Prevention and Control of Rabies in an Age of Global Travel: A Review of Travel‐ and Trade‐Associated Rabies Events – United States, 1986–2012

Rabies prevention and control efforts have been successful in reducing or eliminating virus circulation regionally through vaccination of specific reservoir populations. A notable example of this success is the elimination of canine rabies virus variant from the United States and many other countries. However, increased international travel and trade can pose risks for rapid, long‐distance movements of ill or infected persons or animals. Such travel and trade can result in human exposures to rabies virus during travel or transit and could contribute to the re‐introduction of canine rabies variant or transmission of other viral variants among animal host populations. We present a review of travel‐ and trade‐associated rabies events that highlight international public health obligations and collaborative opportunities for rabies prevention and control in an age of global travel. Rabies is a fatal disease that warrants proactive coordination among international public health and travel industry partners (such as travel agents, tour companies and airlines) to protect human lives and to prevent the movement of viral variants among host populations.     

Application of a Full-scale Constructed Wetland for Tertiary Treatment of Piggery Manure: Monitoring Results

Many industrialized regions in the world are faced with local overproductions of animal manure requiring processing in an economic sound manner. Intensive animal production in Flanders and the Netherlands has resulted in a considerable overproduction of animal manure. Spreading the excess manure over arable land has resulted in contamination and eutrophication of groundwater and surface waters. Over the last 4 years, research was conducted towards the potential of more economic constructed wetlands for the final treatment step. Although, initial results with laboratory flow field experiments were insufficient to reach stringent discharge criteria (Meers et al., Water Air Soil Pollut 160:15–26, 2005a), progressive optimisation of the tertiary treatment as well as of the preceding conditioning has resulted in a consistently performing pilot scale system (1,000 m³ year^?1 capacity) with effluent concentrations below the discharge criteria of 15 mg l^?1 N, 2 mg l^?1 P and 125 mg l^?1 COD (chemical oxygen demand), at a cumulated cost (operational plus investment) of 3–4 € m^?3 of pre-treated pig manure. Construction of full-scale installations with annual capacity of 10,000–25,000 m³ based on this pilot model are scheduled, with the first installation currently under way. The concept has the potential to provide a low cost, in situ treatment system allowing animal farmers to process excess animal manure themselves without the requirement of expensive ex situ treatment based on industrial scale membrane technology facilities. This paper presents the research findings of the first year of the pilot scale installation.     

Heavy Metal Fractionation and Extractability in Dredged Sediment Derived Surface Soils

The objective of this study was to characterise pollution with heavy metals in surface soils sampled at various dredged sediment disposal sites in the Flemish region (Belgium). The sites selected varied in the period since sediment disposal ceased and in current vegetation and land use. Total metal contents (Cd, Co, Cu, Fe, Mn, Ni, Pb, and Zn) in the surface soils varied widely. For some disposal sites Cd and Zn concentrations greatly exceeded reference values for clean soil. The distribution of the metals as determined by sequential extraction differed between elements, but was simular for all the soils. This suggested that metals in these sediment derived surface soils were accumulated and transformed in a similar way. Residual fractions were low compared to total contents (2 – 4% for Cd, 25% – 35% for Co, 7 – 18% for Mn, 4 – 22% for Zn, 12 – 41% for Ni, 11 – 42% for Pb, 20 – 45% for Cu, < 10% for Zn). High metal concentrations in the acid-extractable and reducible fractions may indicate pollution from anthropogenic sources. DTPA-extractable metals, which may be considered indicative of plant-available contents, were relatively high compared to the total contents. The relative extractability, expressed as the ratio of DTPA-extractable to total contents, decreased in the order Cd (38%) > Cu (28%) = Zn (26%) > Pb (13%) > Ni (10%) > Co (3%). Most of the sites studied would be of concern if they were used for agricultural activities. No trends in metal availability in the period following disposal were apparent from the data.     

Energy and fibre intake in a group of captive giraffe (Giraffa camelopardalis) offered increasing amounts of browse

We investigated the effect of diet on intake of energy and fibre in a group of three captive adult giraffe by weighing offered diet items and leftovers for 7 days after an adaptation period of 7 days. Digestion coefficients were calculated using, as internal marker, the acid detergent lignin content of a faecal sample pooled from subsamples taken during the last 5 days of intake measurement. Two lucerne hay-only diets of differing quality (L1, L2) were fed, as well as the regular diet of lucerne hay and concentrates (L2C), and the regular diet supplemented with 3 or 6 kg of edible, fresh browse material (L2CB3, L2CB6). The proportion of roughage in the ingested diets L2CB6 (45 +/- 5% dry matter), L2CB3 (35 +/- 3%) and L2C (37 +/- 10%) did not differ significantly. Digestible energy intake was low on the hay-only diets [L1: 0.28 +/- 0.06 MJ/kg body weight (BW)0.75; L2: 0.33 +/- 0.10 MJ/kg BW0.75] and increased from L2C (0.60 +/- 0.13 MJ/kg BW0.75) to a significant increase with L2CB3 (0.72 +/- 0.17 MJ/kg BW0.75); no further increase was obvious for L2CB6 (0.63 +/- 0.15MJ/kg BW0.75). The results confirm that giraffes are unlikely to meet energy requirements on lucerne hay-only diets. In a feeding scenario where both lucerne hay and the concentrate component of the diet are fed ad libitum, the animals tended to exchange hay for browse when browse was added. Only the higher level of browse supplementation led to a potentially beneficial increase in fibre intake. Whether additional browse supplementation will lead to increased intakes in a feeding scenario with restricted concentrate provision can be suspected but remains to be demonstrated.     

Fate of Macronutrients in Water Treatment of Digestate Using Vibrating Reversed Osmosis

In the transition from a fossil to a bio-based economy, it has become an important challenge to maximally recuperate and recycle valuable nutrients coming from manure and digestate processing. Membrane filtration is a suitable technology to separate valuable nutrients in easily transportable concentrates which could potentially be re-used as green fertilizers, in the meantime producing high quality water. However, traditional membrane filtration systems often suffer technical problems in waste stream treatment. The aim of this study was to evaluate the performance of vibratory shear enhanced processing (VSEP) in the removal of macronutrients (N, P, K, Na, Ca, Mg) from the liquid fraction of digestates, reducing their concentrations down to dischargeable/re-usable water. In addition, the re-use potential of VSEP-concentrates as sustainable substitutes for fossil-based mineral fertilizers was evaluated. Removal efficiencies for N and P by two VSEP filtration steps were high, though not sufficient to continuously reach the Flemish legislation criteria for discharge into surface waters (15 mg N l⁻¹ and 2 mg P l⁻¹). Additional purification can occur in a subsequent lagoon, yet further optimization of the VSEP filtration system is advised. Furthermore, concentrates produced by one membrane filtration step showed potential as N–K fertilizer with an economic value of €6.3 ± 1.1 t⁻¹ fresh weight (FW). Further research is, however, required to evaluate the impact on crop production and soil quality by application of these new potential green fertilizers.     

Feasibility of a counter-current extraction procedure for the removal of heavy metals from contaminated soils

Effective remediation and sanitation technologies for soils contaminated with heavy metals are limited. We investigated the feasibility of a counter-current metal extraction procedure for the removal of selected heavy metals (Cd, Cu, Ph, and Zn) from two contaminated soils. The process involved a decarbonation (removal of carbonates), acid solubilisation, washing, and liming step. Results from batch equilibration experiments simulating the counter-current process showed more than 85% of the Cd present to be removed. Removal efficiencies for Cu and Pb were limited to approximately 15%, this mainly due to resorption of these elements during the decarbonation step. As most Zn was found to be present in a more difficult acid-extractable solid phase, its extractability accounted for only 25%. While reaction (pH) conditions of both decarbonation and solubilisation determined removal efficiencies, washing the extracted soil with deionized water only slightly increased the amount of metals removed. Metal distribution among solid phases — exchangeable, carbonate, reducible, organically bound, and residual — was affected by the different treatments. The amount of metals contained in the exchangeable and residual fractions determined their extractability. Except for Cu, the reducible and organically bound fractions were less important. After solubilisation 13 to 70% of the metals were present in an exchangeable solid phase. This implicates that washing the solubilized soil with a salt may increase the extractability of metals, especially for Zn and Pb. Based on our results the process is critically evaluated and possibilities for optimization formulated.     

Nitrogen release and mineralization potential of derivatives from nutrient recovery processes as substitutes for fossil fuel‐based nitrogen fertilizers

The need to meet rapidly increasing demands for synthetic nitrogen (N) while reducing dependence on fossil fuels has been driving widespread attention to the recuperation and reuse of nutrients present in digestate and animal manure. The N release and mineralization potential of animal manure (AM), digestate (DIG), liquid fraction of digestate (LFDIG) and mineral concentrate (MC) were assessed in comparison with N availability from calcium ammonium nitrate (CAN) as a reference. The release was highly dependent on the product ‐N/N_total ratio, while mineralization occurred only for products containing more than 5% of organic N. The magnitude of the released N, on average after 120 days of an incubation experiment, was in the order: CAN > MC > LFDIG > DIG ≥ AM. These results indicate that only the N release from MC exhibited patterns similar to CAN, suggesting that this product will provide plant available N in a similar fashion as synthetic fertilizers. The N release from LFDIG was higher than AM, but did not closely follow the pattern of CAN. The N availability in LFDIG may be increased using substrates richer in N, such as animal manure or waste food and not only plant residues.     

Laboratory studies on formation of bound residues and degradation of propiconazole in soils

Laboratory studies on the formation of bound residues and on the degradation of the triazole fungicide propiconazole were conducted in two different soils. Soils treated with 14C-propiconazole were incubated at 22 degrees C and extracted exhaustively with a solvent at each sampling date until no further propiconazole was extracted. The solvent-extractable residues were used to measure propiconazole remaining in the soil, and the extracted soils were used to investigate bound residues of propiconazole. Mineralization of propiconazole was investigated by measuring [14C]carbon dioxide evolved from the soil samples. Formation of bound residues of propiconazole was higher in silty clay loam soil than in sandy loam soil, giving approximately 38 and 23% of the applied 14C, respectively. In contrast, the rates of degradation and mineralization of propiconazole were lower in silty clay loam soil than in sandy loam soil. Decreased extractability of the 14C residues with incubation time was observed with increased formation of bound residues. When the propiconazole remaining in the solvent-extractable residues was quantitatively measured by high-pressure liquid chromatographic analysis, the half-life value in sandy loam soil was about 315 days, while the half-life in silty clay loam soil exceeded the duration of the 1 year experimental period. Increased formation of bound residues was observed as propiconazole degraded with incubation time, suggesting that degradation products are involved in the formation of bound residues. Our study suggests that the formation of bound residues of propiconazole contributes to the persistence of this fungicide in soil.