RESUMEN
Child maltreatment has detrimental social and health effects for individuals, families and communities. The ERICA project is a pan-European training programme that equips non-specialist threshold practitioners with knowledge and skills to prevent and detect child maltreatment. This paper describes and presents the findings of a rapid review of good practice examples across seven participating countries including local services, programmes and risk assessment tools used in the detection and prevention of child maltreatment in the family. Learning was applied to the development of the generic training project. A template for mapping the good practice examples was collaboratively developed by the seven participating partner countries. A descriptive data analysis was undertaken organised by an a priori analysis framework. Examples were organised into three areas: programmes tackling child abuse and neglect, local practices in assessment and referral, risk assessment tools. Key findings were identified using a thematic approach. Seventy-two good practice examples were identified and categorised according to area, subcategory and number. A typology was developed as follows: legislative frameworks, child health promotion programmes, national guidance on child maltreatment, local practice guidance, risk assessment tools, local support services, early intervention programmes, telephone or internet-based support services, COVID-19 related good practices. Improved integration of guidance into practice and professional training in child development were highlighted as overarching needs. The impact of COVID-19 on safeguarding issues was apparent. The ERICA training programme formally responded to the learning identified in this international good practice review.
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Gamma-rays from naturally occurring radionuclides are a major component of background radiation. They are an important tool for geology and are also important for radiation protection. In this paper we use over a quarter of a million geochemical measurements of concentrations of potassium, thorium and uranium in soils and in stream sediments to estimate outdoor gamma-ray dose rates across Great Britain. The soil concentrations are generally at a depth of 5-20 cm with some at 35-50 cm. Soil measurements will give spatially relatively precise estimates, but as soil data are not available for much of Scotland, stream sediment data are used there. Kriging methods are used to estimate surface concentrations of K, Th and U and dose rates are imputed from these concentrations. Our results are compared with measurement surveys of both outdoor and indoor gamma-ray dose rates. Recently there has been interest in exploring the carcinogenic risks of low dose radiation by investigating associations between childhood cancer rates and doses from natural background gamma radiation. To achieve adequate statistical power, such studies must be so large that it is impractical to assess exposures by direct measurements in the homes of study subjects. Instead the exposures must be modelled. The results presented here will be an important input to such work.
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Monitoreo de Radiación , Contaminantes Radiactivos del Suelo , Uranio , Radiación de Fondo , Niño , Rayos gamma , Humanos , Radioisótopos de Potasio/análisis , Monitoreo de Radiación/métodos , Suelo , Contaminantes Radiactivos del Suelo/análisis , Torio/análisis , Reino Unido , Uranio/análisisRESUMEN
BACKGROUND: Robotic-assisted laparoscopy (RAL) is an alternative to traditional laparoscopic surgery that might increase a surgeon's ability to offer minimally invasive removal of Müllerian remnants (MR) to patients with complex anatomy. We report on 2 cases of RAL resection of MR. CASES: RAL allowed for adequate resection of MR without complications in 2 cases. Case 1 was a 13 year-old female adolescent with VACTERL and uterine remnant close to the ureter of her ipsilateral single kidney. Case 2 was a 16 year-old female adolescent with cloacal exstrophy and omphalocele with remnant hindgut and cervical remnant deep in the pelvis close to the ileal conduit. SUMMARY AND CONCLUSION: In 2 adolescents with complex anatomy and surgical history, RAL allowed for successful removal of MR.
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Laparoscopía , Procedimientos Quirúrgicos Robotizados , Uréter , Adolescente , Femenino , Humanos , ÚteroRESUMEN
BACKGROUND: Single-incision laparoscopic surgery (SILS) is an exciting new modality in the field of minimal access surgery. This case illustrates the feasibility of single-incision laparoscopic surgery for uterine pathology in the pediatric and adolescent population. CASE: A 19-year-old girl presented with pelvic pain. Transabdominal pelvic ultrasound and magnetic resonance imaging revealed multiple fibroids with rapid enlargement over a year. In collaboration with the Minimally Invasive Gynecologic Surgery team, single incision laparoscopic myomectomy was performed with satisfactory results. SUMMARY AND CONCLUSION: Complex uterine pathology can be managed with minimally invasive surgery with excellent clinical outcomes. SILS is a rapidly developing field that may represent the future of laparoscopic surgery and can be used to treat reproductive pathology in the pediatric and adolescent population.
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Leiomioma/cirugía , Miomectomía Uterina/métodos , Neoplasias Uterinas/cirugía , Femenino , Humanos , Laparoscopía/métodos , Leiomioma/diagnóstico por imagen , Leiomioma/patología , Ultrasonografía , Neoplasias Uterinas/patología , Adulto JovenRESUMEN
BACKGROUND: In order to measure and understand trajectories of parental feeding practices and their relationship with child eating and weight, it is desirable to perform assessment from infancy and across time, in age-appropriate ways. While many feeding practices questionnaires exist, none is presently available that enables tracking of feeding practices from infancy through childhood. The aim of the study was to develop a version of the Feeding Practices and Structure Questionnaire (FPSQ) for parents with infants and toddlers (< 2 years) to be used in conjunction with the original FPSQ for older children (≥2 years) to measure feeding practices related to non-responsiveness and structure across childhood. METHODS: Constructs and items for the FPSQ for infants and toddlers were derived from the existing and validated FPSQ for older children and supplemented by a review of the literature on infant feeding questionnaires. Following expert review, two versions of the questionnaire were developed, one for milk feeding parents and one for solid feeding parents. Data from two studies were combined (child ages 0-24 months) to test the derived constructs with Confirmatory Factor Analysis for the milk feeding (N = 731) and solid feeding (N = 611) versions. RESULTS: The milk feeding version consisted of four factors (18 items) and showed acceptable model fit and good internal reliability: 'feeding on demand vs. feeding routine' (α = 0.87), 'using food to calm' (α = 0.87), 'persuasive feeding' (α = 0.71), 'parent-led feeding' (α = 0.79). The same four factors showed acceptable model fit for the solid feeding version (21 items), likewise with good internal reliability (α = 0.74, 0.86, 0.85, 0.84 respectively). Two additional factors (13 items) were developed for the solid feeding version that appeared developmentally appropriate only for children aged 12 months or older: 'family meal environment' (α = 0.81) and 'using (non-)food rewards' (α = 0.92). The majority of factor-factor correlations were in line with those of the original FPSQ. CONCLUSIONS: The FPSQ milk and solid feeding versions are the first measures specifically developed as precursors to the FPSQ to measure parental feeding practices in children < 2 years, particularly practices related to non-responsiveness and structure. Further validation in more diverse samples is required.
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Métodos de Alimentación/estadística & datos numéricos , Encuestas y Cuestionarios , Australia , Peso Corporal , Alimentación con Biberón , Lactancia Materna , Preescolar , Análisis Factorial , Familia , Conducta Alimentaria , Femenino , Humanos , Lactante , Alimentos Infantiles , Recién Nacido , Masculino , Padres , Reproducibilidad de los ResultadosRESUMEN
Gamma radiation from naturally occurring sources (including directly ionizing cosmic-rays) is a major component of background radiation. An understanding of the magnitude and variation of doses from these sources is important, and the ability to predict them is required for epidemiological studies. In the present paper, indoor measurements of naturally occurring gamma-rays at representative locations in Great Britain are summarized. It is shown that, although the individual measurement data appear unimodal, the distribution of gamma-ray dose-rates when averaged over relatively small areas, which probably better represents the underlying distribution with inter-house variation reduced, appears bimodal. The dose-rate distributions predicted by three empirical and geostatistical models are also bimodal and compatible with the distributions of the areally averaged dose-rates. The distribution of indoor gamma-ray dose-rates in the UK is compared with those in other countries, which also tend to appear bimodal (or possibly multimodal). The variation of indoor gamma-ray dose-rates with geology, socio-economic status of the area, building type, and period of construction are explored. The factors affecting indoor dose-rates from background gamma radiation are complex and frequently intertwined, but geology, period of construction, and socio-economic status are influential; the first is potentially most influential, perhaps, because it can be used as a general proxy for local building materials. Various statistical models are tested for predicting indoor gamma-ray dose-rates at unmeasured locations. Significant improvements over previous modelling are reported. The dose-rate estimates generated by these models reflect the imputed underlying distribution of dose-rates and provide acceptable predictions at geographical locations without measurements.
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Rayos gamma , Modelos Estadísticos , Dosis de Radiación , Reino UnidoRESUMEN
OBJECTIVES: There has been little evaluation of the evidence relating dietary factors to functional capacity in older adults. The aims were to i) conduct a systematic review of studies assessing dietary factors in relation to six key functional indicators which impact on quality of life in adults ≥65 yrs: non-fatal cardiovascular events, cognition, mental health, falls and fractures, physical health (muscle mass, strength) and frailty; and ii) assess if there was sufficient evidence to devise food-based dietary recommendations. DESIGN: Systematic review. PARTICIPANTS: Cross-sectional and prospective cohort studies were included together with intervention studies that evaluated food/drink interventions (excluding supplements). Evidence base statements were determined according to the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) levels of evidence criteria (Grades (A-excellent; B-good; C-satisfactory; D-poor). RESULTS: There was good evidence that the Mediterranean type diet (MD) reduced the risk of non-fatal cardiovascular events (Grade B) and reduced cognitive decline (Grade B). There was some evidence indicating that a MD decreases the likelihood of frailty (Grade C), consistent but weaker evidence that ≥3 servings/d of vegetables is associated with reduced cognitive decline (Grade D), a modest increase in protein may be associated with improved cognition (Grade C) and decreased frailty (Grade C), and that protein plus resistance exercise training in frail elderly may enhance physical strength (Grade C). CONCLUSION: It is recommended that older adults adopt the characteristics of a Mediterranean type diet such as including olive oil and eating ≥3 servings/d of vegetables to reduce their risk of chronic disease, impaired cognition and frailty. Consumption of dietary protein above the current dietary requirements would be recommended to reduce risk of frailty and impaired cognition. A modest increase in dietary protein when combined with resistance exercise would be recommended to help maintain muscle mass and strength and to enhance functional capacity.
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Enfermedad Crónica/epidemiología , Dieta/métodos , Calidad de Vida/psicología , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
Understanding the impact of obesity on elective total joint arthroplasty (TJA) remains critical. Perioperative outcomes were reviewed in 316 patients undergoing primary TJA. Higher percent body fat (PBF) was associated with postoperative blood transfusion, increased hospital length of stay (LOS) >3 days, and discharge to an extended care facility while no significant differences existed for BMI. Additionally, PBF of 43.5 was associated with a 2.4× greater likelihood of blood transfusion, PBF of 36.5 with a 1.9× greater likelihood for LOS >3 days, and PBF of 36.0 with a 1.4× greater likelihood for discharge to an extended care facility. PBF may be a more effective measure than BMI to use in screening for perioperative risks and acute outcomes associated with obese total joint patients.
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Tejido Adiposo , Artroplastia de Reemplazo de Cadera , Artroplastia de Reemplazo de Rodilla , Índice de Masa Corporal , Obesidad/complicaciones , Transfusión Sanguínea/estadística & datos numéricos , Femenino , Humanos , Tiempo de Internación/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Instituciones de Cuidados Especializados de Enfermería/estadística & datos numéricos , Resultado del TratamientoRESUMEN
BACKGROUND: The importance and specific role(s) of eosinophils in modulating the immune/inflammatory phenotype of allergic pulmonary disease remain to be defined. Established animal models assessing the role(s) of eosinophils as contributors and/or causative agents of disease have relied on congenitally deficient mice where the developmental consequences of eosinophil depletion are unknown. METHODS: We developed a novel conditional eosinophil-deficient strain of mice (iPHIL) through a gene knock-in strategy inserting the human diphtheria toxin (DT) receptor (DTR) into the endogenous eosinophil peroxidase genomic locus. RESULTS: Expression of DTR rendered resistant mouse eosinophil progenitors sensitive to DT without affecting any other cell types. The presence of eosinophils was shown to be unnecessary during the sensitization phase of either ovalbumin (OVA) or house dust mite (HDM) acute asthma models. However, eosinophil ablation during airway challenge led to a predominantly neutrophilic phenotype (>15% neutrophils) accompanied by allergen-induced histopathologies and airway hyper-responsiveness in response to methacholine indistinguishable from eosinophilic wild-type mice. Moreover, the iPHIL neutrophilic airway phenotype was shown to be a steroid-resistant allergic respiratory variant that was reversible upon the restoration of peripheral eosinophils. CONCLUSIONS: Eosinophil contributions to allergic immune/inflammatory responses appear to be limited to the airway challenge and not to the sensitization phase of allergen provocation models. The reversible steroid-resistant character of the iPHIL neutrophilic airway variant suggests underappreciated mechanisms by which eosinophils shape the character of allergic respiratory responses.
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Eosinófilos/inmunología , Hipersensibilidad Respiratoria/inmunología , Alérgenos/inmunología , Animales , Asma/genética , Asma/inmunología , Asma/metabolismo , Citotoxicidad Inmunológica , Toxina Diftérica/administración & dosificación , Toxina Diftérica/inmunología , Modelos Animales de Enfermedad , Resistencia a Medicamentos , Eosinófilos/citología , Eosinófilos/efectos de los fármacos , Eosinófilos/metabolismo , Técnicas de Sustitución del Gen , Células Precursoras de Granulocitos/inmunología , Células Precursoras de Granulocitos/metabolismo , Factor de Crecimiento Similar a EGF de Unión a Heparina , Humanos , Péptidos y Proteínas de Señalización Intercelular/genética , Ratones , Ovalbúmina/inmunología , Fenotipo , Neumonía/genética , Neumonía/inmunología , Neumonía/metabolismo , Hipersensibilidad Respiratoria/genética , Hipersensibilidad Respiratoria/metabolismo , Hipersensibilidad Respiratoria/patología , Esteroides/farmacología , Células Th2/inmunología , Células Th2/metabolismoRESUMEN
OBJECTIVE: To investigate the differences in gait biomechanics on the basis of surgical approach 1 year after surgery. DESIGN: This was a descriptive laboratory study to investigate the side-to-side differences in walking mechanics at a self-selected walking speed as well as a functional assessment 1 year after total hip arthroplasty (THA). Temporospatial, kinetic, and kinematic data as well as functional outcomes were collected. Two-way analysis of variance was used to assess for between-group differences and limb-to-limb asymmetries. SETTING: A controlled laboratory study. PARTICIPANTS: This study examined 35 patients with primary, unilateral THA. The THA surgical approaches that were used in these patients included 12 direct lateral, 18 posterior, and 11 anterolateral. All the patients were assessed 1 year after THA. Patients were excluded from the study if they had contralateral hip pain or pathology, or any prior lower extremity total joint replacements. MAIN OUTCOME MEASUREMENTS: Three-dimensional lower extremity kinematics and kinetics as well as spatiotemporal variables were collected. In addition, a series of physical performance measures were collected. RESULTS: No main effects for the physical performance measures or biomechanical variables were observed among the approach groups. Significant limb-to-limb asymmetries were observed among all the patients, with decreased sagittal plane range of motion, peak extension, and peak vertical ground reaction forces on the operative side. CONCLUSION: The results of this study indicated that no significant differences existed among the different surgical approach groups for any study variable. However, 1 year after THA, the patients demonstrated asymmetric gait patterns regardless of surgical approach, which indicated the potential need for continued intervention through physical therapy to regain normal side-to-side symmetry after THA.
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Artroplastia de Reemplazo de Cadera/rehabilitación , Terapia por Ejercicio/métodos , Marcha/fisiología , Caminata/fisiología , Adulto , Fenómenos Biomecánicos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Factores de TiempoRESUMEN
Predictive linear regression (LR) modelling indicates that total Pb is the only highly significant independent variable for estimating Pb bioaccessibility in "mineralisation domains" located in limestone (high pH) and partly peat covered (low pH) shale-sandstone terrains in England. Manganese is a significant minor predictor in the limestone terrain, whilst organic matter and sulphur explain 0.5% and 2% of the variance of bioaccessible Pb in the peat-shale-sandstone terrain, compared with 93% explained by total Pb. Bootstrap resampling shows that LR confidence limits overlap for the two mineralised terrains but the limestone terrain has a significantly lower bioaccessible Pb to total Pb slope than the urban domain. A comparison of the absolute values of stomach and combined stomach-intestine bioaccessibility provides some insight into the geochemical controls on bioaccessibility in the contrasting soil types.
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Fenómenos Geológicos , Plomo/análisis , Contaminantes del Suelo/análisis , Suelo/química , Ciudades , Monitoreo del Ambiente , Plomo/química , Modelos Químicos , Contaminantes del Suelo/química , Reino UnidoRESUMEN
The aim of this study was to evaluate differences between the small and large intestines (SI and LI) with regard to colonization and immunity during infection with Trichinella spiralis. In orally infected C57BL/6 mice, the gender ratios of worms differed among the SI, cecum, and LI. Mucosal mastocytosis developed in the SI but not in the LI, consistent with reduced IL-9 and IL-13 production by explants from the LI. Despite these differences, worms were cleared at the same rate from both sites. Furthermore, IL-10 production was reduced in the LI, yet it was instrumental in limiting local inflammation. Finally, passive immunization of rat pups with tyvelose-specific antibodies effectively cleared fist-stage larvae from all intestinal regions. We conclude that despite regional differences in immune responsiveness and colonization, immune mechanisms that clear T. spiralis operate effectively throughout the intestinal tract.
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Citocinas/inmunología , Intestino Grueso/parasitología , Intestino Delgado/parasitología , Trichinella spiralis/inmunología , Triquinelosis/inmunología , Animales , Animales Recién Nacidos , Anticuerpos Antihelmínticos/inmunología , Citocinas/metabolismo , Femenino , Inmunización Pasiva , Interleucina-10/metabolismo , Intestino Grueso/inmunología , Intestino Delgado/inmunología , Larva , Masculino , Mastocitos/inmunología , Mastocitosis/inmunología , Mastocitosis/parasitología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratas , Organismos Libres de Patógenos Específicos , Triquinelosis/parasitologíaRESUMEN
Intestinal infection with the parasitic nematode, Trichinella spiralis, provides a robust context for the study of mucosal mast cell function. In rats, mucosal mast cells are exposed to parasites during the earliest stage of infection, affording an opportunity for mast cells to contribute to an innate response to infection. During secondary infection, degranulation of rat mucosal mast cells coincides with expulsion of challenge larvae from the intestine. The goal of this study was to evaluate the rat bone marrow-derived mast cells (BMMC) and the rat basophilic leukaemia cell line (RBL-2H3) as models for mucosal mast cells, using parasite glycoproteins and antibody reagents that have been tested extensively in rats in vivo. We found that BMMC displayed a more robust mucosal phenotype. Although T. spiralis glycoproteins bound to mast cell surfaces in the absence of antibodies, they did not stimulate degranulation, nor did they inhibit degranulation triggered by immune complexes. Parasite glycoproteins complexed with specific monoclonal IgGs provoked release of rat mast cell protease II (RMCPII) and ß-hexosaminidase from both cell types in a manner that replicated results observed previously in passively immunized rats. Our results document that RBL-2H3 cells and BMMC model rat mucosal mast cells in the contexts of innate and adaptive responses to T. spiralis.
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Inmunidad Mucosa , Mastocitos/inmunología , Trichinella spiralis/inmunología , Triquinelosis/inmunología , Animales , Complejo Antígeno-Anticuerpo , Células de la Médula Ósea/inmunología , Degranulación de la Célula , Línea Celular , Células Cultivadas , Glicoproteínas/metabolismo , Proteínas del Helminto/metabolismo , Larva/inmunología , Mastocitos/citología , Ratas , Ratas Endogámicas Lew , Trichinella spiralis/crecimiento & desarrolloRESUMEN
BACKGROUND: We believe that there is a need to increase awareness, particularly among foundation year doctors, of the importance of performing a full neurological examination, including ophthalmoscopy, in medical inpatients. Following a serious unexpected incident (missed papilloedema), we implemented a multifaceted intervention, including ensuring greater availability of equipment for neurological/ ophthalmological assessment, education and curriculum redesign in two large teaching hospitals in the UK. METHODS: Following the results of our initial intervention, we introduced a patient assessment scoring system to evaluate patient recollection of the completeness of neurological examination by medical staff in the two Trusts over a four-month period. RESULTS: Of the 93 patients referred to neurology during this period, 33% could not recollect being examined with a tendon hammer and 48% said they had not been examined with an ophthalmoscope. In contrast, the majority (95.7%) remembered the use of a stethoscope in their examination. The data were fed back to medical staff which resulted in greater awareness of the importance of a complete neurological examination. No further adverse incidents of missed papilloedema were reported in the following 12 months, although it would be premature to state that this situation has been resolved. CONCLUSIONS: A patient assessment score can be used by medical staff to raise awareness of the importance of a complete neurological examination from referring physicians.
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Competencia Clínica/normas , Diagnóstico Tardío/prevención & control , Evaluación de Necesidades , Enfermedades del Nervio Óptico/diagnóstico , Participación del Paciente , Examen Físico/normas , Mejoramiento de la Calidad , Adulto , Concienciación , Femenino , Encuestas de Atención de la Salud , Hospitales de Enseñanza , Humanos , Masculino , Recuerdo Mental , Neurología , Oftalmología , Oftalmoscopía/métodos , Oftalmoscopía/estadística & datos numéricos , Pacientes , Examen Físico/métodos , Médicos , Reino Unido , Adulto JovenRESUMEN
Predictive linear regression (LR) modelling between bioaccessible Pb and a range of total elemental compositions and soil properties was executed for the Glasgow, London, Northampton and Swansea urban areas in order to assess the potential for developing a national urban bioaccessible Pb dataset for the UK. LR indicates that total Pb is the only highly significant independent variable for estimating the bioaccessibility of Pb. Bootstrap resampling shows that the relationship between total Pb and bioaccessible Pb is broadly the same in the four urban areas. The median bioaccessible fraction ranges from 38% in Northampton to 68% in London and Swansea. Results of this study can be used as part of a lines of evidence approach to localised risk assessment but should not be used to replace bioaccessibility testing at individual sites where local conditions may vary considerably from the broad overview presented in this study.
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Monitoreo del Ambiente/métodos , Plomo/análisis , Modelos Químicos , Contaminantes del Suelo/análisis , Suelo/química , Contaminación Ambiental/estadística & datos numéricos , Londres , Medición de Riesgo , Reino Unido , GalesRESUMEN
Predictive linear regression (LR) modelling between bioaccessible arsenic (B-As) and a range of total elemental compositions and soil properties was executed in order to assess the potential for developing a national B-As dataset for the UK. LR indicates that total arsenic (As) is the only highly significant independent variable for estimating B-As in urban areas where it explains 75-92% of the variance. The broad compatibility of the London, Glasgow and Swansea regression models suggests that application of these models to estimate bioaccessible As in UK soils impacted by diffuse anthropogenic urban contamination and non-ferrous metal processing should be relatively accurate. In areas dominated by Jurassic ironstones and associated clays and limestones, total As, P and pH are significant, accounting for 53, 14 and 5%, respectively, of the B-As variance. Models based on total As as the sole predictor in the combined Jurassic and Cretaceous sedimentary ironstones datasets explain about 40% of the B-As variance. The median As bioaccessible fraction (%As-BAF) is 19 to 28% in the anthropogenic contamination impacted urban domains, but much lower (5-9%) in geogenic terrains dominated by ironstones. Results of this study can be used as part of a lines of evidence approach to localised risk assessment but should not be used to replace bioaccessibility testing at individual sites where local conditions may vary considerably from the broad overview presented in this study.
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Arsénico/química , Contaminantes del Suelo/química , Suelo/química , Disponibilidad Biológica , Modelos Lineales , Modelos Químicos , Medición de Riesgo , Reino UnidoRESUMEN
The parasitic nematode Parelaphostrongylus tenuis is an important cause of neurologic disease of camelids in central and eastern North America. The aim of this study was to determine whether alpacas develop resistance to disease caused by P. tenuis in response to a previous infection or a combination of controlled infection and immunization. Alpacas were immunized with a homogenate of third-stage larvae (L3) and simultaneously implanted subcutaneously with diffusion chambers containing 20 live L3. Sham-treated animals received adjuvant alone and empty chambers. The protocol was not effective in inducing resistance to oral challenge with 10 L3, and disease developed between 60 and 71 days following infection. Immediately following the onset of neurologic disease, affected animals were treated with a regimen of anthelmintic and anti-inflammatory drugs, and all recovered. One year later, a subset of alpacas from this experiment was challenged with 20 L3 and the results showed that prior infection induced resistance to disease. Primary and secondary infections induced production of conventional and heavy-chain IgGs that reacted with soluble antigens in L3 homogenates but did not consistently recognize a recombinant form of a parasite-derived aspartyl protease inhibitor. Thus, the latter antigen may not be a good candidate for serology-based diagnostic tests. Antibody responses to parasite antigens occurred in the absence of overt disease, demonstrating that P. tenuis infection can be subclinical in a host that has been considered to be highly susceptible to disease. The potential for immunoprophylaxis to be effective in preventing disease caused by P. tenuis was supported by evidence of resistance to reinfection.