27 research outputs found
Nutrientsâ distribution and their impact on Pangani River Basinâs ecosystem â Tanzania
Research Articles published by Taylor & Francis GroupSurface and groundwater from Pangani River Basin (PRB) were sampled in dry and wet seasons,
analysed for dissolved organic and inorganic nutrients (N, P, Si and Urea). There was spatial and
seasonal nutrientsâ variability, with enrichment of dissolved inorganic fractions accumulated from
natural and anthropogenic sources. Silicates increased in dry season, whereas nitrate,
ammonium, phosphate and urea increased in wet season; except for phosphate, other nutrients
increased from upstream to the river mouth. High rate of chemical weathering possibly due to
tropical climate and volcanic rocks has caused PRB to have higher concentration of silicates than
average freshwater African Rivers. Contribution of PRB to the coast of Indian Ocean was 2.6, 39.0,
45.2, 67.4 and 5444.8 (mol/km2/yr) for nitrite, phosphate, ammonium, nitrate and silicates,
respectively, which were lower than most of the tropical rivers in the world. Levels of nitrate and
phosphate for most of the stations were higher than recommended levels for aquatic ecosystem
health. Furthermore, observed hypoxia condition in some stations threatens aquatic life. This
study recommends the efficient use of fertilizers to reduce nutrientsâ uptake into the lakes and
rivers so as to meet the recommended level for aquatic and human health
The chicken or the egg? Exploring bi-directional associations between Newcastle disease vaccination and village chicken flock size in rural Tanzania
Newcastle disease (ND) is a viral disease of poultry with global importance, responsible for the loss of a potential source of household nutrition and economic livelihood in many low-income food-deficit countries. Periodic outbreaks of this endemic disease result in high mortality amongst free-ranging chicken flocks and may serve as a disincentive for rural households to invest time or resources in poultry-keeping. Sustainable ND control can be achieved through vaccination using a thermotolerant vaccine administered via eyedrop by trained "community vaccinators". This article evaluates the uptake and outcomes of fee-for-service ND vaccination programs in eight rural villages in the semi-arid central zone of Tanzania. It represents part of an interdisciplinary program seeking to address chronic undernutrition in children through improvements to existing poultry and crop systems. Newcastle disease vaccination uptake was found to vary substantially across communities and seasons, with a significantly higher level of vaccination amongst households participating in a longitudinal study of children's growth compared with non-participating households (p = 0.009). Two multivariable model analyses were used to explore associations between vaccination and chicken numbers, allowing for clustered data and socioeconomic and cultural variation amongst the population. Results demonstrated that both (a) households that undertook ND vaccination had a significantly larger chicken flock size in the period between that vaccination campaign and the next compared with those that did not vaccinate (p = 0.018); and (b) households with larger chicken flocks at the time of vaccination were significantly more likely to participate in vaccination programs (p < 0.001). Additionally, households vaccinating in all three vaccination campaigns held over 12 months were identified to have significantly larger chicken flocks at the end of this period (p < 0.001). Opportunities to understand causality and complexity through quantitative analyses are limited, and there is a role for qualitative approaches to explore decisions made by poultry-keeping households and the motivations, challenges and priorities of community vaccinators. Evidence of a bi-directional relationship, however, whereby vaccination leads to greater chicken numbers, and larger flocks are more likely to be vaccinated, offers useful insights into the efficacy of fee-for-service animal health programs. This article concludes that attention should be focused on ways of supporting the participation of vulnerable households in ND vaccination campaigns, and encouraging regular vaccination throughout the year, as a pathway to strengthen food security, promote resilience and contribute to improved human nutrition
Ecological and epidemiological findings associated with zoonotic rabies outbreaks and control in Moshi, Tanzania, 2017â2018
Approximately 1500 people die annually due to rabies in the United Republic of Tanzania.
Moshi, in the Kilimanjaro Region, reported sporadic cases of human rabies between 2017 and 2018.
In response and following a One Health approach, we implemented surveillance, monitoring, as well
as a mass vaccinations of domestic pets concurrently in >150 villages, achieving a 74.5% vaccination
coverage (n = 29, 885 dogs and cats) by September 2018. As of April 2019, no single human or animal
case has been recorded. We have observed a disparity between awareness and knowledge levels
of community members on rabies epidemiology. Self-adherence to protective rabies vaccination in
animals was poor due to the challenges of costs and distances to vaccination centers, among others.
Incidence of dog bites was high and only a fraction (65%) of dog bite victims (humans) received
post-exposure prophylaxis. A high proportion of unvaccinated dogs and cats and the relative intense
interactions with wild dog species at interfaces were the risk factors for seropositivity to rabies virus
infection in dogs. A percentage of the previously vaccinated dogs remained unimmunized and some
unvaccinated dogs were seropositive. Evidence of community engagement and multi-coordinated
implementation of One Health in Moshi serves as an example of best practice in tackling zoonotic
diseases using multi-level government e orts. The district-level establishment of the One Health rapid
response team (OHRRT), implementation of a carefully structured routine vaccination campaign,
improved health education, and the implementation of barriers between domestic animals and
wildlife at the interfaces are necessary to reduce the burden of rabies in Moshi and communities with
similar profiles.The USAID funded projectâOSRO/GLO/507/USA on Global Health Security Agenda for the control of zoonosis in Africa.http://www.mdpi.com/journal/ijerpham2020Veterinary Tropical Disease
The costâeffectiveness of prophylaxis strategies for individuals with advanced HIV starting treatment in Africa
Introduction Many HIVâpositive individuals in Africa have advanced disease when initiating antiretroviral therapy (ART) so have high risks of opportunistic infections and death. The REALITY trial found that an enhancedâprophylaxis package including fluconazole reduced mortality by 27% in individuals starting ART with CD4 <100 cells/mm3. We investigated the costâeffectiveness of this enhancedâprophylaxis package versus other strategies, including using cryptococcal antigen (CrAg) testing, in individuals with CD4 <200 cells/mm3 or <100 cells/mm3 at ART initiation and all individuals regardless of CD4 count. Methods The REALITY trial enrolled from June 2013 to April 2015. A decisionâanalytic model was developed to estimate the costâeffectiveness of six management strategies in individuals initiating ART in the REALITY trial countries. Strategies included standardâprophylaxis, enhancedâprophylaxis, standardâprophylaxis with fluconazole; and three CrAg testing strategies, the first stratifying individuals to enhancedâprophylaxis (CrAgâpositive) or standardâprophylaxis (CrAgânegative), the second to enhancedâprophylaxis (CrAgâpositive) or enhancedâprophylaxis without fluconazole (CrAgânegative) and the third to standardâprophylaxis with fluconazole (CrAgâpositive) or without fluconazole (CrAgânegative). The model estimated costs, lifeâyears and qualityâadjusted lifeâyears (QALY) over 48 weeks using three competing mortality risks: cryptococcal meningitis; tuberculosis, serious bacterial infection or other known cause; and unknown cause. Results Enhancedâprophylaxis was costâeffective at costâeffectiveness thresholds of US500 per QALY with an incremental costâeffectiveness ratio (ICER) of US113 per QALY in the CD4 <100 cells/mm3 population) and increased in all individuals regardless of CD4 count (US2.30. Conclusions The REALITY enhancedâprophylaxis package in individuals with advanced HIV starting ART reduces morbidity and mortality, is practical to administer and is costâeffective. Efforts should continue to ensure that components are accessed at lowest available prices
Late Presentation With HIV in Africa: Phenotypes, Risk, and Risk Stratification in the REALITY Trial.
This article has been accepted for publication in Clinical Infectious Diseases Published by Oxford University PressBackground: Severely immunocompromised human immunodeficiency virus (HIV)-infected individuals have high mortality shortly after starting antiretroviral therapy (ART). We investigated predictors of early mortality and "late presenter" phenotypes. Methods: The Reduction of EArly MortaLITY (REALITY) trial enrolled ART-naive adults and children â„5 years of age with CD4 counts .1). Results: Among 1711 included participants, 203 (12%) died. Mortality was independently higher with older age; lower CD4 count, albumin, hemoglobin, and grip strength; presence of World Health Organization stage 3/4 weight loss, fever, or vomiting; and problems with mobility or self-care at baseline (all P < .04). Receiving enhanced antimicrobial prophylaxis independently reduced mortality (P = .02). Of five late-presenter phenotypes, Group 1 (n = 355) had highest mortality (25%; median CD4 count, 28 cells/”L), with high symptom burden, weight loss, poor mobility, and low albumin and hemoglobin. Group 2 (n = 394; 11% mortality; 43 cells/”L) also had weight loss, with high white cell, platelet, and neutrophil counts suggesting underlying inflammation/infection. Group 3 (n = 218; 10% mortality) had low CD4 counts (27 cells/”L), but low symptom burden and maintained fat mass. The remaining groups had 4%-6% mortality. Conclusions: Clinical and laboratory features identified groups with highest mortality following ART initiation. A screening tool could identify patients with low CD4 counts for prioritizing same-day ART initiation, enhanced prophylaxis, and intensive follow-up. Clinical Trials Registration: ISRCTN43622374.REALITY was funded by the Joint Global Health Trials Scheme (JGHTS) of the UK Department for International Development, the Wellcome Trust, and Medical Research Council (MRC) (grant number G1100693). Additional funding support was provided by the PENTA Foundation and core support to the MRC Clinical Trials Unit at University College London (grant numbers MC_UU_12023/23 and MC_UU_12023/26). Cipla Ltd, Gilead Sciences, ViiV Healthcare/GlaxoSmithKline, and Merck Sharp & Dohme donated drugs for REALITY, and ready-to-use supplementary food was purchased from Valid International. A. J. P. is funded by the Wellcome Trust (grant number 108065/Z/15/Z). J. A. B. is funded by the JGHTS (grant number MR/M007367/1). The Malawi-LiverpoolâWellcome Trust Clinical Research Programme, University of Malawi College of Medicine (grant number 101113/Z/13/Z) and the Kenya Medical Research Institute (KEMRI)/Wellcome Trust Research Programme, Kilifi (grant number 203077/Z/16/Z) are supported by strategic awards from the Wellcome Trust, United Kingdom. Permission to publish was granted by the Director of KEMRI. This supplement was supported by funds from the Bill & Melinda Gates Foundation
Ready-to-use supplementary food supplements improve endothelial function, hemoglobin and growth in Tanzanian children with sickle cell anaemia: the Vascular Function Intervention Study (V-FIT), a random order crossover trial
Introduction: Endothelial function is impaired in sickle cell anemia (SCA) and may be prognostic of severity of pathophysiology underlying many complications. Poor nutritional status is documented in SCA in all income settings, yet no strategies exist to improve nutrition. Poor nutritional status and hemoglobin predict death and hospitalization in Tanzanian SCA patients (Cox, et al. Haematologica 96, 2011, Makani et al. PloSONE 6, 2011). The objectives are to determine the combined effect of two ready-to-use-supplementary food (RUSF) interventions on the primary endpoints of endothelial function, assessed by flow mediated dilatation (FMD), growth and body composition and hemoglobin (secondary endpoint).
Methods: Tanzanian children (N=119) (HbSS) aged 8-11.9 years were enrolled in V-FIT (ISRCTN74331412/NCT01718054) in Aug to Nov 2012. Children received in random order a daily RUSF providing 500 kcal, 1 RDA of vitamins and minerals & 1mg folate (Nutriset, France), plus weekly anti-malarial prophylactic chloroquine syrup (150/225mg base) (Wallace manufacturing chemicals, UK), or a vascular-RUSF (RUSFv) fortified with arginine and citrulline (average 0.2g/kg/d & 0.1g/kg/d) plus daily chloroquine syrup (3mg base/kg/d). Patients and investigators were blind to the different interventions. Each intervention was received for 4 months with 4 month washout periods on either side (Figure 1A). Clinic visits were conducted at baseline and at the end of each intervention/washout period when endothelium-dependent and -independent vasodilatation were assessed (Donald et al. JACC 51, 2008), plus height, weight and body composition by impedance (Tanita BC418). Random effects models were used, adjusting for repeated measures within individuals. In multivariable analyses models were a priori adjusted for gender. Possible temporal effects were modelled via Fourier transformation of visit dates and included in models for growth and hemoglobin. Effects of the interventions on FMDmax were adjusted for arterial diameter before vasodilation induction, which was negatively correlated with FMDmax and for magnitude of reactive hyperaemia during induction of vasodilation, which was not correlated with FMDmax.
Results: 115/119 (60% male; mean age at enrolment 10.0, 95% CI 9.8 â 10.2 years) enrolled patients completed the trial and all clinic visits. Endpoints at baseline and the adjusted and unadjusted effects of the interventions are shown in Table 1. FMDmax, baseline brachial diameter, absolute change in blood flow velocity during reactive hyperemia, hemoglobin, height velocity, weight and lean mass gain all increased on the RUSF (Fig 1B-F).
Discussion: We demonstrate that providing extra protein, energy and micronutrients improves hemoglobin, vascular endothelial function and growth. It is possible that the effects observed are limited to the RUSFv, and/or from unadjusted for temporal effects. Unblinded analysis of the effect of RUSFv vs. RUSF on these endpoints, plasma amino acids and arginase are planned. Currently the only intervention for children with SCA is hydroxyurea, which although it improves hemoglobin and reduces hemolysis, does not appear to affect growth while its effect on vascular physiology is unknown (Wang et al. J Pediatr 140, 2002). In addition to specific nutrients, general improvement in nutrition may result in improvement in important intermediate endpoints in SCA. Future research should investigate effects of nutritional supplementation on clinical endpoints
Benefits of enhanced infection prophylaxis at antiretroviral therapy initiation by cryptococcal antigen status
Objectives: To assess baseline prevalence of cryptococcal antigen (CrAg) positivity; and its contribution to reductions in all-cause mortality, deaths from cryptococcus and unknown causes, and new cryptococcal disease in the REALITY trial.
Design: Retrospective CrAg testing of baseline and week-4 plasma samples in all 1805 African adults/children with CD4+ cell count less than 100 cells/ÎŒl starting antiretroviral therapy who were randomized to receive 12-week enhanced-prophylaxis (fluconazole 100 mg/day, azithromycin, isoniazid, cotrimoxazole) vs. standard-prophylaxis (cotrimoxazole).
Methods: Proportional hazards models were used to estimate the relative impact of enhanced-prophylaxis vs. standard-cotrimoxazole on all, cryptococcal and unknown deaths, and new cryptococcal disease, through 24 weeks, by baseline CrAg positivity.
Results: Excluding 24 (1.4%) participants with active/prior cryptococcal disease at enrolment (all treated for cryptococcal disease), 133/1781 (7.5%) participants were CrAg-positive. By 24 weeks, 105 standard-cotrimoxazole vs. 78 enhanced-prophylaxis participants died. Of nine standard-cotrimoxazole and three enhanced-prophylaxis cryptococcal deaths, seven and two, respectively, were CrAg-positive at baseline. Among deaths of unknown cause, only 1/46 standard-cotrimoxazole and 1/28 enhanced-prophylaxis were CrAg-positive at baseline. There was no evidence that relative reductions in new cryptococcal disease associated with enhanced-prophylaxis varied between baseline CrAg-positives [hazard-ratio = 0.36 (95% confidence interval 0.13â0.98), incidence 19.5 vs. 56.5/100 person-years] and CrAg-negatives [hazard-ratio = 0.33 (0.03â3.14), incidence 0.3 vs. 0.9/100 person-years; Pheterogeneity = 0.95]; nor for all deaths, cryptococcal deaths or unknown deaths (Pheterogeneity > 0.3).
Conclusions: Relative reductions in cryptococcal disease/death did not depend on CrAg status. Deaths of unknown cause were unlikely to be cryptococcus-related; plausibly azithromycin contributed to their reduction. Findings support including 100 mg fluconazole in an enhanced-prophylaxis package at antiretroviral therapy initiation where CrAg screening is unavailable/impractical.</p