An unusual human case of leptospirosis

In April 1991, a medical practitioner was admitted to Auckland Hospital with severe sweats, myalgia, headaches, lethargy and pyrexia. Leptospires were isolated from a blood sample taken during one of the fever spikes and referred to a reference laboratory for identification. The initial reference laboratory referred the isolate on to a second reference laboratory where it was identified as Leptospira canicola.     

Lack of toxicity of a nonsporidesmin-producing strain of Pithomyces chartarum in cell culture and when dosed to lambs

In New Zealand the fungus Pithomyces charturum normally produces sporidesmin, a mycotoxin, which is responsible for the hepatogenous photosensitisation disease known as facial eczema. Cultures from an isolate of P. charturum, which does not produce sporidesmin, were examined by cell culture and by dosing to lambs to determine whether other toxic metabolites were produced. Acute and long term toxicity studies were conducted with the toxic response being assessed by weight changes, postmortem and histological examination of tissues, blood biochemistry and haematology tests.

An extract from a sporidesmin-producing isolate was highly toxic in cell culture, while extracts of the nonsporidesmin-producing isolate did not cause a cytotoxic response to HEp 2 cells.

After dosing with a sporidesmin-producing isolate, lambs developed liver lesions and clinical signs of facial eczema. Serum biochemistry changes occurred which were consistent with sporidesmin poisoning.

Lambs dosed with the nonsporidesmin-producing isolate, at the rate of thirty times the number of spores of the sporidesmin-producing isolate, showed no observable toxic effects. All organs were of normal appearance, and histological examination of tissues, blood biochemistry and haematology results showed no abnormal changes. Similarly, long term dosing of extracts of the nonsporidesmin-producing isolate, at a rate equivalent to 100 000 spores/g of grass, produced no indication of a toxic response. It was concluded that the nonsporidesmin-producing isolate of P. churtarum contained no toxic metabolites in significant concentration.     

Non-specific seroreactions against Brucella abortus in ruminants in New Zealand and the presence of Yersinia enterocolitica 0:9

The level of non-specific reactions found in the brucellosis serology of ruminants in New Zealand was very low until July 1992. This changed when, in an export consignment of 1071 deer, 35% reacted in the Brucella abortus tube agglutination test with titres varying from 50 to 200 IU. The reactors were also positive in the Rose-Bengal agglutination test and most of them reacted in the complement fixation test with titres varying from 10 to 80 IU. Yersinia enterocolitica 0:9 was later isolated from one deer of this consignment. It was the first isolate of this serotype recovered in New Zealand from an animal. Shortly after, false reactors occurred more frequently than before in sera from Brucella abortus accredited free cattle herds. As the involvement of Yersinia enterocolitica 0:9 was suspected in these cases, faecal samples from reactors and in-contact animals were cultured for this organism. Yersinia enterocolitica 0:9 was isolated from nine of 19 herds showing one or more false Brucella abortus seroreactions.

Prior to 1990, Yersinia enterocolitica serotype 0:9 had not been isolated in New Zealand, despite the recovery of a number of other bio— or serotypes of the organism from humans and animals. From 1990 onward, serotype 0:9 began to be isolated from human faecal samples with increasing frequency. Since the first isolations from deer and cattle in 1992, it has now also been recovered from a cat and an alpaca and from cattle without any association with false positive Brucella abortus reactions. All serotype 0:9 isolates were of biotype 2.     

Concentrations of faecal coliforms,Escherichia coli,enterococci and Campylobacter spp. in equine faeces

Abstract

AIMS: To determine the concentration of Campylobacter spp. as well as faecal indicator bacteria; faecal coliforms, Escherichia coli and enterococci in the faeces of healthy adult horses in a sample of properties in the Canterbury region of New Zealand.

METHODS: The faeces of healthy adult horses (n=59), including ponies, pleasure horses and Thoroughbreds, were collected from eight properties around Christchurch, New Zealand. The faeces were analysed for concentrations of Campylobacter spp and faecal indicator bacteria; faecal coliforms, Escherichia coli and enterococci. The presence of other animals on the properties sampled as well as the age, feed and health of the horses at the time of sampling was recorded.

RESULTS: Enterococci and faecal coliforms were isolated from all samples, and E. coli was isolated from 58/59 samples. Mean concentrations of faecal coliforms and E. coli did not differ between properties, but there was a significant difference in mean concentration of enterococci between properties. Campylobacter spp. were detected in two faecal samples with one isolate being determined by PCR analysis to be a thermotolerant Campylobacter species, the other C. jejuni.

CONCLUSIONS: This is the first known report quantifying the concentration of Campylobacter spp. present in healthy adult horses in New Zealand. The presence of equine faecal material in water could elevate concentrations of faecal bacteria and therefore needs to be considered as a source of water contamination. The access of horses to waterways and coastal environments may also need to be restricted to prevent transmission of faecal indicator bacteria and potentially zoonotic agents.     

Mycobacterium bovis infections in wild ferrets

Extract

Bovine tuberculosis is one of the more important animal health problems in New Zealand. In contrast to a number of other countries, the classical test and slaughter methods in New Zealand have not led to the eradication of bovine tuberculosis. The failure to eradicate bovine tuberculosis is due to the continual spread of Mycobacterium bovis from wildlife to cattle and farmed deer. Although the Australian brushtail possum Trichosurus vulpecula is the most important wildlife reservoir of infection in New Zealand, M. bovis has also been isolated from wild deer, feral pigs, feral goats, feral cats and feral cattle. In this letter we wish to report the finding of M. bovis-infected wild ferrets (Mustela putorius furo) in seven geographically distinct areas of New Zealand (Figure 1). While there are reports from overseas of M. bovis being isolated from domesticated ferrets, there are no reports of its isolation from wild ferrets or polecats (Mustela putorius)⁽¹⁾.     

A serological and bacteriological survey of leptospiral infection in dogs in Edinburgh and Glasgow

Sera collected from 511 unvaccinated urban dogs were examined for antibodies to serovars of Leptospira interrogans representing nine serogroups found in the United Kingdom. The point estimates of the seroprevalence of leptospiral titres in Edinburgh and Glasgow at a minimum serum dilution of 1:10 were 23-5 per cent and 27-5 per cent, respectively, and, in Glasgow, the seroprevalence was significantly higher in males than females, for both crude and age-adjusted values. Serovar canicola was the dominant strain identified, followed by serovars icterohaemorrhagiae, bratislava and ballum. Antibodies against serovars javanica and hardjo also were detected. Urine samples were collected from 84 of the male blood-sampled dogs, and cultured. Serovars canicola and bratislava were isolated from three and four samples, respectively.     

Actinobacillus suis infection of horses

Nineteen isolates of Actinobacilfus suis were recovered from horses during the period October 197%December 1980. Animals varied in age from a full term foetus to 12 years. One isolate was obtained from the nose of an apparently healthy horse, the remainder were obtained from still-born foetuses (2), foals dying within a week of birth (5), older animals with respiratory (6) or genital infections (3) or abscesses in the jaw (1). One isolate was obtained from the lung of a 2-week-old foal which had shown diarrhoea.

The bacteriological characteristics of the isolates and the pathological lesions present in eight cases are described. The organism has a wide geographical distribution in New Zealand, and in the northern part of the North Island appears to be more common than A. equuli.     

Pulsed-field gel electrophoresis typing of Campylobacter fetus subsp. fetus isolated from sheep abortions in New Zealand

AIMS: To genotype Campylobacter fetus subsp. fetus isolates cultured from sheep abortions submitted to diagnostic laboratories in New Zealand during the year 2000 breeding season. To compare the types found nationally with those found in the Hawke' Bay region in 1999, and strains held in the New Zealand Reference Culture Collection, Medical Section (NZRM) from a study published in 1987.

METHODS: Campylobacter fetus subsp. fetus isolates cultured by veterinary diagnostic laboratories in the year 2000 breeding season, from sheep abortions from throughout New Zealand, were typed using pulsed-field gel electrophoresis (PFGE). In addition, seven freeze-dried C. fetus subsp. fetus isolates (strain numbers 2939–2945) from the NZRM, representing restriction types a–g found amongst sheep abortion isolates in a study published in 1987, were typed using PFGE.

RESULTS: In total, 293 C. fetus subsp. fetus isolates from 200 farms were obtained from veterinary diagnostic laboratories. Twenty-two distinct PFGE profiles were identified amongst the isolates. PFGE type B1 was predominant in each region of New Zealand and was identified from 66% of farms overall. Of the C. fetus subsp. fetus restriction types a–g lodged with the NZRM, 3/7 had PFGE profiles indistinguishable from profiles found in the current study. The other four restriction types had PFGE profiles that were unique but similar to those found in the current study.

CONCLUSIONS: PFGE type B1 was predominant amongst the C. fetus subsp. fetus isolates cultured from sheep abortions in each region of New Zealand in the year 2000, as was found in Hawke' Bay in 1999. The similarity between PFGE profiles of C. fetus subsp. fetus sheep abortion isolates from 1987 and 2000, and the relative prevalence of the PFGE groups, suggests that there has been no major genotypic shift in the population of C. fetus subsp. fetus implicated in sheep abortion in New Zealand during this time.     

Can sheep become infected by grazing pasture contaminated by cattle with Johne's disease?

Extract

Madam:- Transmission of Johne's disease (JD) under natural conditions from sheep to cattle has been demonstrated in iceland⁽²⁾ but not in New Zealand.⁽¹⁾ The reverse, sheep becoming infected with Mycobacterium paratuberculosis of bovine origin, has been shown experimentally with large inocula (c. 5 × 10⁹organisms/lamb),⁽³⁾ but not under natural conditions. It could be important in New Zealand where sheep may be used to “clean up” pasture grazed by paratuberculous cattle.     

Competition of a sporidesmin-producing Pithomyces strain with a non-toxigenic Pithomyces strain

Sporidesmin, a mycotoxin produced by some strains of Pithomyces chartarum, is responsible for the hepatogenous photosensitisation disease facial eczema, which causes severe losses in agricultural revenue in New Zealand. A sporidesmin-producing strain of P. chartarum, isolated in New Zealand, was grown in co-culture with a South African strain that does not produce the mycotoxin. Competition occurred between the two strains when grown both on agar plates and on dried ryegrass, with a significant decrease in the total amount of sporidesmin produced. Biological control of toxkenic P. chartarum can thus occur under laboratory conditions, raising the possibility of similar control in the field situation.     

Re: Use of polymerase chain reaction for the differentiation of Group A bovine rotavirus G6, G8, and G10 genotypes in the North Island of New Zealand

Extract

In the paper by L Howe, H Sugiarto and RA Squires published in the New Zealand Veterinary Journal 56, 218–221, 2008, entitled, “Use of polymerase chain reaction for the differentiation of Group A bovine rotavirus G6, G8, and G10 genotypes in the North Island of New Zealand”, the authors concluded that “Currently, the rotavirus vaccine available in New Zealand contains only the G6 strain, and may not provide optimal protection for animals infected with G10 rotavirus. … This information may be of assistance in the development and optimisation of vaccines, and enhancement of effective control strategies.”     

Presence and diversity of mixed avian Plasmodium spp. infections in introduced birds whose distribution overlapped with threatened New Zealand endemic birds

ABSTRACT

Aims: To determine the presence of infection and co-infection of Plasmodium lineages in introduced birds at translocation sites for the North Island saddleback (Philesturnus rufusater), to investigate their role as Plasmodium spp. reservoirs.

Methods: Blood samples were collected from introduced bird species, with a special focus on blackbirds (Turdus merula) and song thrushes (Turdus philomelos), at six locations in the North Island of New Zealand that were the origin, or translocation sites, for North Island saddleback. Where available, blood smears were examined, and blood samples were tested using nested PCR with subsequent sequence analysis, for the presence of Plasmodium spp.

Results: Of the 55 samples tested using PCR analysis, 39 (71%) were positive for Plasmodium spp., and 28/40 (62%) blood smears were positive for Plasmodium spp. Overall, 31 blood samples were from blackbirds with 28/31 (90%) samples positive for Plasmodium spp. Six distinct avian Plasmodium lineages were identified, including three cosmopolitan lineages; Plasmodium vaughani SYAT05 was detected in 16 samples, Plasmodium matutinum Linn1 in 10 samples and Plasmodium elongatum GRW6 in eight samples. Mixed infections with more than one lineage were detected in 12 samples. Samples from two Australian magpies (Gymnorhina tibicen) were positive for Plasmodium. sp. lineage MYNA02, previously not identified in New Zealand.

Conclusions and clinical relevance: This is the first report from New Zealand in which specific Plasmodium spp. mixed infections have been found in introduced birds. Co-infections with several cosmopolitan Plasmodium lineages were identified, as well as the first report in New Zealand of an exotic avian Plasmodium sp. lineage, in Australian magpies. Whilst the role of introduced birds in maintaining and spreading pathogenic avian malaria in New Zealand is unclear, there is a potential infection risk to native birds, especially where distributions overlap.     

Adenovirus precipitating antibodies in the sera of brush-tailed possums in New Zealand

Sera collected from the Australian brush-tailed possum Trichosurus vulpeculu in New Zealand in 1975 and 1989 were tested for the presence of antibodies to adenovirus. Of the 231 sera tested in an agar gel diffusion test, eight (3.5%) had precipitating antibodies to the group specific antigen of mammalian adenoviruses. Available data allowed 99/231 sera to be classified as being obtained from either adult (total 62) or sexually immature (total 37) possums. From the adult animals, 4/62 (6.5%) sera were positive, while no reactive sera were detected among the 37 immature animals. The results provide evidence that natural infection by an adenovirus occurs in possums in New Zealand. Further work needs to be carried out to isolate this adenovirus to enable detailed serological and epidemiological studies to be performed. A species-specific “possum adenovirus” could have potential in the biological control of this species.     

Prevalence of Neospora antibodies in beef cattle in New Zealand

dAim:To estimate the prevalence of Neospora infection in a sample of New Zealand beef cattle.

dMethods: The prevalence of Neospora caninum infection in New Zealand beef cattle was estimated by collecting blood at slaughter from 499 beef cattle from 40 different farms at 2 slaughter plants in the North Island and 1 in the lower South Island. Sera were tested using an ELISA against Neospora tachyzoite antigen.

dResults: The prevalence of seropositive cattle was 2.5% (n=120), 3.6% (n=166) and 2.3% (n=213) at the plants surveyed, the overall prevalence being 2.8%. The serologically positive cattle came from 9 farms, 3 of which had more than 1 positive animal. The highest prevalence recorded amongst animals from 1 farm was 4/13 (31%), in a group of young steers.

dConclusion: Neosporosis appears to be present at a lower level in the New Zealand beef cattle population than in the New Zealand dairy cattle population. Nevertheless, from the high seroprevalence evident amongst young cattle on 1 farm, we suggest that Neospora may be a cause of infertility in beef cattle in this country.     

Seroprevalence of Toxoplasma gondii in mainland and sub-Antarctic New Zealand sea lion (Phocarctos hookeri) populations

AIMS: To investigate the seroprevalence of antibodies to Toxoplasma gondii in New Zealand sea lions (Phocarctos hookeri), as a potential contributor to reproductive failure.

METHODS: Archived sera were sourced from New Zealand sea lions from two recolonising mainland populations in the Otago Peninsula (n=15) and Stewart Island (n=12), as well as a declining population at Enderby Island (n=28) in the New Zealand sub-Antarctic. Sera were tested for antibodies to T. gondii using a commercially available ELISA (with samples considered positive if the sample to positive ratio was?>30%), and latex agglutination test (LAT; with titres ≥1:32 considered positive). Western blot analysis was used to validate the results of a subset of 14 samples.

RESULTS: Five samples from sea lions in mainland locations were confirmed positive for antibodies to T. gondii. Two adult females exhibited high LAT antibody titres (min 1:2048, max 1:4096) on both occasions when sampled 1 and 2 years apart, respectively. No animals from Enderby Island were seropositive.

CONCLUSIONS: Toxoplasma gondii infection is unlikely to be a major contributor to poor reproductive success in New Zealand sea lions. However, continued surveillance is pertinent to assess subclinical and clinical impacts of the parasite on these threatened populations. The commercial tests evaluated here, with further species-specific threshold refinement could provide a fast, inexpensive and reliable indicator of T. gondii exposure in New Zealand sea lions.     

First detection of Chlamydia psittaci from a wild native passerine bird in New Zealand

AIMS: To undertake disease surveillance for Chlamydia psittaci in native birds as part of a pilot study to examine pathogen diversity on Hauturu-o-Toi/Little Barrier Island. To retrospectively review the Massey University post-mortem database to determine previous cases of avian chlamydiosis in New Zealand.

METHODS:Mistnetting of forest birds was conducted across an elevational gradient on Hauturu-o-Toi/Little Barrier Island. Minitip culture swabs were used to collect cloacal samples from native birds. These swabs were screened for Chlamydia family DNA using two PCR methods. Positive results were sequenced. A retrospective review of the Massey University post-mortem database of all avian cases from 1990 to 2011 was conducted.

RESULTS:Ten native birds including four bellbirds (Anthornis melanura), three rifleman (Acanthisitta chloris), two hihi (Notiomyces cincta), and one whitehead (Mohoua albicilla) were sampled and one otherwise healthy female hihi was positive by both PCR screening methods for Chlamydophila. Sequencing confirmed 99–100% genetic similarity to C. psittaci. A retrospective review of the Massey University post-mortem database revealed no previous diagnoses of avian chlamydiosis in wild native New Zealand birds although it has been detected in captive parrots, and wild and captive exotic pigeons.

CONCLUSIONS:This is the first report of the detection of C. psittaci from a wild native bird in New Zealand. The bird was a Passeriforme from an endangered species that was captured free-living on Little Barrier Island. The incidence of avian chlamydiosis in native birds in New Zealand appears to be very low, based on the retrospective review of the post-mortem database.

CLINICAL RELEVANCE: It is unlikely that avian chlamydiosis is a significant problem for hihi population health. The detection of this organism has greater significance for other more susceptible species on Little Barrier Island and for human health, particularly for conservation workers involved in wildlife translocations. It further suggests that passerine birds may be a reservoir for C. psittaci in New Zealand ecosystems.     

Effect of pre-slaughter environment on some physiological parameters and meat quality in New Zealand rabbits (Oryctolagus cuniculus)

The objective of this study was to examine the effect of pre-slaughter environment on physiology and meat quality in New Zealand rabbits. Pre-slaughter environment consisted of combined effects of social and non-social factors. For the experiment, 18 male New Zealand rabbits (Oryctolagus cuniculus), 3 months of age, were used. Some biochemical and meat quality parameters of the animals were measured, and the results were compared with the control group. The pre-slaughter environment significantly influenced some biochemical and meat quality parameters (P < 0.01 and P < 0.05, respectively). It is concluded that pre-slaughter environment negatively affected the welfare status and decreased the meat quality in New Zealand rabbits.     

Concurrent avian malaria and avipox virus infection in translocated South Island saddlebacks (Philesturnus carunculatus carunculatus)

Abstract

CASE HISTORY: Outbreaks of mortality in South Island saddlebacks (Philesturnus carunculatus carunculatus) that had been translocated to two offshore islands in the Marlborough Sounds of New Zealand were investigated during the summer of 2002 and 2007. Both outbreaks were associated with a severe decrease in numbers of saddlebacks of up to 60% of approximately 200 birds.

CLINICAL AND PATHOLOGICAL FINDINGS: Many of the surviving birds were in poor condition, and had skin lesions on the legs and head. Necropsy showed pale liver and lungs, and a swollen spleen. Histopathology revealed schizonts resembling Plasmodium spp. within the cytoplasm of many hepatocytes and splenic histiocytes. The skin lesions consisted of epithelial proliferations containing numerous Bollinger bodies typical of avipox virus (APV) infection. Two different APV were isolated, using PCR, from two different birds exhibiting skin lesions. Each isolate had 100% sequence homology with APV members from either Clade A or Clade B. In addition, PCR analysis revealed that the Plasmodium elongatum present in infected birdsbelonged to a strain that was endemic in the population of North Island saddlebacks (Philesturnus carunculatus rufusater).

DIAGNOSIS: Concurrent infections with Plasmodium spp. haemoparasites and APV were identified as the likely cause of death in the birds examined.

CONCLUSIONS AND CLINICAL RELEVANCE: Although the Plasmodium spp. identified is thought to be endemic to saddlebacks in New Zealand, the affected birds were likely to be immunocompromised by concurrent APV infection or through lack of genetic diversity. Both the introduced mosquito Culex quinquefasicatus and the native mosquito Culex pervigilans are likely vectors for both these diseases, and the provision of water supplies less favourable to mosquito-breeding is recommended.     

Vitamin E deficiency and perinatal mortality in pigs

In a recent letter ⁽¹⁾ to the New Zealand Veterinary Journal on perinatal mortality in piglets, the reported sow Vitamin E supplementation of 50 IU/sow/day was slightly lower than that typically used on most commercial farms in New Zealand. Normal sow dietary supplementation is in the range of 30-60 IU per kg dry matter (DM).     

Haematological and serum biochemical reference ranges for brushtail possums

Extract

I am writing with reference to the recent article by O'Keefe and Wickstrom (Routine blood values for New Zealand brushtail possums (Trichosurus vulpecula) at capture. New Zealand veterinary Journal 46, 41–2,1998).