Probable Reservoir Research Articles

Identification of a novel lineage bat SARS-related coronaviruses that use bat ACE2 receptor

ABSTRACT Severe respiratory disease coronavirus-2 (SARS-CoV-2) has been the most devastating disease COVID-19 in the century. One of the unsolved scientific questions of SARS-CoV-2 is the animal origin of this virus. Bats and pangolins are recognized as the most probable reservoir hosts that harbour highly similar SARS-CoV-2 related viruses (SARSr-CoV-2). This study identified a novel lineage of SARSr-CoVs, including RaTG15 and seven other viruses, from bats at the same location where we found RaTG13 in 2015. Although RaTG15 and the related viruses share 97.2% amino acid sequence identities with SARS-CoV-2 in the conserved ORF1b region, it only shows less than 77.6% nucleotide identity to all known SARSr-CoVs at the genome level, thus forming a distinct lineage in the Sarbecovirus phylogenetic tree. We found that the RaTG15 receptor-binding domain (RBD) can bind to ACE2 from Rhinolophus affinis, Malayan pangolin, and use it as an entry receptor, except for ACE2 from humans. However, it contains a short deletion and has different key residues responsible for ACE2 binding. In addition, we showed that none of the known viruses in bat SARSr-CoV-2 lineage discovered uses human ACE2 as efficiently as the pangolin-derived SARSr-CoV-2 or some viruses in the SARSr-CoV-1 lineage. Therefore, further systematic and longitudinal studies in bats are needed to prevent future spillover events caused by SARSr-CoVs or to understand the origin of SARS-CoV-2 better.

An update on joint ill in sheep.

This focus article has been prepared by Vanessa Swinson of the APHA Small Ruminant Expert Group.

A brief overview of emergencies and dissemination of Shiga-toxin-producing E. coli (STEC) and Salmonella enterica serovar Typhimurium DT104 in humans and food producing animals

Shiga-toxin-producing Escherichia coli (STEC) and Salmonella enterica serovar Typhimurium (STDT104) are foodborne pathogens of public health significance. It is less known that Shiga-toxin-producing Escherichia coli (with cattle being the most probable natural reservoir) can be isolated from pigs, sheep and wildlife as well. The basic information about detection of Shiga-toxin-producing genes in STEC as well as the origin of Salmonella Typhimurium definite phage type 4 (STDT4) the virulence and resistance mechanisms including their distribution in the world is presented. Due to the foodborne transmission mechanisms we emphasize the role of veterinary scientist in Serbia in implementing good management practice on animal farms and in strengthening laboratory diagnostic capacities.

Modelling and mapping hydrocarbon saturated sand reservoir using Poisson’s impedance (PI) inversion: a case study of Bonna field, Niger Delta swamp depobelt, Nigeria

3D seismic volume and two well logs data labelled Bonna-6 and Bonna-8 were employed in the inversion process. The data set was simultaneously inverted to produce P- and S-impedances, density, VP − VS, and PI seismic attributes. An average “c” term value of 1.37 was obtained from the inverse of the slope of the crossplot of P-impedance versus S-impedance for Bonna-6 and Bonna-8 wells. This value was employed in the inversion process to generate the PI attribute, which aided in reducing the non-uniqueness inherent in discriminating the probable reservoir sands. Five seismic attributes slices were generated to ascertain the superiority of each attribute in delineating the probable reservoir sand. These attributes were: density, S-impedance, P-impedance, VP− VS ratio and PI. These attributes reveal low value of density (1.96 − 2.14 g/cc), P-impedance (1.8 × 104 − 2.1 × 104) ft/s*g/cc, S-impedance (9.2 × 103 − 1.1 × 104) ft/s*g/cc, VP − VS (1.65 − 1.72) and PI (4.9 × 103 − 5.1 × 104) ft/s*g/cc around the area inferred to be hydrocarbon saturated reservoir. Although the attributes considered reveals the same zone suspected to be probable hydrocarbon zone, PI gives a better discrimination when compared to other attributes. A distinctive spread and demarcation of the delineated hydrocarbon sand are observed in the PI attribute slice.

Coyotes as Reservoirs for Onchocerca lupi, United States, 2015-2018.

The Onchocerca lupi nematode infects dogs, cats, and humans, but whether it can be spread by coyotes has been unknown. We conducted surveillance for O. lupi nematode infection in coyotes in the southwestern United States. We identified multiple coyote populations in Arizona and New Mexico as probable reservoirs for this species.

Evaluation of Gas Potential in Early Cretaceous Shale Lower Indus Basin, Pakistan

The shale gas potential of the early Cretaceous Talhar shale member of the lower Goru Formation in lower Indus basin of Sanghar district, Sindh province, has been evaluated using 2D seismic and well logs data. Graphical and empirical techniques were applied to calculate various geochemical parameters for the evaluation of shale plays. Total Organic Carbon (TOC) is calculated by Passey's (∆LogR) Overlay technique and its values are about 2.44 wt.%. Vitrinite Reflectance (Ro) is estimated by graphical and empirical relation and the value lies between 0.95-1.0 which implies that the Talhar shale member is in peak oil and initial gas generation phase. Log-derived Maturity Index (LMI) is calculated by NPHI, RHOB or density log and uranium logs. The average value is about 0.55 which reflects that the formation is probably in the initial maturation phase. Kerogen Volume (Vk) is estimated by empirical relation using RHOB log as input and it is about 13 wt. % which reflects that the formation has enough potential of oil/gas expulsion. The results are compared and validated with a study of the adjacent field of the same basin. This study reveals that Talhar member of lower Goru Formation could be the future probable potential unconventional reservoir for exploration in lower Indus basin of Pakistan.

Evaluation of Gas Potential in Early Cretaceous Shale Lower Indus Basin, Pakistan

The shale gas potential of the early Cretaceous Talhar shale member of the lower Goru Formation in lower Indus basin of Sanghar district, Sindh province, has been evaluated using 2D seismic and well logs data. Graphical and empirical techniques were applied to calculate various geochemical parameters for the evaluation of shale plays. Total Organic Carbon (TOC) is calculated by Passey's (∆LogR) Overlay technique and its values are about 2.44 wt.%. Vitrinite Reflectance (Ro) is estimated by graphical and empirical relation and the value lies between 0.95-1.0 which implies that the Talhar shale member is in peak oil and initial gas generation phase. Log-derived Maturity Index (LMI) is calculated by NPHI, RHOB or density log and uranium logs. The average value is about 0.55 which reflects that the formation is probably in the initial maturation phase. Kerogen Volume (Vk) is estimated by empirical relation using RHOB log as input and it is about 13 wt. % which reflects that the formation has enough potential of oil/gas expulsion. The results are compared and validated with a study of the adjacent field of the same basin. This study reveals that Talhar member of lower Goru Formation could be the future probable potential unconventional reservoir for exploration in lower Indus basin of Pakistan.

Evaluation of Gas Potential in Early Cretaceous Shale Lower Indus Basin, Pakistan

The shale gas potential of the early Cretaceous Talhar shale member of the lower Goru Formation in lower Indus basin of Sanghar district, Sindh province, has been evaluated using 2D seismic and well logs data. Graphical and empirical techniques were applied to calculate various geochemical parameters for the evaluation of shale plays. Total Organic Carbon (TOC) is calculated by Passey's (∆LogR) Overlay technique and its values are about 2.44 wt.%. Vitrinite Reflectance (Ro) is estimated by graphical and empirical relation and the value lies between 0.95-1.0 which implies that the Talhar shale member is in peak oil and initial gas generation phase. Log-derived Maturity Index (LMI) is calculated by NPHI, RHOB or density log and uranium logs. The average value is about 0.55 which reflects that the formation is probably in the initial maturation phase. Kerogen Volume (Vk) is estimated by empirical relation using RHOB log as input and it is about 13 wt. % which reflects that the formation has enough potential of oil/gas expulsion. The results are compared and validated with a study of the adjacent field of the same basin. This study reveals that Talhar member of lower Goru Formation could be the future probable potential unconventional reservoir for exploration in lower Indus basin of Pakistan.

Rock‐physics forward modelling to predict seismic behaviour: A case study for exploration target in Mahanadi basin, East Coast of India

ABSTRACTOne of the major aspects of rock‐physics forward modelling is to predict seismic behaviour at an undrilled location using drilled well data. It is important to model the rock and fluid properties away from drilled wells to characterize the reservoir and investigate the root causes of different seismic responses. Using the forward modelling technique, it is possible to explain the amplitude responses of present seismic data in terms of probable rock and reservoir properties. In this context, rock‐physics modelling adds significant values in the prospect maturation process by reducing the risk of reservoir presence in exploration and appraisal phases. The synthetic amplitude variation with offset gathers from the forward model is compared with real seismic gathers to ensure the fidelity of the existing geological model. ‘Prospect A’ in the study area has been identified from seismic interpretation, which was deposited as slope fan sediments in Mahanadi basin, East Coast of India. The mapped prospect has shown class‐I amplitude variation with offset response in seismic without any direct hydrocarbon indicator support. The existing geological model suggests the presence of an excellent gas reservoir with proven charge access from the fetch area, moderate porosity and type of lithology within this fan prospect. But, whether the seismic response from this geological model will exhibit a class‐I amplitude variation with offset behaviour or ‘dim spot’ will be visible; the objective of the present study is to investigate these queries. A rock‐physics depth trend analysis has been done to envisage the possibilities of class‐I reservoir in ‘Prospect A’. Forward modelling, using a combination of mechanical and chemical compaction, shows the synthetic gas gathers at ‘Prospect A’, which are class I in nature. The study has also depicted 2D forward modelling using lithology and fluid properties of discovery well within similar stratigraphy to predict whether ‘dim spot’ will be seen in seismic. The estimated change in synthetic amplitude response has been observed as ∼5% at contact, which suggests that the changes will not be visible in seismic. The study connects the existing geological model with a top‐down seismic interpretation using rock‐physics forward modelling technique to mature a deep‐water exploratory prospect.

COVID-19: a review.

The enduring epidemic outbreak which started in Wuhan city of China, in December 2019 caused by the 2019 novel coronavirus (COVID- 19) or the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has created a dangerous and deadly Public Health disaster of International apprehension, with cases confirmed in several countries. This novel community health trouble is frightening the universe with clinical, psychological, emotional, collapse of health system and economical slowdown in each and every part of the world infecting nearly 200 countries. A highly virulent and pathogenic COVID-19 viral infection with incubation period ranging from two to fourteen days, transmitted by breathing of infected droplets or contact with infected droplets, belongs to the genus Coronavirus with its high mutation rate in the Coronaviridae. The likely probable primary reservoir could be bats, because genomic analysis discovered that SARSCoV-2 is phylogenetically interrelated to SARS-like bat viruses. The transitional resource of origin and transfer to humans is not known, however, the rapidly developing pandemic has confirmed human to human transfer. Approximately 1,016,128 reported cases, 211,615 recovered cases and 53,069 deaths of COVID-2019 have been reported to date (April 2, 2020). The symptoms vary from asymptomatic, low grade pyrexia, dry cough, sore throat, breathlessness, tiredness, body aches, fatigue, myalgia, nausea, vomiting, diarrhea, to severe consolidation and pneumonia, acute respiratory distress syndrome (ARDS) and multiple organ dysfunction leading to death with case fatality rate ranging from 2 to 3%.

Integration of Well Logs and Seismic Attribute Analysis in Reservoir Identification on PGS Field Onshore Niger Delta, Nigeria

AbstractIntegrated well dataset and seismics delineated the PGS field onshore Niger Delta for reservoir identification. Gamma ray, resistivity, Neutron and density Logs identified four lithologies: sandstone, shaly sandstone, shaly sand and shale. They consist of sand-shale intercalation with the traces of shale sometimes found within the sand Formation. Petrophysical parameters of the reservoirs showed varying degree of lower density, low gamma ray, high porosity and resistivity response with prolific hydrocarbon reservoir G due to its shale volume and the clean sand mapped as a probable hydrocarbon reservoir. 3D seismic data located both seismic scale and sub-seismic scale structural and stratigraphic elements. Risk reduction in dry hole drilling due fault missing in conventional seismic attribute analysis and interpretation, have to be integrated into the Oil companies standard practice.

Identification Sus scrofa and Mus musculus as potential hosts of SARS-CoV-2 via phylogenetic and homologous recombination analysis

Background: Previously, most studies focus on the wild animal being sold in the Wuhan Huanan seafood wholesale market, neglecting that the livestock living around other place could also be the original hosts. Methods: First, relative synonymous codon usage was utilized to analyze the potential hosts of SARS-CoV-2; Then cluster SARS-CoV-2 and related coronavirus through the phylogenetic tree. Next, we used Recombination Detection Program to identify the possible recombination region, as well as verifying via Simplot. Results: Related coronavirus from porcine or murine sources may faciliatate the evolution and reorganization of SARS-CoV-2. Conclusions: Overall, to our knowledge, this is the first paper to illustrate that swine and mice could be probable reservoirs for the SARS-CoV-2.

An intelligent heuristic-clustering algorithm to determine the most probable reservoir model from pressure–time series in underground reservoirs

Precise characterization of underground reservoirs requires accurate calculations of the reservoir’s petrophysical data and accurate selection of the mathematical model governing the reservoir’s dynamic. In this study, we develop a novel heuristic-clustering algorithm, namely GA–DBSCAN–KMEANS, that can be applied over pressure transient data to assess the true reservoir model out of a pool of candidates. In this algorithm, each specific reservoir model is considered a subpopulation in the GA (genetic algorithm). Then, the simultaneous optimization of all the reservoir models is sought using the proposed hybrid algorithm. During the optimization process, the population size of different models will be either decreased, increased, or unchanged based on the average quality match obtained for each model. A combined DBSCAN (density-based spatial clustering of applications with noise)–KMEANS clustering scheme is used to increase the population size for the best reservoir model in each iteration of the GA. The accuracy of the proposed algorithm was verified using several synthetic data and a real field case obtained from the open literature. The tested data were collected from different types of reservoir models, including homogeneous reservoirs, matrix-fracture dual-porosity reservoirs, and fault-limited reservoirs. For uncertainty analyses and to test the performance of the algorithm under large numbers of initializations, Monte Carlo simulations were conducted. Results of the Monte Carlo simulations unveiled high values of P10, P50, and P90 for the probability of the true reservoir model and low values of these statistics for the false reservoir models. This shows that the outcome of the proposed algorithm is not affected by the initial randomization of the solution subspaces; hence, the developed algorithm is a reliable tool in determining the most probable reservoir model from transient well testing data.

Identification Sus scrofa and Mus musculus as potential hosts of SARS-CoV-2 via phylogenetic and homologous recombination analysis

Background: Wuhan Huanan seafood wholesale market is highly suspected as the original place for the outbreak of SARS-CoV-2 previously. Most studies focus on the livestock being sold in the market, neglecting that the livestock living around the city of Wuhan could also be the original hosts. Methods: First, relative synonymous codon usage was utilized to analyze the potential hosts of SARS-CoV-2; Then cluster SARS-CoV-2 and related coronavirus through the phylogenetic tree. Next, we used Recombination Detection Program to identify the possible recombination region, as well as verifying via Simplot. Results: Related coronavirus from porcine or murine sources may faciliatate the evolution and reorganization of SARS-CoV-2. Conclusions: Overall, to our knowledge, this is the first paper to illustrate that swine and mice could be probable reservoirs for the SARS-CoV-2.

Geo-climatic factors in a newly emerging focus of zoonotic visceral leishmaniasis in rural areas of north-eastern Iran.

Visceral leishmaniasis (VL) is the fatal form of leishmaniasis. A newly emerging focus of zoonotic VL (ZVL) including 13 villages has been reported from Maraveh Tappeh County, Golestan province, north-eastern Iran. We investigated the effect of climatic and environmental factors on the occurrence of disease in this focus by geographical information systems (GIS) approaches and logistic regression models. The incidence rate of ZVL in human and dog population was estimated 1.2% and 27.3%, respectively, in the studied areas. Rock soil type (OR=11.7), rainfall (OR=1.04) and elevation (OR=0.99) were found as determinants of ZVL. Also, almost all infected villages were in close proximity of rivers. Cavities of rock soil around rivers are assumed as suitable areas for sandfly resting and growth by providing shadow and moisture. Rainfall also provides appropriate moisture in semi-arid regions for survival of sandflies. The negative effect of higher altitude can be explained by some sandfly life-limiting conditions like freezing weather. Accordingly, regions with lower altitude and higher rainfall, covered by rock and in close proximity of rivers, are the hazard zones for ZVL in the Maraveh Tappeh. Air humidity, temperature, land cover type and slope were not predictors of disease in the current study. Further investigations on human population movement, probable reservoirs and vectors of disease can provide valuable data for modelling the future distribution of ZVL in the Iranian province.

Wastewater as a Probable Environmental Reservoir of Extended-Spectrum-β-Lactamase Genes: Detection of Chimeric β-Lactamases CTX-M-64 and CTX-M-123.

The presence of antimicrobial-resistant bacteria and resistance genes in aquatic environments is a serious public health concern. This study focused on Escherichia coli possessing blaCTX-M genes in wastewater inflows. Twelve crude inflow water samples from wastewater treatment plant (WWTP) A and two samples each from three other WWTPs were collected in 2017 and 2018. A total of 73 E. coli isolates with 31 different sequence types (STs) harboring distinctive blaCTX-M gene repertoires were detected. In WWTP A influents, blaCTX-M-14 (14 isolates) was dominant, followed by blaCTX-M-15 (12 isolates) and blaCTX-M-27 (10 isolates). The chimeric blaCTX-M-64 and blaCTX-M-123 genes were each identified in one of the E. coli isolates from the same WWTP A inflow port. The blaCTX-M-27 gene was associated with five of seven B2-ST131 isolates, including three isolates of the B2-O25b-ST131-H30R/non-Rx lineage. One of the remaining two isolates belonged to the B2-O25b-ST131-H30R/Rx lineage harboring the blaCTX-M-15 gene. As for the B2-O25b-ST131-H30R/non-Rx lineage, two isolates with blaCTX-M-27 were recovered from each of the WWTP B and D influents, and one isolate with blaCTX-M-174 was also recovered from WWTP B influent. Whole-genome sequencing of chimeric blaCTX-M-harboring E. coli isolates revealed that the blaCTX-M-64 gene was integrated into the chromosome of ST10 E. coli B22 via ISEcp1-mediated transposition of a 9,467-bp sequence. The blaCTX-M-123-carrying IncI1 plasmid pB64 was 109,169 bp in length with pST108. The overall findings suggest that wastewater may act as a probable reservoir of clinically significant clonal lineages mediating antimicrobial resistance genes and chimeric genes that have not yet been identified from human isolates of domestic origin in Japan.IMPORTANCE Global spread of CTX-M-type extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is a critical concern in both clinical and community settings. This dominance of CTX-M-type ESBL producers may be largely due to the successful international spread of epidemic clones, as represented by the extraintestinal pathogenic Escherichia coli (ExPEC) ST131. Our findings highlight the worrisome presence of diverse E. coli clones associated with humans, including ExPEC lineages harboring the most common blaCTX-M variants in untreated wastewater samples. Moreover, the chimeric genes blaCTX-M-64 and blaCTX-M-123, which have not yet been identified from human isolates of domestic origin in Japan, were identified. Exposure to untreated wastewater through combined sewer overflow caused by heavy rains derived from abnormal weather change could pose a risk for human health due to ingesting those antimicrobial-resistant bacteria.

Multicomponent Versus Classical Geothermometry: Applicability of Both Geothermometers in a Medium-Enthalpy Geothermal System in India

The Manuguru geothermal area, located in the Khammam district of Telangana state, India, is one of the least explored medium-enthalpy geothermal systems in India. In this study, subsurface reservoir temperature was estimated by applying various methodologies such as chemical geothermometry, multicomponent geothermometry and mixing models. Chemical geothermometers provided wide range in temperature estimation, and most of them (Na–K, Na–K–Ca, Mg-corrected Na–K–Ca) were found to be unsuitable for predicting reservoir temperature due to the absence of attainment of equilibrium between suitable mineral pairs. The temperature range estimated from the quartz geothermometers varied from 72 to 120 °C which matched closely with values obtained from K–Mg geothermometers. To overcome this problem and to better constrain the reservoir temperature, multicomponent solute geothermometry modelling was carried out by applying the GeoT computer code. Fluid reconstruction was done after taking into account both the degassing and mixing phenomena. GeoT modelling of the reconstructed fluid provided excellent clustering of the minerals. From the GeoT modelling study, it was found that minerals like quartz, chalcedony, calcite, etc., attained simultaneous equilibrium with thermal waters in the temperature range of 130 ± 10 °C, which can be taken as the most probable reservoir temperature. The subsurface temperature (137 °C) obtained from the mixing model further validated the results obtained from multicomponent geothermometry. This integrated multicomponent method and the simulation program used in this study take into account various processes (i.e. mixing, degassing, non-attainment of equilibrium, etc.) which affect the composition of the thermal fluids during its ascent to the surface. The statistical approach of ‘best clustering minerals’ used in this model helps to overcome the problems encountered in applying cation or single-component geothermometers in the medium-enthalpy geothermal systems.

Prevalence of Antimicrobial Resistance and Virulence Gene Elements of Salmonella Serovars From Ready-to-Eat (RTE) Shrimps.

Gastrointestinal illnesses continue to be a global public health risk. Exposure to foodborne Salmonella directly or indirectly through consumption of ready-to-eat seafood can be an important route of infection to humans. This study was designed to estimate the population cell density, prevalence, virulence gene signatures, and antibiotic resistance of Salmonella serovars from ready-to-eat shrimps. Ready-to-eat (RTE) shrimp samples were obtained from different open markets in Delta and Edo States, Nigeria from November 2016 to October 2017. We employed classical and polymerase chain reaction (PCR) approaches. The mean Salmonella species enumerated from the RTE shrimps ranged from −0.301 to 5.434 log10 cfu/g with 210/1440 (14.58%) of the RTE shrimp samples harbored Salmonella species. After biochemical and PCR approach, the identified isolates were Salmonella Enteritidis 11(24.4%), Salmonella Typhimurium 14 (31.1%) and other Salmonella spp. 20 (44.4%). All Salmonella species recovered were resistant to penicillin and erythromycin with 100% sensitivity to cefotaxime, cephalothin, colistin, and polymyxin B. Findings on the multidrug-resistant (MDR) profile showed that a total of 9/14 (64.3%) of Salmonella Enteritidis were resistant to 5 antibiotics which belongs to 3 different groups of antimicrobials with a multiple antibiotic-resistant (MAR) index of 0.21; while 3/11 (27.3%) of Salmonella Typhimurium were resistant to 11 antibiotics which belongs to 7 different groups of antimicrobials with a MAR index of 0.46. Virulence genes (spiA, sipB, invA, sif A, fljB, and sefA) and resistance genes (class 1 and II integrase, sul2, catB3, flor, tmp, blaTEM, strB, dfr1, and tetC) were also detected in some of the Salmonella species with variable percentage. This study indicates that ready-to-eat shrimps are probable reservoirs harboring Salmonella strains. The identified Salmonella isolates which exhibited virulence determinants and antibiotic-resistant coupled with high MAR index constitute a consumer health risk to the communities.

DETECTION OF LEISHMANIA INFECTION IN STRAY DOGS IN HUMAN LEISHMANIASIS ENDEMIC AREA IN MYMENSINGH DISTRICT WITH ITS POSSIBLE PUBLIC HEALTH SIGNIFICANCE IN BANGLADESH

Background: Leishmaniasis is primarily caused by two species of Leishmania (L. donovani and L. infantum) of which clinical infection with L. infantum has been recognized in both humans and dogs as zoonotic disease with dogs as the main reservoir hosts in the Mediterranean, the Middle East, Asia and South America. Although L. donovani has been associated with both clinical and asymptomatic infection in humans but it is still associated with asymptomatic infection in dogs in Indian sub-continent without any evidence of zoonotic infection. Objectives: The objective of this research was to investigate the potentiality of dog as reservoir host for visceral leishmaniasis in the human leishmaniasis endemic regions in Bangladesh. Materials and Methods: A total of 20 stray dogs in the human VL endemic areas of Mymensingh district were captured for the detection VL during the period of November 2010 to May 2011. The dipstick test rK39 (Bios International; n = 20), Giemsa’s stained impression smears of liver and spleen (n = 6) and PCR with the tissue of liver and spleen (n = 6) were tested as per manufacturer instructions and conventional standard methods. Results: Out of 20 stray dogs examined, 4 (20.0%) were positive for L. donovani infection with rK39 strip test. Of the six randomly selected dogs tested with Modified Giemsa’s stained of impression smears of spleen and liver showed 2 (33.33%) positive whereas PCR technique detected 5 (83.33%) positive for L. donovani. Results of PCR showed 145bp amplicon, specific for L. donovani infection in 83.33% stray dogs. Conclusions: This study reveals that a high percentage of L. donovani asymptomatic carrier infections occur in dogs and evidence indicates that dogs and humans may potentially serve as a source of infection to sand fly vectors and accordingly dogs can be recognized as a probable animal reservoir for the Leishmania infection in the endemic region in Bangladesh. However, further studies are required to determine the ability of dogs to transmit the L. donovani to the vector sand fly in nature and its evidence on ‘One Health’ perspectives. Keywords: Visceral leishmaniasis, Endemic region, Stray dogs, rK39 strip test, Giemsa’s stained liver and spleen impression smears, PCR, Reservoir host, Mymensingh

Indentifying and modeling the distribution of cryptic reservoirs of Ebola virus using artificial intelligence

Fruit bats (Megachiroptera) have been found to be the principal reservoirs of Ebola virus (EBOV) to humans. However, bats do not appear to be the primary reservoir in the environment and between outbreaks. The cryptic reservoir species of EBOV and its distribution have not been identified. The purpose of the study was to identify the most likely cryptic reservoir species of EBOV and the probable distribution of cryptic reservoir species where EBOV could be maintained in Sierra Leone. The Bioagent Transport and Environmental Modeling System (BioTEMS) was used to analyze mammals, arthropods, plants and protists in order to identify the most likely species to be the cryptic reservoir for EBOV. ArcGIS and BioTEMS were used to determine the probable distribution of cryptic reservoir species. BioTEMS identified free-living pathogenic amoebae (FLPA) as the probable cryptic reservoir species (Test Performance = 93.3). Diptera in the order Chrysops were also identified as possible secondary reservoirs and mechanical vectors of EBOV. Distribution of likely hot spots for FLPA and phytotelmata/tree-holes were identified in several regions of Sierra Leone, primarily in the southeast and are similar to those predicted by other authors, but at a much higher resolution (15 m for BioTEMS verses up to 5 km in other studies). Water-filled cavities (phytotelmata), specifically tree-holes, were identified as the most likely sites for the cycle of transmission to occur among FLPA and susceptible secondary reservoirs. Free-living pathogenic amoebae are not only pathogenic to humans and animals but they serve as reservoirs and Trojan horses of infection as well. Identifying what and where cryptic reservoirs of EBOV persist between outbreaks provides an opportunity for the first time to conduct environmental epidemiologic surveillance to mitigate outbreaks and to test anti-microbial delivery systems such as the ProVector® to reduce EBOVand FLPA.Keywords: Filovirus, Amoeba, Epidemiology, Machine Learning, Vector, Disaster Management