Identifying research priorities for infection prevention and control. A mixed methods study with a convergent design

Background

Meaningful research creates evidence for Infection Prevention and Control (IPC) practice.

Aim

To establish Infection Prevention Society (IPS) members' research priorities to support future research projects.

Methods

A mixed methods convergent parallel design incorporating a cross-sectional survey of IPS members (2022-2023), and focus group findings from the IPS Consultative Committee, (October 2022). Quantitative data were analysed using descriptive statistics. Qualitative data were transcribed verbatim, entered into NVivo 12, and analysed using a thematic analysis approach.

Findings/Results

132 IPS members responded to the survey, including 120 (90.9%) nurses. The three most prevalent priorities were: Quality Improvement and Patient Safety (n = 84, 16.1%); IPC Training and Education (n = 77, 14.8%); and IPC Evidence-based Guidelines (n = 76, 14.6%). Analysis of the focus group transcripts identified six emergent themes 'Patient Centred Care', 'Training and Education', 'IPC Role and Identity', 'IPC Leadership', 'IPC is Everyone's Responsibility', and 'Research Activity'. Triangulation of findings demonstrated concordance between quantitative and qualitative findings with Quality Improvement and Patient Safety (QIPS) and Training and Education identified as priority research areas.

Discussion

This study highlights the necessity of developing support systems and incorporating research priorities in QIPS, as well as Training and Education. The findings of this study align with the recommended core competencies and components for effective infection prevention and control programs, making them relevant to QIPS initiatives. The outcomes of the study will serve as a valuable resource to guide the IPS Research and Development Committee in delivering practical support to IPS members.

The tricot approach: an agile framework for decentralized on-farm testing supported by citizen science. A retrospective

Matching crop varieties to their target use context and user preferences is a challenge faced by many plant breeding programs serving smallholder agriculture. Numerous participatory approaches proposed by CGIAR and other research teams over the last four decades have attempted to capture farmers' priorities/preferences and crop variety field performance in representative growing environments through experimental trials with higher external validity. Yet none have overcome the challenges of scalability, data validity and reliability, and difficulties in capturing socio-economic and environmental heterogeneity. Building on the strengths of these attempts, we developed a new data-generation approach, called triadic comparison of technology options (tricot). Tricot is a decentralized experimental approach supported by crowdsourced citizen science. In this article, we review the development, validation, and evolution of the tricot approach, through our own research results and reviewing the literature in which tricot approaches have been successfully applied. The first results indicated that tricot-aggregated farmer-led assessments contained information with adequate validity and that reliability could be achieved with a large sample. Costs were lower than current participatory approaches. Scaling the tricot approach into a large on-farm testing network successfully registered specific climatic effects of crop variety performance in representative growing environments. Tricot's recent application in plant breeding networks in relation to decision-making has (i) advanced plant breeding lines recognizing socio-economic heterogeneity, and (ii) identified consumers' preferences and market demands, generating alternative breeding design priorities. We review lessons learned from tricot applications that have enabled a large scaling effort, which should lead to stronger decision-making in crop improvement and increased use of improved varieties in smallholder agriculture.

Using machine learning for image-based analysis of sweetpotato root sensory attributes

The sweetpotato breeding process involves assessing different phenotypic traits, such as the sensory attributes, to decide which varieties to progress to the next stage during the breeding cycle. Sensory attributes like appearance, taste, colour and mealiness are important for consumer acceptability and adoption of new varieties. Therefore, measuring these sensory attributes is critical to inform the selection of varieties during breeding. Current methods using a trained human panel enable screening of different sweetpotato sensory attributes. Despite this, such methods are costly and time-consuming, leading to low throughput, which remains the biggest challenge for breeders. In this paper, we describe an approach to apply machine learning techniques with image-based analysis to predict flesh-colour and mealiness sweetpotato sensory attributes. The developed models can be used as high-throughput methods to augment existing approaches for the evaluation of flesh-colour and mealiness for different sweetpotato varieties. The work involved capturing images of boiled sweetpotato cross-sections using the DigiEye imaging system, data pre-processing for background elimination and feature extraction to develop machine learning models to predict the flesh-colour and mealiness sensory attributes of different sweetpotato varieties. For flesh-colour the trained Linear Regression and Random Forest Regression models attained R 2 values of 0.92 and 0.87, respectively, against the ground truth values given by a human sensory panel. In contrast, the Random Forest Regressor and Gradient Boosting model attained R 2 values of 0.85 and 0.80, respectively, for the prediction of mealiness. The performance of the models matched the desirable R 2 threshold of 0.80 for acceptable comparability to the human sensory panel showing that this approach can be used for the prediction of these attributes with high accuracy. The machine learning models were deployed and tested by the sweetpotato breeding team at the International Potato Center in Uganda. This solution can automate and increase throughput for analysing flesh-colour and mealiness sweetpotato sensory attributes. Using machine learning tools for analysis can inform and quicken the selection of promising varieties that can be progressed for participatory evaluation during breeding cycles and potentially lead to increased chances of adoption of the varieties by consumers.

End-user preferences to enhance prospects for varietal acceptance and adoption in potato breeding in Uganda

BACKGROUND

Potato varieties have diverse biophysical characteristics, so it is important for breeders to have the capacity to choose those that meet the preferences of end users, such as mealiness, firmness, and taste, among others. Combining user preferences with descriptive information regarding the sensory characteristics of boiled potatoes can contribute to the improvement of consumer-driven varieties. This study aimed to factor in the preferences of end users to improve the prospects for varietal acceptance, adoption, and discrimination among genotypes in potato breeding.

RESULTS

The priority quality traits (traits that play the most significant roles in acceptance and adoption) of the boiled potatoes were determined by evaluating gender and livelihood using the G+ tool. The G+ tool is designed to assess gender impact on roots, tubers and bananas (RTB) traits by serving as a validation check to reflect on important gender-based issues in agricultural food systems in order to reduce harm and promote positive impact. Potato genotypes were differentiated by penetration (textural parameters as measured by standard texture probe) and the procedure was repeatable, as there was no significant difference between the cooking replicates at 40 min of cooking. Instrument-based texture parameters, such as penetration peak force (hardness/firmness) and area (area under the curve, which represents energy needed to penetrate) of boiled potato tubers were significantly associated with sensory attributes such as fracturability and hardness in the mouth. An attempt to differentiate genotypes using near-infrared spectroscopy (NIRS) revealed that the average results observed for the calibration for yellow color (r2  = 0.70), homogeneity of color (r2  = 0.48), moisture in mass (r2  = 0.40), and uniformity of texture (r2  = 0.56) suggested that these parameters could be used for initial breeding screening purposes.

CONCLUSIONS

The preferred traits of the boiled potato can be integrated into the potato-breeding program/product profile. Near-infrared spectroscopy shows strong potential to predict potato color and the ability of NIRS models to predict some texture attributes is also promising. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Decision tree scoring system to guide selection for consumer preference in sweetpotato breeding trials

BACKGROUND

Previously, a lexicon and protocol for quantitative descriptive analysis (QDA) was established for the Uganda sweetpotato breeding program. The implication of QDA scores for priority sensory attributes on consumer preference should be determined to interpret results efficiently and make decisions effectively. This study aimed to develop a gender-responsive decision tree to obtain an overall sweetpotato eating quality score to facilitate demand-led targeted breeding selection. It focused on Kamuli and Hoima districts (Uganda) and uses pre-lease advanced clones ('NKB3', 'NKB105', 'NKB135', 'D11', and 'D20'), released varieties ('NASPOT 8', 'NAROSPOT 1'), and landraces ('Muwulu-Aduduma', 'Umbrella').

RESULTS

Including boiled sweetpotato sensory characteristics, namely mealy, sweet taste, sweetpotato smell, firm and not fibrous in breeding design would benefit end-users, especially women given their role in varietal selection, food preparation and marketing. 'D20', 'NASPOT 8' and 'NAROSPOT 1' were most liked in both districts. 'NKB3' and 'D11' were the least liked in Hoima, while 'Muwulu-Aduduma' was the least liked in Kamuli. There was a positive correlation between color and overall liking (R² = 0.8) and consumers liked the color (average rating ≥ 6 on 9-point hedonic scale) of all genotypes. Threshold values (average rating on 11-point scales) for consumer acceptability were identified (sweet taste=6, sweetpotato aroma and flavor=6, firmness=3, and mealiness=4). A regression decision tree tool was created to calculate an eating quality selection index when screening lines in breeding programs using the values.

CONCLUSION

Decision trees that include consumer needs and gender considerations would facilitate demand-led breeding and make varietal selection in sweetpotato breeding programs more effective. This article is protected by copyright. All rights reserved.

Sensory guided selection criteria for breeding consumer-preferred sweetpotatos in Uganda

Prioritizing sensory attributes and consumer evaluation early in breeding trials to screen for end-user preferred traits could improve adoption rates of released genotypes. In this study, a lexicon and protocol for descriptive sensory analysis (DSA) was established for sweetpotato and used to validate an instrumental texture method for which critical values for consumer preference were set. The study comprised several phases: lexicon development during a 4-day workshop; 3-day intensive panel training; follow-up virtual training, evaluation of 12 advanced genotypes and 101 additional samples from two trials in 2021 by DSA and instrumental texture analysis using TPA double compression; and DSA, instrumental texture analysis and consumer acceptability tests on 7 genotypes in on-farm trials. The established sweetpotato lexicon comprising 27 sensory attributes enabled characterization and differentiation of genotypes by sensory profiles. Significant correlation was found between sensory firmness by hand and mouth with TPA peak positive force (r = 0.695 and r = 0.648, respectively) and positive area (r = 0.748, r = 0.715, respectively). D20, NAROSPOT 1, NASPOT 8, and Umbrella were the most liked genotypes in on-farm trials (overall liking = 7). An average peak positive force of 3700 gf was proposed as a minimum texture value for screening sweetpotato genotypes, since it corresponded with at least 46 % of consumers perceiving sweetpotatoes as just-about-right in firmness and a minimum overall liking of 6 on average. Combining DSA with instrumental texture analysis facilitates efficient screening of genotypes in sweetpotato breeding programs.

Effect of Orange-Fleshed Sweet Potato Purée and Wheat Flour Blends on β-Carotene, Selected Physicochemical and Microbiological Properties of Bread

Partial substitution of wheat flour with orange-fleshed sweet potato (OFSP) purée in bread can increase vitamin A intake among consumers. The study investigated the influence of wheat flour substitution with 20–50% of OFSP purée on proximate composition, color, β-carotene, water activity, and microbial keeping quality. The moisture content, crude protein, crude fat, total ash, crude fiber, and carbohydrate in bread ranged from 28.6–32.7%, 9.9–10.6%, 5.0–5.5%, 1.9–3.2%, 1.4–1.8%, and 79.1–80.9%, respectively. β-carotene, total ash, and crude fiber contents in bread, and Hunter color values a*, b*, chroma, and ∆E significantly increased with the addition of OFSP purée. Total viable counts (TVC), yeast, and molds in bread ranged from 2.82–3.64 log10 cfu/g and 1.48–2.16 log10 cfu/g, respectively, on the last day of storage. Water activity, TVC, and fungal counts were low in sweet potato composite bread as compared to white bread. Total β-carotene in OFSP bread ranged from 1.9–5.4 mg/100 g (on dry weight). One hundred grams of bread portion enriched with 40% and 50% OFSP purée provides more than 50% of vitamin A dietary requirements to children aged 4–8 years. Incorporation of up to 50% OFSP purée in wheat flour produces a relatively shelf-stable, nutritious, and health-promoting functional bread.

Analysis of β-amylase gene (Amyβ) variation reveals allele association with low enzyme activity and increased firmness in cooked sweetpotato (Ipomoea batatas) from East Africa

β-amylase is a thermostable enzyme that hydrolyses starch during cooking of sweetpotato (Ipomoea batatas) storage roots, thereby influencing eating quality. Its activity is known to vary amongst genotypes but the genetic diversity of the beta-amylase gene (Amyβ) is not well studied. Amyβ has a highly conserved region between exon V and VI, forming part of the enzyme's active site. To determine the gene diversity, a 2.3 kb fragment, including the conserved region of the Amyβ gene was sequenced from 25 sweetpotato genotypes. The effect of sequence variation on gene expression, enzyme activity, and firmness in cooked roots was determined. Six genotypes carrying several SNPs within exon V, linked with an AT or ATGATA insertion in intron V were unique and clustered together. The genotypes also shared an A336E substitution in the amino acid sequence, eight residues upstream of a substrate-binding Thr344. The genotypes carrying this allele exhibited low gene expression and low enzyme activity. Enzyme activity was negatively correlated with firmness (R = -0.42) in cooked roots. This is the first report of such an allele, associated with low enzyme activity. These results suggest that genetic variation within the AmyB locus can be utilized to develop markers for firmness in sweetpotato breeding.

Development of a food product profile for boiled and steamed sweetpotato in Uganda for effective breeding

This study sought to understand user preferences of raw, boiled and steamed sweetpotato, a staple food in Uganda. A sequential methodology involving state of knowledge review, gendered food mapping, processing diagnosis and consumer testing was used in Lira and Kamwenge districts. Preferred raw sweetpotato characteristics were large roots (≥ 3 cm diameter) with a sweet taste, smooth skin and hard texture, while mealiness, sweet taste and good sweetpotato smell were important attributes for boiled sweetpotato. Processors, mostly women, highlighted ease of peeling and sappiness of raw roots. There were gender differences in quality characteristic preferences and perceived importance. The released variety, NASPOT 8, had the highest overall liking in Kamwenge and was well liked in Lira. Penalty analysis of consumer data showed that sweetness and firmness were key drivers of overall liking. The results will support breeding programmes in meeting specific end-user product profiles, selection criteria and uptake of new varieties.

Consumer Preference Testing of Boiled Sweetpotato Using Crowdsourced Citizen Science in Ghana and Uganda

Crowdsourced citizen science is an emerging approach in plant sciences. The triadic comparison of technologies (tricot) approach has been successfully utilized by demand-led breeding programmes to identify varieties for dissemination suited to specific geographic and climatic regions. An important feature of this approach is the independent way in which farmers individually evaluate the varieties on their own farms as “citizen scientists.” In this study, we adapted this approach to evaluate consumer preferences to boiled sweetpotato [Ipomoea batatas (L.) Lam] roots of 21 advanced breeding materials and varieties in Ghana and 6 released varieties in Uganda. We were specifically interested in evaluating if a more independent style of evaluation (home tasting) would produce results comparable to an approach that involves control over preparation (centralized tasting). We compiled data from 1,433 participants who individually contributed to a home tasting (de-centralized) and a centralized tasting trial in Ghana and Uganda, evaluating overall acceptability, and indicating the reasons for their preferences. Geographic factors showed important contribution to define consumers' preference to boiled sweetpotato genotypes. Home and centralized tasting approaches gave similar rankings for overall acceptability, which was strongly correlated to taste. In both Ghana and Uganda, it was possible to robustly identify superior sweetpotato genotypes from consumers' perspectives. Our results indicate that the tricot approach can be successfully applied to consumer preference studies.

Continence, quality of life and depression following surgical repair of obstetric vesicovaginal fistula: a cohort study

OBJECTIVE

We evaluated residual incontinence, depression, and quality of life among Malawian women who had undergone vesicovaginal fistula (VVF) repair 12 or more months previously.

DESIGN

Prospective cohort study.

SETTING

Fistula Care Centre in Lilongwe, Malawi.

POPULATION

Women who had undergone VVF repair in Lilongwe, Malawi at least 12 months prior to enrolment.

METHODS

Self-report of urinary leakage was used to evaluate for residual urinary incontinence; depression was evaluated with the Patient Health Questionnaire-9; quality of life was evaluated with the King's Health Questionnaire.

MAIN OUTCOME MEASURES

Prevalence and predictors of residual incontinence, quality of life scores, and prevalence of depression and suicidal ideation.

RESULTS

Fifty-six women (19.3%) reported residual urinary incontinence. In multivariable analyses, predictors of residual urinary incontinence included: pre-operative Goh type 3 [adjusted risk ratio (aRR) 2.82; 95% confidence interval (CI) 1.61-5.27) or Goh type 4 1.08-2.78), positive postoperative cough stress test (aRR = 2.42; 95% CI 1.24-4.71) and the positive 1-hour postoperative pad test (aRR = 2.20; 95% CI 1.08-4.48). Women with Goh types 3 and 4 VVF reported lower quality of life scores. Depressive symptoms were reported in 3.5% of women; all reported residual urinary incontinence.

CONCLUSIONS

While the majority of women reported improved outcomes in the years following surgical VVF repair, those with residual urinary incontinence had a poorer quality of life. Services are needed to identify and treat this at-risk group.

TWEETABLE ABSTRACT

Nearly one in five women reported residual urinary incontinence at follow up, 12 or months after vesicovaginal fistula repair.

RADIATION PROTECTION MEASURES TAKEN DURING REPATRIATION OF SEALED HIGH ACTIVITY RADIOACTIVE SOURCES IN CAMEROON

Operational measures taken for the repatriation of Alcyon II 60Co Teletherapy head and El Dorado 6 60Co Teletherapy devices located in Yaounde and Douala respectively are reported. Operations carried out have permit to store Alcyon head in the CC 33 container and to transfer 60Co source from El Dorado 6 device to YKT1B container. These containers are approved as Type B package for securely transport. Optically stimulated luminescence dosimeters had been distributed to all involved persons to estimate the received effective dose during operations. It appears by the present study that, the most received individual effective dose is 130 μSv during the whole process.

Simultaneous oxidative determination of antibacterial drugs in aqueous solutions using an electrode modified with MWCNTs decorated with Fe3O4 nanoparticles

The present study describes a simple sensor developed from Fe₃O₄ and MWCNT nanoparticles for the simultaneous detection of sulfamethoxazole (SMX) and trimethoprim (TMP).

Use of a postoperative pad test to identify continence status in women after obstetric vesicovaginal fistula repair: a prospective cohort study

OBJECTIVE

Determine whether a 1-hour pad test at discharge can identify continence status within 120 days of obstetric vesicovaginal fistula (VVF) repair.

DESIGN

Prospective cohort study.

SETTING

Fistula Care Centre in Lilongwe, Malawi.

POPULATION

Women with VVF who underwent repair between January 2012 and December 2014.

METHODS

Data on demographics, obstetric history, physical exam findings, operative management, postoperative findings, and follow up evaluations were collected on women with VVF repair.

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive and negative predictive values (PPV and NPV), and a receiver operating curve (ROC) were calculated to assess the utility of using a discharge pad test at three thresholds to identify women likely to be continent at follow up.

RESULTS

After VVF repair, 346 women had a 1-hour pad test performed at the time of hospital discharge and completed follow up within 120 days of repair. Of these, 79.8% (n = 276) were completely continent, whereas 20.2% (n = 70) had some degree of incontinence. The sensitivity and specificity of a negative 1-hour pad test at predicting continence is 68.1% and 82.9%, respectively. With this prevalence, a negative pad test at a 1.5-g threshold demonstrates a high predictive value (PPV = 94.0%, 95% CI 90.0-96.9) in detecting women with continence after repair.

CONCLUSIONS

At the 1.5-g threshold, a negative pad test at discharge identifies 94% of women who will remain continent after VVF repair. Adding the pad test to fistula care can identify women who are likely to remain continent and may not need further therapies in settings where resources are limited and follow up after repair is difficult.

TWEETABLE ABSTRACT

A negative pad test after repair is associated with continued continence at follow up.

Cowpea pod (Vigna unguiculata) biomass as a low-cost biosorbent for removal of Pb(II) ions from aqueous solution

The use of cowpea pod (CPP) biomass for the removal of Pb(II) ions from aqueous solution was investigated. The effects of factors such as dosage concentration (0.2 to 1.6 g L^-1), pH (2 to 8), contact time (5 to 120 min), metal ion concentrations (10 to 80 mg L^-1) and temperature (20 to 50 °C) were examined through batch studies. The biosorption data conformed best to the Langmuir model at the three working temperatures (20, 30 and 40 °C) as revealed by the correlation coefficients (R ²) which were greater than 0.940. The maximum sorption capacity of the CPP for Pb(II) was 32.96 mg g^-1 at 313 K. Furthermore, the kinetic data fitted well to the pseudo-second-order model as it had the lowest sum of square error (SSE) values and correlation coefficients close to unity (R ² > 0.999). The thermodynamic parameters (ΔG°, ΔS° and ΔH°) showed that the biosorption process was spontaneous, feasible and endothermic. The results obtained in the present study indicated that cowpea pod biomass could be used for the effective removal of Pb(II) from aqueous solution.

Investigating the effect of cadmium and aluminium on growth and stress-induced responses in the micropropagated medicinal plant Hypoxis hemerocallidea

Hypoxis hemerocallidea is a highly utilized medicinal plant in South Africa. Its cultivation has received considerable attention in order to meet the high demand. High levels of cadmium (Cd) and aluminum (Al) in H. hemerocallidea plants sold in traditional medicinal markets was previously reported. The present study used an in vitro propagation model to investigate the uptake of Cd and Al by H. hemerocallidea and their effect on plant growth, elemental uptake and some stress-induced responses such as pigment, malondialdehyde (MDA), proline content and ultrastructural changes. Shoot and root growth of plantlets exposed to Cd, Cd:Al and high concentrations of Al was significantly reduced. Highest concentrations of Cd accumulated in the corms of Cd-treated plantlets while highest Al concentrations occurred in the leaves and roots. There was higher accumulation of Cd and Al when applied singularly compared to the Cd:Al combination treatments. Cd and Al also reduced accumulation of trace elements in micropropagted H. hemerocallidea with lowest concentrations in the Cd:Al combination treatments. Exposure to Cd, Al and Cd:Al significantly reduced the level of chlorophyll but increased the levels of carotenoids, MDA and proline. Ultrastructural changes were also observed in H. hemerocallidea exposed to Cd and Al. All these factors contributed to the inhibition of plant growth and could potentially affect the ability of this important medicinal plant to synthesize bioactive compounds. It is thus necessary to understand heavy metal stress-induced responses in this highly valued medicinal plant to ensure a high quality product for the consumer.

Association between parity and fistula location in women with obstetric fistula: a multivariate regression analysis

OBJECTIVE

To compare primiparous and multiparous women who develop obstetric fistula (OF) and to assess predictors of fistula location.

DESIGN

Cross-sectional study.

SETTING

Fistula Care Centre at Bwaila Hospital, Lilongwe, Malawi.

POPULATION

Women with OF who presented between September 2011 and July 2014 with a complete obstetric history were eligible for the study.

METHODS

Women with OF were surveyed for their obstetric history. Women were classified as multiparous if prior vaginal or caesarean delivery was reported. The location of the fistula was determined at operation: OF involving the urethra, bladder neck, and midvagina were classified as low; OF involving the vaginal apex, cervix, uterus, and ureters were classified as high.

MAIN OUTCOME MEASURES

Demographic information was compared between primiparous and multiparous women using chi-squared and Mann-Whitney U-tests. Multivariate logistic regression models were implemented to assess the relationship between variables of interest and fistula location.

RESULTS

During the study period, 533 women presented for repair, of which 452 (84.8%) were included in the analysis. The majority (56.6%) were multiparous when the fistula formed. Multiparous women were more likely to have laboured <1 day (62.4 versus 44.5%, P < 0.001), delivered a live-born infant (26.8 versus 17.9%, P = 0.026), and have a high fistula location (37.5 versus 11.2%, P < 0.001). Multiparity [adjusted odds ratio (aOR) = 4.55, 95% confidence interval (CI) 2.27-9.12)] and history of caesarean delivery (aOR = 4.11, 95% CI 2.45-6.89) were associated with development of a high fistula.

CONCLUSIONS

Multiparity was common in our cohort, and these women were more likely to have a high fistula. Additional research is needed to understand the aetiology of high fistula including potential iatrogenic causes.

TWEETABLE ABSTRACT

Multiparity and caesarean delivery were associated with a high tract fistula in our Malawian cohort.

Intra-assay reliability and robustness of QuantiFERON(R)-TB Gold In-Tube test in Zambia

BACKGROUND

Interferon-gamma (IFN-gamma) release assays (IGRAs), such as the QuantiFERON-TB Gold In-Tube test (QFT-GIT), are becoming a preferred method for diagnosis of tuberculosis (TB) infection in many industrialised countries. However, data on the effectiveness of IGRAs in high TB-HIV (human immunodeficiency virus) endemic and resource-limited settings, such as Zambia, are limited.

OBJECTIVE

To determine the intra-assay reliability and robustness of QFT-GIT in a field setting in Zambia.

DESIGN

During July-October 2007, 109 adult smear-positive TB patients were recruited to determine QFT-GIT reliability and the effect of a 24-h delay in incubation. Two simulated laboratory experiments were also performed using 9-14 volunteers, to explore the effect of power outages during incubation and storage temperature of collection tubes on IFN-gamma responses.

RESULTS

QFT-GIT intra-assay concordance was 91.7% (kappa = 0.8). Discordance was observed for nine patients, of whom six were HIV-positive. There was evidence of an association between HIV status and discordant results (OR 1.98, 95%CI 1.06-3.67, P = 0.03). A 24-h delay in incubation changed results for 25 of the 109 (22.9%) patients. Power outages that altered incubation time reduced IFN-gamma responses.

CONCLUSION

Although QFT-GIT seems reliable in this setting, we have identified operational factors that affect its robustness. These factors may influence the effectiveness of this test in similar resource-limited settings.

Anaesthetic effects of Adenia gummifera distillates on Apis mellifera (Honeybee)

The anaesthetic activities of steam distillates of Adenia gummifera stem on Apis mellifera were evaluated by a diffusion method. Live, direct and fractional (61-80 degrees C fraction) distillates had greater anaesthetic effect while vacuum distillates were mild. The anaesthetic activity significantly increased with concentration up to 6% (v/v), and then it levelled off, while excessive exposure was lethal. The number of bees in a given volume had no significant effect on anaesthetic activity but container volume (F(cal) = 66.4; F(3,8) = 4.07) and bee-distillate distance (F(cal) = 31.0; F(2,6) = 5.14) did, suggesting the rate of diffusion of active component could be the determining factor. The active component is likely to contain amines and the rest halogenated alkane.

Child sexual abuse in Matabeleland, Zimbabwe

The extent, nature, causes and consequences of child sexual abuse in Matabeleland. Zimbabwe, are explored by an intersectoral working group consisting of health, legal and AIDS prevention workers who were struck in the course of their work by the regularity with which they saw sexually abused children infected with HIV and STDs. Methods used in this study are record review, focus group discussions, structured and in-depth interviews. Child sexual abuse cases form between 40-60% of the rape cases brought to the attention of hospitals, police and court and many more are believed to remain unreported. Half of the sexual abuse in children is detected through STDs and some have HIV. The majority of offenders are mature men known to the child. Factors influencing child sexual abuse are male dominance in society, men's professed inability to control sexual desire, and magic beliefs. Victims are traumatized by the abuse itself as well as by subsequent problems in family, health and in court. Since child sexual abuse may endanger the life and well-being of the child, it is a serious problem that requires urgent action.

Modelling of digesta passage rates in grazing and browsing domestic and wild ruminant herbivores

Ruminant utilization of poor-quality feeds is governed by rates of digestion and of passage through the rumen. The passage rate of feed material determines the quantity of bypass nutrients and the efficiency of synthesis of microbial protein in the rumen, making modelling of passage rate important. Artificial neural networks were used to develop models of liquid and solid passage rates. Studies that reported fractional passage rates, along with class and body mass of ruminants, were included in the dataset. Factors that affect rates of passage in all the studies were identified, which included animal and feed factors. The dataset was composed of observations of domestic and wild ruminants of variable body mass (1.5 to 1238 kg) from 74 studies and 17 ruminant species from various climatic regions. Observations were randomly divided into two data subsets: 75% for training and 25% for validation. Developed models accounted for 66 and 82% of the variation in prediction of passage rates for solid and liquid, respectively. On validation with an independent dataset, these models attained 42 and 64% of precision in predicting passage rates for solid and liquid, respectively. Liquid and solid prediction passage rate models had no linear and mean bias in prediction. This study developed better prediction models for solid and liquid passage rates for ruminants fed on a variety of diets and/or feeds from different climatic regions.Keywords: Artificial neural networks, intake, mean retention time, prediction equation, rumen

Prediction of solid digesta passage rate using liquid passage rate as one of the input variables in ruminants

This study ascertained the influence of liquid passage rates on solid digesta passage rates and the possibilities of simultaneous prediction of solid and liquid passage rates in ruminants. Artificial neural networks were used to develop models of solid and solid-plus-liquid passage rates. Studies that reported fractional passage rates, class and body mass of ruminants were included in the dataset. Animal and feed factors that affect the rate of passage were identified. The database had observations of domestic and wild ruminants of variable body mass from 74 (solid using predicted liquid passage rate) and 31 (solid using observed liquid passage rate) studies. Observations were randomly divided into two data subsets: 75% for training and 25% for validation. Developed models accounted for 76% and 77% of the variation in prediction of solid passage rates using predicted and observed liquid passage rate as inputs, respectively. Simultaneous prediction accounted for 83% and 89% of the variation of solid and liquid passage rates, respectively. On validation using an independent dataset, these models attained 45% (solid using predicted liquid), 66% (solid using observed liquid), 50% (solid predicted with liquid) and 69% (liquid predicted with solid) of precision in predicting passage rates. Simultaneous prediction of solid and liquid passage rate yielded better predictions compared with independent predictions of solid passage rate. Simultaneous prediction of solid and liquid passage rates accounted for more variation compared with independent predictions of solid rates. Inclusion of liquid passage rate as an input variable gave better predictions of solid passage rates.Keywords: Fractional passage rate, prediction model, simultaneous predictions