Retrospective evaluation of an integrated molecular-epidemiological approach to cyclosporiasis outbreak investigations - United States, 2021.

Cyclosporiasis results from an infection of the small intestine by Cyclospora parasites after ingestion of contaminated food or water, often leading to gastrointestinal distress. Recent developments in temporally linking genetically related Cyclospora isolates demonstrated effectiveness in supporting epidemiological investigations. We used 'temporal-genetic clusters' (TGCs) to investigate reported cyclosporiasis cases in the United States during the 2021 peak-period (1 May - 31 August 2021). Our approach split 655 genotyped isolates into 55 genetic clusters and 31 TGCs. We linked two large multi-state epidemiological clusters (Epidemiologic Cluster 1 [n = 136 cases, 54 genotyped] and Epidemiologic Cluster 2 [n = 42 cases, 15 genotyped]) to consumption of lettuce varieties; however, product traceback did not identify a specific product for either cluster due to the lack of detailed product information. To evaluate the utility of TGCs, we performed a retrospective case study comparing investigation outcomes of outbreaks first detected using epidemiological methods with those of the same outbreaks had TGCs been used to first detect them. Our study results indicate that adjustments to routine epidemiological approaches could link additional cases to epidemiological clusters of cyclosporiasis. Overall, we show that CDC's integrated genotyping and epidemiological investigations provide valuable insights into cyclosporiasis outbreaks in the United States.

How Hospital Patients Experience Pain the Previous 24 Hours-A Prevalence Assessment of Pain in Five Hospitals in Sweden.

BACKGROUND: Previous studies show that pain is common among hospital inpatients. AIM: This study measures the prevalence of pain and the impact of pain on sleep in patients admitted to five hospitals in Sweden. METHODS: The patients were admitted to a surgical or a medical ward. They answered on a self-reported questionnaire about their average pain intensity and how much their pain interfered with their sleep the previous 24 hours, on a 010 numerical rating scale (NRS). RESULTS: Of the 500 patients, 308 experienced pain (62%), (NRS ≥ 3) and 111 (22%) rated their pain as NRS ≥ 7. We found no difference between surgical and medical specialty regarding pain prevalence. The results suggest that roughly the same proportion of patients with pain also experienced poor sleep due to pain265 patients (53%) reported pain interference on sleep, NRS ≥ 3. CONCLUSIONS AND CLINICAL IMPLICATIONS: This study shows that there is still an unacceptable high pain prevalence in inpatients and that patients experience pain as negatively impacting their sleep. Future pain care is likely to include a more comprehensive implementation strategy for the dissemination of knowledge, especially related to the complex context of today's healthcare system. That is, the possibility that anchoring new knowledge also benefits the patient is probably associated with optimization of the structural context. Future research should take this question further by examining how the organizational structure should be optimized for the dissemination of knowledge in healthcare professionals about pain and pain interference with sleep.

Cultivation of common bacterial species and strains from human skin, oral, and gut microbiota.

BACKGROUND: Genomics-driven discoveries of microbial species have provided extraordinary insights into the biodiversity of human microbiota. In addition, a significant portion of genetic variation between microbiota exists at the subspecies, or strain, level. High-resolution genomics to investigate species- and strain-level diversity and mechanistic studies, however, rely on the availability of individual microbes from a complex microbial consortia. High-throughput approaches are needed to acquire and identify the significant species- and strain-level diversity present in the oral, skin, and gut microbiome. Here, we describe and validate a streamlined workflow for cultivating dominant bacterial species and strains from the skin, oral, and gut microbiota, informed by metagenomic sequencing, mass spectrometry, and strain profiling. RESULTS: Of total genera discovered by either metagenomic sequencing or culturomics, our cultivation pipeline recovered between 18.1-44.4% of total genera identified. These represented a high proportion of the community composition reconstructed with metagenomic sequencing, ranging from 66.2-95.8% of the relative abundance of the overall community. Fourier-Transform Infrared spectroscopy (FT-IR) was effective in differentiating genetically distinct strains compared with whole-genome sequencing, but was less effective as a proxy for genetic distance. CONCLUSIONS: Use of a streamlined set of conditions selected for cultivation of skin, oral, and gut microbiota facilitates recovery of dominant microbes and their strain variants from a relatively large sample set. FT-IR spectroscopy allows rapid differentiation of strain variants, but these differences are limited in recapitulating genetic distance. Our data highlights the strength of our cultivation and characterization pipeline, which is in throughput, comparisons with high-resolution genomic data, and rapid identification of strain variation.

Amplification of pathogenic Leptospira infection with greater abundance and co-occurrence of rodent hosts across a counter-urbanizing landscape.

Land use change can elevate disease risk by creating conditions beneficial to species that carry zoonotic pathogens. Observations of concordant global trends in increased pathogen prevalence or disease incidence and landscape change have generated concerns that urbanization could increase transmission risk of some pathogens. Yet host-pathogen relationships underlying transmission risk have not been well characterized within cities, even where contact between humans and species capable of transmitting pathogens of concern occurs. We addressed this deficit by testing the hypothesis that areas in cities experiencing greater population loss and infrastructure decline (i.e., counter-urbanization) can support a greater diversity of host species and a larger and more diverse pool of pathogens. We did so by characterizing pathogenic Leptospira infection relative to rodent host richness and abundance across a mosaic of abandonment in post-Katrina New Orleans (Louisiana, USA). We found that Leptospira infection loads were highest in areas that harboured increased rodent species richness (which ranged from one to four rodent species detected). Areas with greater host co-occurrence also harboured a greater abundance of hosts, including the host species most likely to carry high infection loads, indicating that Leptospira infection can be amplified by increases in overall and relative host abundance. Evidence of shared infection among rodent host species indicates that cross-species transmission of Leptospira probably increases infection at sites with greater host richness. Additionally, evidence that rodent co-occurrence and abundance and Leptospira infection load parallel abandonment suggests that counter-urbanization can elevate zoonotic disease risk within cities, particularly in underserved communities that are burdened with disproportionate concentrations of derelict properties.

Sensor-Based Upper-Extremity Frailty Assessment for the Vascular Surgery Risk Stratification.

BACKGROUND: Available methods for determining outcomes in vascular surgery patients are often subjective or not applicable in nonambulatory patients. The purpose of the present study was to assess the association between vascular surgery outcomes and a previously validated upper-extremity function (UEF) method, which incorporates wearable motion sensors for the physical frailty assessment. MATERIALS AND METHODS: Patients (≥50 y old) undergoing vascular surgery were recruited. Participants performed the 20-s UEF test, which involved rapid elbow flexion. This technology quantifies physical frailty features including slowness, weakness, exhaustion, and flexibility, which allows grouping individuals into nonfrail, prefrail, and frail categories. Surgical outcomes included length of hospital stay, discharged disposition, and 30-d mortality, complications, readmission, and reintervention(s). Associations between outcomes and frailty were assessed using nominal logistic regression models, adjusted for age, gender, body mass index, and wound classification. RESULTS: Thirty-seven participants were recruited: eight nonfrail (age = 62.0 ± 10.6); 22 prefrail (age = 65.6 ± 11.6); and seven frail (age = 68.0 ± 8.0). Significant associations were observed between frailty and length of hospital stay (three times longer among frail participants, P = 0.03), mortality after surgery (two incidents among frail participants, P < 0.01), and adverse discharge disposition (all nonfrail patients were discharged home, whereas only 43% of frail patients discharged home, P = 0.01). CONCLUSIONS: This is the first study to validate the utility of UEF among patients undergoing any vascular surgery. Findings suggest that UEF may provide an objective and simple approach for assessing frailty to predict adverse events after vascular surgery, especially for nonambulatory patients.

Dynamic Nanocellulose Networks for Thermoset-like yet Recyclable Plastics with a High Melt Stiffness and Creep Resistance.

Many polymers, including polyethylene, feature a relatively low melting point and hence must be cross-linked to make them viable for applications that demand a high stiffness and creep resistance at elevated temperatures. The resulting thermoset plastics cannot be recycled, and therefore alternative materials with a reconfigurable internal network structure are in high demand. Here, we establish that such a thermoset-like yet recyclable material can be realized through the addition of a nanocellulose reinforcing agent. A network consisting of cellulose nanocrystals, nano- or microfibrils imparts many of the characteristics that are usually achieved through chemical cross-linking. For instance, the addition of only 7.5 wt % of either nanocellulose material significantly enhances the melt stiffness of an otherwise molten ethylene-acrylate copolymer by at least 1 order of magnitude. At the same time, the nanocellulose network reduces the melt creep elongation to less than 10%, whereas the neat molten matrix would rupture. At high shear rates, however, the molten composites do not display a significantly higher viscosity than the copolymer matrix, and therefore retain the processability of a thermoplastic material. Repeated re-extrusion at 140 °C does not compromise the thermomechanical properties, which indicates a high degree of recyclability. The versatility of dynamic nanocellulose networks is illustrated by 3D printing of a cellulose composite, where the high melt stiffness improves the printability of the resin.

Nurses' Advocacy of Clinical Pain Management in Hospitals: A Qualitative Study.

BACKGROUND AND AIMS: In hospitals, efficient pain care given by nurses is warrented because pain prevalence in the previous 24 hours has been reported to be high. This study aims to clarify nurse's experiences with pain management as a specific responsibility added to their regular clinical duties. In addition, this study aims to elucidate these nurses' attitudes about sharing their pain knowledge with their colleagues. DESIGN, PARTICIPANTS AND METHODS: This study includes semi-structured interviews of 17 registered staff nurses at the University Hospital, Linköping Sweden. The interviews were analyzed using a qualitative content analysis. RESULTS: A main thematic category emerged: Selected nurses experience shortcomings and obstacles in clinical pain management and are willing to improve their knowledge and share it with their colleagues. This main category was based on the following four sub-categories: a valued but unclear assignment; the presence of facilitators and obstacles; in need of support and collaboration; and a deficit of own knowledge and future teaching of colleagues. CONCLUSIONS: Overall, the nurses maintained a constructive attitude about their responsibilities to teach colleagues about pain management in spite the difficulties they experienced fulfilling all their responsibilities. Nurses who have the added responsibility to teach their colleagues pain management need specialized education in pain management and pedagogic skills for teaching clinical pain management. Moreover, these nurses need to be given the time, support, and collaborative opportunities to develop their knowledge. A nursing model that provides nurses trained in pain management education should be developed and evaluated.

Autophagic clearance of proteasomes in yeast requires the conserved sorting nexin Snx4.

Turnover of the 26S proteasome by autophagy is an evolutionarily conserved process that governs cellular proteolytic capacity and eliminates inactive particles. In most organisms, proteasomes are located in both the nucleus and cytoplasm. However, the specific autophagy routes for nuclear and cytoplasmic proteasomes are unclear. Here, we investigate the spatial control of autophagic proteasome turnover in budding yeast (Saccharomyces cerevisiae). We found that nitrogen starvation-induced proteasome autophagy is independent of known nucleophagy pathways but is compromised when nuclear protein export is blocked. Furthermore, via pharmacological tethering of proteasomes to chromatin or the plasma membrane, we provide evidence that nuclear proteasomes at least partially disassemble before autophagic turnover, whereas cytoplasmic proteasomes remain largely intact. A targeted screen of autophagy genes identified a requirement for the conserved sorting nexin Snx4 in the autophagic turnover of proteasomes and several other large multisubunit complexes. We demonstrate that Snx4 cooperates with sorting nexins Snx41 and Snx42 to mediate proteasome turnover and is required for the formation of cytoplasmic proteasome puncta that accumulate when autophagosome formation is blocked. Together, our results support distinct mechanistic paths in the turnover of nuclear versus cytoplasmic proteasomes and point to a critical role for Snx4 in cytoplasmic agglomeration of proteasomes en route to autophagic destruction.

Rat Lungworm Infection in Rodents across Post-Katrina New Orleans, Louisiana, USA.

Rat lungworm (Angiostrongylus cantonensis), a parasitic nematode that can cause eosinophilic meningitis in humans, was first detected in New Orleans, Louisiana, USA, in the mid-1980s and now appears to be widespread in the southeastern United States. We assessed the distribution, prevalence, and intensity of A. cantonensis infection in New Orleans by examining lung biopsy samples of rodents trapped at 96 sites in 9 areas in Orleans Parish and 1 area in neighboring St. Bernard Parish during May 2015 through February 2017. These areas were selected to capture contrasting levels of income, flooding, and pos-disaster landscape management after Hurricane Katrina in 2005. We detected A. cantonensis in all areas and in 3 of the 4 rat species trapped. Overall prevalence was ≈38% but varied by area, host species, and host species co-occurrence. Infection intensity also varied by host species. These findings suggest that socioecological analysis of heterogeneity in definitive and intermediate host infection could improve understanding of health risks across the city.

Specific exercises for subacromial pain.

Background and purpose - We have previously shown that specific exercises reduced the need for surgery in subacromial pain patients at 1-year follow-up. We have now investigated whether this result was maintained after 5 years and compared the outcomes of surgery and non-surgical treatment. Patients and methods - 97 patients were included in the previously reported randomized study of patients on a waiting list for surgery. These patients were randomized to specific or unspecific exercises. After 3 months of exercises the patients were asked if they still wanted surgery and this was also assessed at the present 5-year follow-up. The 1-year assessment included Constant-Murley score, DASH, VAS at night, rest and activity, EQ-5D, and EQ-VAS. All these outcome assessments were repeated after 5 years in 91 of the patients. Results - At the 5-year follow-up more patients in the specific exercise group had declined surgery, 33 of 47 as compared with 16 of 44 (p = 0.001) in the unspecific exercise group. The mean Constant-Murley score continued to improve between the 1- and 5-year follow-ups in both surgically and non-surgically treated groups. On a group level there was no clinically relevant change between 1 and 5 years in any of the other outcome measures regardless of treatment. Interpretation - This 5-year follow-up of a previously published randomized controlled trial found that specific exercises reduced the need for surgery in patients with subacromial pain. Patients not responding to specific exercises may achieve similar good results with surgery. These findings emphasize that a specific exercise program may serve as a selection tool for surgery.

Patterns in diurnal airspace use by migratory landbirds along an ecological barrier.

Migratory bird populations and survival are affected by conditions experienced during migration. While many studies and conservation and management efforts focus on terrestrial stoppage and staging areas, the aerial environment through which migrants move also is subjected to anthropogenic impacts with potential consequences to migratory movement and survival. During autumn migration, the northern coastline of Lake Superior acts as an ecological barrier for many landbirds migrating out of the boreal forests of North America. From 24 observation points, we assessed the diurnal movements of birds throughout autumn migration, 2008-2010, within a 210 × 10 km coastal region along the northern coast of Lake Superior. Several raptor species showed patterns in airspace associated with topographic features such as proximity to the coastline and presence of ridgelines. Funneling movement, commonly used to describe the concentration of raptors along a migratory diversion line that either prevents or enhances migration progress, occurred only for Bald and Golden Eagles. This suggests a "leaky" migration funnel for most migratory raptors (e.g., migrating birds exiting the purported migration corridor). Passerines migrating during the late season showed more spatial and temporal structure in airspace distribution than raptors did, including funneling and an association with airspace near the coast. We conclude that (1) the diurnal use of airspace by many migratory landbirds is patterned in space and time, (2) autumn count sites situated along ecological barriers substantially underestimate the number of raptors due to "leakage" out of these concentration areas, and (3) the magnitude and structure of diurnal passerine movements in airspace have been overlooked. The heavy and structured use of airspace by migratory landbirds, especially the airspace associated with anthropogenic development (e.g., buildings, towers, turbines) necessitates a shift in focus to airspace management and conservation attention for these animals.

Sources and Prevalence of Cyclospora cayetanensis in Southeastern U.S. Growing Environments.

Recent cyclosporiasis outbreaks associated with fresh produce grown in the United States highlight the need to better understand Cyclospora cayetanensis prevalence in U.S. agricultural environments. In this study, C. cayetanensis occurrence was assessed in municipal wastewater sludge, on-farm portable toilets, irrigation pond water, and spent packing house dump tank water in a Southeastern Georgia growing region over two years. Detection of the C. cayetanensis 18S rRNA qPCR gene target in pond samples was 0%, 28%, and 42% (N = 217) depending on the detection definition used, and ≤1% in dump tank samples (N = 46). However, no qPCR detections were confirmed by sequencing, suggesting false detection occurred due to cross-reactions. C. cayetanensis qPCR detections were confirmed in 9% of wastewater sludge samples (N = 76). The human-specific fecal markers HF183 and crAssphage were detected in 33% and 6% of pond samples, respectively, and 4% and 0% of dump tank samples, respectively. Despite community Cyclospora shedding and evidence of human fecal contamination in irrigation water, there was no correlation between C. cayetanensis and HF183 qPCR detections, further supporting that 18S gene target qPCR amplifications were due to cross-reactions. When evaluating C. cayetanensis qPCR environmental detection data, the impact of assay specificity and detection criteria should be considered. Moreover, additional sequence-based testing may be needed to appropriately interpret Cyclospora qPCR environmental data.

Evaluation of the Increased Genetic Resolution and Utility for Source Tracking of a Recently Developed Method for Genotyping Cyclospora cayetanensis.

Cyclospora cayetanensis is a foodborne parasite that causes cyclosporiasis, an enteric illness in humans. Genotyping methods are used to genetically discriminate between specimens from cyclosporiasis cases and can complement source attribution investigations if the method is sufficiently sensitive for application to food items. A very sensitive targeted amplicon sequencing (TAS) assay for genotyping C. cayetanensis encompassing 52 loci was recently designed. In this study, we analyzed 66 genetically diverse clinical specimens to assess the change in phylogenetic resolution between the TAS assay and a currently employed eight-marker scheme. Of the 52 markers, ≥50 were successfully haplotyped for all specimens, and these results were used to generate a hierarchical cluster dendrogram. Using a previously described statistical approach to dissect hierarchical trees, the 66 specimens resolved into 24 and 27 distinct genetic clusters for the TAS and an 8-loci scheme, respectively. Although the specimen composition of 15 clusters was identical, there were substantial differences between the two dendrograms, highlighting the importance of both inclusion of additional genome coverage and choice of loci to target for genotyping. To evaluate the ability to genetically link contaminated food samples with clinical specimens, C. cayetanensis was genotyped from DNA extracted from raspberries inoculated with fecal specimens. The contaminated raspberry samples were assigned to clusters with the corresponding clinical specimen, demonstrating the utility of the TAS assay for traceback efforts.

Successful treatment of refractory immune thrombocytopenia with rituximab in a 10-week-old infant.

Immune thrombocytopenic purpura (ITP) that is unresponsive to conventional treatment is uncommon. In this situation, additional therapeutic options are limited and management is challenging. We describe the case of a 10-week-old infant that developed life-threatening ITP that was unresponsive to immunoglobulin and corticosteroids that was successfully managed with the monoclonal antibody rituximab. The literature on the use of rituximab in nonresponsive ITP is reviewed.

Novel insights on the genetic population structure of human-infecting Cyclospora spp. and evidence for rapid subtype selection among isolates from the USA.

Human-infecting Cyclospora was recently characterized as three species, two of which (C. cayetanensis and C. ashfordi) are currently responsible for all known human infections in the USA, yet much remains unknown about the genetic structure within these two species. Here, we investigate Cyclospora genotyping data from 2018 through 2022 to ascertain if there are temporal patterns in the genetic structure of Cyclospora parasites that cause infections in US residents from year to year. First, we investigate three levels of genetic characterization: species, subpopulation, and strain, to elucidate annual trends in Cyclospora infections. Next, we determine if shifts in genetic diversity can be linked to any of the eight loci used in our Cyclospora genotyping approach. We observed fluctuations in the abundance of Cyclospora types at the species and subpopulation levels, but no significant temporal trends were identified; however, we found recurrent and sporadic strains within both C. ashfordi and C. cayetanensis. We also uncovered major shifts in the mitochondrial genotypes in both species, where there was a universal increase in abundance of a specific mitochondrial genotype that was relatively abundant in 2018 but reached near fixation (was observed in over 96% of isolates) in C. ashfordi by 2022. Similarly, this allele jumped from 29% to 82% relative abundance of isolates belonging to C. cayetanensis. Overall, our analysis uncovers previously unknown temporal-genetic patterns in US Cyclospora types from 2018 through 2022 and is an important step to presenting a clearer picture of the factors influencing cyclosporiasis outbreaks in the USA.

Metabolic Acidosis Results in Sexually Dimorphic Response in the Heart Tissue.

Metabolic acidosis (MA) is a highly prevalent disorder in a significant proportion of the population, resulting from imbalance in blood pH homeostasis. The heart, being an organ with very low regenerative capacity and high metabolic activity, is vulnerable to chronic, although low-grade, MA. To systematically characterize the effect of low-grade MA on the heart, we treated male and female mice with NH4Cl supplementation for 2 weeks and analyzed their blood chemistry and transcriptomic signature of the heart tissue. The reduction of pH and plasma bicarbonate levels without an associated change in anion gap indicated a physiological manifestation of low-grade MA with minimal respiratory compensation. On transcriptomic analysis, we observed changes in cardiac-specific genes with significant gender-based differences due to MA. We found many genes contributing to dilated cardiomyopathy to be altered in males, more than in females, while cardiac contractility and Na/K/ATPase-Src signaling were affected in the opposite way. Our model presents a systems-level understanding of how the cardiovascular tissue is affected by MA. As low-grade MA is a common ailment with many dietary and pharmaceutical interventions, our work presents avenues to limit chronic cardiac damage and disease manifestation, as well as highlighting the sex differences in MA-induced cardiovascular damage.

Comparison of two novel one-tube nested real-time qPCR assays to detect human-infecting Cyclospora spp.

IMPORTANCE: Human-infecting Cyclospora spp. cause gastrointestinal distress among healthy individuals contributing to morbidity and putting stress on the economics of countries and companies in the form of produce recalls. Accessible and easy-to-use diagnostic tools available to a wide variety of laboratories would aid in the early detection of possible outbreaks of cyclosporiasis. This, in turn, will assist in the timely traceback investigation to the suspected source of an outbreak by informing the smallest possible recall and protecting consumers from contaminated produce. This manuscript describes two novel detection methods with improved performance for the causative agents of cyclosporiasis when compared to the currently used 18S assay.

Wnt-associated adult stem cell marker Lgr6 is required for osteogenesis and fracture healing.

Despite the remarkable regenerative capacity of skeletal tissues, nonunion of bone and failure of fractures to heal properly presents a significant clinical concern. Stem and progenitor cells are present in bone and become activated following injury; thus, elucidating mechanisms that promote adult stem cell-mediated healing is important. Wnt-associated adult stem marker Lgr6 is implicated in the regeneration of tissues with well-defined stem cell niches in stem cell-reliant organs. Here, we demonstrate that Lgr6 is dynamically expressed in osteoprogenitors in response to fracture injury. We used an Lgr6-null mouse model and found that Lgr6 expression is necessary for maintaining bone volume and efficient postnatal bone regeneration in adult mice. Skeletal progenitors isolated from Lgr6-null mice have reduced colony-forming potential and reduced osteogenic differentiation capacity due to attenuated cWnt signaling. Lgr6-null mice consist of a lower proportion of self-renewing stem cells. In response to fracture injury, Lgr6-null mice have a deficiency in the proliferation of periosteal progenitors and reduced ALP activity. Further, analysis of the bone regeneration phase and remodeling phase of fracture healing in Lgr6-null mice showed impaired endochondral ossification and decreased mineralization. We propose that in contrast to not being required for successful skeletal development, Lgr6-positive cells have a direct role in endochondral bone repair.

The limit of detection of the BioFire® FilmArray® gastrointestinal panel for the foodborne parasite Cyclospora cayetanensis.

Cyclosporiasis is a foodborne diarrheal illness caused by the parasite Cyclospora cayetanensis. The BioFire® FilmArray® gastrointestinal (FilmArray GI) panel is a common method for diagnosing cyclosporiasis from clinical stool samples. The currently published limit of detection (LOD) of this panel is in genome equivalents; however, it is unclear how this relates to the number of C. cayetanensis oocysts in a clinical sample. In this study, we developed a technique to determine the LOD in terms of oocysts, using a cell sorter to sort 1 to 50 C. cayetanensis oocyst(s) previously purified from three human stool sources. We found the FilmArray GI panel detected samples with ≥20 C. cayetanensis oocysts in 100% of replicates, with varying detection among samples with 1, 5, or 10 C. cayetanensis oocysts. This method provides a parasitologically relevant LOD that should enable comparison among C. cayetanensis detection techniques, including the FilmArray GI panel.

Broad host susceptibility of North American amphibian species to Batrachochytrium salamandrivorans suggests high invasion potential and biodiversity risk.

Batrachochytrium salamandrivorans (Bsal) is a fungal pathogen of amphibians that is emerging in Europe and could be introduced to North America through international trade or other pathways. To evaluate the risk of Bsal invasion to amphibian biodiversity, we performed dose-response experiments on 35 North American species from 10 families, including larvae from five species. We discovered that Bsal caused infection in 74% and mortality in 35% of species tested. Both salamanders and frogs became infected and developed Bsal chytridiomycosis. Based on our host susceptibility results, environmental suitability conditions for Bsal, and geographic ranges of salamanders in the United States, predicted biodiversity loss is expected to be greatest in the Appalachian Region and along the West Coast. Indices of infection and disease susceptibility suggest that North American amphibian species span a spectrum of vulnerability to Bsal chytridiomycosis and most amphibian communities will include an assemblage of resistant, carrier, and amplification species. Predicted salamander losses could exceed 80 species in the United States and 140 species in North America.