The identification of a new Giardia duodenalis assemblage in marine vertebrates and a preliminary analysis of G. duodenalis population biology in marine systems

Giardia duodenalis is an intestinal parasite of many vertebrates. The presence of G. duodenalis in the marine environment due to anthropogenic and wildlife activity is well documented, including the contributions from untreated sewage and storm water, agricultural run-off and droppings from terrestrial animals. Recently, studies have detected this protistan parasite in the faeces of marine vertebrates such as whales, dolphins, seals and shore birds. To explore the population biology of G. duodenalis in marine life, we determined the prevalence of G. duodenalis in two species of seal (Halichoerus grypus, Phoca vitulina vitulina and Phoca vitulina richardsi) from the east and west coasts of the USA, sequenced two loci from G. duodenalis-positive samples to assess molecular diversity and examined G. duodenalis distribution amongst these seals and other marine vertebrates along the east coast. We found a significant difference in the presence of G. duodenalis between east and west coast seal species. Only the zoonotic lineages of G. duodenalis, Assemblages A and B and a novel lineage, which we designated as Assemblage H, were identified in marine vertebrates. Assemblages A and B are broadly distributed geographically and show a lack of host specificity. Only grey seal (Halichoerus grypus) samples and one gull sample (Larus argentatus) from a northern location of Cape Cod, Massachusetts, USA, showed the presence of Assemblage H haplotypes; only one other study of harbour seals from the Puget Sound region of Washington, USA previously recorded the presence of an Assemblage H haplotype. Assemblage H sequences form a monophyletic clade that appears as divergent from the other seven Assemblages of G. duodenalis as these assemblages are from each other. The discovery of a previously uncharacterised lineage of G. duodenalis suggests that this parasite has more genetic diversity and perhaps a larger host range than previously believed.     

Identification of a novel Assemblage B subgenotype and a zoonotic Assemblage C in human isolates of Giardia intestinalis in Egypt

Giardia intestinalis (G. intestinalis) is a flagellate parasite which has been considered the most common protozoan infecting human. Molecular techniques are of great value in studying the taxonomy, the zoonotic potential of animal isolates and the correlation between the genetic variability of the parasite and the range of clinical symptoms observed in humans. The present work aims at genotyping G. intestinalis isolates from Egypt using molecular techniques. PCR targeting the β-giardin locus, RFLP and sequencing were applied to 12 microscopically positive and 3 microscopically negative samples (which were positive by real time PCR targeting SSUr DNA). Two other loci, triose phosphate isomerase (TPI) gene and glutamate dehydrogenase (GDH) gene PCR and RFLP were also applied to all study isolates. The most frequent genotype was Assemblage B (13 out of 15), while Assemblage A and C were present in one sample each. This is the first report on zoonotic transmission of Assemblage C (dog genotype) to human in Egypt. Sequencing of the Assemblage B isolates revealed new subgenotypes with consistent mutations at specific positions, some of which were not characterized previously. The results shed light on the possibility that G. intestinalis can infect humans through a zoonotic route and open the door to wider investigations using different genetic loci to genotype Giardia isolates.     

Marine vertebrate zoonoses: an overview of the DAO special issue

The role of marine birds, mammals, turtles and fish as vectors of infectious agents of potential risk to humans can be examined from a variety of perspectives. The studies in this DAO Special include a broad survey of multiple agents and species, a sequencing study of Giardia intestinalis haplotypes known to be pathogenic to humans, an assessment of risks to humans working with marine mammals, a source tracking study using E. coli ribotypes, studies of regional Salmonella and Brucella epizootiology, a serology survey and a case report of a herpes simplex infection in a dolphin. Additionally, a recently published study (Venn-Watson et al. 2008; Dis Aquat Org 79:87-93) classifying pure cultures of bacteria from a captive dolphin colony also pertains to this theme. These studies raise the following questions: whether the presence of zoonotic agents in marine vertebrates represents a risk to other marine vertebrates, humans, or both; what are the routes by which these marine vertebrate zoonotic infections are acquired and circulated in the marine ecosystem; to what degree are such agents subclinical versus causes of overt disease in marine vertebrates; what are the subsets of the human population most likely to be affected by such infections; and which human health preventive measures would seem reasonable?     

Detection of Giardia intestinalis assemblages A, B and D in domestic cats from Warsaw, Poland

Giardia intestinalis is a complex species divided into 7 assemblages (A - G). Two of them (A and B) are infective for both humans and animals. In cats four assemblages can occur: A, B, D, and F Assemblages A and B infect either cats, dogs and humans, assemblage D infects cats and dogs and assemblage F only cats. The purpose of this study was to determine the prevalence and genotypes of G. intestinalis in cats from Warsaw. From November 2006 to March 2007 a hundred sixty samples of stool were collected and examined by light microscopy. G. intestinalis cysts were detected in 3.75% of samples. DNA extracted from positive samples was used as template for PCR-RFLP using Giardia specific primers and the amplicons were sequenced. A comparison of the obtained DNA sequences with the Giardia sequences in the GeneBank database revealed assemblage A in 1.25% of the investigated cats, assemblage B in 1.25% and D in 1.25%.     

Identification of Zoonotic Genotypes of Giardia duodenalis

Giardia duodenalis, originally regarded as a commensal organism, is the etiologic agent of giardiasis, a gastrointestinal disease of humans and animals. Giardiasis causes major public and veterinary health concerns worldwide. Transmission is either direct, through the faecal-oral route, or indirect, through ingestion of contaminated water or food. Genetic characterization of G. duodenalis isolates has revealed the existence of seven groups (assemblages A to G) which differ in their host distribution. Assemblages A and B are found in humans and in many other mammals, but the role of animals in the epidemiology of human infection is still unclear, despite the fact that the zoonotic potential of Giardia was recognised by the WHO some 30 years ago. Here, we performed an extensive genetic characterization of 978 human and 1440 animal isolates, which together comprise 3886 sequences from 4 genetic loci. The data were assembled into a molecular epidemiological database developed by a European network of public and veterinary health Institutions. Genotyping was performed at different levels of resolution (single and multiple loci on the same dataset). The zoonotic potential of both assemblages A and B is evident when studied at the level of assemblages, sub-assemblages, and even at each single locus. However, when genotypes are defined using a multi-locus sequence typing scheme, only 2 multi-locus genotypes (MLG) of assemblage A and none of assemblage B appear to have a zoonotic potential. Surprisingly, mixtures of genotypes in individual isolates were repeatedly observed. Possible explanations are the uptake of genetically different Giardia cysts by a host, or subsequent infection of an already infected host, likely without overt symptoms, with a different Giardia species, which may cause disease. Other explanations for mixed genotypes, particularly for assemblage B, are substantial allelic sequence heterogeneity and/or genetic recombination. Although the zoonotic potential of G. duodenalis is evident, evidence on the contribution and frequency is (still) lacking. This newly developed molecular database has the potential to tackle intricate epidemiological questions concerning protozoan diseases.     

Giardia duodenalis and Cryptosporidium spp. in the intestinal contents of ringed seals (Phoca hispida) and bearded seals (Erignathus barbatus) in Nunavik, Quebec, Canada

The prevalence of Giardia duodenalis and Cryptosporidium spp. was determined for ringed and bearded seals harvested for food in the Nunavik region in northern Quebec, Canada. Flow cytometric results demonstrated that G. duodenalis was present in the intestinal contents of 80% of the ringed seals and 75% of the bearded seals tested, while Cryptosporidium spp. were present in 9% of the ringed seals and none of the bearded seals. Prevalence of both parasites was highest in animals less than 1 yr of age. Giardia sp. isolates from ringed seals were identified as G. duodenalis Assemblage B, which is commonly identified in human infections. The high prevalence of G. duodenalis in ringed seals, and the presence of Assemblage B in these animals, highlights the potential for zoonotic transmission to the Inuit people, who consume dried seal intestines and uncooked seal meat.     

Zoonotic potential of Giardia

Giardia duodenalis (syn. Giardia lamblia and Giardia intestinalis) is a common intestinal parasite of humans and mammals worldwide. Assessing the zoonotic transmission of the infection requires molecular characterization as there is considerable genetic variation within G. duodenalis. To date eight major genetic groups (assemblages) have been identified, two of which (A and B) are found in both humans and animals, whereas the remaining six (C to H) are host-specific and do not infect humans. Sequence-based surveys of single loci have identified a number of genetic variants (genotypes) within assemblages A and B in animal species, some of which may have zoonotic potential. Multi-locus typing data, however, has shown that in most cases, animals do not share identical multi-locus types with humans. Furthermore, interpretation of genotyping data is complicated by the presence of multiple alleles that generate “double peaks” in sequencing files from PCR products, and by the potential exchange of genetic material among isolates, which may account for the non-concordance in the assignment of isolates to specific assemblages. Therefore, a better understanding of the genetics of this parasite is required to allow the design of more sensitive and variable subtyping tools, that in turn may help unravel the complex epidemiology of this infection.     

Genetic heterogeneity at the beta-giardin locus among human and animal isolates of Giardiaduodenalis and identification of potentially zoonotic subgenotypes

Human giardiasis, caused by the intestinal flagellate Giardia duodenalis, is considered a zoonotic infection, although the role of animals in the transmission to humans is still unclear. Molecular characterisation of cysts of human and animal origin represents an objective means to validate or reject this hypothesis. In the present work, cysts were collected in Italy from humans (n=37) and animals (dogs, one cat and calves, n=46), and were characterised by PCR amplification and sequencing of the beta-giardin gene. As expected, only Assemblages A and B were identified among human isolates. The host-specific Assemblages C and D were found in the majority of dog isolates; however, 6 dog isolates were typed as Assemblage A. The cat-specific Assemblage F has been identified in the single feline isolate available. Among calf isolates, most were typed as Assemblages A (n=12) and B (n=5), whereas the host-specific Assemblage E was rarely found (n=3). Sequence heterogeneity in the beta-giardin gene allowed a number of subgenotypes to be identified within Assemblage A (8 subgenotypes), B (6 subgenotypes), D (2 subgenotypes), and E (3 subgenotypes). Five of these subgenotypes, namely A1, A2, A3, A4 and B3, were found to be associated with infections of humans, of dogs and of calves; these data, therefore, supported the role of these animals as a source of infection for humans.     

Prevalence,Environmental Loading,and Molecular Characterization of Cryptosporidium and Giardia Isolates from Domestic and Wild Animals along the Central California Coast

The risk of disease transmission from waterborne protozoa is often dependent on the origin (e.g., domestic animals versus wildlife), overall parasite load in contaminated waterways, and parasite genotype, with infections being linked to runoff or direct deposition of domestic animal and wildlife feces. Fecal samples collected from domestic animals and wildlife along the central California coast were screened to (i) compare the prevalence and associated risk factors for fecal shedding of Cryptosporidium and Giardia species parasites, (ii) evaluate the relative importance of animal host groups that contribute to pathogen loading in coastal ecosystems, and (iii) characterize zoonotic and host-specific genotypes. Overall, 6% of fecal samples tested during 2007 to 2010 were positive for Cryptosporidium oocysts and 15% were positive for Giardia cysts. Animal host group and age class were significantly associated with detection of Cryptosporidium and Giardia parasites in animal feces. Fecal loading analysis revealed that infected beef cattle potentially contribute the greatest parasite load relative to other host groups, followed by wild canids. Beef cattle, however, shed host-specific, minimally zoonotic Cryptosporidium and Giardia duodenalis genotypes, whereas wild canids shed potentially zoonotic genotypes, including G. duodenalis assemblages A and B. Given that the parasite genotypes detected in cattle were not zoonotic, the public health risk posed by protozoan parasite shedding in cattle feces may be lower than that posed by other animals, such as wild canids, that routinely shed zoonotic genotypes.     

It’s a wormy world: Meta‐analysis reveals several decades of change in the global abundance of the parasitic nematodes Anisakis spp. and Pseudoterranova spp. in marine fishes and invertebrates

The Anthropocene has brought substantial change to ocean ecosystems, but whether this age will bring more or less marine disease is unknown. In recent years, the accelerating tempo of epizootic and zoonotic disease events has made it seem as if disease is on the rise. Is this apparent increase in disease due to increased observation and sampling effort, or to an actual rise in the abundance of parasites and pathogens? We examined the literature to track long‐term change in the abundance of two parasitic nematode genera with zoonotic potential: Anisakis spp. and Pseudoterranova spp. These anisakid nematodes cause the disease anisakidosis and are transmitted to humans in undercooked and raw marine seafood. A total of 123 papers published between 1967 and 2017 met our criteria for inclusion, from which we extracted 755 host–parasite–location–year combinations. Of these, 69.7% concerned Anisakis spp. and 30.3% focused on Pseudoterranova spp. Meta‐regression revealed an increase in Anisakis spp. abundance (average number of worms/fish) over a 53 year period from 1962 to 2015 and no significant change in Pseudoterranova spp. abundance over a 37 year period from 1978 to 2015. Standardizing changes to the period of 1978–2015, so that results are comparable between genera, we detected a significant 283‐fold increase in Anisakis spp. abundance and no change in the abundance of Pseudoterranova spp. This increase in Anisakis spp. abundance may have implications for human health, marine mammal health, and fisheries profitability.     

Zoonotic genotype of Giardia intestinalis detected in a ferret

Giardia intestinalis has been found in a variety of mammals, including humans, and consists of host-specific and zoonotic genotypes. There has been only 1 study of G. intestinalis infection in weasels, but the genotype of its isolate remains unclear. In this study, we report the isolation of Giardia in a ferret exhibited at a pet shop. The isolate was analyzed genetically to validate the possibility of zoonotic transmission. Giardia diagnostic fragments of the small subunit ribosomal RNA, beta-giardin, and glutamate dehydrogenase genes were amplified from the ferret isolate and sequenced to reveal the phylogenetic relationships between it and other Giardia species or genotypes of G. intestinalis reported previously. The results showed that the ferret isolate represented the genetic group A-I in assemblage A, which could be a causative agent of human giardiasis.     

The mitochondrial genome of Toxocara canis

Toxocara canis (Ascaridida: Nematoda), which parasitizes (at the adult stage) the small intestine of canids, can be transmitted to a range of other mammals, including humans, and can cause the disease toxocariasis. Despite its significance as a pathogen, the genetics, epidemiology and biology of this parasite remain poorly understood. In addition, the zoonotic potential of related species of Toxocara, such as T. cati and T. malaysiensis, is not well known. Mitochondrial DNA is known to provide genetic markers for investigations in these areas, but complete mitochondrial genomic data have been lacking for T. canis and its congeners. In the present study, the mitochondrial genome of T. canis was amplified by long-range polymerase chain reaction (long PCR) and sequenced using a primer-walking strategy. This circular mitochondrial genome was 14162 bp and contained 12 protein-coding, 22 transfer RNA, and 2 ribosomal RNA genes consistent for secementean nematodes, including Ascaris suum and Anisakis simplex (Ascaridida). The mitochondrial genome of T. canis provides genetic markers for studies into the systematics, population genetics and epidemiology of this zoonotic parasite and its congeners. Such markers can now be used in prospecting for cryptic species and for exploring host specificity and zoonotic potential, thus underpinning the prevention and control of toxocariasis in humans and other hosts.     

The EG95 Antigen of Echinococcus spp. Contains Positively Selected Amino Acids,which May Influence Host Specificity and Vaccine Efficacy

Echinococcosis is a worldwide zoonotic parasitic disease of humans and various herbivorous domestic animals (intermediate hosts) transmitted by the contact with wild and domestic carnivores (definitive hosts), mainly foxes and dogs. Recently, a vaccine was developed showing high levels of protection against one parasite haplotype (G1) of Echinococcus granulosus, and its potential efficacy against distinct parasite variants or species is still unclear. Interestingly, the EG95 vaccine antigen is a secreted glycosylphosphatydilinositol (GPI)-anchored protein containing a fibronectin type III domain, which is ubiquitous in modular proteins involved in cell adhesion. EG95 is highly expressed in oncospheres, the parasite life cycle stage which actively invades the intermediate hosts. After amplifying and sequencing the complete CDS of 57 Echinococcus isolates belonging to 7 distinct species, we uncovered a large amount of genetic variability, which may influence protein folding. Two positively selected sites are outside the vaccine epitopes, but are predicted to alter protein conformation. Moreover, phylogenetic analyses indicate that EG95 isoform evolution is convergent with regard to the number of beta-sheets and alpha-helices. We conclude that having a variety of EG95 isoforms is adaptive for Echinococcus parasites, in terms of their ability to invade different hosts, and we propose that a mixture of isoforms could possibly maximize vaccine efficacy.     

Prevalence of Cryptosporidium spp. and Giardia spp. in five marine mammal species

Cryptosporidium spp. and Giardia spp. are protozoan parasites that are often associated with severe diarrheal disease in a variety of mammals. Although these parasites have been extensively studied in terrestrial ecosystems, little is known about either parasite in the marine environment. Therefore, the objective of this study was to determine the prevalence of both Cryptosporidium spp. and Giardia spp. in 5 marine mammal species. Fecal samples were collected from 39 bowhead whales (Balaena mysticetus), 49 North Atlantic right whales (Eubalaena glacialis), 31 ringed seals (Phoca hispida), 22 bearded seals (Erignathus barbatus), and 18 beluga whales (Delphinapterus leucas) between 1998 and 2003. Using an immunofluorescent assay, parasites were detected in the feces of bowhead whales, right whales, and ringed seals, while neither parasite was detected in samples from bearded seals or beluga whales. Overall, prevalences were highest in ringed seals (Cryptosporidium spp., 22.6%; Giardia spp., 64.5%) and right whales (Cryptosporidium spp., 24.5%; Giardia spp., 71.4%) and lowest in bowhead whales (Cryptosporidium spp., 5.1%; Giardia spp., 33.3%). To our knowledge, this is the first report of Cryptosporidium spp. and Giardia spp. in either whale species and of Cryptosporidium spp. in the ringed seal.     

Goats in the city: prevalence of <Emphasis Type="Italic">Giardia duodenalis</Emphasis> and <Emphasis Type="Italic">Cryptosporidium</Emphasis> spp. in extensively reared goats in northern India

Background

Various characteristics of goats mean they are highly suitable livestock for backyard rearing by people with limited resources. They are a popular livestock choice in India, where they are often kept to supplement an already scarce income. In these settings, hygiene and sanitation standards tend to be low, and weakens the interface between humans and animals, thus reducing the barrier between them and thereby increasing the likelihood that zoonotic and anthroponotic infections will occur.

Results

This study reports an investigation of the occurrence of Cryptosporidium spp. and Giardia duodenalis in goats being reared in different settings in urban and peri-urban areas in northern India, and addressed the zoonotic potential of these important protozoan parasites shed from goats living close to humans. The overall prevalence of G. duodenalis was 33.8 and 0.5% for Cryptosporidium spp.; the relatively low prevalence of cryptosporidiosis may reflect that most samples were derived from adult animals. The prevalence of G. duodenalis excretion was found to be similar to that reported in other studies. However, although other studies have reported a predominance of non-zoonotic Assemblage E in goats, in this study potentially zoonotic Assemblages predominated [Assemblage A (36%) and Assemblage B (32%)].

Conclusions

The results of this study indicate that in this area where goats and humans are living in close proximity, there may be sharing of intestinal parasites, which can be detrimental for both host species.

     

Anticoagulants in vector arthropods

Arthropod-borne diseases cause significant morbidity and mortality worldwide. Mosquitoes alone may account for as many as three million deaths annually via the transmission of malaria. Because these diseases are transmitted to humans and to other vertebrates as a result of the ability of arthropods to feed on blood, the study of the biochemical mechanisms and adaptations that arthropods have evolved to facilitate hematophagy may provide insight into how this feeding behavior contributes to the transmission of disease. In this review, Kenneth Stark and Anthony James examine the diversity of arthropod anticoagulants and their role in hematophagy and potential implications for parasite transmission.     

Coxiella burnetii infection of marine mammals in the Pacific Northwest, 1997-2010

Q fever is a zoonotic disease caused by the bacterium Coxiella burnetii. Humans are commonly exposed via inhalation of aerosolized bacteria derived from the waste products of domesticated sheep and goats, and particularly from products generated during parturition. However, many other species can be infected with C. burnetii, and the host range and full zoonotic potential of C. burnetii is unknown. Two cases of C. burnetii infection in marine mammal placenta have been reported, but it is not known if this infection is common in marine mammals. To address this issue, placenta samples were collected from Pacific harbor seals (Phoca vitulina richardsi), harbor porpoises (Phocoena phocoena), and Steller sea lions (Eumetopias jubatus). Coxiella burnetii was detected by polymerase chain reaction (PCR) in the placentas of Pacific harbor seals (17/27), harbor porpoises (2/6), and Steller sea lions (1/2) collected in the Pacific Northwest. A serosurvey of 215 Pacific harbor seals sampled in inland and outer coastal areas of the Pacific Northwest showed that 34.0% (73/215) had antibodies against either Phase 1 or Phase 2 C. burnetii. These results suggest that C. burnetii infection is common among marine mammals in this region.     

Parasites of free-ranging black howler monkeys (Alouatta pigra) from Belize and Mexico

Parasites are important members of the ecological web within which an animal lives, and can be used as indicators of ecosystem health. However, few baseline parasitological data are available for free-ranging animals, particularly for the black howler monkey (Alouatta pigra). In this study a total of 283 fecal samples were collected from 50 individually identified A. pigra during 2003 and 2004 and examined for parasites. The samples were processed using standard quantitative centrifugation concentration techniques, with sugar and zinc sulfate used as flotation media. The slides were examined using bright-field and phase microscopy. Antigen capture enzyme-linked immunosorbent assays (ELISAs) were used to detect protozoa. Four parasites were detected: 1) Controrchis biliophilus (Dicrocoeliidae), 2) Trypanoxyuris minutus (Oxyuridae), 3) Giardia sp. (Hexamitidae), and 4) Entamoeba sp. (Endamoebidae). Controrchis biliophilus was detected in 80% (wet season) and 81% (dry season) of the A. pigra samples; Trypanoxyuris minutus was detected in 8% (wet season) and 27% (dry season) of samples; and Giardia sp. was detected in 40% (wet season) and 27% (dry season) of samples. For the first time, DNA from Giardia sp.-positive fecal samples was extracted from A. pigra. Alouatta pigra individuals that lived near human settlements in Belize were infected with Giardia duodenalis (syn. G. lamblia, G. intestinalis) Assemblages A and B. These results suggest that G. duodenalis is transmitted from people and/or domestic animals to A. pigra.     

Navigating parasite webs and parasite flow: emerging and re-emerging parasitic zoonoses of wildlife origin

Wildlife are now recognised as an important source of emerging human pathogens, including parasites. This paper discusses the linkages between wildlife, people, zoonotic parasites and the ecosystems in which they co-exist, revisits definitions for 'emerging' and 're-emerging', and lists zoonotic parasites that can be acquired from wildlife including, for some, estimates of the associated global human health burdens. The paper also introduces the concepts of 'parasite webs' and 'parasite flow', provides a context for parasites, relative to other infectious agents, as causes of emerging human disease, and discusses drivers of disease emergence and re-emergence, especially changes in biodiversity and climate. Angiostrongylus cantonensis in the Caribbean and the southern United States, Baylisascaris procyonis in California and Georgia, Plasmodium knowlesi in Sarawak, Malaysia, Human African Trypanosomiasis, Sarcoptes scabiei in carnivores, and Cryptosporidium, Giardia and Toxoplasma in marine ecosystems are presented as examples of wildlife-derived zoonotic parasites of particular recent interest. An ecological approach to disease is promoted, as is a need for an increased profile for this approach in undergraduate and graduate education in the health sciences. Synergy among scientists and disciplines is identified as critical for the study of parasites and parasitic disease in wildlife populations. Recent advances in techniques for the investigation of parasite fauna of wildlife are presented and monitoring and surveillance systems for wildlife disease are discussed. Some of the limitations inherent in predictions for the emergence and re-emergence of infection and disease associated with zoonotic parasites of wildlife are identified. The importance of public awareness and public education in the prevention and control of emerging and re-emerging zoonotic infection and disease are emphasised. Finally, some thoughts for the future are presented.     

Zoonoses of occupational health importance in contemporary laboratory animal research

In contemporary laboratory animal facilities, workplace exposure to zoonotic pathogens, agents transmitted to humans from vertebrate animals or their tissues, is an occupational hazard. The primary (e.g., macaques, pigs, dogs, rabbits, mice, and rats) and secondary species (e.g., sheep, goats, cats, ferrets, and pigeons) of animals commonly used in biomedical research, as classified by the American College of Laboratory Animal Medicine, are established or potential hosts for a large number of zoonotic agents. Diseases included in this review are principally those wherein a risk to biomedical facility personnel has been documented by published reports of human cases in laboratory animal research settings, or under reasonably similar circumstances. Diseases are listed alphabetically, and each section includes information about clinical disease, transmission, occurrence, and prevention in animal reservoir species and humans. Our goal is to provide a resource for veterinarians, health-care professionals, technical staff, and administrators that will assist in the design and on-going evaluation of institutional occupational health and safety programs.