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PB2452, a neutralizing monoclonal antibody fragment that binds the antiplatelet drug ticagrelor with high affinity, is being developed as a ticagrelor reversal agent. To identify a clinically useful intravenous (i.v.) reversal regimen, a semimechanistic exposure‐response model was developed during the PB2452 first‐in‐human phase I study. From a randomized, double‐blind, placebo‐controlled, single‐dose trial to evaluate the safety, efficacy, and pharmacokinetics (PKs) of PB2452 in 61 healthy volunteers pretreated with ticagrelor, sequential dose cohort data were used to build and refine an exposure‐response model that combined population PK models for ticagrelor (TICA), ticagrelor active metabolite (TAM), and PB2452, and related their binding relationships to the PK of uncomplexed TICA and TAM which is predictive of platelet inhibition. Platelet function was assessed by multiple assays. The model was developed using Bayesian methods in NONMEM. Human PK and pharmacodynamic data from sequential dose cohorts were used to initially define and then refine model parameters. Model simulations indicated that an initial i.v. bolus of PB2452, followed by a high‐rate infusion, and then a slower‐rate infusion would provide immediate and sustained reversal of the antiplatelet effects of ticagrelor. Based on model predictions, a 6 g i.v. bolus followed by 6 g infused over 4 h and then 6 g over 12 h was identified and tested in study subjects and shown to provide complete reversal within 5 min of infusion onset that was sustained for 20–24 h. The model is predictive of the reversal profile of PB2452 and will inform future trials of PB2452.

Transfer of contaminants to and from the skin surface has been postulated to occur through a number of different pathways and compartments including: object(s)-to-skin, skin-to-skin, skin-to-clothing, skin-to-gloves, air-to-skin, skin-to-lips, and skin-to-saliva. However, many identified transfer pathways have been only minimally examined to determine the potential for measurable transfer. The purpose of this study was to quantitatively evaluate repeated transfer between different compartments using elemental metallic lead (Pb) in the solid form using a series of systematic measurements in human subjects. The results demonstrated that some transfer pathways and compartments are significantly more important than others. Transfer of Pb could not be measured from skin to cotton clothing or skin to laminate countertop surfaces. However, transfer was consistently measured for skin-to-skin and between the skin and the surface of nitrile gloves, suggesting the potential for significant transfer to or from these compartments in real-world exposure scenarios, and the importance of these pathways. With repeated contacts, transfer increased non-linearly between 1 and 5 contacts, but appeared to approach a steady state distribution among the compartments within 10 contacts. Consistent with other studies, relative to 100% transfer for a single contact, the quantitative transfer efficiency decreased with repeated contacts to 29% after 5 contacts and 11-12% after 10 contacts; for skin-to-skin transfer measurements, transfer efficiency after either 5 or 10 contacts was approximately 50% of the single contact transfer. These data are likely to be useful for refining current approaches to modeling of repeated contacts for dermal exposure and risk assessment.

Ticagrelor is an oral P2YIn this randomized, double-blind, placebo-controlled, phase 1 trial, we evaluated intravenous PB2452, a monoclonal antibody fragment that binds ticagrelor with high affinity, as a ticagrelor reversal agent. We assessed platelet function in healthy volunteers before and after 48 hours of ticagrelor pretreatment and again after the administration of PB2452 or placebo. Platelet function was assessed with the use of light transmission aggregometry, a point-of-care P2YOf the 64 volunteers who underwent randomization, 48 were assigned to receive PB2452 and 16 to receive placebo. After 48 hours of ticagrelor pretreatment, platelet aggregation was suppressed by approximately 80%. PB2452 administered as an initial intravenous bolus followed by a prolonged infusion (8, 12, or 16 hours) was associated with a significantly greater increase in platelet function than placebo, as measured by multiple assays. Ticagrelor reversal occurred within 5 minutes after the initiation of PB2452 and was sustained for more than 20 hours (P0.001 after Bonferroni adjustment across all time points for all assays). There was no evidence of a rebound in platelet activity after drug cessation. Adverse events related to the trial drug were limited mainly to issues involving the infusion site.In healthy volunteers, the administration of PB2452, a specific reversal agent for ticagrelor, provided immediate and sustained reversal of the antiplatelet effects of ticagrelor, as measured by multiple assays. (Funded by PhaseBio Pharmaceuticals; ClinicalTrials.gov number, NCT03492385.).

Background/aim Estimating domestic assistance requirements within the medicolegal field is a role for occupational therapists. It is a complex multidimensional process of clinical reasoning with no published research outlining how an occupational therapist translates assessment data into the number of hours of domestic assistance required. This study describes the current occupational therapy practice of estimating domestic assistance hours within the medicolegal context. Method Three focus groups, totalling 14 occupational therapists providing medicolegal reports in New South Wales, were conducted. Sydney University provided ethics approval. Focus group data were thematically analysed. Results Four themes were identified: Tasks included as housework. Assessment process - interview of pre-injury and recovery status; functional performance on specific tasks and a tour of the home. Influential factors - include legal system restrictions, medical management, cultural and society values, family expectations, location and impact of diagnosis. Strategies to determine care - triangulation of observed data with medical reports and clinical experience. Knowledge of community and own performance times within the framework of occupational therapy philosophy DISCUSSION: No single method of translating assessment data to hours of care was identified. Therapists use of their own housework performance raises ethical issues. Use of claimant only statements raises issues of inaccurate data on which to base decisions. Therapists should refer to occupational therapy process of clinical reasoning to explain their recommendations even though the reasoning does not give a definite number of care hours. Conclusion Therapists need to understand the factors influencing their clinical reasoning when integrating all available information into an estimating of domestic assistance hours. Further study analysing the content of medicolegal report may provide information as to how therapists document their clinical reasoning for court.

Background Current animal models of glioma are limited to small animal models, which are less predictive of treatment of human disease. Canines often develop gliomas de novo, but the natural history of the disease is not well described. Objective We provide data for naturally occurring canine gliomas; evaluating medical and surgical therapies. Methods We reviewed medical records of pet dogs with a presumptive diagnosis of glioma from MRI imaging that underwent surgery as part of the Canine Brain Tumor Clinical Trials Program. Breed, age, sex, median progression-free, and overall survival times and cause of death were recorded for multivariate analysis. Results Ninety five dogs (56 male; mean age = 8.3 years) were included, but nine were excluded as final pathology was non-neoplastic. Gross total resection was reported in 81 cases based on postoperative MRI. Seventy had high-grade tumors (grade III or IV). Eighty three dogs presented with seizures, being the most common presenting clinical sign. Median survival after surgery was 723 days (95% CI 343-1103) for grade II tumors, 301 days (197-404) for grade III and 200 days (126-274) for grade IV (p = .009 Kaplan-Meier survival analysis; Log Rank test). Age (cox regression, p = .14) or sex (Kaplan-Meier test, p = .22) did not predict survival. Conclusions This study establishes normative data for a model exploiting dogs with naturally occurring glioma, which can be used to test novel therapies prior to translation to human trials. Further work will focus on the effects of different therapies, including chemotherapy, radiation therapy, and immunotherapy.

Purpose/objectives To develop and test a worksite intervention that protects healthcare workers who handle antineoplastic drugs from work-related exposures. . Design Intervention study. . Setting A university hospital in a large midwestern metropolitan area and its outpatient chemotherapy infusion clinic. . Sample 163 staff (nurses, pharmacists, and pharmacy technicians) who work with antineoplastic agents. . Methods A self-report survey measured workplace and individual factors to assess use of personal protective equipment (PPE). Wipe samples were tested for surface contamination. An intervention incorporating study findings and worker input was developed. . Main research variables PPE use was the dependent variable, and the independent variables included knowledge of the hazard, perceived risk, perceived barriers, interpersonal influence, self-efficacy, conflict of interest, and workplace safety climate. . Findings PPE use was lower than recommended and improved slightly postintervention. Self-efficacy and perceived risk increased on the post-test survey. Chemical residue was found in several areas. Awareness of safe-handling precautions improved postintervention. The unit where nurses worked was an important predictor of safety climate and PPE use on the pretest but less so following the intervention. . Conclusions Involving staff in developing an intervention for safety ensures that changes made will be feasible. Units that implemented workflow changes had decreased contamination. . Implications for nursing Worksite analysis identifies specific targets for interventions to improve antineoplastic drug handling safety.

Importance Clinical genomic tests that examine the DNA sequence of large numbers of genes are commonly used in the diagnosis and management of epilepsy in pediatric patients. The permanence of genomic test result interpretations is not known. Objective To investigate the value of reinterpreting previously reported genomic test results. Design, Setting, and Participants This study retrospectively reviewed and reinterpreted genomic test results from July 1, 2012, to August 31, 2015, for pediatric patients who previously underwent genomic epilepsy testing at a single tertiary care pediatric health care facility. Reinterpretation of previously reported variants was conducted in May 2017. Main Outcomes and Measures Patient reports from clinical genomic epilepsy tests were reviewed, and all reported genetic variants were reinterpreted using 2015 consensus standards and guidelines for interpreting hereditary genetic variants. Three classification tiers were used in the reinterpretation: pathogenic or likely pathogenic variant, variant of uncertain significance (VUS), or benign or likely benign variant. Results A total of 309 patients had genomic epilepsy tests performed (mean [SD] age, 5.6 [0.8] years; 163 [52.8%] male), and 185 patients had a genetic variant reported. The reported variants resulted in 61 patients with and 124 patients without a genetic diagnosis (VUS variants only). On reinterpretation of all reported variants, 67 of the 185 patients (36.2%) had a change in variant classification. Of the 67 patients with a genetic variant change in interpretation, 21 (31.3%) experienced a change in diagnosis. During the 5 years of the study, 19 of 61 patients (31.1%) with a genetic diagnosis and 48 of 124 patients (38.7%) with undiagnosed conditions (VUS only) had their results reclassified. Review of genomic reports issued during the final 2 years of the study identified reclassification of variants in 4 of 16 patients (25.0%) with a pathogenic or likely pathogenic variant and 11 of 41 patients (26.8%) with a VUS. Conclusions and Relevance The identified high rate of reinterpretation in this study suggests that interpretation of genomic test results has rapidly evolved during the past 5 years. These findings suggest that reinterpretation of genomic test results should be performed at least every 2 years.

Case management is a service frequently provided to clients following a traumatic brain injury (TBI); however, the time required for this service is uncertain. To identify factors that influence case management for clients with TBI, a descriptive analysis of 64 client files were provided with case management services of a rehabilitation provider based in Sydney, Australia. These files were then further examined by using qualitative measures to determine the relationship among case management factors, time required, and the severity of the injury. This information was statistically analyzed to identify what factors predicted the greatest use of case management time. The analysis identified inappropriate behavior, family dynamics, accommodation, and formal relationships as primary affectors on case management time. Other issues identified as less demanding of case management time were sustaining employment and provision of equipment.In terms of case management hours, the mean was 2.5 hr/ month. Where there was a combination of three factors, the time for case management increased to a mean of 3.97 hr, and up to 4.34 hr/month (range: 1.5-14.0 hr) of case management time where 4 factors were identified. A positive relationship between severity of posttraumatic amnesia (PTA) and care and needs score was also noted to impact on amount of case management time and duration of service.Keywords: estimating time; plan costs; case management; traumatic brain injury(ProQuest: ... denotes formula omitted.)The provision of case management services is an integral part of the rehabilitation process for those people who have sustained a traumatic brain injury (TBI). Although there are guidelines within each of the New South Wales (NSW) compensable systems (worker's compensation and motor accident insurance) regarding the provision of case management services, there are no guidelines about how much time is required to reasonably conduct case management interventions. When a rehabilitation provider is developing a rehabilitation plan, the allocation of time for case management is frequently a "best guess" based on experience in relation to the identified goals.Prior to this study, the anecdotal consensus experience of the case managers at Sydney-based rehabilitation provider service was that a client with a moderate-to-severe TBI would require an average of at least 2 hr of case management services for each month the program operated. Those with mild-to-moderate TBI required 1-2 hr/month. These recommendations were based on the absence of crisis events occurring. Crisis events were defined as including change of care providers, change of marital status, change of residence, change of medication or surgical intervention, delays in the provision of adaptive equipment, difficulties regarding return to work, and deterioration in mental, physical, or cognitive health.To provide consistent guidelines regarding the amount of case management assistance required for clients with TBI, a review of previous cases was undertaken. The purpose of this review was to (a) identify the amount of case management time used by clients with TBI at the rehabilitation service and (b) determine what factors may predict a greater use of case management time.LITERATURE REVIEWThe published literature regarding the benefit of case management is somewhat uncertain; for example, there are various interpretations of the role of the case manager, the base qualifications required by a case manager, as well as the benefit of case management (Khan, Baguely, & Cameron, 2003). However, each of the compensable systems in NSW has established their own definitions regarding the role of case management. For example, in the compulsory third party (CTP) system, the Motor Accidents Authority (2003) has established Guideline Case Management for the NSW Motor Accident Scheme, whereas WorkCover NSW (2005) defines case management as "a set of clearly defined practices, underpinned by quality assurance and continuous improvement. …

Background The C8 Health Project was created, authorized, and funded as part of the settlement agreement reached in the case of Jack W. Leach, et al. v. E.I. du Pont de Nemours & Company (no. 01-C-608 W.Va., Wood County Circuit Court, filed 10 April 2002). The settlement stemmed from the perfluorooctanoic acid (PFOA, or C8) contamination of drinking water in six water districts in two states near the DuPont Washington Works facility near Parkersburg, West Virginia. Objectives This study reports on the methods and results from the C8 Health Project, a population study created to gather data that would allow class members to know their own PFOA levels and permit subsequent epidemiologic investigations. Methods Final study participation was 69,030, enrolled over a 13-month period in 2005-2006. Extensive data were collected, including demographic data, medical diagnoses (both self-report and medical records review), clinical laboratory testing, and determination of serum concentrations of 10 perfluorocarbons (PFCs). Here we describe the processes used to collect, validate, and store these health data. We also describe survey participants and their serum PFC levels. Results The population geometric mean for serum PFOA was 32.91 ng/mL, 500% higher than previously reported for a representative American population. Serum concentrations for perfluorohexane sulfonate and perfluorononanoic acid were elevated 39% and 73% respectively, whereas perfluorooctanesulfonate was present at levels similar to those in the U.S. population. Conclusions This largest known population study of community PFC exposure permits new evaluations of associations between PFOA, in particular, and a range of health parameters. These will contribute to understanding of the biology of PFC exposure. The C8 Health Project also represents an unprecedented effort to gather basic data on an exposed population; its achievements and limitations can inform future legal settlements for populations exposed to environmental contaminants.

A major burn injury during childhood interrupts normal school experiences and friendships. The recovery period is difficult for patients and classmates. Recognizing the important role of school-related social networking during convalescence, the "Remember Me" program was initiated to keep the patients in touch with peers while hospitalized. The purpose of this study was to evaluate program effectiveness in school-aged children (K-8) who sustained burn injuries involving > 20% TBSA. The program was introduced to patients meeting enrollment criteria. After a signed release by the legal guardian, the child's residential school was contacted and oriented to the program. A Remember Me tool kit (program instructions, a teddy bear and a large, postage-paid return envelope) was forwarded to the school. The bear was positioned in the patient's seat at school for the duration of the child's hospitalization. Placed with the bear was an envelope to collect classmate's letters, cards, photos, and other forms of communication, which were forwarded to the patient. The process was completed by a survey that assessed patient/parent/school satisfaction to gauge the utility of the program. Thirty patients (mean age, 8.4 years) from 18 states participated in the Remember Me program. The children had burn injuries involving approximately 44% TBSA. The mean length of hospitalization was 52.4 days. One hundred percent of the patients received a response from classmates as a result of this program. A survey sent to the parents of the child indicated that 100% judged the program to be useful. The Remember Me program was effective at maintaining communication between the burned child and his or her classmates during lengthy hospital stays. The program was overwhelmingly popular with not only the children treated, but also their parents, teachers, and classmates.

Topiramate (TPM), an anti-epileptic drug with4 million users, increases renal stones in adults. We screened outpatient TPM-treated children without history of stones to estimate the prevalence of renal stones and to characterize urine stone-risk profiles.Children taking TPM ≥1 month underwent an interview, renal ultrasound, and spot urine testing in this prospective study. Normal spot urine values were defined as: calcium/creatinine ratio ≤0.20 mg/mg (12 months) or ≤0.60 mg/mg (≤12 months), citrate/creatinine ratio0.50 mg/mg, and pH ≤ 6.7.Of 41 patients with average age of 9.2 years (range 0.5-18.7), mean TPM dose of 8.0 mg/kg/day (range 1.4-23.6), and mean treatment duration of 27 months (range 1-112), two (4.9%) had renal stones. The majority of children taking TPM had lithogenic abnormalities on spot urine testing, including 21 (51%) with hypercalciuria, 38 (93%) with hypocitraturia, and 28 (68%) with pH ≥ 6.7. Hypercalciuria and hypocitraturia were independent of TPM dose and duration; urine pH increased with dose. 24-h urine parameters improved in 1 stone-former once TPM was weaned.Asymptomatic stones were found in 2/41 (4.8%) children taking TPM. Risk factors for stones were present in the spot urine of most children, including hypocitraturia (93%) and hypercalciuria (51%), independent of TPM dose and duration. High urine pH, found in 68%, correlated with TPM dose. Pediatric specialists should be aware of increased risks for stones, hypercalciuria, hypocitraturia, and alkaline urine in children taking TPM.

Object. Unilateral resection of the hippocampus and amygdala can be used to treat medically intractable mesial temporal lobe seizures. To date seizure outcome and the extent of cognitive morbidity have been unknown in children following the transparahippocampal variation of selective amygdalohippocampectomy (TSA), which prompted the present prospective study.Methods. Preoperative examinations and outcomes in 22 consecutive children and adolescents who underwent TSA were studied. Cognitive and psychological morbidity were assessed using standard neuropsychological instruments. The authors evaluated relationships between seizure control and cognitive morbidity and 13 and nine clinical variables, respectively.Seizure control was achieved in 11 (65%) of 17 patients (> 2 years follow up). Among 13 clinical variables, the only preoperative finding that had a significant bearing on seizure control was the presence of unilateral hypometabolism, which could be observed on [18F]fluorodeoxyglucose—positron emission tomography scans (p < 0.001). Patients with seizure control showed significant improvements in verbal and full scale intelligence quotients (both p = 0.05). Patients with longer preoperative durations of seizures exhibited more cognitive impairment that persisted postoperatively. Cognitive outcome analysis based on nine clinical factors revealed no significant difference in cognitive parameters postoperatively, except that significant improvement occurred in rote verbal memory scores among patients who underwent right-sided TSA (p = 0.01). Individually, 81% of the children achieved significant improvement in at least one of seven cognitive parameters, and 52% had stable or improved scores in all parameters.Conclusions. The results indicate that TSA is a safe effective approach for the treatment of medically intractable mesial temporal lobe seizures in children with minimum effect on cognitive morbidity. Given that the literature suggests that children suffer progressive cognitive morbidity from persistent seizures, the results of this study support early surgical intervention for this group of children.

Language regression is observed both in autistic regression and as part of acquired epileptic aphasia (Landau-Kleffner Syndrome). We prospectively identified 177 children with language regression at four major medical centers, and their clinical characteristics were recorded. Their mean age at regression was 22.8 months. The mean time-to-specialist referral was 38 months of age. Most children (88%) met criteria for autism or manifested autistic features. Males (P = 0.02) and children less than 3 years of age who regressed (P = 0.016) had a higher probability of developing autistic behaviors. Seizures were more common in children who regressed after they reached 3 years of age (P < 0.001), and children with seizures were less likely to have associated autistic regression (P < 0.001). Electroencephalogram abnormalities were reported in 37% of patients and were more common in children with seizures (P < 0.001). At last follow-up, language function was impaired in 88% of the children, although some improvement was noted in 57%. We conclude that the loss of previously acquired language at any age, even if that language only includes a few words or communicative gestures, is often associated with a more global regression in cognition and/or behavior and has serious implications for future function. Early identification and referral of these children is necessary to allow for diagnosis and intervention.

Children with cerebral palsy who receive selective dorsal rhizotomy (SDR) for treatment of spasticity may show suprasegmental changes in upper limb function and control of speech musculature. Anecdotal reports suggest that supra-segmental effects may extend to cognitive functions such as attention and language. This study examined the performance of 16 children with spastic diplegic cerebral palsy on tests of visual attention and other cognitive functions 1 day prior to and 6 months following SDR. Children undergoing SDR were compared with 9 children with spastic diplegia, matched for severity of cerebral palsy and amount of therapy, who did not receive SDR, and 24 age- and sex-matched normal children tested at initial and 6-month follow-up sessions. Children with cerebral palsy treated with SDR showed disproportionately greater improvement in specific attentional and cognitive operations than either of the other groups. These results document cognitive changes following SDR which heretofore were reportedly anecdotally. This improvement may be due to improved mood, reduced physical discomfort, increased therapeutic intervention, or possible cortical effects of SDR.

SUMMARYIn 1977, a parasitological survey was undertaken of stool samples collected from 335 people from 5 villages in semi-arid regions of peninsular India. Stools, which were collected from various individuals in a stratified sample of 40 matched households from each village, were examined by standard diagnostic procedures. Eggs ofAscaris lumbricoidesand protozoan cysts, which were identified on morphological grounds as belonging toEntamoebaspp., were most common. Other protozoan cysts were considered to be those ofBalantidium coli, and eggs of hookworm andHymenolepis nanawere also observed in some of the stool specimens. The prevalence of parasitic infections varied between villages. The village with the highest prevalence ofAscaris(70%) appeared to have the greatest demands made on its meagre drinking-water supply. This village is located in a dry, windy and dusty region and it is speculated that, in addition to well-established transmission mechanisms, the villagers may be exposed, perhaps through contamination of uncovered drinking-water wells and inhalation, to wind-borneAscariseggs. In 1967, a WHO Expert Committee Report on the Control of Ascariasis pointed out that information on the frequency of dust-borne infection withAscarisin man was inadequate.

Five children with autism and one with dysphasia were studied using a pragmatic measure of dyadic interpretation formerly used only in normal populations. It was shown that such a measure could be used to describe the interactive behavior of deviant children in a reliable and valid way. Mothers of these children are, by and large, less able to set up successful dialogues because they frequently redirect them. After a nursery program of 5 to 8 months, mothers became less asynchronous and approximated a teacher's success in synchronous dialogue. Autistic children's development can be enhanced by better interaction with their adult environment. This study demonstrates how this new application of a method can measure such changes.

SummaryBy means of conventional light microscopical and counting procedures, estimations have been made of the average number and size of ovarian balls from unfertilized and fertilized femaleMoniliformis dubius. The observations were made on worms recovered from experimental primary infections lasting 1, 2, 3, 4, 5, 8, 11, 14, 17 and 20 weeks in male rats. The number of ovarian balls rises to about 6300 per worm, with the maximum being attained more rapidly in unfertilized than in fertilized females. On average more ovarian balls were present in unfertilized than in fertilized females, but a marked decline in number occurred in both groups of worms towards the end of the experimental period. Similarly, on the basis of the area within the elliptical profiles of fixed ovarian balls, it appeared that those from unfertilized females were generally larger on average than those from fertilized worms.

General nutritional effects on female CFLP mice harbouring larval Taenia crassiceps were investigated using groups of mice fed ad libitum on purified diets containing 2%, 4%, 8% and 16% (w/w) protein respectively. When uninfected and infected mice were compared over an experimental period of 20 weeks, it was established that a significantly higher proportion of uninfected mice survived the course of the experiment than infected mice. There was no evidence of the presence of the parasites having any effect on the overall food intake of the mice. Infected mice, however, were found to be significantly heavier, on a fresh weight basis, than their uninfected partners, but the pattern was reversed when the dry weights of mouse carcasses were compared following the removal of parasites. In general, more parasite tissue was recovered from mice feeding on the higher protein diets (8% and 16%).

To understand the apparently paradoxical appearance of phosphorylase in muscle cultured from patients with McArdle disease, the enzyme in muscle culture was studied immunologically and electrophoretically. Antibody against normal human muscle phosphorylase completely inhibited the enzyme of adult muscle, but it had no effect on phosphorylase activity of muscle cultures from normal individuals or patients with McArdle disease. Also, amounts of antibody that would completely inhibit phosphorylase in mature muscle left about 30% of the activity in muscle obtained from human fetus at four months' gestation. Acrylamide-disc and slab-gel electrophoresis showed a single band of phorphorylase activity in adult muscle and two bands in fetal muscle. This suggested that at four months' gestation, both fetal and mature forms are present but that only the mature isoenzyme is inhibited by the antibody. The enzyme from cultured muscle gave only a single band, with the electrophoretic mobility of the fetal isoenzyme. These data suggest that phosphorylase activity in muscle cultured from patients with McArdle disease is due to a fetal isoenzyme whose genetic control is different from that of the mature enzyme.

SUMMARYEvidence for the presence of 11 intestinal parasites in pre-school children from 4 rural villages in Ghana was obtained from an examination of stool samples. Striking differences were detected between the prevalence of some of the 6 common infections in the 4 villages. The prevalance of Ascaris lumbricoides varied from about 76% in one village (Oshiyie, coastal savanna) to apparently 0% in another (Akuma, forest zone). No differences in prevalence for any infection were observed to be sex dependent. Investigation of the relationship between age of the children and prevalance showed that the degree of prevalence of both A. lumbricoides and Trichuris trichiura had essentially levelled off by the time the children were 4 years old. There was no evidence to suggest that the prevalence of either Entamoeba sp. or spp. or hookworm was approaching a maximum value, even in the oldest children. These trends applied across the villages regardless of the differences in prevalence values for the infections. On average, the children of Oshiyie were found to harbour twice as many infections as the children of the other villages. The investigation of the prevalence data revealed evidence of associations between pairs of infections, particularly those involving hookworm and T. trichiura.

The patent period has been observed to last for 106 ± 16 days. On average, egg release usually began when the worms were 38 days old and ended when they were 144 days old. Considerable variation was observed from day to day in the number of eggs released by worms in an individual rat and in the numbers released by similar infections in other rats. Some infections showed a peak period of egg production and others a plateau phase. On average, a female worm releases about 5500 eggs/day and about 600,000 eggs during an average patent period. These estimates and all the other results in this work relate to infections of 12 cystacanths per male rat.