341 research outputs found
Traceability, Moral Hazard, and Food Safety
Errors in traceability can significantly impact the moral hazard associated with producing safe food. The effect of moral hazard depends on the proportion of unsafe food costs that can be allocated to the responsible producer, which depends on the efficiency of the traceability system. In this paper, we develop a model that identifies the minimum level of traceability needed to mitigate moral hazard and motivate suppliers to produce safe food. Regulators and consumer can use the results of this research to design regulations and contracts that mitigate moral hazard and motivate producers to deliver safe food.Food safety, traceability, moral hazard, Food Consumption/Nutrition/Food Safety,
The Cameroon Academy of Sciences model of evidence-based science advice
The evidence-based science advice (ESA) effort of the Cameroon Academy of Sciences (CAS) since 23 years has been reviewed. The objective throughout has been to enable science influence policy/decision making at all levels – national, regional and global. The key partners of CAS included the United States National Academy of Sciences (USNAS), the German Academy of Sciences (Leopoldina), the Royal Society of United Kingdom, as well as the Network of African Science Academies (NASAC), the InterAcademy Partnership (Science, Health, Research), the Commonwealth Science Academies and the International Science Council. The mechanisms used included consensus studies, workshops, public lectures, participation in sectoral committees, summaries of key scientific publications and joint statements. Priorities handled through convening activities were triggered by policy/decision making sector requests or Academy foresights. The response/impact of the effort varied from media coverage through policy/programme change/orientation. The major challenges faced included insufficient financial/human resources, inadequate office space, and weak links with government. These challenges must be addressed to enable effective evidence-based science advice which is increasingly unavoidable for sustainable development.Keywords: Evidence-based science, advice, policy, decision-make
What are the benefits and risks of inhaled corticosteroids for COPD?
Q: What are the benefits and risks of inhaled corticosteroids for COPD? A: Inhaled corticosteroids (ICS), either alone or with a long-acting [beta] agonist (LABA), reduce the frequency of exacerbations of chronic obstructive pulmonary disease (COPD) and statistically, but not clinically, improve quality of life (QOL) (strength of recommendation [SOR]: B, meta-analyses of heterogeneous studies). However, ICS have no mortality benefit and don't consistently improve forced expiratory volume in 1 second (FEV1) (SOR: B, meta-analyses of secondary outcomes). They increase the risk of pneumonia, oropharyngeal candidiasis, and bruising (SOR: B, meta-analyses of secondary outcomes). Withdrawal of ICS doesn't significantly increase the risk of COPD exacerbation (SOR: B, a meta-analysis)
Lipid profiling of the filarial nematodes Onchocerca volvulus, Onchocerca ochengi and Litomosoides sigmodontis reveals the accumulation of nematode-specific ether phospholipids in the host
Onchocerciasis, a neglected tropical disease prevalent in western and central Africa, is a major health problem and has been targeted for elimination. The causative agent for this disease is the human parasite Onchocerca volvulus. Onchocerca ochengi and Litomosoides sigmodontis, infectious agents of cattle and rodents, respectively, serve as model organisms to study filarial nematode infections. Biomarkers to determine infection without the use of painful skin biopsies and microscopic identification of larval worms are needed and their discovery is facilitated by an improved knowledge of parasite-specific metabolites. In addition to proteins and nucleic acids, lipids may be suitable candidates for filarial biomarkers that are currently underexplored. To fill this gap, we present the phospholipid profile of the filarial nematodes O. ochengi, O. volvulus and L. sigmodontis. Direct infusion quadrupole time-of flight (Q-TOF) mass spectrometry was employed to analyze the composition of phospholipids and their molecular species in the three nematode species. Analysis of the phospholipid profiles of plasma or serum of uninfected and infected hosts showed that nematode-specific phospholipids were below detection limits. However, several phospholipids, in particular ether lipids of phosphatidylethanolamine (PE), were abundant in O. ochengi worms and in bovine nodule fluid, suggesting that these phospholipids might be released from O. ochengi into the host, and could serve as potential biomarkers. (C) 2017 The Author(s). Published by Elsevier Ltd on behalf of Australian Society for Parasitology
Efficacy of Three-Week Oxytetracycline or Rifampin Monotherapy Compared with a Combination Regimen against the Filarial Nematode Onchocerca ochengi
Onchocerciasis (river blindness), caused by the filarial nematode Onchocerca volvulus, is a major cause of visual impairment and dermatitis in sub-Saharan Africa. As O. volvulus contains an obligatory bacterial symbiont (Wolbachia), it is susceptible to antibiotic chemotherapy, although current regimens are considered too prolonged for community-level control programs. The aim of this study was to compare the efficacies of oxytetracycline and rifampin, administered separately or in combination, against a close relative of O. volvulus (Onchocerca ochengi) in cattle. Six animals per group were treated with continuous or intermittent oxytetracycline regimens, and effects on adult worm viability, dermal microfilarial loads, and Wolbachia density in worm tissues were assessed. Subsequently, the efficacies of 3-week regimens of oxytetracycline and rifampin alone and a combination regimen were compared, and rifampin levels in plasma and skin were quantified. A 6-month regimen of oxytetracycline with monthly dosing was strongly adulticidal, while 3-week and 6-week regimens exhibited weaker adulticidal effects. However, all three regimens achieved >2-log reductions in microfilarial load. In contrast, rifampin monotherapy and oxytetracycline-rifampin duotherapy failed to induce substantive reductions in either adult worm burden or microfilarial load, although a borderline effect on Wolbachia density was observed following duotherapy. Dermal rifampin levels were maintained above the MIC for >24 h after a single intravenous dose. We conclude that oxytetracycline-rifampin duotherapy is less efficacious against O. ochengi than oxytetracycline alone. Further studies will be required to determine whether rifampin reduces oxytetracycline bioavailability in this system, as suggested by human studies using other tetracycline-rifampin combinations
Repeated high doses of avermectins cause prolonged sterilisation, but do not kill, Onchocerca ochengi adult worms in African cattle
BACKGROUND: Ivermectin (Mectizan™, Merck and CO. Inc.) is being widely used in the control of human onchocerciasis (Onchoverca volvulus) because of its potent effect on microfilariae. Human studies have suggested that, at the standard dose of 150 μg/kg an annual treatment schedule of ivermectin reversibly interferes with female worm fertility but is not macrofilaricidal. Because of the importance of determining whether ivermectin could be macrofilaricidal, the efficacy of high and prolonged doses of ivermectin and a related avermectin, doramectin, were investigated in cattle infected with O. ochengi. METHODS: Drugs with potential macrofilaricidal activity, were screened for the treatment of human onchocerciasis, using natural infections of O. ochengi in African cattle. Three groups of 3 cows were either treated at monthly intervals (7 treatments) with ivermectin (Ivomec(®), Merck and Co. Inc.) at 500 μg/kg or doramectin (Dectamax(®), Pfizer) at 500 μg/kg or not treated as controls. Intradermal nodules were removed at 6 monthly intervals and adult worms were examined for signs of drug activity. RESULTS: There was no significant decline in nodule diameter, the motility of male and female worms, nor in male and female viability as determined by the ability to reduce tetrazolium, compared with controls, at any time up to 24 months from the start of treatments (mpt). Embryogenesis, however, was abrogated by treatment, which was seen as an accumulation of dead and dying intra-uterine microfilariae (mf) persisting for up to 18 mpt. Skin mf densities in treated animals had fallen to zero by <3 mpt, but by 18 mpt small numbers of mf were found in the skin of some treated animals and a few female worms were starting to produce multi-cellular embryonic stages. Follow-up of the doramectin treated group at 36 mpt showed that mf densities had still only regained a small proportion of their pre-treatment levels. CONCLUSION: These results have important implications for onchocerciasis control in the field. They suggest that ivermectin given at repeated high does may sterilise O. volvulus female worms for prolonged periods but is unlikely to kill them. This supports the view that control programmes may need to continue treatments with ivermectin for a period of decades and highlights the need to urgently identify new marcofiliaricidal compounds
Serological Patterns of Brucellosis, Leptospirosis and Q Fever in Bos indicus Cattle in Cameroon
Brucellosis, leptospirosis and Q fever are important infections of livestock causing a range of clinical conditions including abortions and reduced fertility. In addition, they are all important zoonotic infections infecting those who work with livestock and those who consume livestock related products such as milk, producing non-specific symptoms including fever, that are often misdiagnosed and that can lead to severe chronic disease. This study used banked sera from the Adamawa Region of Cameroon to investigate the seroprevalences and distributions of seropositive animals and herds. A classical statistical and a multi-level prevalence modelling approach were compared. The unbiased estimates were 20% of herds were seropositive for Brucella spp. compared to 95% for Leptospira spp. and 68% for Q fever. The within-herd seroprevalences were 16%, 35% and 39% respectively. There was statistical evidence of clustering of seropositive brucellosis and Q fever herds. The modelling approach has the major advantage that estimates of seroprevalence can be adjusted for the sensitivity and specificity of the diagnostic test used and the multi-level structure of the sampling. The study found a low seroprevalence of brucellosis in the Adamawa Region compared to a high proportion of leptospirosis and Q fever seropositive herds. This represents a high risk to the human population as well as potentially having a major impact on animal health and productivity in the region
UMF-078: A modified flubendazole with potent macrofilaricidal activity against Onchocerca ochengi in African cattle
<p>Abstract</p> <p>Background</p> <p>Human onchocerciasis or river blindness, caused by the filarial nematode <it>Onchocerca volvulus</it>, is currently controlled using the microfilaricidal drug, ivermectin. However, ivermectin does not kill adult <it>O. volvulus</it>, and in areas with less than 65% ivermectin coverage of the population, there is no effect on transmission. Therefore, there is still a need for a macrofilaricidal drug. Using the bovine filarial nematode <it>O. ochengi </it>(found naturally in African cattle), the macrofilaricidal efficacy of the modified flubendazole, UMF-078, was investigated.</p> <p>Methods</p> <p>Groups of 3 cows were treated with one of the following regimens: (a) a single dose of UMF-078 at 150 mg/kg intramuscularly (im), (b) 50 mg/kg im, (c) 150 mg/kg intraabomasally (ia), (d) 50 mg/kg ia, or (e) not treated (controls).</p> <p>Results</p> <p>After treatment at 150 mg/kg im, nodule diameter, worm motility and worm viability (as measured by metabolic reduction of tetrazolium to formazan) declined significantly compared with pre-treatment values and concurrent controls. There was abrogation of embryogenesis and death of all adult worms by 24 weeks post-treatment (pt). Animals treated at 50 mg/kg im showed a decline in nodule diameter together with abrogated reproduction, reduced motility, and lower metabolic activity in isolated worms, culminating in approximately 50% worm mortality by 52 weeks pt. Worms removed from animals treated ia were not killed, but exhibited a temporary embryotoxic effect which had waned by 12 weeks pt in the 50 mg/kg ia group and by 24 weeks pt in the 150 mg/kg ia group. These differences could be explained by the different absorption rates and elimination half-lives for each dose and route of administration.</p> <p>Conclusion</p> <p>Although we did not observe any signs of mammalian toxicity in this trial with a single dose, other studies have raised concerns regarding neuro- and genotoxicity. Consequently, further evaluation of this compound has been suspended. Nonetheless, these results validate the molecular target of the benzimidazoles as a promising lead for rational design of macrofilaricidal drugs.</p
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