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Biomedical subjects

S Bennett

Publications and source records attributed to S Bennett.

270 records · Page 15Linked to original sources
PubMedDate not supplied

Clinical case definitions for malaria: clinical malaria associated with very low parasite densities in African infants.

In areas endemic for Plasmodium falciparum, clinical malaria is believed to be less common in infants than in older children, but specific case definitions have rarely been determined for this age group. As malaria case definitions are known to be both age- and site-specific, assessment of the risk of disease in infancy requires the development of appropriate diagnostic criteria. In southern Ghana, 154 children were recruited at birth and monitored for fever and malaria infection until 2 years of age. Logistic regression was used to model fever risk as a continuous function of parasite density to determine case definitions for the diagnosis of clinical malaria, and to determine age- and season-specific estimates of the fraction of fevers attributable to malaria (AF); 2360 observations were made on 154 children. For fevers defined by a measured temperature > or = 37.5 degrees C, the estimated population AF was 44% (95% confidence interval 34-53). Estimates of AF varied with age and season. For infants, AF was 51% during the wet season and 22% during the dry season; for children over one year of age, AF was 89% during the wet season and 36% during the dry season. The estimated parasite density threshold for initiation of a febrile episode was 100 parasites per microL of blood in infants, compared with 3500 parasites per microL for children over one year of age. Using these case definitions, the incidence of clinical malaria was estimated at 0.09 cases per child-year at risk for children less than 6 months of age, 0.40 for children aged 6-11 months, and 0.69 for children aged 12-23 months. Of 66 cases of clinical malaria, only 3 were observed in children under 5 months of age. We concluded that, although most fevers in infants are not due to malaria, infant clinical malaria may occur at extremely low parasite densities. This may be indicative of a lack of anti-disease immunity in this age group. In southern Ghana, an infant with axillary temperature > or = 37.5 degrees C and parasitaemia > or = 100/microL should be considered to have clinical malaria. Nevertheless, the incidence of clinical malaria is very low in children under 6 months of age, confirming that they are significantly protected from clinical malaria compared to older children.

Age Factors↗
PubMedDate not supplied

Prevalence of hydrocele as a rapid diagnostic index for lymphatic filariasis.

The real burden of lymphatic filariasis in most endemic areas remains unknown even thought it is a major public health problem in many tropical countries, particularly in sub-saharan African. The nocturnal periodicity of the parasite requires parasitological examinations to be done at night. The aim of this study was to develop and validate rapid epidemiological assessment tools for the community diagnosis of lymphatic filariasis, that may be used in the future to determine the distribution of the disease and identify high risk communities in Ghana. Twenty communities with varying endemicity of filariasis were sampled from 3 endemic districts. Community members were selected for the study using a modified Expanded Programme for Immunization (EPI) cluster sampling technique. The prevalence of hydrocele was high (range 4.5-40.75%, mean = 17.78%) and the community prevalence of microfilaraemia correlated well with that of hydrocele (r = 0.84). The findings suggest that it is possible to obtain reliable and valid estimates of the community burden of lymphatic filariasis using the prevalence of hydrocele as a diagnostic index.

Adolescent↗
PubMedDate not supplied

Clinical predictors of malaria in Gambian children with fever or a history of fever.

Diagnosis of malaria in children is difficult without laboratory support because the symptoms and signs of malaria overlap with those of other febrile illnesses such as pneumonia. Nevertheless, in many parts of Africa diagnosis of malaria must be made without laboratory investigation. Therefore, a scoring system has been developed to assist peripheral health care workers in making this diagnosis. Four hundred and seven Gambian children aged 6 months to 9 years who presented to a rural clinic with fever or a recent history of fever were investigated. A diagnosis of malaria was made in 159 children who had a fever of 38 degrees C or more and malaria parasitaemia of 5000 parasites/microL or more. Symptoms and signs in children with malaria were compared with those in children with other febrile illnesses to identify features which predicted malaria. Symptoms and signs were incorporated into various logistic regression models to test which were best independent predictors of malaria and these regression models were used to construct simple scoring systems which predicted malaria. A nine terms model predicted clinical malaria with a sensitivity of 89% and a specificity of 61%, values comparable to those obtained by an experienced paediatrician without laboratory support. The ability of peripheral health care workers to diagnose malaria using this approach is now being investigated in a prospective study.

Antimalarials↗
PubMedDate not supplied

Stimulation of wound healing by positively charged dextran beads depends upon clustering of beads and cells in close proximity to the wound.

We have previously shown that positively charged dextran (DEAE A25) increases wound breaking strength in linear incisions in rats and nonhuman primates at days 10-14 postwounding. In this article, we examined the cellular responses to different types of charged dextran beads (DEAE A50 and Cytodex-1) in culture studies and in rat incisional wounds. We show that Cytodex 1 and DEAE A50 beads also increased wound breaking strength in a rat linear incisional model. However, the increase was approximately 30-40% less than that observed in wounds treated with DEAE A25 beads. The main distinction between the three types of beads was the presence of bead clusters observed in tissue sections. Wounds treated with DEAE A25 beads formed distinct clusters while both Cytodex 1 and DEAE A50 beads clustered to a lesser extent or failed to cluster at all. We propose that the different types of charged dextran beads improve healing by promoting cell adhesion and encouraging proliferation in close proximity to the wound. We also hypothesize that the 30-40% improvement in wound breaking strength seen with DEAE A25 beads compared to other types of charged dextran beads (DEAE A50 and Cytodex-1) originates from the unique characteristic of DEAE A25 beads in forming cell-bead aggregates adjacent to the wounded area. This clustering, in turn, affects the distribution of cells infiltrating the wounded area (such as macrophages) during the healing process and, as a consequence, alters the distribution of matrix molecules and growth factors secreted by these cells.

Animals↗
PubMedDate not supplied

Affected sib-pair analysis in endometriosis.

This paper (i) reviews the current clinical and molecular genetic data which strongly suggest that endometriosis has a genetic basis; (ii) outlines the general principles of affected-sib pair analysis; and (iii) describes the Oxford Endometriosis Gene (OXEGENE) Study which aims, using a positional cloning approach, to identify susceptibility genes involved in the development of the disease.

Adult↗
PubMedDate not supplied

Comparison of surgical techniques in the treatment of laryngeal polypoid degeneration.

Surgical excision has been the accepted treatment of laryngeal polypoid degeneration, or chronic polypoid corditis. We report on 29 women with polypoid degeneration who received one of three surgical treatments: vocal fold stripping, carbon dioxide laser obliteration, or the Hirano technique. The duration of postoperative dysphonia was longest with the laser removal and shortest with the Hirano technique. A combination of vocal hygiene management and the Hirano technique of removal provided the most efficacious treatment.

Chronic Disease↗
PubMedDate not supplied

Understanding young children's health beliefs and diabetes regimen adherence.

Previous studies of chronic illness management in children have focused mainly on parents' health beliefs. However, children's health beliefs also can be an important factor in predicting adherence. Indeed, children 6 to 10 years old spend most waking hours away from home, are under less parental supervision, and are becoming more responsible for their own care. The purpose of this study was to develop a pictorial, multi-item instrument to measure dimensions of the Health Belief Model (HBM) and self-efficacy (SE), designed specifically for children with diabetes, thus making it possible to examine both the parent's and child's health beliefs; to explore the relationship between their beliefs; and to examine the extent to which these beliefs are predictors of adherence and metabolic control.

Attitude to Health↗
PubMedDate not supplied

Hemoglobin concentration in children in a malaria holoendemic area is determined by cumulated Plasmodium falciparum parasite densities.

In malaria holoendemic areas children are anemic, but the exact influence of falciparum malaria on hemoglobin (Hb) concentration remains largely unsettled. Prospective data were therefore collected in children < 24 months of age during five months in a Tanzanian village. Children with mean asymptomatic parasitemia > or = 400/microl had lower median Hb levels during the study than those with mean density < 400/microl. The difference was 9.7 g/L (95% confidence interval [CI] 2.8-17). In children with one or more clinical malaria episodes, the median Hb was 8.3 g/L (95% CI 0.9-16) lower than those without episode. If early treatment failure was recorded, the immediate effect on Hb was particularly important with a mean drop of 17 g/L. Interestingly, at study-end the Hb concentration represented a function of the area under the parasitemia curve (AUPC) during the previous five months, adjusting for age. In conclusion, stepwise deterioration in median Hb levels was found by asymptomatic parasitemia, clinical malaria episode, and most significantly, treatment failure.

Animals↗
PubMedDate not supplied

Recent epidemiological studies to test microbiological quality guidelines for wastewater use in agriculture and aquaculture.

BACKGROUND: New guidelines for wastewater reuse (WHO 1989) are controversial. Epidemiological studies are needed to test their validity. Cross-sectional studies of the impact of excreta use in aquaculture in Indonesia, and of wastewater use in irrigation in Mexico have been carried out. METHODS: Each study involved an exposed group using wastewater/excreta with no treatment, a control group with no wastes use, and an intermediate group, where wastewater/excreta was used but some health protection measure existed. In Mexico, the intermediate group used wastewater from a storage reservoir which met the new WHO guideline for restricted irrigation. In Indonesia, the intermediate group did not have domestic exposure to pondwater, whose quality was around forty times higher than the tentative WHO bacterial guideline for fishpond water. RESULTS: In Indonesia, the prevalence of diarrhoeal disease was low in adults, and unrelated to exposure, but high in children under 5 years. Multiple logistic regression analysis gave odds ratios of 1.4 (p = .06) for consumer exposure, 1.9 (p = .01) for recreational or occupational exposure and 1.6 (p = .01) for domestic exposure, when allowance was made for all other exposures and several confounding factors. In Mexico, preliminary analysis of the wet season data suggests that the increased risks of Ascaris infection and diarrhoeal disease from the use of raw wastewater are removed when water of WHO guideline quality from storage reservoirs is used. CONCLUSION: WHO (1989) guidelines can be tested using cross-sectional epidemiological studies which indicate that guidelines for restricted irrigation and for aquaculture may be around the right level.

Adolescent↗
PubMedDate not supplied

Health impact evaluation of wastewater use in Mexico.

Wastewater from Mexico city is used to irrigate over 85 000 hectares, mainly of fodder and cereal crops in the Mezquital Valley. A cross-sectional study method is being used to test the impact of exposure to raw wastewater and wastewater from storage reservoirs on diarrhoeal disease and parasitic infections in farmworkers and their families. The study population in the rainy season survey included 1 900 households: 680 households where the farmworker is exposed to untreated wastewater (exposed group), 520 households exposed to reservoir water (semi exposed group), and 700 households where the farmworker practices rain-fed agriculture (control group). Preliminary analysis of the data from the rainy season study (dry season study in progress) has been carried out. Current information indicates that the risk of Ascaris lumbricoides infection is much higher in the exposed group than in the semi-exposed and the control groups. According to the procedures employed Entamoeba histolytica infection was more frequent in individuals aged 5 to 14 years exposed to wastewater, than in those in the control group. When diarrhoeal disease rates were analyzed, children under age 15 years from exposed households had a significantly higher prevalence than controls. The final results of this study are expected to aid decisions on low cost treatment options and other health protection measures within the National Wastewater Reuse Programme in Mexico. The implications for assessment of the WHO guidelines for the use of wastewater in agriculture are discussed.

Adolescent↗
PubMedDate not supplied

A content validation study of five nursing diagnoses by critical care nurses.

OBJECTIVE: To identify frequently used nursing diagnoses as perceived by critical care nurses and to examine content validity of defining characteristics of five selected nursing diagnoses. DESIGN: Retrospective, descriptive. SETTING: Critical care units in one midwestern state. SUBJECTS: Registered nurses, members of American Association of Critical Care Nurses, currently practicing in critical care units (n = 59). OUTCOME MEASURES: Diagnostic content validity (DCV) scores and the most frequently used diagnoses as perceived by the subjects as recorded on the Nursing Diagnoses Validation Instrument. PROCEDURE: Mailed to subjects, self-administered. RESULTS: Major defining characteristics were identified for all five nursing diagnoses. Alterations in Comfort and Impaired Skin Integrity were perceived as most frequently used diagnoses. CONCLUSIONS: Despite limitations of this study, findings reflected a consensus concerning defining characteristics of the nursing diagnoses Impaired Skin Integrity, Sleep Pattern Disturbance (Adult), and Activity Intolerance. Beginning support was found for defining characteristics of Sleep Pattern Disturbance (Child) and Parental Role Conflict. Additional content validation research that focuses on perceived frequently used diagnoses is indicated to generate clinically relevant nursing diagnoses.

Critical Care↗
PubMedDate not supplied

[Epidemiologic setting of the agricultural use of sewage: Valle del Mezquital, Mexico].

Wastewater from Mexico City is used to irrigate over 85,000 hectares mainly of fodder and cereal crops in the Mezquital Valley. A cross-sectional study method is being used to test the impact of exposure to raw wastewater and wastewater from storage reservoirs on diarrheal disease and parasitic infections in farmworkers and their families. The study population in the rainy season survey included 1,900 households: 680 households where the farmworker is exposed to untreated wastewater (exposed group), 520 households exposed to reservoir water (semiexposed group), and 700 households where the farmworker practices rain-fed agriculture (control group). Preliminary analysis of the data from the rainy season study (dry season study in progress) has been carried out. Current information indicates that the risk of Ascaris lumbricoides infection is much higher in the exposed group than in the control group (95% CL = 2.9-10.8). According to the procedures employed Entamoeba histolytica infection was more frequent among subjects aged 5 to 14 years from households exposed to raw wastewater, than among subjects of the same ages belonging to the control group (95% CL = 1.07-1.72). When diarrheal disease rates were analyzed, children under 5 years from exposed households had a significantly higher prevalence than controls (95% CL = 1.03-1.64). The final results of this study are expected to aid decisions within the National Wastewater Reuse Programme in Mexico.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

[The health problems associated with irrigation with wastewater in Mexico].

Over 85,000 hectares in the Mezquital Valley of central Mexico are irrigated with wastewater. The main crops are fodder and cereal crops. A two cross-sectional survey was carried out to test the impact of exposure to raw wastewater and from storage of that wastewater in reservoirs. The main outcomes were diarrhoeal disease and parasitic infections in farmworkers and their families. The total study population in the dry season included 2,049 households. The study population was classified in households where the farmworker is exposed to untreated wastewater (exposed group), households exposed to reservoir water (semi-exposed group), and households where the farmworker practices rain-fed agriculture (control group). Preliminary analysis of the data has been carried out. Current information indicates that the risk of Ascaris lumbricoides infection is much higher in the exposed group than in the control group (95% CL = 4.0-67.3 and 4.7-78.8). According to the procedures employed, exposed children from exposed households were at higher risks of diarrhoeal disease than controls (95% CL = 1.03-2.03). The final results of this study are expected to aid decisions within the reuse programmes in developing countries.

Adolescent↗