Process evaluation of an intervention to improve HIV treatment outcomes among children and adolescents.

SETTING: Children and adolescents with HIV encounter challenges in initiation and adherence to antiretroviral therapy (ART). A community-based support intervention of structured home visits, aimed at improving initiation, adherence and treatment, was delivered by community health workers (CHWs) to children and adolescents newly diagnosed with HIV. OBJECTIVES: To 1) describe intervention delivery, 2) explore CHW, caregiver and adolescents' perceptions of the intervention, 3) identify barriers and facilitators to implementation, and 4) ascertain treatment outcomes at 12 months' post-HIV diagnosis. DESIGN: We drew upon: 1) semi-structured interviews (n = 22) with 5 adolescents, 11 caregivers and 6 CHWs, 2) 28 CHW field manuals, and 3) quantitative data for study participants (demographic information and HIV clinical outcomes). RESULTS: Forty-one children received at least a part of the intervention. Of those whose viral load was tested, 26 (n = 32, 81.3%) were virally suppressed. Interviewees felt that the intervention supported ART adherence and strengthened mental health. Facilitators to intervention delivery were convenience and rapport between CHWs and families. Stigma, challenges in locating participants and inadequate resources for CHWs were barriers. CONCLUSION: This intervention was helpful in supporting HIV treatment adherence among adolescents and children. Facilitators and barriers may be useful in developing future interventions.

CONTEXTE: Les enfants et les adolescents séropositifs rencontrent des difficultés dans l'initiation et l'adhésion à la thérapie antirétrovirale (TAR). Des agents de santé communautaires (CHW) ont mis en place une intervention de soutien communautaire sous forme de visites structurées à domicile visant à améliorer l'initiation, l'adhésion et le traitement, auprès d'enfants et d'adolescents nouvellement diagnostiqués séropositifs. OBJECTIFS: 1) Décrire la mise en œuvre de l'intervention, 2) explorer les perceptions de l'intervention par les CHW, les soignants et les adolescents, 3) identifier les obstacles et les facilitateurs de la mise en œuvre, et 4) vérifier les résultats du traitement 12 mois après le diagnostic du VIH. METHODES: Nous nous sommes appuyés sur 1) des entretiens semi-structurés (n = 22) avec 5 adolescents, 11 soignants et 6 CHW, 2) 28 manuels de terrain des CHW, et 3) des données quantitatives sur les participants à l'étude (informations démographiques et résultats cliniques du VIH). RÉSULTATS: Quarante et un enfants ont reçu au moins une partie de l'intervention. Parmi ceux dont la charge virale a été testée, 26 (n = 32 ; 81,3%) étaient sous suppression virale. Les personnes interrogées ont estimé que l'intervention soutenait l'adhésion au TAR et renforçait la santé mentale. Les facilitateurs de la mise en œuvre de l'intervention étaient la commodité et les rapports entre les CHW et les familles. La stigmatisation, les difficultés à trouver des participants et les ressources inadéquates pour les CHW étaient des obstacles. CONCLUSION: Cette intervention a été utile pour soutenir l'adhésion au traitement du VIH chez les adolescents et les enfants. Les facilitateurs et les obstacles peuvent être utiles pour développer de futures interventions.

Ruminal fermentation kinetics in ewes offered a maize stover basal diet supplemented with cowpea hay, groundnut hay, cotton seed meal or maize meal.

The effect on ruminal digestive kinetics of supplementing maize stover (MS) with cowpea hay (CW), groundnut hay (GN), cotton seed meal (CSM) or maize meal (MM) was evaluated in a 5 x 5 Latin square using five Merino ewes with ruminal cannulae. CW and GN were offered at 30% w/w to MS, while CSM and MM were given at 15 g/kg0.75 per day. There were significant time (p < 0.001) and time x diet (p < 0.05) effects on pH but the effect of diet alone was not significant (p > 0.05). There was a significant (p < 0.05) increase in the concentration of ammonia with time on the supplemented diets. There were no significant (p > 0.05) differences in the concentrations of total volatile fatty acids (VFAs). Butyrate increased with supplementation (p < 0.05). Supplementation increased the concentrations of branched-chain and total VFAs with time (p < 0.05). The non-glucogenic ratio was not significantly (p > 0.05) lower on supplemented diets owing to the higher butyrate concentration. The degradation curve constants were not significantly different (p > 0.05), the average effective dry matter degradation being 27.80% +/- 0.618% at 0.05 h-1 flow rate. The chemical and physical characteristics of the cell wall of MS may have presented few sites for microbial colonization, so limiting degradation. These results showed that small quantities of forage supplements can improve the ruminal environment in animals subsisting on low-quality forages and form a basis for comparison with bought-in protein and energy sources.

Effect of cowpea hay, groundnut hay, cotton seed meal and maize meal supplementation to maize stover on intake, digestibility, microbial protein supply and acetate kinetics in weaner lambs.

Ten weaner lambs were used in a double 5 x 5 Latin square design to evaluate the effect of supplementing maize stover (MS) with cowpea hay (CW), groundnut hay (GN), cotton seed meal (CSM) or maize meal (MM) on the intake, digestion kinetics and acetate clearance rate. CW and GN were offered at 30% w/w to MS, while CSM and MM were given at 15 g/kg0.75 per day. Supplementation reduced (p < 0.01) MS intake but enhanced (p < 0.01) total dry matter intake. There were no significant differences (p > 0.05) in digestibility. However, the estimated ME intake was significantly (p < 0.05) improved by supplementation. The estimated microbial protein supply was almost significantly (p < 0.06) improved by 22.68%, 5.35%, 17.58% and 47.90% on the CW-, GN-, CSM- and MM-supplemented diets, compared to the control (7.85 g/day). Microbial protein synthesis efficiency was not significantly affected (p > 0.05) by diet, and nor were the acetate clearance rates (p > 0.05), which averaged 0.0475 +/- 0.0078/min. The improvement in ME intake may have been due to a faster flow rate of digesta and a better balance of nutrients in the end-products of digestion. These results demonstrate that small amounts of forage supplements can improve nutrient intake when animals consume low-quality forages and provide a basis for comparing such supplements with bought-in protein and energy supplements.

Effect of different dietary energy level intakes on efficiency of estrus synchronization and fertility in Mashona goat does.

The objective of the study was to determine the effects of three dietary energy levels: 0.27 (low level: LL); 0.53 (medium level: ML), and 1.06 (high level: HL) MJMEkg(-1)W(0.75) on estrus synchronization and fertility in Mashona goat does. Forty-five multiparous Mashona goat does of average bodyweight 19.9+/-2.5kg were randomly allocated in equal numbers to the three dietary energy levels. The diets were made from a complete feed ration providing 9.83MJMEkg(-1)DM and 15.5% CPkg(-1)DM. Does were fed initially during a 60-day pre-synchronization period, and blood samples were collected twice a week for the determination of plasma progesterone concentrations to ascertain ovarian activity. Intramuscular injections of cloprostenol (100µg each) were administered 11 days apart. Immediately after the second injection of cloprostenol, three fertile bucks were introduced to the does and were left with the does for 21 days. The does were maintained on their dietary treatments throughout gestation except for those does in the LL treatment. Pregnancy was diagnosed 90 days post-mating using an ultrasound scanner. After pregnancy diagnosis, does on the LL treatment were randomly allocated to ML (n=7) and HL (n=8) treatments. During the pre-synchronization period, does on the LL treatment lost 12.3% whereas those on ML and HL treatments gained 2.1 and 28.8% of their initial bodymasses, respectively. The proportion of does exhibiting overt estrus within 96h after the last cloprostenol injection was significantly lower (P<0.05) for does on the LL treatment (60%) than for those on ML (93%) or HL (100%) treatments, respectively. However, based on plasma progesterone concentrations, the percentage of does on the LL treatment that exhibited ovarian cycles was numerically lower than that of does that were bred (40 versus 73%). Conception, fecundity and twinning rates were significantly lower (P<0.05) on the LL treatment than on the ML and HL treatments. These results indicate that feeding Mashona goat does 0.27MJMEkg(-1)W(0.75) compared to 0.53 and 1.06MJMEkg(-1)W(0.75) reduces the expression of estrus, conception, fecundity and twinning rates, and that feeding 0.53MJMEkg(-1)W(0.75) suffices for optimum reproduction. In addition, the results suggest that cloprostenol administration may induce ovarian cycles in reproductively quiescent does on dietary energy restriction.

Purification and biochemical characteristics of beta-D-xylanase from a thermophilic fungus, Thermomyces lanuginosus-SSBP.

An extracellular xylanase was purified to homogeneity from the culture filtrate of a thermophilic fungus, Thermomyces lanuginosus-SSBP, and its biochemical characteristics were studied. A yield of 70-80% was achieved through the procedures of 80%-satd. ammonium sulphate precipitation, DEAE-Sephadex A25 and quaternary aminoethyl (QAE)-Sephadex A25 column chromatography. The molecular mass of the purified xylanase was 23.6 kDa, as analysed by SDS/PAGE, with a pI value of 3.8. The molar absorption coefficient of the absorbance at 280 nm was 6.8x10(4) M(-1).cm(-1). The specific activity, calculated using the dinitrosalicylic acid (DNS) method, was 3500 units/mg. The enzyme reactions followed Michaelis-Menten kinetics with K app m and V(max) values of 3.26 mg/ml and 6300 units/ml per mg of protein respectively, as obtained from a Lineweaver-Burk plot. The xylanase contained no other enzyme activity (cellulase, beta-glucosidase, beta-mannosidase, alpha-arabinofuranosidase, or beta-xylosidase) except for the hydrolysis of xylan substrate. The optimal temperature of the enzyme assay was 70-75 degrees C. The enzyme retained full activity after a 60 degrees C incubation for 3 h. The optimal pH of xylanase activity was 6.5 and the enzyme appeared to be stable over a broad pH range (pH 5-12) under the assay conditions. The majority of the metal ions tested had no effect on the enzyme activity, with the exception of Pb(2+) (modest inhibitor) and Hg(2+) (strong inhibitor). The results showed that one or two tryptophan residues oxidized by N-bromosuccinamide per enzyme molecule was sufficient to inhibit the enzyme activity completely, thus indicating that the tryptophan residues play an important role in the catalytical processes of the enzyme reaction. Because of the outstanding properties of the purified xylanase from the SSBP strain, this xylanase has a potential use in biopulping processes and other industrial applications.

Performance of draught cattle in communal farming areas in Zimbabwe after dry season supplementation.

Sixty-four pairs of oxen owned by smallholders were randomly allocated to one of 3 supplementary treatments offered at one kg per head per day from July to October or to a control where no supplement was offered. The supplements were maize stover plus silverleaf hay (2:1 w/w), urea-treated maize stover (50 g urea/kg stover) and plain maize stover. Animals fed plain maize stover or no supplement lost weight (6 to 7% of initial weight), whilst those fed the other 2 supplements maintained their liveweights. Supplementation reduced time spent on feeding activities by 10 per cent. Animals fed on urea-treated maize stover or maize stover plus silverleaf hay ploughed at speeds that were 29% faster than oxen on the other treatments and covered 45% more area. Blood parameters indicated a general deficiency of nitrogen intake throughout the dry season. It was concluded that supplements of good quality have the potential to improve the working ability of communal area oxen.

Improving feeding management and work performance of Mashona oxen through strategic supplementation with cobsheath-groundnut stover.

Six pairs of Mashona oxen ploughed dry, red clay soils in August (winter) and in mid-November (spring). Between September and November the oxen were randomly assigned to 3 feeding groups: no supplement (control), 400 g/head per day of cobsheath-groundnut stover for 70 days and 800 g/head per day of the same supplement for 35 days. Cobsheath-groundnut stover was fed in order to determine its potential as supplementary feed for draught oxen during the dry season. The liveweight (LW) lost by heavy oxen during winter ploughing was lower (P < 0.001) than that of light oxen. During spring ploughing heavy oxen again lost less (P < 0.001) LW than light ones. In addition, non-supplemented oxen lost more LW than those supplemented. Therefore feeding strategies for Mashona draught oxen should aim at providing adequate nutrients to at least maintain LW during the dry season. Heavy oxen outperformed (P < 0.001) light ones during winter ploughing. Work output of supplemented oxen in spring was also significantly greater (P < 0.05) than that of non-supplemented ones. This result demonstrated the benefits of supplementary feed during the dry season. Concentrations of lactate and free fatty acids in plasma, heart rates and rectal temperatures increased (P < 0.05) markedly during work. The increases were higher (P < 0.05) for light oxen, particularly those not fed supplement.