Outbreak of human trichinellosis in Northern California caused by Trichinella murrelli

From wildlife to humans: The global distribution of Trichinella species and genotypes in wildlife and wildlife-associated human trichinellosis

Zoonotic nematodes of the genus Trichinella are foodborne parasites that have a global distribution in wild carnivores and omnivores, with spillover and spillback into domestic livestock and people, with concomitant trade and health consequences. Historically, most human cases were linked to domestic pigs infected with Trichinella spiralis, but under current high biosecurity swine production in many countries, wildlife have become a more important source of human trichinellosis. The aim of this review is to update the global distribution of Trichinella species and genotypes reported in wildlife, as well as reported human outbreaks from the consumption of wildlife. Using several online databases and by "snowballing" references, hundreds of reports of Trichinella spp. in wildlife published between January 1991 and December 2023 provide an important update to the host and geographic range for each of the recognized 13 species/genotypes, grouped by continent. Surveillance effort was highest in Europe and North America, while Africa, Asia, Central and South America have had limited surveillance, in some instances with human cases serving as sentinels of transmission in a region. Dozens of human outbreaks are described, with wild boars (Sus scrofa) being the most frequently implicated wildlife species in human outbreaks globally. Bears are an important source of infection in North America, for wildlife tourism, and importation of bear meat has also been implicated in multicountry outbreaks. The largest study limitation was the dearth of molecular identification of larvae in both wildlife surveillance studies and human outbreaks, particulary in under-studied regions. We highlight the need for enhanced molecular epidemiological approaches to outbreaks of this important foodborne parasite, and emphasize the need for a One Health approach to manage Trichinella spp. which transmit among terrestrial and marine wildlife (including migratory birds), pigs, horses, and people, often across large geographic scales and borders.

Outbreak of Human Trichinellosis - Arizona, Minnesota, and South Dakota, 2022

Trichinellosis is a parasitic zoonotic disease transmitted through the consumption of meat from animals infected with Trichinella spp. nematodes. In North America, human trichinellosis is rare and is most commonly acquired through consumption of wild game meat. In July 2022, a hospitalized patient with suspected trichinellosis was reported to the Minnesota Department of Health. One week before symptom onset, the patient and eight other persons shared a meal that included bear meat that had been frozen for 45 days before being grilled and served rare with vegetables that had been cooked with the meat. Investigation identified six trichinellosis cases, including two in persons who consumed only the vegetables. Motile Trichinella larvae were found in remaining bear meat that had been frozen for >15 weeks. Molecular testing identified larvae from the bear meat as Trichinella nativa, a freeze-resistant species. Persons who consume meat from wild game animals should be aware that that adequate cooking is the only reliable way to kill Trichinella parasites and that infected meat can cross-contaminate other foods.

The challenge of diagnosing and classifying eosinophilia and eosinophil disorders: A review

Eosinophilia is a feature of multiple conditions, both hematologic and non-hematologic, and may be associated with organ damage. The pathogenesis of eosinophilia can follow two distinct pathways. Primary eosinophilia is caused by a cell-intrinsic mechanism originating from clonal expansion of eosinophils through acquisition of a somatic mutation, such as FIP1L1-PDGFRA. In recent years, great progress has been made in the field of pathogenesis and molecularly targeted therapy of neoplastic eosinophilia. The diagnostic procedure should include, among other things, morphologic analysis of blood and bone marrow samples, cytogenetics and fluorescence in situ-hybridization tests to detect evidence of an acute or chronic myeloid or lymphoid disorder. Secondary eosinophilia follows a cell-extrinsic mechanism as a response to exogenous cytokines. In most clinical cases, peripheral blood eosinophilia is reactive and typically associated with non-hematological disorders such as infections, allergic conditions, connective tissue disorders, vasculitis, malignancy, or endocrinopathies. Nonetheless, the cause of most cases of hypereosinophilic syndrome remains unknown. In this article, we present a short review focused on differential diagnosis of eosinophilia and eosinophilic disorders. The diagnosis of eosinophilia is a challenge for physicians; thus this review may be useful in clinical practice.

Trichinellosis dissemination among wild carnivores in the Republic of Kazakhstan: A 10-year study

Background and Aim

Trichinellosis is caused by a species of roundworm called Trichinella and is an invasive disease causing severe medical, veterinary, and socioeconomic problems worldwide. More than 100 mammalian species are Trichinella hosts. Among domestic animals, pigs and dogs are prone to trichinellosis. An essential aspect of controlling the spread of infection is to identify the number and level of infections in wild carnivores in the country. However, the number, habitats, and movements of wild animal Trichinella hosts in Kazakhstan have not been reported yet. This study aimed to monitor the wild animal habitat nearby the settlements for tracking the trichinellosis speading among carnivores.

Materials and Methods

Wild carnivorous animals were captured in seven regions of the Republic of Kazakhstan. The carcasses of corsacs, wolves, foxes, wild boars, and badgers were studied. Muscle tissue samples from spontaneously infected wild animals were collected. The digestion method in "GASTROS-2M" was used to isolate Trichinella spp. from animal muscles. The species of the parasite was determined by a polymerase chain reaction for 5S spacer of Trichinella ribosomal DNA with subsequent sequencing by Senger. Statistical analysis methods were performed for average value in Microsoft Excel 2010.

Results

The results of the research showed that among 155 animals wolves (20.4%) and foxes (26.7%) were the most infected with invasive Trichinella larvae. The invasion intensity was 503.6% in foxes and 289.7% in wolves. However, badgers (164%), wild boars (0%), and corsacs (0%) presented lower invasion levels. Using specific primers, larvae samples were identified as Trichinella nativa.

Conclusion

The results of monitoring revealed the spread of trichinosis among wild animals: wolves, foxes, badgers. The Karaganda, Kostanay, Western Kazakhstan, and Akmola regions had the largest distribution of wild animals infected with trichinellosis. In total, 20% of the 155 studied animals were infected. The greatest invasion intensity was typical for wolves, foxes and badgers. It is necessary to monitor the spread of trichinellosis among wild carnivores to control the epidemiological situation and reduce the level of spontaneous infection among animals. Regular monitoring of habitats and carnivores must be conducted within the country and in the border areas.

Regulatory effects of Trichinella spiralis and a serine protease inhibitor on the endoplasmic reticulum stress response of intestinal epithelial cells

The accumulation of unfolded or misfolded proteins in the endoplasmic reticulum can cause an endoplasmic reticulum stress (ERS) response. If ERS continues or cannot be alleviated, it will cause the production of proapoptotic factors and eventually lead to apoptosis. Therefore, this study mainly explored whether Trichinella spiralis Kazal-type serine protease inhibitor (TsKaSPI) contributed to the invasion of intestinal epithelial cells during the infectious stage of T. spiralis by regulating ERS. First, in the T. spiralis infection model, H&E staining was used to analyse the damage to jejunum tissue, a TUNEL assay was used to examine cell apoptosis, and the expression of ERS-related and apoptosis-related molecules was also measured. The results showed that ERS occurred during the intestinal phase of T. spiralis infection, while remission began during the cyclic phase. Then, we selected TsKaSPI, one of the important components of T. spiralis ES antigens, for in vitro experiments. The results showed that TsKaSPI could induce apoptosis in a porcine small intestinal epithelial cell line (IPEC cells) by activating ERS and promote activation of the NF-κB signalling pathway. Inhibition experiments confirmed that the occurrence of ERS was accompanied by the activation of NF-κB, and the two processes regulated each other. Finally, we conducted in vivo experiments and administered TsKaSPI to mice. The results confirmed that TsKaSPI could activate ERS and lead to apoptosis in intestinal epithelial cells. In conclusion, T. spiralis infection and TsKaSPI can promote cell apoptosis by activating the ERS response in intestinal epithelial cells and activate the NF-κB signalling pathway to promote the occurrence and development of inflammation.

An annotated checklist of the eukaryotic parasites of humans, exclusive of fungi and algae

The classification of "parasites" in the medical field is a challenging notion, a group which historically has included all eukaryotes exclusive of fungi that invade and derive resources from the human host. Since antiquity, humans have been identifying and documenting parasitic infections, and this collective catalog of parasitic agents has expanded considerably with technology. As our understanding of species boundaries and the use of molecular tools has evolved, so has our concept of the taxonomy of human parasites. Consequently, new species have been recognized while others have been relegated to synonyms. On the other hand, the decline of expertise in classical parasitology and limited curricula have led to a loss of awareness of many rarely encountered species. Here, we provide a comprehensive checklist of all reported eukaryotic organisms (excluding fungi and allied taxa) parasitizing humans resulting in 274 genus-group taxa and 848 species-group taxa. For each species, or genus where indicated, a concise summary of geographic distribution, natural hosts, route of transmission and site within human host, and vectored pathogens are presented. Ubiquitous, human-adapted species as well as very rare, incidental zoonotic organisms are discussed in this annotated checklist. We also provide a list of 79 excluded genera and species that have been previously reported as human parasites but are not believed to be true human parasites or represent misidentifications or taxonomic changes.

Detection of Trichinella murrelli and Trichinella pseudospiralis in bobcats (Lynx rufus) from Oklahoma

Trichinella spp. infect wild carnivores throughout the world. We determined the prevalence and mean infection intensity of Trichinella spp. in bobcats (Lynx rufus) from 41 counties in Oklahoma (USA). Tongues from 306 bobcats were examined using artificial tissue digestion. The prevalence (95% confidence interval) of Trichinella spp. was 5.9% (3.7%-9.2%) in which 18 of the 301 bobcats were infected. Bobcats infected with Trichinella spp. were detected in 10 of the 41 (24.4%; 13.7%-39.5%) counties sampled. Although variable, a statistically significant difference was not detected in the prevalence of Trichinella spp. among counties where bobcats were collected. The mean (standard deviation) and median (range) infection intensity of Trichinella sp. larvae were 30.9 (39.8) and 9.6 (0.6-119.9) larvae per gram of tissue examined. Genotyping results demonstrated that 17 bobcats were infected with T. murrelliand one bobcat was infected with T. pseudospiralis. This is the first report of T. pseudospiralis in bobcats and in Oklahoma. These data suggest the bobcat, as an obligate carnivore, is likely an important host in maintaining T. murrelli sylvatic cycles in Oklahoma.

Food Safety Considerations Related to the Consumption and Handling of Game Meat in North America

Emerging foodborne pathogens present a threat to public health. It is now recognized that several foodborne pathogens originate from wildlife as demonstrated by recent global disease outbreaks. Zoonotic spillover events are closely related to the ubiquity of parasitic, bacterial, and viral pathogens present within human and animal populations and their surrounding environment. Foodborne diseases have economic and international trade impacts, incentivizing effective wildlife disease management. In North America, there are no food safety standards for handling and consumption of free-ranging game meat. Game meat consumption continues to rise in North America; however, this growing practice could place recreational hunters and game meat consumers at increased risk of foodborne diseases. Recreational hunters should follow effective game meat food hygiene practices from harvest to storage and consumption. Here, we provide a synthesis review that evaluates the ecological and epidemiological drivers of foodborne disease risk in North American hunter populations that are associated with the harvest and consumption of terrestrial mammal game meat. We anticipate this work could serve as a foundation of preventive measures that mitigate foodborne disease transmission between free-ranging mammalian and human populations.

The Disease Ecology, Epidemiology, Clinical Manifestations, and Management of Trichinellosis Linked to Consumption of Wild Animal Meat

Historically, human trichinellosis was caused by Trichinella spiralis and transmitted to humans by consumption of undercooked domestic pork. Today, most cases of trichinellosis are caused by other Trichinella species and transmitted by consumption of raw or undercooked wild game meats. Given the increasing global prevalence of wild animal meat-linked trichinellosis, the objectives of this review are: 1) to describe the life cycle and global distribution of Trichinella worms; 2) to describe the changing epidemiology of trichinellosis; 3) to describe the clinical phases of trichinellosis; 4) to recommend the latest diagnostic tests; and 5) to recommend treatment and prevention strategies. Internet search engines were queried with keywords as subject headings to meet the objectives of this review. Although trichinellosis surveillance systems and laws regulating commercial pork production have limited T spiralis-caused trichinellosis in Europe and the United States, trichinellosis due to consumption of raw and undercooked wild boar and feral hog meat continues to occur throughout Southeast Asia. Trichinellosis due to consumption of raw or undercooked meats of other infected game, such as bear, deer, moose, and walrus, continues to occur worldwide. Only adherence to hygienic practices when preparing wild game meats and cooking wild game meats to recommended internal temperatures can prevent transmission of trichinellosis to humans. Wilderness medicine clinicians should be prepared to advise hunters and the public on the risks of game meat-linked trichinellosis and on how to diagnose and treat trichinellosis to prevent fatal complications.

Test sensitivity of a commercial serine protease digestion kit for the detection of Trichinella spiralis and Trichinella pseudospiralis larvae in pig muscle

The reference method for Trichinella detection at meat inspection is the magnetic stirrer method (MSM) utilising HCl-pepsin for pooled sample digestion. Due to availability and quality issues with pepsin, alternative digestion methods are being offered, such as the Priocheck Trichinella AAD kit (T-AAD), based on serine endopeptidase digestion. In this study the T-AAD kit was compared to the reference method. Minced pork samples were spiked with T. spiralis muscle larvae (ML) with- and without capsule or T. pseudospiralis ML, and analysed with both tests. Test results of individually spiked test samples were analysed by generalised linear modelling. The T-AAD test kit was comparable to the reference method for the qualitative detection of T. spiralis in pigs, but not quantitatively. Overall, 94% of spiked T. spiralis were recovered using MSM against 75.2% when using T-AAD (p < 0.0001). Using the MSM 80.0% of spiked T. pseudospiralis were recovered against 20% with the T-AAD (p < 0.0001). Based on our experience with the T-AAD kit, we strongly recommend validating the method on site prior to introduction into routine diagnostic laboratories, but this will not alleviate the poor test sensitivity of the T-AAD for the detection of T. pseudospiralis.

Biomolecular Changes and Cortical Neurodegenerative Lesions in Trichinella Spiralis Infected BALB/c Mice: A Preliminary Study Elucidating a Potential Relationship Between Systemic Helminthic Infections and Idiopathic Parkinson's

Idiopathic Parkinson's (IP) is a neurodegenerative disease that is suspected to be due to exposure to infections during early life. Toxoplasmosishas been the only suspected parasitic infection in IP (Celik et al., 2010). Recently, some non-central nervous system bacterial and viral infections have been incriminated in IP (Çamcı & Oğuz, 2016). So in the current study, we tried to explore if the systemic inflammatory reactions triggered by some helminths like Trichinella spiralis can induce Parkinsonian lesions in the brain, especially that the cerebral complications have been reported in 10-20% of Trichinella spiralis infected patients . An experimental study was designed to assess the neurodegenerative and biomolecular changes that may occur in Trichinella spiralis infected BALB/C mice in comparison to rotenone induced PD model and apparently healthy ones. The motor affection was significantly lesser in the Trichinella infected mice than the Parkinson's model, but when the catalepsy score was calculated (through the grid and bar tests) it was found to be significantly higher in the infected mice than in the healthy ones. A significant increase in the blood advanced oxidative protein products (AOPP), IFN-γ, TGF-β, and brain DNA fragmentation was also detected in the Trichinella spiralis infected mice. After histopathological examination, a significant increase in the cortical apoptotic neurons and Lewy's body were observed in the Trichinella infected and the rotenone induced Parkinson's model sections. A significant decrease in the immunohistochemical expression of the tyrosine hydroxylase expression in the brain sections and the ELISA measured dopamine level in the brain homogenate was also reported in the infected mice group. This study findings may collectively suggest that the systemic inflammatory reactions and the oxidative stresses associated with some systemic helminthic infections like trichinellosis are possible to precipitate neurodegenerative lesions and biomolecular changes in the brain , and manifest with IPD later in life.

Multiplex TaqMan qPCR assay for specific identification of encapsulated Trichinella species prevalent in North America

BACKGROUND Human trichinellosis is a foodborne parasitic zoonotic disease caused by ingestion of raw or undercooked meat infected with nematode larvae of the genus Trichinella. In the USA, sporadic cases and outbreaks caused by the consumption of wild game meat infected with Trichinella have been reported. The current methods for diagnosis such as serology and microscopy are not specific, may result in false negative results, and cannot differentiate encapsulated Trichinella larvae to species level. The molecular protocols currently available for the differentiation of all encapsulate Trichinella species prevalent in North America have some limitations such as the inability to identify and resolve the presence of several Trichinella species in a single test. OBJECTIVES/METHODS In this study we developed and evaluated a multiplex TaqMan quantitative real-time polymerase chain reaction (qPCR) assay, which can simultaneously detect, identify and differentiate all species of encapsulated Trichinella occurring in North America i.e., T. nativa, T. spiralis, T. murrelli and Trichinella T6, even in cases of multiple infection in a single sample. We investigated two human biopsies and 35 wild animal meat samples considered as having a high likelihood of harboring Trichinella larvae obtained from the United States during 2009-2017. FINDINGS Using the multiplex assay describe here, 22 (59%) samples that tested positive contained Trichinella spp., were identified as: T. nativa (n = 7, including a human biopsy), T. spiralis (n = 9, including a human biopsy), T. murrelli (n = 3), Trichinella T6 (n = 1). Results also included two rare mixed infection cases in bears, a T. nativa/T. spiralis from Alaska and a T. spiralis/Trichinella T6 from California. The species identifications were confirmed using a conventional PCR targeting the rRNA ITS1-ITS2 region, followed by DNA sequencing analysis. The estimated limit of detection (LOD) was approximately seven larvae per gram of meat. MAIN CONCLUSIONS Differentiation of Trichinella spp. is needed to improve efforts on identification of case, optimize food safety control and better understand the geographic distribution of Trichinella species. The Trichinella qPCR multiplex proved to be a robust, easy to perform assay and is presented as an improved technique for identification of all known encapsulated species occurring in North America continent.

Detection of natural Trichinella murrelli and Trichinella spiralis infections in horses by routine post-slaughter food safety testing

Trichinella spiralis typically infects domestic swine, wild boar and occasionally horses, has a cosmopolitan distribution, and consequently is most frequently associated with food-borne outbreaks of trichinellosis in humans. Trichinella murrelli is typically found in wild carnivores in temperate areas of North America, where it has been responsible for outbreaks of human trichinellosis due to consumption of infected wild game. There has previously been only indirect evidence of natural infection with T. murrelli in a horse originating from Connecticut and implicated in an outbreak of trichinellosis in France in 1985. We describe a T. murrelli infection detected during routine testing of a horse from the USA imported to Canada for slaughter and export to the European Union (EU). Approximately 5 or more larvae per gram were recovered from digested tongue and diaphragm samples and identified as T. murrelli by PCR. This case provides the first direct evidence of naturally acquired T. murrelli infection in a horse, and further supports the potential food safety risk posed by this parasite species. It is the first instance in Canada of the detection of a Trichinella-infected horse via routine post-mortem testing. Trichinella spiralis-infected horses have been similarly detected by regulatory testing in France, and further details of two such previously reported cases are also provided here. The cases described herein underscore the importance of continued vigilance in quality assured food safety testing of horse meat to mitigate the risk of human trichinellosis.

Estimated Cost to a Restaurant of a Foodborne Illness Outbreak

OBJECTIVES

Although outbreaks of restaurant-associated foodborne illness occur periodically and make the news, a restaurant may not be aware of the cost of an outbreak. We estimated this cost under varying circumstances.

METHODS

We developed a computational simulation model; scenarios varied outbreak size (5 to 250 people affected), pathogen (n = 15), type of dining establishment (fast food, fast casual, casual dining, and fine dining), lost revenue (ie, meals lost per illness), cost of lawsuits and legal fees, fines, and insurance premium increases.

RESULTS

We estimated that the cost of a single foodborne illness outbreak ranged from $3968 to $1.9 million for a fast-food restaurant, $6330 to $2.1 million for a fast-casual restaurant, $8030 to $2.2 million for a casual-dining restaurant, and $8273 to $2.6 million for a fine-dining restaurant, varying from a 5-person outbreak, with no lost revenue, lawsuits, legal fees, or fines, to a 250-person outbreak, with high lost revenue (100 meals lost per illness), and a high amount of lawsuits and legal fees ($1 656 569) and fines ($100 000). This cost amounts to 10% to 5790% of a restaurant's annual marketing costs and 0.3% to 101% of annual profits and revenue. The biggest cost drivers were lawsuits and legal fees, outbreak size, and lost revenue. Pathogen type affected the cost by a maximum of $337 000, the difference between a Bacillus cereus outbreak (least costly) and a listeria outbreak (most costly).

CONCLUSIONS

The cost of a single foodborne illness outbreak to a restaurant can be substantial and outweigh the typical costs of prevention and control measures. Our study can help decision makers determine investment and motivate research for infection-control measures in restaurant settings.

Molecular identification of Trichinella species by multiplex PCR: new insight for Trichinella murrelli

In order to identify Trichinella at the species level, the commonly used test is a multiplex PCR, allowing the discrimination of nine out of the twelve taxa described so far. This test is based on five primer pairs amplifying fragments of the large subunit rDNA. Each taxon produces one or two bands of different sizes, resulting in a specific band pattern. By multiplex PCR, Trichinella murrelli shows two bands of 127 bp and 316 bp. However, a third band of 256 bp can occur. This band can lead to misidentification, since it is similar to the 253 bp band displayed by Trichinella britovi. BLAST analysis confirmed that the 256 bp band is from T. murrelli. The aim of this short note is to inform analysts that T. murrelli larvae may display either two- or three-band patterns.

Long-read sequencing improves assembly of Trichinella genomes 10-fold, revealing substantial synteny between lineages diverged over 7 million years

Genome assemblies can form the basis of comparative analyses fostering insight into the evolutionary genetics of a parasite's pathogenicity, host-pathogen interactions, environmental constraints and invasion biology; however, the length and complexity of many parasite genomes has hampered the development of well-resolved assemblies. In order to improve Trichinella genome assemblies, the genome of the sylvatic encapsulated species Trichinella murrelli was sequenced using third-generation, long-read technology and, using syntenic comparisons, scaffolded to a reference genome assembly of Trichinella spiralis, markedly improving both. A high-quality draft assembly for T. murrelli was achieved that totalled 63·2 Mbp, half of which was condensed into 26 contigs each longer than 571 000 bp. When compared with previous assemblies for parasites in the genus, ours required 10-fold fewer contigs, which were five times longer, on average. Better assembly across repetitive regions also enabled resolution of 8 Mbp of previously indeterminate sequence. Furthermore, syntenic comparisons identified widespread scaffold misassemblies in the T. spiralis reference genome. The two new assemblies, organized for the first time into three chromosomal scaffolds, will be valuable resources for future studies linking phenotypic traits within each species to their underlying genetic bases.

A Review of Zoonotic Infection Risks Associated with the Wild Meat Trade in Malaysia

The overhunting of wildlife for food and commercial gain presents a major threat to biodiversity in tropical forests and poses health risks to humans from contact with wild animals. Using a recent survey of wildlife offered at wild meat markets in Malaysia as a basis, we review the literature to determine the potential zoonotic infection risks from hunting, butchering and consuming the species offered. We also determine which taxa potentially host the highest number of pathogens and discuss the significant disease risks from traded wildlife, considering how cultural practices influence zoonotic transmission. We identify 51 zoonotic pathogens (16 viruses, 19 bacteria and 16 parasites) potentially hosted by wildlife and describe the human health risks. The Suidae and the Cervidae families potentially host the highest number of pathogens. We conclude that there are substantial gaps in our knowledge of zoonotic pathogens and recommend performing microbial food safety risk assessments to assess the hazards of wild meat consumption. Overall, there may be considerable zoonotic risks to people involved in the hunting, butchering or consumption of wild meat in Southeast Asia, and these should be considered in public health strategies.

Trichinella and polar bears: a limited risk for humans

In this review, we identified 63 cases reported since World War II of human trichinellosis linked to the consumption of parasitized polar bear (Ursus maritimus) meat. This low number contrasts to the numerous cases of human trichinellosis related to consumption of the meat of black (U. americanus) or brown bears (U. arctos). The prevalence of Trichinella infection is high in bears, but larval muscular burden is usually lower in polar bears compared to other bear species. Polar bears, therefore, seem to play a limited role in the transmission of trichinellosis to humans, as native residents living in the Arctic traditionally consume well-cooked bear meat, and travellers and foreign hunters have only limited access to this protected species due to the declining polar bear population.

Pathogens of Food Animals: Sources, Characteristics, Human Risk, and Methods of Detection

Pathogens associated with food production (livestock) animals come in many forms causing a multitude of disease for humans. For the purpose of this review, these infectious agents can be divided into three broad categories: those that are associated with bacterial disease, those that are associated with viruses, and those that are parasitic in nature. The goal of this chapter is to provide the reader with an overview of the most common pathogens that cause disease in humans through exposure via the food chain and the consequence of this exposure as well as risk and detection methods. We have also included a collection of unusual pathogens that although rare have still caused disease, and their recognition is warranted in light of emerging and reemerging diseases. These provide the reader an understanding of where the next big outbreak could occur. The influence of the global economy, the movement of people, and food makes understanding production animal-associated disease paramount to being able to address new diseases as they arise.

Eosinophilia in Infectious Diseases

In determining the etiology of eosinophilia, it is necessary to consider the type of patient, including previous travel and exposure history, comorbidities, and symptoms. In this review, we discuss the approach to the patient with eosinophilia from an infectious diseases perspective based on symptom complexes.

Review of Telemicrobiology

CONTEXT

Microbiology laboratories are continually pursuing means to improve quality, rapidity, and efficiency of specimen analysis in the face of limited resources. One means by which to achieve these improvements is through the remote analysis of digital images. Telemicrobiology enables the remote interpretation of images of microbiology specimens. To date, the practice of clinical telemicrobiology has not been thoroughly reviewed.

OBJECTIVE

To identify the various methods that can be employed for telemicrobiology, including emerging technologies that may provide value to the clinical laboratory.

DATA SOURCES

Peer-reviewed literature, conference proceedings, meeting presentations, and expert opinions pertaining to telemicrobiology have been evaluated.

CONCLUSIONS

A number of modalities have been employed for telemicroscopy, including static capture techniques, whole slide imaging, video telemicroscopy, mobile devices, and hybrid systems. Telemicrobiology has been successfully implemented for several applications, including routine primary diagnosis, expert teleconsultation, and proficiency testing. Emerging areas of telemicrobiology include digital plate reading of bacterial cultures, mobile health applications, and computer-augmented analysis of digital images. To date, static image capture techniques have been the most widely used modality for telemicrobiology, despite newer technologies being available that may produce better quality interpretations. Telemicrobiology adds value, quality, and efficiency to the clinical microbiology laboratory, and increased adoption of telemicrobiology is anticipated.

Outbreak of trichinellosis due to wild boar meat and evaluation of the effectiveness of post exposure prophylaxis, Germany, 2013

BACKGROUND

Food safety authorities discovered that wild boar meat products contaminated with Trichinella spiralis had entered the food chain in Germany in March 2013. Public health authorities issued guidelines for health professionals including post-exposure prophylaxis (PEP) using mebendazole and advised the public to seek medical advice if exposed. Our objective was to identify factors associated with the development of trichinellosis and to evaluate post exposure prophylaxis.

METHODS

Persons who reported to local public health departments as exposed were interviewed concerning exposure, symptoms, and medication. Serum samples were tested by an in-house Trichinella-specific enzyme-linked innunosorbent assay. Cases were defined as persons presenting with myalgia and/or periorbital edema and Trichinella-specific immunoglobulin M and immunoglobulin G antibodies after exposure to implicated products.

RESULTS

Of 101 persons interviewed, 71 were exposed and serologically tested. Antibodies were detected in 21/71 (30%) and 14/71 (20%) met the case definition. Attack rates were positively correlated to the amount of implicated product consumed. Among n = 37 persons who received anthelmintics as PEP, 6 persons developed trichinellosis. These cases exclusively occurred among persons starting PEP 6 days or later post-exposure. Exposure to implicated products and delaying PEP were also significantly associated with developing trichinellosis (P < .01) in a multivariable analysis.

CONCLUSIONS

Concerted efforts by food safety and public health authorities lead to timely outbreak control and facilitated the provision of early PEP. PEP appears to be effective in preventing trichinellosis when given early, preferably within 6 days. We therefore recommend initiating PEP without delay in similar settings and encourage public health professionals to fast-track this intervention.

Trichinella spp. imported with live animals and meat

Nematodes of the genus Trichinella are widely distributed throughout the world in omnivorous and carnivorous animals (mammals, birds, and reptiles) and in incidental hosts. To prevent the transmission of these zoonotic parasites to humans, meat samples from Trichinella spp. susceptible animals are tested at the slaughterhouse or in game processing plants. The aim of the present review was to collect documented cases on Trichinella infected animals, meat, or meat derived products which reached the international trade or were illegally introduced from one to another country in personal baggage. In the course of the last 60 years in the international literature, there have been 43 reports of importation of Trichinella spp. infected animals or meat, most of which (60%, 26/43) related to live horses or their meat. Meat or meat derived products from pigs, wild boar and bears, account only for 18.6% (8/43), 4.7% (3/43), and 14.3% (6/43), respectively. However, only live horses or their meat intended for human consumption, meat from a single wild boar, and live polar bears caught in the wild for zoos, were imported through the international market; whereas, meat from pigs, wild boars and bears were illegally introduced in a country in personal baggage. Trichinella infected animals or meat which were officially or illegally introduced in a country were the source of 3443 Trichinella infections in humans in a 40-year period (1975-2014). Most of these infections (96.8%) have been linked to horsemeat consumption, whereas meat from pigs, wild boars and bears accounted only for 2.2%, 0.7% and 0.3% of cases, respectively. This review shows the Trichinella spp. risk in the international animal and meat trade has been linked mainly to horses and only one time to wild boar, if they carcasses are not adequately tested, whereas pigs and other wild animals or their derived products infected with Trichinella spp. are unlikely to reach the international market by the official animal and meat trade.

Outbreak of Trichinella spiralis infections associated with a wild boar hunted at a game farm in Iowa

BACKGROUND

Rates of trichinellosis have declined significantly in the United States due to improved pork production practices and public awareness of the danger of eating raw or undercooked pork. In April 2011, the Minnesota Department of Health received a report of presumptive trichinellosis in a 50-year-old man with a history of wild boar consumption. A public health investigation was initiated.

METHODS

Medical record reviews and patient and family interviews were conducted. Trichinella species serology was performed on patient and family serum samples, and larval identification was attempted on clinical specimens and meat samples.

RESULTS

The index patient harvested a wild boar from an Iowa game farm; he processed the meat after returning home and developed gastrointestinal symptoms 2 days later. Four days after his illness onset, all 5 family members consumed a roast from the boar. The index patient sought healthcare 4 times after illness onset before being definitively diagnosed with trichinellosis. Following initiation of albendazole therapy, the index patient developed atrial fibrillation. One additional family member who processed the raw meat was diagnosed with trichinellosis. Trichinella spiralis larvae were identified in wild boar meat samples.

CONCLUSIONS

Trichinellosis has long been recognized as a potential hazard of consuming undercooked wild carnivore meat, and historically has been associated with consumption of pork from domestic swine, but may be unfamiliar to practicing clinicians in the United States. Education of hunters and the broader population on the potential for trichinellosis and the importance of proper handling and cooking meat from wild or free-range animals needs to be reinforced.

New pieces of the Trichinella puzzle

Contrary to our understanding of just a few decades ago, the genus Trichinella now consists of a complex assemblage of no less than nine different species and three additional genotypes whose taxonomic status remains in flux. New data and methodologies have allowed advancements in detection and differentiation at the population level which in turn have demonstrably advanced epidemiological, immunological and genetic investigations. In like manner, molecular and genetic studies have permitted us to hypothesise biohistorical events leading to the worldwide dissemination of this genus, and to begin crystalising the evolution of Trichinella on a macro scale. The identification of species in countries and continents otherwise considered Trichinella-free has raised questions regarding host adaptation and associations, and advanced important findings on the biogeographical histories of its members. Using past reviews as a backdrop, we have ventured to present an up-to-date assessment of the taxonomy, phylogenetic relationships and epidemiology of the genus Trichinella with additional insights on host species, survival strategies in nature and the shortcomings of our current understanding of the epidemiology of the genus. In addition, we have begun compiling information available to date on genomics, proteomics, transcriptomics and population studies of consequence in the hope we can build on this in years to come.