Epidemiological and socio-legal overview

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Investigation of risk factors for Echinococcus coproantigen positivity in dogs in the Alay valley, Kyrgyzstan

Echinococcosis caused by the zoonotic cestodes Echinococcus granulosus (sensu lato) and Echinococcus multilocularis is highly endemic in the Central Asian Republic of Kyrgyzstan, and is increasingly being identified as public health problem especially amongst pastoral communities. As domestic dogs are considered to be the main source of human infection in these communities, the identification of potential transmission pathways can be of use when considering implementing a control scheme for echinococcosis. The current report describes the results of an analytic study of canine echinococcosis (based on the results of coproantigen ELISA testing) in the Alay valley of southern Kyrgyzstan prior to the commencement of a praziquantel dosing scheme amongst dogs. A logistic regression model using a form of Bayes modal estimation was used to identify possible risk factors for coproantigen positivity, and the output was interpreted in a Bayesian context (posterior distributions of the coefficients of interest). The study found that sheepdogs had lower odds of coproantigen positivity, as did households with donkeys, some knowledge of echinococcosis, and which did not engage in home slaughtering. There was no evidence of an association between free roaming or previous praziquantel dosing and coproantigen positivity, as has been found in previous studies. Possible reasons for these findings are discussed and suggestions made for further work

Development and Deployment of a Bioreactor for the Removal of Sulfate and Manganese from Circumneutral Coal Mine Drainage

Surface mining, in the form of contour mining and mountain-top removal, is a common means for retrieving coal in the Appalachian Coal Belt region of Kentucky. Overburden or excess spoil generated by these two methods is placed in valley fills. Traditionally Constructed fills have been shown to adversely impact headwater ecosystems via stream burial and through alterations to the hydrology, sediment supply, water quality and biological composition of downstream reaches. Mine drainages emanating from the toe of valley fills often contain elevated levels of total dissolved solids and heavy metals. Drainage chemistry from Guy Cove, a valley fill located in eastern Kentucky, exhibited a mean pH of 6.5 and Fe, Mn and SO4 concentrations of 1.5, 14, and 1264 mg L-1, respectively. The objective of this research was to develop an anaerobic bioreactor for the purpose of reducing Mn and SO4 concentrations in the mine drainage. Development began with batch experiments that tested five different organic carbon sources and five different inorganic substrates. A synthetic mine drainage with a pH of 6.2 and Mn and SO4 concentrations of 90 and 1,500 mg/L, respectively, was used in the experiment. Manganese and SO4 removal varied widely between treatment matrices, with removal rates \u3c 10 to 100% for Mn and \u3c 10 to \u3e 80% for SO4. The substrate sources which provided the most treatment were hardwood mulch and biosolids combined with creek sediment. Subsequent experiments were performed using the synthetic mine drainage in small bioreactors (55 liter plastic tanks) filled with creek sediment with either hardwood mulch or biosolids, each replicated three times. Over a 65 day treatment period \u3e 90% of the Mn and 70% of the SO4 was removed. There were no statistical differences between the two organic substrates. Using this information, in-situ bioreactors consisting of two 5,500 liter plastic septic tanks filled with creek sediment, hardwood mulch and manure compost were installed at Guy Cove. Mine drainage was collected in a sump and conveyed through the inline bioreactors by gravity. Gate valves were used to control flow through the bioreactors. After a 10-month monitoring period, the in-situ bioreactors removed 12, 11, and 64% of Mn, SO4 and Fe from the drainage, respectively. Results from the field differed greatly from those observed under controlled laboratory conditions. Efforts to improve the efficiency of the in-situ bioreactors are underway

Dog ownership, dog behaviour and transmission of Echinococcus spp. in the Alay Valley, southern Kyrgyzstan

Echinococcosis is a re-emerging zoonotic disease in Kyrgyzstan, and the incidence of human infection has increased substantially since the collapse of the Soviet Union in 1991. Domestic dogs are hosts of Echinococcus spp. and play an important role in the transmission of these parasites. The demography, ecology and behaviour of dogs are therefore relevant in studying Echinococcus spp. transmission. Dog demographics, roles of dogs, dog movements and faecal environmental contamination were assessed in four rural communities in the Alay Valley, southern Kyrgyzstan. Arecoline purge data revealed for the first time that E. granulosus, E. canadensis and E. multilocularis were present in domestic dogs in the Alay Valley. Surveys revealed that many households had dogs and that dogs played various roles in the communities, as pets, guard dogs or sheep dogs. Almost all dogs were free to roam, and GPS data revealed that many moved outside their communities, thus being able to scavenge offal and consume rodents. Faecal environmental contamination was high, presenting a significant infection risk to the local communitie

Current status of cystic echinococcosis control in the Falkland Islands: has elimination been achieved?

Attempts to control cystic echinococcosis (CE) caused by Echinococcus granulosus in the Falkland Islands have been ongoing for over 50 years. No human cases have been recorded since the 1980s but there is a need to establish if the parasite has been completely eliminated from domestic animals. A study was carried out in 2018/2019 to identify dogs infected with E. granulosus using copro-antigen and copro-polymerase chain reaction (PCR) analysis. In addition, annual slaughter data were analysed to establish infection levels of E. granulosus and 2 other taeniid parasites. Results showed that 4 out of 589 dogs (0.7%) tested positive by copro-antigen analysis. Results from similar surveys carried out in 2010, 2012 and 2014 showed 17 (3%), 0 and 6 (1%) copro-antigen-positive dogs, respectively, with 8 dogs being confirmed by PCR in 2010. Annual abattoir data showed that from 2006 to 2020, 36 sheep were identified with E. granulosus (mean 0.0055%), 14 186 sheep with Taenia hydatigena (mean 2.2%) and 465 with Taenia ovis (mean 0.072%). Prevalences of T. hydatigena and T. ovis showed spontaneous rises in certain years where the infections could also be detected in lambs indicating that viable taeniid eggs were present. Observations of farm management procedures indicated that there were occasions when dogs could get access to infective taeniid material. In conclusion, E. granulosus is still present in sheep and dogs but at low prevalences. The increasing presence of T. hydatigena however, indicates that control measures are defective in some areas and there is potential for a re-emergence of CE

Helminth parasites in the endangered Ethiopian wolf, Canis simensis

Ethiopian wolves, Canis simensis, are an endangered carnivore endemic to the Ethiopian highlands. Although previous studies have focused on aspects of Ethiopian wolf biology, including diet, territoriality, reproduction and infectious diseases such as rabies, little is known of their helminth parasites. In the current study, faecal samples were collected from 94 wild Ethiopian wolves in the Bale Mountains of southernEthiopia,betweenAugust 2008andFebruary 2010,andwere screened for the presence of helminth eggs using a semi-quantitative volumetric dilutionmethodwithmicroscopy.We found that 66 of the 94 faecal samples (70.2%) contained eggs from at least one group of helminths, including Capillaria, Toxocara, Trichuris, ancylostomatids, Hymenolepis and taeniids. Eggs of Capillaria sp. were found most commonly, followed by Trichuris sp., ancylostomatid species and Toxocara species. Three samples contained Hymenolepis sp. eggs, which were likely artefacts from ingested prey species. Four samples contained taeniid eggs, one of whichwas copro-polymerase chain reaction (copro-PCR) and sequence positive for Echinococcus granulosus, suggesting a spillover from a domestic parasite cycle into this wildlife species. Associations between presence/absence of Capillaria, Toxocara and Trichuris eggs were found; and egg burdens of Toxocara and ancylostomatids were found to be associated with geographical location and sampling season.Institute for Breeding Rare and Endangered African Mammals (IBREAM), the Born Free Foundation and the Wildlife Conservation Network. University of Salford.http://journals.cambridge.org/action/displayJournal?jid=JHL2016-01-31hb201

The Shapes of Tight Composite Knots

We present new computations of tight shapes obtained using the constrained gradient descent code RIDGERUNNER for 544 composite knots with 12 and fewer crossings, expanding our dataset to 943 knots and links. We use the new data set to analyze two outstanding conjectures about tight knots, namely that the ropelengths of composite knots are at least 4\pi-4 less than the sums of the prime factors and that the writhes of composite knots are the sums of the writhes of the prime factors.Comment: Summary text file of tight knot lengths and writhing numbers stored in anc/ropelength_data.txt. All other data freely available at http:://www.jasoncantarella.com/ and through Data Conservanc

Ash generation and distribution from the April-May 2010 eruption of Eyjafjallajökull, Iceland

The 39-day long eruption at the summit of Eyjafjallajökull volcano in April–May 2010 was of modest size but ash was widely dispersed. By combining data from ground surveys and remote sensing we show that the erupted material was 4.8±1.2·1011 kg (benmoreite and trachyte, dense rock equivalent volume 0.18±0.05 km3). About 20% was lava and water-transported tephra, 80% was airborne tephra (bulk volume 0.27 km3) transported by 3–10 km high plumes. The airborne tephra was mostly fine ash (diameter <1000 µm). At least 7·1010 kg (70 Tg) was very fine ash (<28 µm), several times more than previously estimated via satellite retrievals. About 50% of the tephra fell in Iceland with the remainder carried towards south and east, detected over ~7 million km2 in Europe and the North Atlantic. Of order 1010 kg (2%) are considered to have been transported longer than 600–700 km with <108 kg (<0.02%) reaching mainland Europe

Forecasting the duration of volcanic eruptions: an empirical probabilistic model

The ability to forecast future volcanic eruption durations would greatly benefit emergency response planning prior to and during a volcanic crises. This paper introduces a probabilistic model to forecast the duration of future and on-going eruptions. The model fits theoretical distributions to observed duration data and relies on past eruptions being a good indicator of future activity. A dataset of historical Mt. Etna flank eruptions is presented and used to demonstrate the model. The data has been compiled through critical examination of existing literature along with careful consideration of uncertainties on reported eruption start and end dates between the years 1300 AD and 2010 and data following 1600 is considered to be reliable and free of reporting biases. The distribution of eruption durations between the years 1600 and 1670 is found to be statistically different from that following 1670 and represents the culminating phase of a century-scale cycle. The forecasting model is run on two datasets ofMt. Etna flank eruption durations; 1600-2010 and 1670-2010. Each dataset is modelled using a log-logistic distribution with parameter values found by maximum likelihood estimation. Survivor function statistics are applied to the model distributions to forecast (a) the probability of an eruption exceeding a given duration, (b) the probability of an eruption that has already lasted a particular number of days exceeding a given total duration and (c) the duration with a given probability of being exceeded. Results show that excluding the 1600-1670 data has little effect of the forecasting model result, especially where short durations are involved. By assigning the terms ‘likely’ and ‘unlikely’ to probabilities of 66 % and 33 %, respectively the forecasting model is used on the 1600-2010 dataset to indicate that a future flank eruption on Mt. Etna would be likely to exceed 20 days (± 7 days) but unlikely to exceed 68 days (± 29 days). This model can easily be adapted for use on other highly active, well-documented volcanoes or for different duration data such as the duration of explosive episodes or the duration of repose periods between eruptions