New Zealand, to investigate potential transmission pathways for avian influenza (AI), and to investigate the presence of AI in these flocks. METHODS: During August-October 2006 a questionnaire was sent to 105 farms in the Bay of Plenty and Wairarapa with poultry flocks comprising fewer than 50 chickens, located near wetlands where AI virus had been detected previously in wild ducks. Information was collected on the number and species of poultry reared, opportunities for interaction between wild birds and poultry, farm biosecurity measures, and health status of poultry. Between September and November 2006, blood and tracheal/cloacal swabs were collected from poultry on a subset of 12 high-risk farms in each location. Influenza A-specific antibodies in sera were assayed using ELISA, and positive sera were further tested for the presence of H5 and H7 subtype-specific antibodies, using haemagglutination inhibition (HI) assay. The presence of influenza A virus in swabs was detected using real-time reverse transcriptase-PCR (RRT-PCR). RESULTS: Returned questionnaires were received from 54 farms. Overall, 80% had only chickens, 13% chickens and ducks, and 7% had chickens and other galliform species. Nearly all (96%) kept backyard chickens for personal consumption of eggs, with a small proportion (19%) preparing birds for the table. On surveyed farms wild waterfowl were seen on pastures (70%) and/or farm waterways (46%). Waterfowl were recorded as visiting areas where domestic birds were kept on 31% of farms. Bird litter and manure were composted (94%) or buried (6%) on-farm, as were most (82%) dead birds. During the targeted cross-sectional survey of 24 farms clinical disease was not recorded in any poultry flock. Of 309 chicken sera tested, 11 (3.6%) from five farms across both regions tested positive for influenza A antibodies. In contrast, 16/54 (30%) duck sera from three farms in the Wairarapa were positive. Avian influenza H5 and H7 subtype-specific antibodies were excluded in ELISA positive sera using HI testing, and influenza A virus was not detected using RRT-PCR. CONCLUSIONS: The study confirmed that small backyard poultry flocks located near waterfowl habitats were exposed to non-notifiable low-pathogenic AI viruses. Findings indicate a number of potential risk pathways for the transmission of AI viruses between wild birds and non-commercial poultry, and hence the need for continued surveillance for AI in backyard flocks and wild birds in New Zealand.

Comparison of the Q-fever complement fixation test and two commercial enzyme-linked immunosorbent assays for the detection of serum antibodies against Coxiella burnetti (Q-fever) in ruminants : recommendations for use of serological tests on imported animals in New Zealand.

AIM: To make valid recommendations on the use of serological test methods for the detection of serum antibodies in ruminants against Coxiella burnetii (Q-fever), by comparing the performance of the complement fixation test (CFT) and two ELISA, and by identifying reasons for discrepancies between the test methods. METHODS: A total of 73 serum samples from infected cattle, 69 from infected goats, and 100 samples from non-infected cattle and 57 samples from non-infected sheep, as well as 95 samples from infected cattle herds (mix of seropositive and seronegative samples), were tested using the CFT, the IDEXX ELISA (I-ELISA) and the Pourquier ELISA (P-ELISA). A mixed panel of 12 serum samples from sheep from inter-laboratory proficiency testing (proficiency panel) was also tested using the CFT and both ELISA, and further investigated using IgG- and IgM-specific ELISA. RESULTS: Generally, the two commercial ELISA were more sensitive than the CFT for the detection of infected ruminants. Good agreement between ELISA for positive and negative results was found for samples from the infected herd, while results for the positive panels varied between the two ELISA. For the total of the positive serum panels, the I-ELISA detected 95% of samples as positive or suspicious, while the P-ELISA detected only 81%. In the P-ELISA, more samples were considered suspicious (18%) than in the I-ELISA (14%). All sera from non-infected sheep and cattle tested negative in the serological test methods employed, except for one positive sample from a sheep in the P-ELISA. Further investigation revealed that a CFT-positive but ELISA-negative result was due to high IgM and low IgG reactivity. CONCLUSIONS: The two commercial ELISA were more sensitive than the CFT in all panels from infected ruminants. However, they could only detect IgG. The I-ELISA should be the serological test method of choice for cattle, sheep and goats for import testing of animals into New Zealand because it was more sensitive than the P-ELISA and was equally specific to the PELISA and the CFT. For other animal species, such as deer and camelids, the CFT should still be used since none of the ELISA has been evaluated for these species. This study has shown that the two commercial ELISA will detect the majority of infected ruminants but may miss animals that have not developed an IgG response.

Specificity of non-structural protein enzyme-linked immunosorbent assays for the detection of serum antibodies against foot-and-mouth disease virus in a target population in New Zealand.

AIMS: To determine the diagnostic specificities of two commercial screening ELISA, the Bommeli/IDEXX Chekit FMD 3ABC indirect ELISA (ELISA-1) and the Ceditest FMDV NS blocking ELISA (ELISA-2), for foot-and-mouth disease (FMD) in cattle, sheep and pigs in New Zealand, and to compare them with other published studies. To consider the implications for FMD surveillance of using two ELISA in series, a consideration arising from the absence of a gold standard virus neutralisation test (VNT) in New Zealand. METHODS: Serum samples from non-infected cattle (n=1,015), sheep (n=1,185), and pigs (n=233) from New Zealand were tested in ELISA-1 and ELISA-2 for the detection of serum antibodies against non-structural proteins of the FMD virus. The ELISA were performed according to the manufacturers' instructions. RESULTS: The diagnostic specificities for ELISA-1 for cattle, sheep and pigs were 99.9%, 99.7% and 99.6%, respectively, and for ELISA-2 were 99.5%, 99.7% and 99.6%, respectively. False-positive reactors in one ELISA were negative in the other ELISA, and vice versa. Using the diagnostic sensitivity data taken from international studies and the diagnostic specificities calculated in this study resulted in overall specificities of 100% in cattle and sheep using serial test interpretation, and 99.2% and 99.0%, respectively, using parallel test interpretation. Diagnostic sensitivities available in the literature varied considerably, and the associated overall serial sensitivity could be as low as 78.7% in cattle and 33.2% in sheep. CONCLUSIONS: Diagnostic specificities for both ELISA for the target population were comparable with those obtained in livestock populations elsewhere. In surveillance to re-establish New Zealand's freedom from FMD, the use of two ELISA in series would improve the overall specificity in individual animals. However, care would be required to ensure that herd sensitivity was sufficient to detect infection.

A real-time polymerase chain reaction assay for the detection of Mycoplasma agalactiae.

AIM: To develop a real-time PCR for the detection of Mycoplasma agalactiae, using PCR primers targeting the ma-mp81 gene. METHODS: A group of 15 M. agalactiae isolates, 21 other Mycoplasma spp. isolates and 21 other bacterial isolates was used in evaluation of the assay. RESULTS: All M. agalactiae isolates were detected by the assay and none of the non-target isolates was amplified. The analytical detection limit of the assay was 10 fg of purified genomic DNA and 104 cfu/ml milk inoculated with M. agalactiae. When applied to goat-milk samples collected from three herds free of M. agalactiae infection, the assay had a specificity of 100%. CONCLUSIONS: The assay would be useful in a diagnostic laboratory, providing specific, sensitive and rapid detection of M. agalactiae.

Infection trials in pigs with a human isolate of Brucella ( isolate 02/611 'marine mammal type' ).

AIM: To determine if pigs could support infection of a human Brucella isolate (Brucella 02/611) from New Zealand, and to study seroconversion to this isolate using a competitive ELISA. METHODS: Ten weaner piglets were challenged with 4.8 x 10(8) cfu of organisms by the oral and ocular routes. Culture was attempted on blood samples taken prior to challenge, and 4, 7, 9, 11, 14, 21 and 28 days post-challenge, and on tissue samples taken at the termination of the trial, 1 month after challenge. Sera were analysed for antibody using an ELISA. For reference comparison, similar trials were conducted in two pigs using an isolate of Brucella suis biovar 1, and two pigs using an isolate of B. suis biovar 3. RESULTS: Brucella 02/611 organisms were re-isolated from one lymph node each from three pigs; all other samples were negative. Low and transient antibody titres were detected using a competitive ELISA in three pigs, two of which were culture negative. Organisms of B. suis reference strains were re-isolated from multiple samples from each of the four animals. CONCLUSION: Brucella 02/611 does not seem to replicate readily in pigs. It is unlikely that pigs were the original maintenance hosts for Brucella 02/611.

Real-time polymerase chain reaction assays for the detection of members of the Mycoplasma mycoides cluster.

AIM: To develop real-time PCR assays for the detection and differentiation of members of the Mycoplasma mycoides cluster. METHODS: Five real-time PCR assays were designed to allow differentiation of members of the M. mycoides cluster: an assay for detection of the M. mycoides subspecies, viz M. mycoides subsp mycoides large colony (MmmLC), M. mycoides subsp capri (Mmc), and M. mycoides subsp mycoides small colony (MmmSC); one for the detection of the M. capricolum subspecies, viz M. capricolum subsp capricolum (Mcc), M. capricolum subsp capripneumoniae (Mccp), and Mycoplasma sp bovine group 7 (BG7); and three for the specific detection of MmmSC, Mccp, and BG7. A panel of 74 Mycoplasma isolates from various geographical origins and a panel of 21 other bacterial isolates were used to evaluate the sensitivity and specificity of the assays. RESULTS: The assays displayed 100% analytical sensitivity in detecting all target Mycoplasma isolates. The analytical detection limit for the assays to detect the M. mycoides subspecies, M. capricolum subspecies, and MmmSC was determined to be 100 fg of genomic DNA, while the Mccp and BG7 assays had a detection limit of 100 fg and 10 fg of genomic DNA, respectively. The M. mycoides subspecies assay had a detection limit of 10(3) (SD 10(2)) cfu/ml milk, 10(4) (SD 10(4)) cfu per swab, and 10(3) (SD 10(3)) cfu/g lung in inoculated samples. The assays displayed 100% specificity when applied to non-target bacterial isolates and to 110 culture-negative milk samples. CONCLUSIONS: The assays were highly sensitive and specific, and provide accurate detection and differentiation of the members of the M. mycoides cluster.

Distribution of prion protein genotypes in breeds of sheep in New Zealand.

AIM: To use an established high through-put genotyping procedure to gain an estimate of the frequency of alleles of the prion protein (PrP) gene in some common sheep breeds in New Zealand. METHODS: Using a genotyping procedure based on matrix-assisted laser desorption ionisation-time of flight (MALDI-TOF), DNA samples from 3,024 sheep from New Zealand, including breeds such as Romney, Texel, Coopworth, Merino and mixed breed, were isolated, genotyped and the results analysed. RESULTS: The 15 scrapie genotypes commonly reported, and derived from the five commonly reported allelic variants (ARR, ARQ, AHQ, ARH and VRQ), were all observed in the samples analysed. The estimates were indicative of the frequencies in the population of alleles present in breeds of sheep in New Zealand. There was a significant difference between the frequencies of alleles between breeds, but the ARQ, followed by the ARR allele, were, except in Carwell sheep, the most common alleles present. CONCLUSION: This study gave an indication of the percentages of PrP gene alleles in sheep in New Zealand, including data previously unreported from breeds in this country. It is of interest because of the relatively large size of the sheep population in New Zealand compared with many countries, and it provides some useful information on the genetic susceptibility or resistance of the sheep population in New Zealand to scrapie. The frequencies of the alleles can be different for an individual breed compared between countries.

Genetic characterisation of bovine herpesvirus 1 in New Zealand.

AIM: To genotype bovine herpesvirus type 1 (BHV-1) isolates from cattle in New Zealand. METHODS: Twenty-eight BHV-1 isolates were collected from clinical samples from cattle over 28 years. They were characterised and compared using restriction endonuclease analysis (REA), and polymerase chain reaction (PCR) and DNA sequencing. RESULTS: Twenty-four isolates were classified as bovine herpesvirus subtype 1.2b (BHV-1.2b) by REA. The remaining four isolates were distinct from the others in REA profiles of one of the major enzymes (HindIII) by which the classification was made. However, these four isolates were closely related to others when the REA profiles of other restriction enzymes were studied, and therefore were regarded as divergent strains of BHV- 1.2b. All BHV-1 isolates were detectable by PCR, and sequence analysis of selected PCR products did not indicate any significant differences between isolates. CONCLUSION: BHV-1.2b appears to be the predominant strain of BHV-1 in cattle in New Zealand. There was no evidence that more virulent strains of BHV-1, e.g. subtype 1.1 and BHV type 5, are, or have been, present in New Zealand. Genetic variations exist among these BHV-1.2b isolates.

Comparison of four diagnostic tests for the identification of serum antibodies in small ruminants infected with Mycoplasma agalactiae.

AIM: To determine the diagnostic capability of a newly developed Western blot (WB) assay for the detection of serum antibodies against Mycoplasma agalactiae compared with conventional serological tests, and to identify the best test for routine diagnostic use. METHODS: The serological test methods used were: two commercial indirect enzyme-linked immunosorbent assays (ELISA), viz ELISA-1, using a bacterial antigen preparation, and ELISA-2, using a recombinant protein (lipoprotein p48) antigen; the complement fixation test (CFT); and a newly developed WB assay, the latter both using a bacterial antigen preparation. Thirty sera from goats infected with M. agalactiae and 97 sera from non-infected sheep were tested using all four methods. RESULTS: Staining patterns in the WB were quite variable. An immuno-dominant band of 41 kDa was detected in 63% of sera from infected animals. The same band also appeared, although mostly very weakly, in 10% of sera from non-infected animals. When suspicious or very weak reactors were omitted, the diagnostic sensitivity (DSE) and diagnostic specificity (DSP), respectively, for the four assays were: WB=56.7%, 97.9%; ELISA-1=76.7%, 99.0%; ELISA-2=56.7%, 100%; and CFT=40.0%, 94.8%. CONCLUSIONS: ELISA-1 performed best in this comparison. While the WB can be used, it did not have a technical advantage over the ELISA. The CFT should be discouraged as the primary screening method for contagious agalactia and should be replaced by ELISA-1. Results from this study confirm that serological test methods for contagious agalactia are useful for the detection of infected flocks but will not detect every individual infected animal.

Serological survey of pre-weaned New Zealand fur seals (Arctocephalus forsteri) for brucellosis and leptospirosis.

AIM: To conduct a longitudinal serological survey for evidence of Brucella spp and Leptospira spp infection of pre-weaned New Zealand fur seals in a colony on the Otago Peninsula. METHODS: Seal pups were repeatedly captured on a monthly basis from February through to July 2001. Pups were tagged at first capture and a blood sample was taken at each capture event. A total of 163 sera were collected from 118 seal pups. Where sufficient volume was collected, the sera were tested for leptospirosis using the microscopic agglutination test (MAT), and for brucellosis using the competitive enzyme-linked immunosorbent assay (ELISA) for Brucella abortus. RESULTS: None of 128 sera from 101 seals tested positive to the ELISA for B. abortus. All tests for Leptospira interrogans serovars Grippotyphosa, Copenhageni, Bratislava and Leptospira borgpetersenii serovar Ballum were negative at a cut-off of <1/100 dilution. Positive or suspicious titres were found to L. interrogans serovars Canicola and Pomona and L. borgpetersenii serovar Hardjo. The highest titres (12,800) were found to serovar Pomona. The titre to serovar Pomona in one seal rose from <1/50 in March to 12,800 in April and was <1/50 when re-sampled in July. The titre to serovar Pomona in another seal dropped from 12,800 in May to <1/50 in June. These seals also had titres to serovar Hardjo, which rose or fell in the same manner. All suspicious or positive titres occurred in late April and early May, when the pups were approximately 4-5 months old. In June and July, all seals tested were negative. CONCLUSIONS: There was no serological evidence of Brucella infection in the pre-weaned fur seals at the colony. Positive titres to serovars Pomona, Hardjo, or Canicola suggest that a Leptospira species was present at the colony, however isolation or visualisation of the organism is required to confirm this. Care should be exercised when handling New Zealand fur seals to prevent human infection or inadvertent transfer of leptospirosis to another marine mammal species.

Detection and molecular characterisation of bovine polyomavirus in bovine sera in New Zealand.

AIM: To investigate the prevalence of bovine polyomavirus (BPyV) DNA in commercial batches of bovine serum products, cell lines and cattle in New Zealand and to characterise the viral DNA detected. METHODS: Two nested polymerase chain reaction (PCR) assays were applied to detect BPyV in bovine sera. One was used to screen for the VP1 gene of BPyV DNA in: 140 batches of commercial bovine serum products, including 66 batches of fetal bovine serum (FBS), 34 batches of calf serum, and 40 batches of adult bovine serum (ABS)/plasma; 112 individual adult bovine sera; and 16 cell lines of various species origin. Fifty batches of serum samples were also tested, using the second nested PCR assay that screened for the Large T gene. Restriction fragment length polymorphism (RFLP) was conducted with 36 PCR products amplified from the VP1 gene of BPyV using EcoRI. Five selected VP1 PCR products were subjected to DNA sequencing and phylogenetic analysis. RESULTS: BPyV DNA was detected in 46 (70%) batches of FBS, 11 (32%) batches of calf sera and two (5%) batches of ABS/plasma, an overall prevalence of 42%. None of 112 adult bovine sera was BPyV-positive. RFLP analysis demonstrated a uniform digestion pattern in the majority (31/36) of amplicons tested, while the remaining PCR amplicons did not show enzyme cleavage. Sequence analysis of the PCR products (a 263 base pair (bp) fragment of the VP1 gene) obtained from five batches of FBS showed 96.2-98.9% homology to that of published sequences of BPyV. CONCLUSION: BPyV is a frequent contaminant of commercial bovine serum in New Zealand. The incidence of BPyV in adult bovine serum products is much lower than in FBS and calf serum. Genomic variations exist among different viruses. The clinical significance of the high prevalence of BPyV DNA in bovine serum products is yet to be determined.

Experimental infection of possums with macropodid herpesvirus 1.

AIM: To determine whether macropodid herpesvirus 1 (MaHV-1) could infect brushtail possums (Trichosurus vulpecula) and whether such infection would lead to latency in possums. METHODS: Possums (n=9) were instilled with 1.9 x 10(8) TCID50 of MaHV-1 into the conjunctivae and nostrils, while controls (n=3) were administrated with sterile saline. For virus isolation, all possums were swabbed from the conjunctivae and nasal cavities prior to inoculation, and on Days 1, 3, 7, 10 and 14 post-inoculation (p.i.), and then at weekly intervals for up to a further 6 weeks. Sera were collected on Day 0 immediately prior to inoculation and fortnightly thereafter, for the measurement of antibody. Corticosteroids were administrated to 4/9 virus-inoculated possums on Days 36 and 41 p.i. to determine whether latent MaHV-1 infection could be reactivated. Trigeminal ganglia and other tissues were collected at necropsy for viral detection. A nested polymerase chain reaction (PCR) targeting the DNA-dependent DNA polymerase (DNA pol) gene of the herpesviruses using degenerate primers was conducted on DNA samples isolated from the ganglia and livers from the possums, and blind-passaged cell cultures, for viral detection. RESULTS: A mild conjunctivitis was observed in the majority of the virus-inoculated possums between Days 3 and 21 p.i. Virus was recovered from the conjunctiva and/or nasal swabs from 8/9 virus-inoculated possums on Days 1 and 3 p.i. and from 3/9 on Day 7 p.i., but not following administration of corticosteroids. No virus was recovered from the trigeminal ganglia of the virus inoculated possums and possum DNA samples were negative for viral DNA following nested PCR. All of the virus-inoculated possums produced a virus neutralisation antibody response by Day 28 p.i., and five had a titre >/=512. The sequence of a 133 base pair (bp) segment of the MaHV-1 DNA pol gene was considerably different from that of other published data. CONCLUSION: This study demonstrated that MaHV-1 might have established a transient infection at the inoculation sites, and the inoculation of MaHV-1 via intranasal and conjunctival routes could elicit MaHV-1-specific antibody responses in possums. However, systemic and latent infection of MaHV-1 in possums was not demonstrated.

A brief review on the laboratory diagnosis of leptospirosis.

Leptospirosis is a ubiquitous zoonotic disease that may be maintained in either wild or domesticated animal species. These bacteria have been classified into serovars based on their antigenic characteristics and, more recently, into species based on genomic studies. They produce both chronic and acute infections. Chronic infections of serovars in the host species to which they have become adapted can result in long term shedding, providing a source of acute infection for other species. As clinical presentation can vary greatly, diagnosis often depends on laboratory methods. In addition to diagnostic testing, herd health monitoring and screening for international trade purposes are performed at veterinary laboratories. The test method selected varies depending on the samples available and the purpose of testing. An increasing variety of laboratory methods are being described for detection of bacteria and antibodies. In addition to classical methods such as culture, dark-field, microscopy and the microscopic agglutination test (MAT), a variety of polymerase chain reaction (PCR), indirect enzyme-linked immunosorbent assay (ELISA), competitive ELISA and other rapid serological tests have been described. This review describes the advantages and limitations of these assays together with other factors that may affect results and their interpretation, such as species variation, vaccination and antibiotic administration.

A serosurvey for antibodies to Leptospira in dogs in the lower North Island of New Zealand.

AIMS: To investigate the prevalence of antibodies to endemic and exotic Leptospira serovars in samples from a serum bank, collected from dogs in the lower North Island of New Zealand. METHODS: Sera (n=466), which had been collected from apparently healthy dogs, were screened using the microscopic agglutination test (MAT) for antibodies to serovars L. borgpeterseni serovar hardjo, L. interrogans serovars pomona, copenhageni and canicola, and L. kirschneri serovar grippotyphosa. RESULTS: Antibody to Leptospiral antigen was found in 14.2% of dogs tested. The highest level of reactivity was with serovar copenhageni, to which 9.5% (41/433) of sera were positive. Antibodies to serovars grippotyphosa and canicola were not detected in this population of dogs. CONCLUSIONS: Leptospira infection is relatively common in dogs in the lower North Island . CLINICAL RELEVANCE: Vaccination of dogs against leptospirosis should be considered using vaccine containing antigen to serovars hardjo, pomona and copenhageni. The presence of moderate levels of copenhageni antibody in dogs in the lower North Island raises the possibility that this serovar has become established in rodent populations in this region.

Failure of a new double glove hole detection system in the Emergency Department.

The purpose of this study was to evaluate the performance of a new double glove hole detection system in the Emergency Department. First, the frequency of holes in both gloves of the double glove hole detection system was determined using a watertight test method. Second, the frequency of glove puncture was determined first by searching for the optical color change that occurs with the ingress of fluid in the double glove hole detection system. These same gloves were then removed and also checked for holes by the watertight test method. After removal from the package, no holes were detected in the two gloves of the system using the watertight test method. In 50 consecutive patients, there was no color change in the inner glove indicating glove puncture. When these same gloves were then tested with the watertight test method, 14 of the 50 double glove hole detection systems failed; all 14 outer gloves were punctured, and three of the inner gloves had holes without demonstrable injury to the skin. This double glove hole detection system is not a reliable system to detect holes in relatively dry clinical settings because the ingress of fluid by capillary action between the gloves is necessary to cause a color change in the inner glove that signals the presence of a hole.

Serology of rabbit haemorrhagic disease virus in wild rabbits before and after release of the virus in New Zealand.

Rabbit haemorrhagic disease virus (RHDV) was illegally released in New Zealand in August 1997. The initial release and spread of the virus was conducted by landholders in an effort to reduce costs associated with more conventional control methods (poisoning and shooting). Serum was collected from wild rabbits throughout the Otago region prior to the release and from 13 sites in the months following the first epizootic. Following the occurrence of the first RHDV epizootic on 13 pastoral farming properties a range of survival rates was found. The major factor influencing the survival rate was found to be the method of release, with widespread use of carrot or oat baits containing RHDV resulting in poor kills. Widespread use of baits also resulted in higher levels of antibody in surviving adult rabbits with a higher proportion of adult females surviving the epizootic, compared with properties where the disease was allowed to spread naturally. A correlation was found between survival rate and the percentage of surviving adults with high levels of antibody. These results suggest that poor kill rates are not due to poor spread of the virus, that the large-scale use of baits resulted in protective immunisation and that rabbit control should in the future be achieved through establishing naturally spreading epidemics rather than widespread use of baits.

Balcony collapse at the University of Virginia graduation: what hath Jefferson wrought?

The purpose of this report is to describe the emergency medical response to a disaster caused by the collapse of a balcony in Pavilion I on the Lawn of the University of Virginia during graduation. The emergency medical response to rescue of the injured was hindered by five major factors: (1) a metal linked chain blocked access of rescue vehicles, (2) inability to identify an emergency medical command officer, (3) failure to transfer injured patients with stable vital signs and secured to backboards to a triage area away from the scene of the accident, (4) ineffective crowd control, and (5) the failure to delay procession until completion of patient transport from the disaster site. Sixteen people were injured in the accident and one patient died. The cause of the accident was the absence of a redundant architectural support system for the balcony.

Influence of absorbable dusting powders on wound infection.

Surgical glove dusting powders are commonly used as mold-release agents and to facilitate donning. Cornstarch and CaCO3 are commonly used absorbable dusting powders. This experimental study demonstrates that these absorbable dusting powders significantly potentiate bacterial growth and enhance a wound's inflammatory response. The infection-potentiating effects of CaCO3 are significantly greater than those of cornstarch.

Ease of donning commercially available latex examination gloves.

There are a wide variety of latex examination gloves now available for use by health care providers. A prospective randomized trial was completed to quantify the forces required to don a sample of seven cornstarch-lubricated gloves and 13 powder-free latex examination gloves. The data collected was analyzed by a 20 x 2 general factorial ANOVA, as well as two 1-way ANOVAs using a least significance difference post hoc test. Some powder-free gloves can be easily donned with dry or wet hands without tearing with forces comparable to those encountered with powdered gloves. With the advent of these powder-free examination gloves, powdered gloves can now be abandoned, protecting health professionals and patients from the dangers of absorbable dusting powders. Despite the dangers of the absorbable dusting powders and the Food and Drug Administration's requirement for labeling examination glove boxes, some manufacturers of powdered examination gloves do not appropriately label their boxes with a warning to the health professional and patient of the presence of powder.