Emx2 lineage tracing reveals antecedent patterns of planar polarity in the mouse inner ear.

The planar polarized organization of hair cells in the vestibular maculae is unique because these sensory organs contain two groups of cells with oppositely oriented stereociliary bundles that meet at a line of polarity reversal (LPR). EMX2 is a transcription factor expressed by one hair cell group that reverses the orientation of their bundles, thereby forming the LPR. We generated Emx2-CreERt2 transgenic mice for genetic lineage tracing and demonstrate Emx2 expression before hair cell specification when the nascent utricle and saccule constitute a continuous prosensory domain. Precursors labeled by Emx2-CreERt2 at this stage give rise to hair cells located along one side of the LPR in the mature utricle or saccule, indicating that this boundary is first established in the prosensory domain. Consistent with this, Emx2-CreERt2 lineage tracing in Dreher mutants, where the utricle and saccule fail to segregate, labels a continuous field of cells along one side of a fused utriculo-saccular-cochlear organ. These observations reveal that LPR positioning is pre-determined in the developing prosensory domain, and that EMX2 expression defines lineages of hair cells with oppositely oriented stereociliary bundles.

The dark kinase STK32A regulates hair cell planar polarity opposite of EMX2 in the developing mouse inner ear.

The vestibular maculae of the inner ear contain sensory receptor hair cells that detect linear acceleration and contribute to equilibrioception to coordinate posture and ambulatory movements. These hair cells are divided between two groups, separated by a line of polarity reversal (LPR), with oppositely oriented planar-polarized stereociliary bundles that detect motion in opposite directions. The transcription factor EMX2 is known to establish this planar polarized organization in mouse by regulating the distribution of the transmembrane receptor GPR156 at hair cell boundaries in one group of cells. However, the genes regulated by EMX2 in this context were previously not known. Using mouse as a model, we have identified the serine threonine kinase STK32A as a downstream effector negatively regulated by EMX2. Stk32a is expressed in hair cells on one side of the LPR in a pattern complementary to Emx2 expression in hair cells on the opposite side. Stk32a is necessary to align the intrinsic polarity of the bundle with the core planar cell polarity (PCP) proteins in EMX2-negative regions, and is sufficient to reorient bundles when ectopically expressed in neighboring EMX2-positive regions. We demonstrate that STK32A reinforces LPR formation by regulating the apical localization of GPR156. These observations support a model in which bundle orientation is determined through separate mechanisms in hair cells on opposite sides of the maculae, with EMX2-mediated repression of Stk32a determining the final position of the LPR.

A new early hominin calcaneus from Kromdraai (South Africa).

The Kromdraai site in South Africa has yielded numerous early hominin fossils since 1938. As a part of recent excavations within Unit P, a largely complete early hominin calcaneus (KW 6302) was discovered. Due to its role in locomotion, the calcaneus has the potential to reveal important form/function relationships. Here, we describe KW 6302 and analyze its preserved morphology relative to human and nonhuman ape calcanei, as well as calcanei attributed to Australopithecus afarensis, Australopithecus africanus, Australopithecus sediba, Homo naledi, and the Omo calcaneus (either Paranthropus or early Homo). KW 6302 calcaneal morphology is assessed using numerous quantitative metrics including linear measures, calcaneal robusticity index, relative lateral plantar process position, Achilles tendon length reconstruction, and a three-dimensional geometric morphometric sliding semilandmark analysis. KW 6302 exhibits an overall calcaneal morphology that is intermediate between humans and nonhuman apes, although closer to modern humans. KW 6302 possesses many traits that indicate it was likely well-adapted for terrestrial bipedal locomotion, including a relatively flat posterior talar facet and a large lateral plantar process that is similarly positioned to modern humans. It also retains traits that indicate that climbing may have remained a part of its locomotor repertoire, such as a relatively gracile tuber and a large peroneal trochlea. Specimens from Kromdraai have been attributed to either Paranthropus robustus or early Homo; however, there are no definitively attributed calcanei for either genus, making it difficult to taxonomically assign this specimen. KW 6302 and the Omo calcaneus, however, fall outside the range of expected variation for an extant genus, indicating that if the Omo calcaneus was Paranthropus, then KW 6302 would likely be attributed to early Homo (or vice versa).

Footprint evidence of early hominin locomotor diversity at Laetoli, Tanzania.

Bipedal trackways discovered in 1978 at Laetoli site G, Tanzania and dated to 3.66 million years ago are widely accepted as the oldest unequivocal evidence of obligate bipedalism in the human lineage1-3. Another trackway discovered two years earlier at nearby site A was partially excavated and attributed to a hominin, but curious affinities with bears (ursids) marginalized its importance to the paleoanthropological community, and the location of these footprints fell into obscurity3-5. In 2019, we located, excavated and cleaned the site A trackway, producing a digital archive using 3D photogrammetry and laser scanning. Here we compare the footprints at this site with those of American black bears, chimpanzees and humans, and we show that they resemble those of hominins more than ursids. In fact, the narrow step width corroborates the original interpretation of a small, cross-stepping bipedal hominin. However, the inferred foot proportions, gait parameters and 3D morphologies of footprints at site A are readily distinguished from those at site G, indicating that a minimum of two hominin taxa with different feet and gaits coexisted at Laetoli.

Evidence for an elongated Achilles tendon in Australopithecus.

Modern humans have the longest Achilles tendon (AT) of all the living primates. It has been proposed that this anatomy increases locomotor efficiency and that its elongation may have played a crucial role in the origin and early evolution of the genus Homo. Unfortunately, determining the length of the AT in extinct hominins has been difficult as tendons do not fossilize. Several methods have been proposed for estimating the length of the AT from calcaneal morphology, but the results have been inconclusive. This study tested the relationship between the area of the superior calcaneal facet and AT length in extant primates. The superior facet is instructive because it anchors the retrocalcaneal bursa, a soft tissue structure which helps to reduce friction between the AT and the calcaneus. Calcanei from 145 extant anthropoid primates from 12 genera were photographed in posterior view and the relative superior facet size quantified. AT lengths were obtained from published sources. The relative area of the superior facet is predictive of AT length in primates (R2 = 0.83; p < .001) and differs significantly between the great apes and humans (p < 0.001). When applied to fossil Australopithecus calcanei, our results suggest that australopiths possessed a longer, more human-like, AT than previously thought. These findings have important implications for the locomotor capabilities of Australopithecus, including their capacity for endurance running and climbing.

Extracorporeal shock wave lithotripsy versus ureteroscopy for management of pediatric nephrolithiasis in upper urinary tract stones: multi-institutional outcomes of efficacy and morbidity.

INTRODUCTION: As the incidence of pediatric nephrolithiasis rises, understanding the efficacy and morbidity of surgical treatment options is critical. Currently, there are limited comparative data assessing shock wave lithotripsy (SWL) and ureteroscopy (URS) outcomes in children. OBJECTIVE: The objective of this study was to compare stone clearance, 30-day emergency department visits, and the number of general anesthetics required per stone treatment for both modalities. STUDY DESIGN: A multi-institutional retrospective review of children presenting for either URS or SWL between 2000 and 2017 was performed. Stone clearance, need for retreatment, the number of anesthetics, as well as the number and reason for emergency room visit were captured and compared between groups. Multivariate statistical analysis accounting for age, stone location, stone diameter, pre-intervention stent, and provider volume was performed for adjusted analysis. RESULTS: A total of 84 SWL and 175 URS procedures were included. Complete stone clearance and rates of residual stone fragments <4 mm after final procedure for SWL were 77.0% and 90.8% and for URS were 78.5% and 91.7%, respectively. Retreatment rates for both procedures were not significantly different (17.9% SWL vs. 18.9% URS, P = 0.85). Children who underwent SWL had lower rates of emergency room visits for infections (0% vs. 5.1%, P = 0.03) and flank pain (3.6% vs. 10.9%, P = 0.05) and required fewer general anesthetics per treatment (1.2 vs. 2.0, P < 0.01) than those who underwent URS (Figure). DISCUSSION: Stone clearance after both the initial and final treatments and need for repeat interventions were similar between surgical modalities. However, SWL carries less morbidity than URS. Specifically, patients who underwent SWL experienced lower rates of ED visits for urinary tract infection and for flank pain, parallel to conclusions in current comparative literature. In addition, SWL requires less general anesthetics (2.0 vs. 1.2), secondary to lower rates of ureteral stent placement and removal. Data on the potential risk of general anesthetics to neurodevelopment support thoughtful utilization of these medications. Limitations of this study include its retrospective nature and the prolonged 20-year time period over which data were collected. CONCLUSIONS: When adjusting for confounders, SWL and URS achieve similar stone clearance. In the setting of equivalent efficacy, considerations regarding necessity of repeat interventions, morbidity of anesthesia, and complications should be integrated into clinical practice.

A clinical pathway to minimize computed tomography for suspected nephrolithiasis in children.

INTRODUCTION: Ultrasound (US) imaging is preferred in the initial evaluation for children with suspected nephrolithiasis; however, computed tomography (CT) continues to be used in this setting with resultant unnecessary ionizing radiation exposure. The study institution implemented a standardized clinical pathway to reduce rates of CT utilization for children with nephrolithiasis. OBJECTIVE: The aim of this study was to evaluate the impact of this pathway on initial imaging strategies for children with suspected nephrolithiasis. STUDY DESIGN: A standardized pathway was designed and implemented using a systematic quality improvement process. A suspected cohort was created using 'reason for study' search terms consistent with a nephrolithiasis diagnosis. A confirmed cohort of children with a final diagnosis of nephrolithiasis was derived from this suspected cohort. The primary outcome was CT use as the initial imaging study in children with suspected or confirmed nephrolithiasis presenting to the emergency department (ED) between October 2013 and February 2018. Comparisons were made before and after pathway implementation (October 2015). Secondary outcomes included rates of CT scan within 30 days, while balancing measures included rates of admission, ED length of stay, and return visits. RESULTS: A total of 534 children with suspected (220 prepathway; 314 postpathway) and 90 children with confirmed (37 prepathway; 53 postpathway) nephrolithiasis were included. For the suspected cohort, CT scans performed as the initial imaging evaluation (9.2% vs 2.5%, P = 0.001) and at any time during the index visit (15.7% vs 5.7%, P = 0.001) decreased after pathway implementation. Within the confirmed cohort, a non-significant decrease in initial CT rates was observed after implementation. No differences were observed in admission rates or ED length of stay after implementation. A trend toward lower return visits to the ED was seen after pathway implementation (5.5% vs 2.2%, P = 0.058). DISCUSSION: Within a tertiary care pediatric ED associated with a strong institutional experience with clinical pathways, initial CT rates were decreased after pathway implementation for children with suspected nephrolithiasis. While retrospective assessment of suspected disease is limited, this is one of the first studies to address imaging patterns for nephrolithiasis beyond the final discharge diagnosis, thus capturing a broader cohort of children. Children with suspected nephrolithiasis can be safely managed with an US-first approach, and postvisit CT scans are rarely necessary for management. CONCLUSIONS: A standardized clinical pathway for suspected nephrolithiasis can reduce rates of initial and overall CT utilization without adversely impacting downstream care.

A Societies for Pediatric Urology survey of opioid prescribing practices after ambulatory pediatric urology procedures.

INTRODUCTION: Opioid dependence and abuse has been declared a national public health emergency, and overprescribing of opioids after surgery has been identified as a driving factor. To date, opioid prescribing after pediatric urology ambulatory surgery has not been well-described. OBJECTIVE: The study's objective was to assess pediatric urologists' practices in prescribing opioids for routine ambulatory procedures. STUDY DESIGN: A 23-question survey was created, including eight case vignettes describing routine procedures (orchiopexy, hydrocele repair, circumcision) across three age groups (8 months, 3 years, 13 years). Multiple choice questions asked about typical opioid type and duration for each case. Respondent attitudes and practice types were also evaluated. The survey was administered through the Societies for Pediatric Urology. RESULTS: Of the 102 respondents, 48% reported prescribing postoperative opioids for all cases described (Figure 1). Fourteen percent reported prescribing no opioids for all cases. Longer prescription duration was associated with older age (p = 0.003). Acetaminophen-hydrocodone was prescribed most commonly, while a few respondents reported prescribing acetaminophen-codeine. North Central and Southeastern respondents were more likely to prescribe opioids for all cases described (p = 0.003). The majority of respondents work in academic settings and had >10 years in practice. Only 16% believe that their patients take the majority of opioids prescribed, while only 35% provide education to their patients on proper disposal. DISCUSSION: There is significant variability in reported opioid prescribing practices after ambulatory procedures amongst pediatric urologists. Only 16% of respondents believe that patients take the majority of opioids prescribed, and only 14% reported never prescribing opioids for these procedures. There is an opportunity for guidelines and standardization of care for postoperative analgesia in this patient population. Given that overprescribing can lead to abuse and misuse, further work needs to be done to establish postoperative analgesia needs and to educate providers and families on proper prescribing and disposal. CONCLUSION: Pediatric urologists report prescribing opioids frequently after routine ambulatory procedures in infants, children, and adolescents despite believing that patients do not take the majority of the prescribed medication.

Protective role for the N-terminal domain of α-dystroglycan in Influenza A virus proliferation.

α-Dystroglycan (α-DG) is a highly glycosylated basement membrane receptor that is cleaved by the proprotein convertase furin, which releases its N-terminal domain (α-DGN). Before cleavage, α-DGN interacts with the glycosyltransferase LARGE1 and initiates functional O-glycosylation of the mucin-like domain of α-DG. Notably, α-DGN has been detected in a wide variety of human bodily fluids, but the physiological significance of secreted α-DGN remains unknown. Here, we show that mice lacking α-DGN exhibit significantly higher viral titers in the lungs after Influenza A virus (IAV) infection (strain A/Puerto Rico/8/1934 H1N1), suggesting an inability to control virus load. Consistent with this, overexpression of α-DGN before infection or intranasal treatment with recombinant α-DGN prior and during infection, significantly reduced IAV titers in the lungs of wild-type mice. Hemagglutination inhibition assays using recombinant α-DGN showed in vitro neutralization of IAV. Collectively, our results support a protective role for α-DGN in IAV proliferation.

The evolution of the human foot.

There are 26 bones in each foot (52 in total), meaning that roughly a quarter of the human skeleton consists of foot bones. Yet, early hominin foot fossils are frustratingly rare, making it quite difficult to reconstruct the evolutionary history of the human foot. Despite the continued paucity of hominid or hominin foot fossils from the late Miocene and early Pliocene, the last decade has witnessed the discovery of an extraordinary number of early hominin foot bones, inviting a reassessment of how the human foot evolved, and providing fresh new evidence for locomotor diversity throughout hominin evolution. Here, we provide a review of our current understanding of the evolutionary history of the hominin foot.

A quantification of calcaneal lateral plantar process position with implications for bipedal locomotion in Australopithecus.

The evolution of bipedalism in the hominin lineage has shaped the posterior human calcaneus into a large, robust structure considered to be adaptive for dissipating peak compressive forces and energy during heel-strike. A unique anatomy thought to contribute to the human calcaneus and its function is the lateral plantar process (LPP). While it has long been known that humans possess a plantarly positioned LPP and apes possess a more dorsally positioned homologous structure, the relative position of the LPP and intraspecific variation of this structure have never been quantified. Here, we present a method for quantifying relative LPP position and find that, while variable, humans have a significantly more plantar position of the LPP than that found in the apes. Among extinct hominins, while the position of the LPP in Australopithecus afarensis falls within the human distribution, the LPP is more dorsally positioned in Australopithecus sediba and barely within the modern human range of variation. Results from a resampling procedure suggest that these differences can reflect either individual variation of a foot structure/function largely shared among Australopithecus species, or functionally distinct morphologies that reflect locomotor diversity in Plio-Pleistocene hominins. An implication of the latter possibility is that calcaneal changes adaptive for heel-striking bipedalism may have evolved independently in two different hominin lineages.

Estimating chronic disease rates in Canada: which population-wide denominator to use? / Taux de maladies chroniques au Canada : quel dénominateur utiliser pour l'estimation de l'ensemble de la population?

INTRODUCTION: Chronic disease rates are produced from the Public Health Agency of Canada's Canadian Chronic Disease Surveillance System (CCDSS) using administrative health data from provincial/territorial health ministries. Denominators for these rates are based on estimates of populations derived from health insurance files. However, these data may not be accessible to all researchers. Another source for population size estimates is the Statistics Canada census. The purpose of our study was to calculate the major differences between the CCDSS and Statistics Canada's population denominators and to identify the sources or reasons for the potential differences between these data sources. METHODS: We compared the 2009 denominators from the CCDSS and Statistics Canada. The CCDSS denominator was adjusted for the growth components (births, deaths, emigration and immigration) from Statistics Canada's census data. RESULTS: The unadjusted CCDSS denominator was 34 429 804, 3.2% higher than Statistics Canada's estimate of population in 2009. After the CCDSS denominator was adjusted for the growth components, the difference between the two estimates was reduced to 431 323 people, a difference of 1.3%. The CCDSS overestimates the population relative to Statistics Canada overall. The largest difference between the two estimates was from the migrant growth component, while the smallest was from the emigrant component. CONCLUSION: By using data descriptions by data source, researchers can make decisions about which population to use in their calculations of disease frequency.

INTRODUCTION: Les taux de maladies chroniques du Système canadien de surveillance des maladies chroniques (SCSMC) de l'Agence de la santé publique du Canada sont fondés sur les données administratives sur la santé fournies par les ministères de la Santé des provinces et des territoires. Les dénominateurs utilisés pour calculer ces taux reposent sur des estimations de population tirées des dossiers d'assurance-maladie, données toutefois pas systématiquement accessibles à tous les chercheurs. Le recensement de Statistique Canada constitue quant à lui une autre source d'estimation de la taille de la population. Notre étude visait d'abord à calculer les principaux écarts entre les dénominateurs de population à partir des estimations du SCSMC et à partir de celles de Statistique Canada et ensuite à déterminer les causes à l'origine des écarts entre ces sources de données. MÉTHODOLOGIE: Nous avons comparé pour 2009 les dénominateurs fournis par le SCSMC et ceux fournis par Statistique Canada. Le dénominateur du SCSMC a été ajusté pour tenir compte des composantes de la croissance (naissances, décès, émigrants et immigrants) tirées des données de recensement de Statistique Canada. RÉSULTATS: Le dénominateur non ajusté du SCSMC était de 34 429 804 personnes, soit une différence de + 3,2 % par rapport à l'estimation de population de Statistique Canada pour 2009. Après ajustement du dénominateur du SCSMC pour tenir compte des composantes de la croissance, la différence entre les deux estimations s'est trouvé réduite à 431 323 personnes, soit un écart de 1,3 %. L'estimation tirée du SCSMC constitue une surestimation par rapport à celle de Statistique Canada. Le plus grand écart entre les deux estimations relève de la composante de croissance liée à l'immigration, alors que l'écart le moindre provient de la composante de croissance liée à la population émigrante. CONCLUSION: Disposant des descriptions de données par source de données, les chercheurs peuvent choisir quelle estimation de la population utiliser dans leurs calculs des fréquences de maladies.

A critical appraisal of continence in bladder exstrophy: Long-term outcomes of the complete primary repair.

INTRODUCTION: Long-term continence outcomes for patients with bladder exstrophy are lacking in the literature. The complete primary repair of exstrophy (CPRE) is a widely adopted approach that seeks to normalize anatomy at the initial repair, thereby allowing early bladder filling and cycling. Previous reports of continence following CPRE, however, are limited by variable follow-up duration and continence definitions. OBJECTIVE: To assess continence and factors associated with a positive outcome in a cohort of patients following CPRE with long-term follow-up. STUDY DESIGN: A retrospective chart review was conducted of all patients with primary bladder closure using CPRE at the present institution for classic bladder exstrophy from 1990 to 2010. Patients <6 years of age or with an incomplete continence assessment at last follow-up were excluded. Continence was defined as voiding volitionally with dry intervals of ≥3 h, which was consistent with other high-volume series in the literature. RESULTS: Twenty-nine of the 52 patients (56%) were eligible for inclusion. Twelve patients were continent at last follow-up, including seven boys and five girls. Mean follow-up for the entire cohort was 148 months. The Summary table displays comparisons between continent and incontinent patients. Of patients achieving continence, 42% did not require further continence operations, while 17% required only one additional continence operation. DISCUSSION: Long-term CPRE continence rates were lower than previously reported, but comparable to other series in the literature. Of those achieving continence, 59% will do so with zero or one additional operation. Sex and osteotomy status were not associated with continence outcomes, although age at follow-up was a predictor of continence, favoring older patients in the present series. The study was limited by lack of standardized, patient-reported continence outcomes and by the retrospective nature of the review. However, the data add to the literature of long-term continence outcomes and are important for counseling families both at initial repair and follow-up. CONCLUSIONS: Complete primary repair of exstrophy can achieve continence without additional operations in a subset of patients. Some patients, however, may not achieve continence until adolescence, underscoring the need for long-term urologic follow-up in patients with bladder exstrophy.

Phenotype analysis impacts testing strategy in patients with Currarino syndrome.

Currarino syndrome (OMIM 175450) presents with sacral, anorectal, and intraspinal anomalies and presacral meningocele or teratoma. Autosomal dominant loss-of-function mutations in the MNX1 gene cause nearly all familial and 30% of sporadic cases. Less frequently, a complex phenotype of Currarino syndrome can be caused by microdeletions of 7q containing MNX1. Here, we report one familial and three sporadic cases of Currarino syndrome. To determine the most efficient genetic testing approach for these patients, we have compared results from MNX1 sequencing, chromosomal microarray, and performed a literature search with analysis of genotype-phenotype correlation. Based on the relationship between the type of mutation (intragenic MNX1 mutations vs 7q microdeletion) and the presence of intellectual disability, growth retardation, facial dysmorphism, and associated malformations, we propose a testing algorithm. Patients with the classic Currarino triad of malformations but normal growth, intellect, and facial appearance should have MNX1 sequencing first, and only in the event of a normal result should the clinician proceed with chromosomal microarray testing. In contrast, if growth delay and/or facial dysmorphy and/or intellectual disability are present, chromosomal microarray should be the first method of choice for genetic testing.

Effect of anabolic implants on adrenal cortisol synthesis in feedlot beef cattle implanted early or late in the finishing phase.

Implantation of anabolic steroids to increase growth rate in beef cattle impacts adrenal glucocorticoid production. The mechanism by which combination androgen and estrogen implants reduce cortisol biosynthesis in heifers is not clear. The objective of this study was to identify whether pituitary or adrenal gene expression and liver enzyme activity may contribute to altered serum cortisol concentrations in heifers receiving a combination implant. On d 0 of a 122-d finishing phase, 187 predominantly Angus heifers (361 kg) approximately 14 months old were randomly assigned to one of three implant groups: (1) non-implanted control, (2) implanted at the beginning of the finishing phase (d 0; early implant) with a combination implant (200mg TBA+20mg E2; Revalor 200®), and (3) implanted during the late stage of the finishing phase (d 56; late implant) with Revalor 200®. At d 56, body weight (BW) was greater (P<0.0001) for the early implanted heifers (456 ± 1.9 kg) compared to 437 and 435 (± 1.8) kg for control and late implanted heifers, respectively. Final BW (d 122) was similar between both implanted groups and heavier than non-implanted controls (P<0.0001). Serum cortisol was similar among groups at d 0 (P=0.86) however, by d 28 heifers receiving the combination implant had reduced (P<0.05) serum cortisol concentrations (31.2 ng/mL) compared to controls (49.4 ng/mL) and late (48.2 ng/mL) groups. On d 84 cortisol was similar (P=0.75) among implanted heifers and was less (P<0.01) than non-implanted heifers. Expression of pituitary and adrenal genes involved in glucocorticoid synthesis was evaluated at d 28/29 or 84/85; however, despite decreased serum cortisol in implanted heifers, no change in mRNA expression was demonstrated. Liver CYP3A enzyme activity at d 28/29 was decreased 59% in early implanted heifers compared to control heifers (P=0.01). Additionally, at d 84/85 AKR1C activity was greatest (P=0.01) in control heifers compared to both implanted groups. Data suggest that components of hypothalamic-pituitary-adrenal axis are influenced by exposure to exogenous hormones and this should be recognized when considering cortisol levels as a marker for stress response.

Oral vaccination and protection of striped skunks (Mephitis mephitis) against rabies using ONRAB®.

Skunks are one of the most important rabies vector species in North America due to their wide geographic distribution, high susceptibility to the rabies virus, and tendency to inhabit areas around human dwellings and domestic animals. Oral vaccination is a cost-effective, socially acceptable technique often used to control rabies in terrestrial wildlife; however, control of rabies in skunks has proven especially challenging due to the lack of a vaccine effective by the oral route in this species. In this study, we examined the antibody response of captive striped skunks (Mephitis mephitis) to ONRAB(®) and tested the protection afforded by the vaccine against rabies virus. Thirty-one skunks were each offered one ONRAB(®) vaccine bait, 25 skunks were administered ONRAB(®) via direct instillation into the oral cavity (DIOC) and ten controls received no vaccine. A blood sample was collected from controls and vaccinates 6 weeks prior to treatment, and then 5 and 7 weeks post-vaccination (PV). A competitive ELISA was used to detect rabies antibody (RAb). Pre-vaccination sera for all skunks, and sera for all controls throughout the serology study, were negative for RAb. Fifty-eight percent (18/31) of skunks in the bait group and 100% (25/25) of skunks that received ONRAB(®) DIOC had detectable RAb by 7 week PV. All 10 controls succumbed to experimental rabies infection. In the group of skunks administered ONRAB(®) DIOC, 100% (23/23) survived challenge 247 days PV. Survival of skunks presented ONRAB(®) baits was 81% (25/31). In the bait group, all 18 skunks that had detectable RAb by 7 week PV survived challenge. Seven additional skunks without detectable RAb prior to week 7 PV also survived. Lack of any remarkable pathology in study animals, together with positive serology and challenge results, supports that ONRAB(®) is a safe and effective oral rabies vaccine for use in skunks.

Oral vaccination and protection of red foxes (Vulpes vulpes) against rabies using ONRAB, an adenovirus-rabies recombinant vaccine.

Twenty-seven red foxes (Vulpes vulpes) were each offered a bait containing ONRAB, a recombinant oral rabies vaccine that uses a human adenovirus vector to express the immunogenic rabies virus glycoprotein; 10 controls received no vaccine baits. Serum samples collected from all foxes before treatment, and each week post-treatment for 16 weeks, were tested for the presence of rabies virus neutralizing antibody (RVNA). In the bait group, a fox was considered a responder to vaccination if serum samples from 3 or more consecutive weeks had RVNA ≥0.5 IU/ml. Using this criterion, 79% of adult foxes (11/14) and 46% of juveniles (6/13) responded to vaccination with ONRAB. Serum RVNA of adults first tested positive (≥0.5 IU/ml) between weeks 1 and 3, about 4 weeks earlier than in juveniles. Adults also responded with higher levels of RVNA and these levels were maintained longer. Serum samples from juveniles tested positive for 1-4 consecutive weeks; in adults the range was 2-15 weeks, with almost half of adults maintaining titres above 0.5 IU/ml for 9 or more consecutive weeks. Based on the kinetics of the antibody response to ONRAB, the best time to sample sera of wild adult foxes for evidence of vaccination is 7-11 weeks following bait distribution. Thirty-four foxes (25 ONRAB, 9 controls) were challenged with vulpine street virus 547 days post-vaccination. All controls developed rabies whereas eight of 13 adult vaccinates (62%) and four of 12 juvenile vaccinates (33%) survived. All foxes classed as non-responders to vaccination developed rabies. Of foxes considered responders to vaccination, 80% of adults (8/10) and 67% of juveniles (4/6) survived challenge. The duration of immunity conferred to foxes would appear adequate for bi-annual and annual bait distribution schedules as vaccinates were challenged 1.5 years post-vaccination.