Browsing by Subject "Mongolia"

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Open Access
A Cross-Sectional Study of Small Mammals for Tickborne Pathogen Infection in Northern Mongolia
(2016) Pulscher, Laura Ann
Introduction: Extensive studies on tickborne pathogens (TBPs) have been conducted in developed nations, relatively less has been done in developing nations leaving a large gap of knowledge. Mongolia, a country built upon nomadic culture and pastoralism is an ideal system to study TBPs as the population is at an increased risk due to increased time spent outside herding livestock. Discoveries of TBPs in Mongolia include Babesia spp., Anaplasma spp., Borrelia spp., Rickettsia spp. and tick-borne encephalitis virus. While research has focused on TBPs in humans and ticks in Mongolia, little research has assessed animal reservoirs, specifically small mammal species, as reservoirs for TBPs. This project aimed to 1) identify the role of small mammal species in the ecology of TBPs in Mongolia, specifically Rickettsia spp., Anaplasma spp., and Borrelia spp. using serological and molecular analysis and 2) identify risk factors associated with the prevalence of TBPs in small mammal populations in Mongolia.
Methods: From June to July 2016, rodents were live-trapped, and whole blood, serum and ear biopsy samples were collected. Sixty-four rodents were trapped in three aimags (provinces) in northern Mongolia. Whole blood samples were tested by PCR to detect the presence of Rickettsia spp., Anaplasma spp., and Borrelia spp.. In addition, ear biopsy samples were tested by PCR to detect the presence of Borrelia spp.. All rodents were serologically tested for antibodies to Anaplasma phagocytophilum and Rickettsia rickettsii. A multivariate model was used to assess risk factors for the presence of tickborne pathogens. Risk factors examined included species and sex of animal, location and presence of ticks.
Results: 56.0%, 39.0% and 0.0% of animals were positive by PCR for Borrelia spp., Rickettsia spp. and Anaplasma spp., respectively. 41.9% and 24.2% of animals were seropositive for A. phagocytophilum and Rickettsia rickettsii, respectively. Risk factors found to be important predictors of Borrelia spp. molecular detection included small mammal capture in Tov aimag (OR, 4.1; 95% CI, 1.00 – 16.80), male small mammals (OR, 3.07; 95% CI, 0.99 – 9.51) and ground squirrel species type (OR, 3.24; 95% CI, 0.90 – 11.70). The risk factor found to be an important predictor of Rickettsia spp. molecular detection was Mongolian gerbil species type (OR, 246.5; 95% CI, 20.77 – 2925.88). Presence of ticks on small mammals (OR, 4.62; 95% CI, 0.92 – 23.24) was an important risk factor for A. phagocytophilum antibody detection. No risk factors were identified as being important predictors of antibody detection of R. Rickettsii.
Conclusion: The results of this study provide considerable evidence of TBPs circulating in small mammal populations in Northern Mongolia. Further information on TBPs in ticks, humans, livestock and wildlife reservoirs will be important to address public health interventions for TBPs in Mongolia in the future.
Open Access
Environmental Risk Sharing in the Oyu Tolgoi Mining Project
(2007-05) Mancinelli, Lauri
In 2005, Ivanhoe Mines Ltd. released a development plan for open pit and underground copper and gold mining of the Oyu Tolgoi porphyry deposits in Mongolia’s Gobi desert. Ivanhoe refers to the project as the largest copper-gold development project in the world. Under Mongolian law, the national government maintains ownership of all mineral reserves, and private parties license exploration and mining rights from the government. A contract agreement between the government and the private mining company stipulates the terms of the license. The size of the state’s share in the copper deposit will be determined by the contract and the Minerals Law of Mongolia. The purpose of this project is to analyze how the contract under consideration distributes environmental risk when environmental financial assurance is included. The basis for this analysis is a cash flow model developed by Robert Conrad for the Open Society Forum Mongolia and Revenue Watch. Two new cash flow models are created by adding self insurance and environmental fund assurance schemes to the Conrad model. Monte Carlo simulations are used to estimate the effects of environmental damages on the relative risk shares born by the Mongolian government and Ivanhoe Mines. Under both financial assurance models, risk shares diverge as the probability that environmental damage will occur increases. Risk shares also diverge as damages increase. The sum of the standard deviations on NPV to the government and the investor is higher than the standard deviation on the NPV to the project as a whole. The results of this analysis are general with respect to the contract but independent of the environmental parameters. The results also imply that the interactions between environmental assurance and other contract terms will ultimately determine the value of the project to the parties. Given the current contract structure, any risk of environmental damages will necessarily result in a cost to the government. This risk may be unnecessary and may dampen any development benefits of the Oyu Tolgoi license.
Open Access
Exploring Tick Borne Pathogens Circulating Mongolia Through Collection of Ticks
(2017) Moore, Thomas Christopher
Abstract
Introduction: Mongolia is a country known for its rich nomadic and pastoral culture, with populations of people who work in environments that are densely populated with ticks and TBP animal reservoirs. TBPs typically undergo transstadial transmission, but transovarial transmission may also occur. Transovarial transmission events have been demonstrated in laboratory settings, but few studies have evaluated transovarial transmission of TBPs in field settings within the host-vector ecosystem. Tick borne pathogens of most concern in Mongolia are Rickettsia spp., Anaplasma spp., Borrelia spp., Babesia spp., Ehrlichia spp., and tick-borne encephalitis. In this study, specific aims were: 1) To determine the prevalence of tick borne pathogens, particularly Rickettsia spp., Anaplasma spp., and Ehrlichia spp. among various tick species at different developmental life stages; and 2) To understand the role of animal reservoirs and vertical transmission of TBPs among feeding ticks at different life stages using larval and nymph ticks collected in the wild from small mammal reservoirs, as well as eggs laid by engorged wild-caught adult female ticks and reared in the laboratory.
Methods: In this cross-sectional study, ticks in their larvae and nymph life stages were collected off of captured rodents across seven soums (districts) in three aimags (provinces) situated in the Northern region of Mongolia from June 20th to July 23rd, 2016. Engorged adult ticks were collected from livestock located in three soums within three aimags from May 6th to 22nd, 2016. Tick eggs were collected from engorged ticks from May 9th to June 1st, 2016. Ticks were tested by PCR to detect the presence of Rickettsia spp., Anaplasma spp., and Ehrlichia spp.
Results: There were 546 (88%) larval and 72 (12%) nymphal Dermacentor spp. ticks collected. There were 588 (95%) of 618 ticks allocated into 42 larvae and 18 nymph pools (60 pools total). All tick pools were PCR-positive for Rickettsia spp. and no tick pools were PCR-positive for Anaplasma/Ehrlichia spp. minimum infection rate (MIR) for R. raoultii ranged from 6.7% to 28.6%. Of the 60 tick pools, 50 (522 ticks total) were matched with rodent rickettsial infection history status. There were 31 (62%) tick pools or 362 (69%) of individual ticks found on rodents with no history of rickettsial infection. The majority of ticks discovered to have no association with rodents with rickettsial infection history were larvae (352/362 individual ticks). There were 38 adult fed female ticks collected. All adult fed ticks were PCR-positive for Rickettsia spp. and 2 (5%) were PCR-positive for Anaplasma/Ehrlichia spp. There were 33 ticks that laid eggs. PCR testing of eggs showed a 91% (30/33) positivity for Rickettsia spp. and one pool of eggs was PCR-positive for Anaplasma/Ehrlichia spp. All sequenced Rickettsia spp. products were identified to be R. raoultii and all sequenced Anaplasma/Ehrlichia spp. were An. ovis.
Conclusions: This study identified transovarial transmission of Rickettsia spp. and Anaplasma spp. among D. nuttalli ticks. This study also found a low association between rodents with history of Rickettsia spp. infection and infection status of biting ticks. Additional study is needed to further assess the proportion of transovarial transmission found in nature. Specifically, testing of individual tick eggs and larvae should be conducted. A better understanding of the ecology of TBPs in nature can provide public health and human and veterinary medicine with a greater awareness of the burden of TBPs in Mongolia.