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Aims: This pilot study describes the experiences of six people who reported post-leptospirosis symptoms. Our aim was to perform an exploratory qualitative study to document participants' experiences and to identify themes to gain understanding of the impact and burden experienced., Methods: Participants self-recruited, meaning they had directly contacted the first author prior to the study commencing and had offered to tell their stories. Face-to-face semi-structured interviews were conducted in January 2016 and summative content analysis was used to distil themes., Results: The participants were male, had been employed in livestock slaughter plants (n=2) or farming (n=4) when they first contracted leptospirosis and claimed they had been suffering from post-leptospirosis symptoms for 1-35 years. Symptoms included exhaustion, brain fog and mood swings, and participants' lifestyles and relationships were severely affected. Participants and their partners reported poor awareness and knowledge of leptospirosis when they sought help, and that employers and the Accident Compensation Corporation (ACC) were dismissive of post-leptospirosis symptoms. Participants also reported some positive experiences and had advice to share., Conclusion: Leptospirosis may have severe long-term consequences for patients, their families and their communities. We recommend that the aetiology, pathogenesis and burden of the persistence of leptospirosis symptoms become topics for future research., Competing Interests: Nil, (© PMA.)

In New Zealand (NZ), leptospirosis is a mostly occupational zoonosis, with >66% of the recently notified cases being farm or abattoir workers. Livestock species independently maintain Leptospira borgpetersenii serovar Hardjo and L. interrogans serovar Pomona, and both are included in livestock vaccines. The increasing importance in human cases of Ballum, a serovar associated with wildlife, suggests that wildlife may be an overlooked source of infection. Livestock could also act as bridge hosts for humans. Drawing from disease ecology frameworks, we chose five barriers to include in this review based on the hypothesis that cattle act as bridge hosts for Ballum. Using a narrative methodology, we collated published studies pertaining to (a) the distribution and abundance of potential wild maintenance hosts of Ballum, (b) the infection dynamics (prevalence and pathogenesis) in those same hosts, (c) Ballum shedding and survival in the environment, (d) the exposure and competency of cattle as a potential bridge host, and (e) exposure for humans as a target host of Ballum. Mice ( Mus musculus ), rats ( Rattus rattus , R. norvegicus ) and hedgehogs ( Erinaceus europaeus ) were suspected as maintenance hosts of Ballum in NZ in studies conducted in the 1970s-1980s. These introduced species are distributed throughout NZ, and are present on pastures. The role of other wildlife in Ballum (and more broadly Leptospira ) transmission remains poorly defined, and has not been thoroughly investigated in NZ. The experimental and natural Ballum infection of cattle suggest a low pathogenicity and the possibility of shedding. The seroprevalence in cattle appears higher in recent serosurveys (3 to 14%) compared with studies from the 1970s (0 to 3%). This review identifies gaps in the knowledge of Ballum, and highlights cattle as a potential spillover host. Further studies are required to ascertain the role that wild and domestic species may play in the eco-epidemiology of Ballum in order to understand its survival in the environment, and to inform control strategies.

A cross-sectional survey was conducted to determine the seroprevalence of Leptospira in a cohort of horses and to evaluate potential risk factors for Leptospira seropositivity in horses in New Zealand. The convenience sample included 499 Thoroughbred racing and breeding horses from 25 commercial properties in North Island, New Zealand. A questionnaire was used to collect demographic data on horses and property-level information on grazing and management practices, pest (rodent) management, access to natural waterways, other livestock on the property, and possible contact with wildlife. The microscopic agglutination test was used to test sera for serovars Ballum, Copenhageni, Hardjo (bovis), Pomona, and Tarassovi. Logistic regression was used to investigate the risk factors for Leptospira seropositivity to at least one serovar and for each serovar individually. A total of 124 (25%, 95% confidence interval (CI) 21-29%) horses had positive titres to any one of the five serovars. The seroprevalence of Ballum, Copenhageni, Hardjo (bovis), Pomona, and Tarassovi was 5% (95% CI 3-7%), 9% (95% CI 7-12%), 6% (95% CI 4-8%), 6% (95% CI 4-8%), and 6% (95% CI 4-8%), respectively. Broodmares, compared to racehorses and alternately grazing horses with sheep, increased the odds of exposure to any one serovar, whilst grazing the same time as sheep and alternately grazing horses with cattle increased the odds of exposure to Ballum and Hardjo (bovis), respectively. Historical exposure to Leptospira in racing and breeding horses was identified, and risk factors were consistent with pasture-based exposure.

Background: Ross River virus (RRV) is a zoonotic alphavirus transmitted by several mosquito species. Until recently, endemic transmission was only considered possible in the presence of marsupial reservoirs., Methods: RRV seroprevalence was investigated in placental mammals (including horses, cows, goats, pigs, dogs, rats, and mice) in Fiji, where there are no marsupials. A total of 302 vertebrate serum samples were collected from 86 households from 10 communities in Western Fiji., Results: Neutralizing antibodies against RRV were detected in 28% to 100% of sera depending on the species, and neutralization was strong even at high dilutions., Conclusions: These results are unlikely to be due to cross-reactions. Chikungunya is the only other alphavirus known to be present in the Pacific Islands, but it rarely spills over into non-humans, even during epidemics. The study findings, together with a recent report of high RRV seroprevalence in humans, strongly suggest that RRV is circulating in Fiji in the absence of marsupial reservoirs. Considering that all non-human vertebrates present in Fiji are pan-global in distribution, RRV has the potential to further expand its geographic range. Further surveillance of RRV and access to RRV diagnostics will be critical for the early detection of emergence and outbreaks., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

In 2006, New Zealand had the highest notification rate of campylobacteriosis in the world, and poultry was considered the leading source of campylobacteriosis. Implementation of food safety interventions by the poultry industry led to a decrease in the campylobacteriosis notification rate. The aim is to examine the impact of targeted food safety interventions implemented by the New Zealand poultry industry on the source attribution of Campylobacter jejuni infections in a sentinel region. Campylobacter jejuni isolates collected from the Manawatu region of New Zealand between 2005 and 2007 ("before intervention") and 2008 and 2015 ("after intervention") from human clinical cases, chicken meat, ruminant feces, environmental water, and wild bird sources were subtyped by multilocus sequence typing. Viable counts of Campylobacter spp. from carcasses were analyzed using a zero-inflated Poisson regression model. In the period before intervention, sequence type 474 (ST-474) was the most common sequence type (ST) recovered from human cases, accounting for 28.2% of the isolates. After intervention, the proportion of human cases positive for ST-474 reduced to 9.3%. Modeling indicated that chicken meat, primarily from one supplier, was the main source of C. jejuni infection in the Manawatu region before intervention. However, after intervention poultry collectively had a similar attribution to ruminants, but more human cases were attributed to ruminants than any single chicken supplier. Viable counts on carcasses were lower in all poultry suppliers after intervention. This study provides evidence of changes in the source attribution of campylobacteriosis following targeted food safety interventions in one sector of the food supply chain. IMPORTANCE This study provides a unique insight into the effects of food safety interventions implemented in one sector of the food industry on the transmission routes of a major foodborne agent. Following the implementation of food safety interventions by the poultry industry, shifts in the molecular epidemiology of Campylobacter jejuni infections in a sentinel region of New Zealand were observed. Targeted interventions to reduce disease incidence are effective but require continued surveillance and analysis to indicate where further interventions may be beneficial., (Copyright © 2020 American Society for Microbiology.)

Campylobacter jejuni , a leading cause of gastroenteritis worldwide, has been frequently isolated from recreational rivers and streams in New Zealand, yet the public health significance of this is unknown. This study uses molecular tools to improve our understanding of the epidemiology and sources of Campylobacter in recreational waterways, with a view to preventing human infection. Epidemiological and microbiological data were collected between 2005 and 2009 from six high-use recreational waterways in the Manawatu-Wanganui region of the North Island. Campylobacter spp. and C. jejuni were isolated from 33.2% and 20.4% of 509 samples, respectively. Isolation of Campylobacter was observed in both low and high river flows. After adjusting for the confounding effects of river flow, there was a significantly higher likelihood of isolating Campylobacter in the winter month of June compared to January. A high diversity of C. jejuni multilocus sequence types was seen, with the most commonly isolated being the water rail-associated ST-2381 (19/91 isolates [20.9%]), ST-1225 (8/91 isolates [8.8%]), and ST-45 (6/91 isolates [6.6%]). The ST-2381 was found in all rivers, while the most commonly isolated ST from human cases in New Zealand, the poultry-associated strain ST-474, was isolated only in one river. Although the majority of Campylobacter sequence types identified in river water were strains associated with wild birds that are rarely associated with human disease, poultry and ruminant-associated Campylobacter strains that are found in human infection were also identified and could present a public health risk. IMPORTANCE In 2016, there was a large-scale waterborne outbreak of campylobacteriosis in New Zealand, which was estimated to have affected over 5,000 people. This highlighted the need for a greater understanding of the sources of contamination of both surface and groundwater and risks associated with exposure to both drinking and recreational water. This study reports the prevalence and population structure of Campylobacter jejuni in six recreational waters of the Manawatu-Wanganui region of New Zealand and models the relationship between Campylobacter spp. and ruminant-associated Campylobacter and the parameters "sites," "months," and "river flow." Here, we demonstrate that both low and high river flows, month of the year, and recreational sites could influence the Campylobacter isolation from recreational waters. The presence of genotypes associated with human infection allowed us to describe potential risks associated with recreational waters., (Copyright © 2019 American Society for Microbiology.)

Unlabelled: Campylobacteriosis is one of the most important foodborne diseases worldwide and a significant health burden in New Zealand. Campylobacter jejuni is the predominant species worldwide, accounting for approximately 90% of human cases, followed by Campylobacter coli Most studies in New Zealand have focused on C. jejuni; hence, the impact of C. coli strains on human health is not well understood. The aim of this study was to genotype C. coli isolates collected in the Manawatu region of New Zealand from clinical cases, fresh poultry meat, ruminant feces, and environmental water sources, between 2005 and 2014, to study their population structure and estimate the contribution of each source to the burden of human disease. Campylobacter isolates were identified by PCR and typed by multilocus sequence typing. C. coli accounted for 2.9% (n = 47/1,601) of Campylobacter isolates from human clinical cases, 9.6% (n = 108/1,123) from poultry, 13.4% (n = 49/364) from ruminants, and 6.4% (n = 11/171) from water. Molecular subtyping revealed 27 different sequence types (STs), of which 18 belonged to clonal complex ST-828. ST-1581 was the most prevalent C. coli sequence type isolated from both human cases (n = 12/47) and poultry (n = 44/110). When classified using cladistics, all sequence types belonged to clade 1 except ST-7774, which belonged to clade 2. ST-854, ST-1590, and ST-4009 were isolated only from human cases and fresh poultry, while ST-3232 was isolated only from human cases and ruminant sources. Modeling indicated ruminants and poultry as the main sources of C. coli human infection., Importance: We performed a molecular epidemiological study of Campylobacter coli infection in New Zealand, one of few such studies globally. This study analyzed the population genetic structure of the bacterium and included a probabilistic source attribution model covering different animal and water sources. The results are discussed in a global context., (Copyright © 2016, American Society for Microbiology. All Rights Reserved.)

This study assessed seroprevalence and risk factors for Leptospira (serovars Hardjo, Pomona, Ballum, Copenhageni, Tarassovi) exposure in New Zealand veterinarians. Veterinarians (n = 277) at one of two conferences were voluntarily enrolled and blood samples taken. Microscopic agglutination test (MAT) titres ⩾48 were considered seropositive. Fourteen veterinarians (5·1%, 95% confidence interval 2·8-8·3) were seropositive to Leptospira. Home slaughter of cattle or pigs were significant risk factors for Leptospira exposure. There were no clear relationships between the animal species handled at work and serostatus. However, veterinarians spending a 'mid to high' proportion of their time (>50% to ⩽75%) with pets had higher odds of being seropositive than those not working with pets. A borderline positive association (P = 0·09) was observed between seropositivity and clinical influenza-like illness (⩾3 days off work) in the 18 months before the study. Assuming causality, this suggests that 8·3% of these cases may be attributed to Leptospira exposure.

A study was performed to investigate interlaboratory test agreement between a research and a commercial veterinary diagnostic laboratory on blood and urine samples, and to investigate test agreement between blood, urine, and kidney samples (research laboratory) for leptospirosis diagnosis. Samples were sourced from 399 sheep and 146 beef cattle from a local abattoir. Interlaboratory agreement for real-time quantitative polymerase chain reaction (qPCR) results on urine samples was almost perfect (kappa = 0.90), despite the use of different amplification targets (DNA gyrase subunit B gene vs. 16s ribosomal RNA gene), chemistries (SYTO9 vs. TaqMan probe), and pre-PCR processing. Interlaboratory agreement for microscopic agglutination test (MAT) positivity was almost perfect (kappa = 0.93) for Leptospira borgpetersenii serovar Hardjo subtype Hardjobovis (Hardjobovis) but moderate (kappa = 0.53) for Leptospira interrogans serovar Pomona (Pomona). Among animals that had different titers recorded, higher Hardjobovis and lower Pomona titers were reported by the commercial laboratory than by the research laboratory (P < 0.005). These interlaboratory comparisons can assist researchers and diagnosticians in interpreting the sometimes discrepant test results. Within the research laboratory, the comparison of qPCR results on urine and kidney showed almost perfect agreement (kappa = 0.84), suggesting that the qPCR on these 2 specimens can be used interchangeably. The agreement between MAT positivity and urine and kidney qPCR results was fair (kappa = 0.32 and kappa = 0.33, respectively). However, the prevalence ratio of urine and kidney qPCR positivity in Hardjobovis-seropositive versus Hardjobovis-seronegative sheep indicated that Hardjobovis seropositivity found in sheep may be able to predict shedding or renal carriage., (© 2014 The Author(s).)

A SYTO9 real-time polymerase chain reaction assay for detection of pathogenic Leptospira spp. based on amplification of DNA gyrase subunit B (gyrB) gene has been optimized and evaluated for sensitivity and specificity on kidney and urine samples of New Zealand farmed deer. The detection limit was 10(3) cells/ml (2-10 copies/reaction). Comparison of the assay on deer kidneys (n = 268) with culture as the gold standard revealed a sensitivity and specificity of 85% and 99.2%, respectively. For deer urine (n = 113), the assay was compared with known inoculated samples and revealed a sensitivity and specificity of 96.7% and 100%, respectively. The assay was applied for quantifying pathogenic leptospires shed naturally in deer urine and revealed a detectable concentration of 3.7 × 10(3) to 1.7 × 10(6) cells/ml. To assess the assay's capability for identifying pathogenic Leptospira spp., 14 field isolates of L. borgpetersenii serovar Hardjo-bovis and L. interrogans serovar Pomona were amplified for polymerase chain reaction (PCR) product, purified, and sequenced. When compared with the National Center for Biotechnology Information database, sequence data matched with L. borgpetersenii serovar Hardjo-bovis in 13 samples and L. interrogans serovar Pomona in 1 sample, which was consistent with the microscopic agglutination test (MAT). Sequence analysis of purified PCR product amplified directly from kidney and urine samples also yielded serovar-comparable MAT results. Results suggest that the assay is rapid, sensitive, and specific for detection of pathogenic leptospires in deer clinical samples. The developed assay can also be used for estimating the concentration of leptospires and identifying Leptospira spp. in combination with DNA sequencing.

This study estimated the frequency of exposure of meat workers to carcasses infected with Leptospira serovars Hardjobovis or Pomona in a sheep-only abattoir in New Zealand. A stochastic spreadsheet model was developed to assess the daily risk of exposure of eviscerators, meat inspectors and offal handlers to live leptospires in sheep carcasses from May to November 2004 (high-risk period), and from December 2004 to June 2005 (low-risk period). The average sheep processed per day were 225 for an eviscerator, 374 for a meat inspector, and 1123 for an offal handler. The median daily exposures during high- and low-risk periods were 11 [95% distribution interval (DI) 5-19] and three (95% DI 1-8) infected carcasses/day for eviscerators, 18 (95% DI 9-29) and six (95% DI 2-12) for meat inspectors, and 54 (95% DI 32-83) and 18 (95% DI 8-31) for offal handlers, respectively. Stochastic risk modelling provided evidence that processing of sheep carcasses exposed meat workers regularly to live leptospires with substantial seasonal variation.

The epidemiology of human campylobacteriosis is complex but in recent years understanding of this disease has advanced considerably. Despite being a major public health concern in many countries, the presence of multiple hosts, genotypes and transmission pathways has made it difficult to identify and quantify the determinants of human infection and disease. This has delayed the development of successful intervention programmes for this disease in many countries including New Zealand, a country with a comparatively high, yet until recently poorly understood, rate of notified disease. This study investigated the epidemiology of Campylobacter jejuni at the genotype-level over a 3-year period between 2005 and 2008 using multilocus sequence typing. By combining epidemiological surveillance and population genetics, a dominant, internationally rare strain of C. jejuni (ST474) was identified, and most human cases (65.7%) were found to be caused by only seven different genotypes. Source association of genotypes was used to identify risk factors at the genotype-level through multivariable logistic regression and a spatial model. Poultry-associated cases were more likely to be found in urban areas compared to rural areas. In particular young children in rural areas had a higher risk of infection with ruminant strains than their urban counterparts. These findings provide important information for the implementation of pathway-specific control strategies.

In New Zealand the number of campylobacteriosis notifications increased markedly between 2000 and 2007. Notably, this country's poultry supply is different than that of many developed countries as the fresh and frozen poultry available at retail are exclusively of domestic origin. To examine the possible link between human cases and poultry, a sentinel surveillance site was established to study the molecular epidemiology of Campylobacter jejuni over a 3-year period from 2005 to 2008 using multilocus sequence typing. Studies showed that 60.1 to 81.4% of retail poultry carcasses from the major suppliers were contaminated with C. jejuni. Differences were detected in the probability and level of contamination and the relative frequency of genotypes for individual poultry suppliers and humans. Some carcasses were contaminated with isolates belonging to more than one sequence type (ST), and there was evidence of both ubiquitous and supplier-associated strains, an epidemiological pattern not recognized yet in other countries. The common poultry STs were also common in human clinical cases, providing evidence that poultry is a major contributor to human infection. Both internationally rare genotypes, such as ST-3069 and ST-474, and common genotypes, such as ST-45 and ST-48, were identified in this study. The dominant human sequence type in New Zealand, ST-474, was found almost exclusively in isolates from one poultry supplier, which provided evidence that C. jejuni has a distinctive molecular epidemiology in this country. These results may be due in part to New Zealand's geographical isolation and its uniquely structured poultry industry.

Campylobacter jejuni is widely distributed in the environment, and river water has been shown to carry high levels of the organism. In this study, 244 C. jejuni isolates from three river catchment areas in New Zealand were characterized using multilocus sequence typing. Forty-nine of the 88 sequence types identified were new. The most common sequence types identified were ST-2381 (30 isolates), ST-45 (25 isolates), and ST-1225 (23 isolates). The majority of the sequence types identified in the river water could be attributed to wild bird fecal contamination. Two novel clonal complexes (CC) were identified, namely, CC ST-2381 (11 sequence types, 46 isolates) and CC ST-3640 (6 sequence types, 12 isolates), in which all of the sequence types were new. CC ST-2381 was the largest complex identified among the isolates and was present in two of the three rivers. None of the sequence types associated with the novel complexes has been identified among human isolates. The ST-2381 complex is not related to complexes associated with cattle, sheep, or poultry. The source of the novel complexes has yet to be identified.

The size and distribution of histological lesions was studied in 14 cases of avian pseudotuberculosis using a combination of serotype-specific immunohistochemistry and image analysis. The material was derived from recent and archival cases in six canaries (Serinus canaria), two zebra finches (Poephila guttata), three psittaciformes (a kaka, Nestor meriondalis, one rainbow lorikeet, Trichoglossus mollucanus, and one budgerigar, Melopsittacus undulatus), and three New Zealand wood pigeons (Hemiphaga novaeseelandiae). The disease observed in the passerine species appeared to have an acute clinical course and the bacterial lesions were predominately enteric. In the pigeons and the psittaciformes examined, the clinical course of the disease was more chronic in nature and involved the liver and spleen. A correlation was found between the amount of stainable iron in the liver of affected birds and the area of bacterial lesions. All of the 11 strains of Yersinia pseudotuberculosis isolated from fresh necropsy material were serotype II, as determined using a standard serum agglutination test. Immunohistochemistry indicated the presence of antigen(s) common to serotype II in histological material from confirmed cases and in another three cases where the organism had been cultured but the serotype not specified. The in vitro virulence characteristics and plasmid profiles of Y. pseudotuberculosis isolates were also determined.