Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Epidemiology”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources
USGS2014

Evaluation of monkeypox virus infection of prairie dogs (Cynomys ludovicianus) using in vivo bioluminescent imaging

Monkeypox (MPX) is a re-emerging zoonotic disease that is endemic in Central and West Africa, where it can cause a smallpox-like disease in humans. Despite many epidemiologic and field investigations of MPX, no definitive reservoir species has been identified. Using recombinant viruses expressing the firefly luciferase (luc) gene, we previously demonstrated the suitability of in vivo bioluminescent imaging (BLI) to study the pathogenesis of MPX in animal models. Here, we evaluated BLI as a novel approach for tracking MPX virus infection in black-tailed prairie dogs (Cynomys ludovicianus). Prairie dogs were affected during a multistate outbreak of MPX in the US in 2003 and have since been used as an animal model of this disease. Our BLI results were compared with PCR and virus isolation from tissues collected postmortem. Virus was easily detected and quantified in skin and superficial tissues by BLI before and during clinical phases, as well as in subclinical secondary cases, but was not reliably detected in deep tissues such as the lung. Although there are limitations to viral detection in larger wild rodent species, BLI can enhance the use of prairie dogs as an animal model of MPX and can be used for the study of infection, disease progression, and transmission in potential wild rodent reservoirs.

South Dakota↗
USGS2015

Epizootiology of cranial abscess disease in white-tailed deer ( Odocoileus virginianus ) of Georgia, USA

Intracranial abscess disease is a cause of natural mortality for mature male white-tailed deer ( Odocoileus virginianus ). Most cases of abscesses are associated with bacterial infection by Trueperella ( Arcanobacterium ) pyogenes , but a complete understanding of the epidemiology of this disease is lacking. We quantified the effects of individual characteristics, site-specific herd demographics, land cover, and soil variables in estimating the probability of this disease. We examined 7,545 white-tailed deer from 60 sites throughout Georgia US for signs of cranial abscesses, the predecessor of intracranial abscesses, and recorded the presence or absence of cranial abscesses for each individual examined. We detected no cranial abscesses in 2,562 female deer but 91 abscesses in 4,983 male deer examined (1.8%). A generalized linear mixed model, treating site as a random effect, was used to examine several potential explanatory risk factors including site-level landscape and soil characteristics (soil and forest type), demographic factors (deer density and male to female ratio), and individual host factors (deer sex and age). Model results indicated that the probability of a male having a cranial abscess increased with age and that adult sex ratio (male:female) was positively associated with this disease. Site-specific variables for land cover and soil types were not strongly associated with observations of the disease at the scale measured and a large amount of among-site variability remained. Given the demonstrated effect of age, gender, and local sex ratios but the remaining unexplained spatial variability, additional investigation into spatiotemporal variation of the presumed bacterial causative agent of cranial abscesses appears warranted.

Journal of Wildlife Diseases↗
USGS2017

Prevalence and distribution of Wellfleet Bay virus exposure in the Common Eider ( Somateria mollissima )

Between 1998 and 2014, recurrent mortality events were reported in the Dresser's subspecies of the Common Eider ( Somateria mollissima dresseri ) on Cape Cod, Massachusetts, USA near Wellfleet Harbor. The early die-offs were attributed to parasitism and emaciation, but beginning in 2006 a suite of distinct lesions was observed concomitant with the isolation of a previously unknown RNA virus. This novel pathogen was identified as an orthomyxovirus in the genus Quaranjavirus and was named Wellfleet Bay virus (WFBV). To assess evidence of exposure to this virus in Common Eiders, we conducted a longitudinal study of the prevalence of WFBV antibodies at multiple locations from 2004–14; we collected 2,258 serum samples from six locations and analyzed each using a microneutralization assay. Results corroborate the emergence of WFBV in 2006 based on the first detection of antibodies in that year. Significantly higher prevalence was detected in Common Eiders sampled in Massachusetts compared to those in Maine, Nova Scotia, and Québec. For birds breeding and wintering in Massachusetss, viral exposure varied by age, sex, and season of sampling, and prevalence by season and sex were highly interrelated with greater numbers of antibody-positive males in the autumn and females in the spring. No evidence of viral exposure was detected in the Northern subspecies ( Somateria mollissima borealis ). Among the locations sampled, Massachusetts appears to be the epicenter of Common Eider exposure to WFBV. Further research is warranted to understand the factors controlling the epidemiology of WFBV in Massachussetts, including those that may be limiting geographic expansion of this virus.

Journal of Wildlife Diseases↗
USGS2004

Impacts of West Nile Virus on wildlife

The recent epidemic of West Nile virus in the United States proved to be unexpectedly active and was the largest epidemic of the virus ever recorded. Much remains to be discovered about the ecology and epidemiology of West Nile virus in the United States, including which species are important in maintaining the virus in nature, why some species are more susceptible to lethal infection, and what environmental factors are important in predicting future epidemics. These factors will likely vary regionally, depending on local ecological characteristics. Until scientists better understand the virus and factors influencing its activity, predicting its effects for future seasons is impossible. However, experts are certain about one thing: West Nile virus is here to stay.

Park Science↗
USGS2002

Application of diagnostic tests for mycoplasmal infections of desert and gopher tortoises with management recommendations

Mycoplasmosis is a transmissible upper respiratory tract disease that has affected plans for management and conservation of wild desert and gopher tortoises in the United States. Although impact of mycoplasmosis on populations of desert and gopher tortoises is unknown, increased prevalence of seropositive animals as well as field observations of clinically ill tortoises have occurred in association with declining populations. In order to help in the identification of potentially infected animals, three tests have been developed to diagnose mycoplasmal infections of tortoises: 1) direct mycoplasmal culture; 2) detection of mycolplasmal chromosomal DNA by polymerase chain reaction (PCR); and 3) detection of anti-Mycoplasma antibodies in tortoise plasma by enzyme-linked immunosorbent assay (ELISA). Each test provides different, complementary information that collectively can be used to define tortoise mycoplasmal infection status. The types of samples required, the predictive value, interpretation, and cost vary among tests. These assays have been used for epidemiological surveys and in decision making for relocation, repatriation, or captive management of tortoises to minimize the risk of outbreaks of mycoplasmal respiratory disease and spread of the causative agent of this disease. Certain features of mycoplasmal infections of tortoises and other animals create a diagnostic dilemma. Multiple Mycoplasma species can cause respiratory disease with identical clinical presentations. Further, individual strains of a given species may vary with respect to their virulence potential, and some species may be commensals rather than pathogens. Current diagnostic tests may not differentiate among mycoplasmal species or strains or permit determination of pathogenicity of individual isolates. Thus, the information provided by testing is not a simple 'positive' vs. 'negative' issue. While these tests provide much needed information on the exposure of tortoise populations to Mycoplasma species, they do not provide a complete picture of the overall health status of individual tortoises or populations. Unfortunately, test results are often used to make life and death decisions concerning disposition of tortoises being displaced by land development without a complete understanding of the limitations of the diagnostic tests or any consideration of other infectious agents that might be present.

AZ, CA, FL, NV, UT↗
USGS2010

Persistence of highly pathogenic avian influenza H5N1 virus defined by agro-ecological niche

The highly pathogenic avian influenza (HPAI) H5N1 virus has spread across Eurasia and into Africa. Its persistence in a number of countries continues to disrupt poultry production, impairs smallholder livelihoods, and raises the risk a genotype adapted to human-to-human transmission may emerge. While previous studies identified domestic duck reservoirs as a primary risk factor associated with HPAI H5N1 persistence in poultry in Southeast Asia, little is known of such factors in countries with different agro-ecological conditions, and no study has investigated the impact of such conditions on HPAI H5N1 epidemiology at the global scale. This study explores the patterns of HPAI H5N1 persistence worldwide, and for China, Indonesia, and India includes individual provinces that have reported HPAI H5N1 presence during the 2004–2008 period. Multivariate analysis of a set of 14 agricultural, environmental, climatic, and socio-economic factors demonstrates in quantitative terms that a combination of six variables discriminates the areas with human cases and persistence: agricultural population density, duck density, duck by chicken density, chicken density, the product of agricultural population density and chicken output/input ratio, and purchasing power per capita. The analysis identifies five agro-ecological clusters, or niches, representing varying degrees of disease persistence. The agro-ecological distances of all study areas to the medoid of the niche with the greatest number of human cases are used to map HPAI H5N1 risk globally. The results indicate that few countries remain where HPAI H5N1 would likely persist should it be introduced.

EcoHealth↗
USGS2003

Human-induced contaminant impacts on migratory birds: Lessons from the North American eared grebe ( Podiceps nigricollis )

The effects of aquatic contaminants generated by soda ash mining processes on the North American eared grebe ( Podiceps nigricollis ) population illustrates important issues associated with human-induced habitat degradation on the health of migratory species. Eared grebes have been extensively studied in their staging and breeding habitats, but little is known about their 2- to 3-day migratory periods. During migration, few bodies of water are available to the birds for refuge between freshwater breeding areas in Canada and hypersaline lakes (e.g., Great Salt Lake in Utah or Mono Lake in California) to which they migrate. One geographic refuge area includes a series of "tailings" ponds associated with soda ash mining operations in southwestern Wyoming. The ponds range from 100-1200 acres, with water containing high concentrations of sodium decahydrate (Na 2 CO 3 &bull;10H 2 O). At cool temperatures (generally < 40&deg;F) sodium decahydrate precipitates out of the water and crystallizes on solid objects in the ponds or on the water surface. Bird mortality on these ponds has been recognized since the early 1970's, and the mining companies have developed hazing strategies and rehabilitation programs in order to minimize mortality. In order to determine causes of grebe mortality and devise strategies to reduce mortality, a field epidemiologic investigation was developed with the following objectives: 1) to determine whether eared grebes have quantifiable physiologic abnormalities associated with exposure to soda ash mine pond water; 2) to evaluate physical effects of sodium decahydrate crystallization on grebe survival; 3) to establish cause of death based on necropsy of deceased grebes; 4) to determine long-term survivability of eared grebes after exposure to the pond water; and 5) to evaluate water quality and determine whether aquatic invertebrates are present in the ponds as a possible food source.

California, Utah↗
USGS1984

SURVEY OF ASBESTOS-RELATED DISEASES IN TRADES AND MINING OCCUPATIONS AND IN FACTORY AND MINING COMMUNITIES AS A MEANS OF PREDICTING HEALTH RISKS OF NONOCCUPATIONAL EXPOSURE TO FIBROUS MINERALS.

A review based on 36 published epidemiological studies is given of disease patterns that have developed among industrial workers, miners, and millers who had been exposed to dusts of one or more of the commercial asbestos minerals or to dusts from minerals perceived to be asbestos-like. Health data are also reviewed for individuals exposed to asbestos dusts in nonoccupational settings. From the published reports it is clear that there are very significant differences in the health effects of the several asbestos or asbestos-like minerals.

Conference Paper↗
USGS1991

Relationship between weathered coal deposits and the etiology of Balkan endemic nephropathy

Field studies in epidemiology and environmental geochemistry in areas in Yugoslavia containing villages with a high incidence of Balkan endemic nephropathy (BEN), indicate a possible relationship between the presence of low-rank coal deposits and the etiology of BEN. Preliminary results from qualitative chemical analyses of drinking water from shallow farm wells indicate the presence of soluble polar aromatic and polynuclear aromatic hydrocarbons. These compounds may be derived from weathering of low-rank coals occurring in the vicinity of the endemic villages. All of the endemic villages are in alluvial valleys of tributaries to the Danube River. All except one of the clusters of endemic villages are located in the vicinity of known Pliocene age coals. Detailed sampling of the drinking waters and the nearby coals are being undertaken to identify a possible etiologic factor.

Conference Paper↗
USGS2013

Environmental management of mosquito-borne viruses in Rhode Island

West Nile Virus (WNV) and Eastern Equine Encephalitis Virus (EEEV) are both primarily bird viruses, which can be transmitted by several mosquito species. Differences in larval habitats, flight, and biting patterns of the primary vector species result in substantial differences in epidemiology, with WNV more common, primarily occurring in urban areas, and EEEV relatively rare, typically occurring near swamp habitats. The complex transmission ecology of these viruses complicates prediction of disease outbreaks. The Rhode Island Department of Environmental Management (DEM) and Department of Health (DoH) provide prevention assistance to towns and maintain a mosquito surveillance program to identify potential disease risk. Responses to potential outbreaks follow a protocol based on surveillance results, assessment of human risk, and technical consultation.

Rhode Island↗
USGS2014

The role of infectious disease in marine communities

Marine ecologists recognize that infectious diseases play and important role in ocean ecosystems. This role may have increased in some host taxa over time (Ward and Lafferty 2004). We begin this chapter by introducing infectious agents and their relationships with their hosts in marine systems. We then put infectious disease agents with their hosts in marine systems. We then put infectious disease agents in the perspective of marine biodiversity and discuss the various factors that affect parasites. Specifically, we introduce some basin epidemiological concepts, including the effects of stress and free-living diversity on parasites. Following this, we give brief consideration to communities of parasites within their hosts, particularly as these can lead to general insights into community ecology. We also give examples of how infectious diseases affect host populations, scaling up to marine communities. Finally, we present examples of marine infectious disease that impair conservation and fisheries.

Book chapter↗
USGS2014

Impact of stressors on transmission potential of Renibacterium salmoninarum in Chinook salmon

Renibacterium salmoninarum is the causative agent of bacterial kidney disease (BKD) affecting several species of Pacific salmon. The severity of BKD can range from a chronic infection to overt disease with high mortality as in the case of large losses of adult Chinook salmon ( Oncorhynchus tshawytscha ) in the Great Lakes during late 1980s. The goal of this study was to empirically evaluate how environmental stressors relevant to the Great Lakes impact R. salmoninarum disease progression and bacterial shedding, the latter parameter being a proxy of horizontal transmission. In the first study (Aim 1), we focused on how endogenous host thiamine levels and dietary fatty acids impacted resistance of Chinook salmon to R. salmoninarum . Juvenile fish were fed one of four experimental diets, including a (1) thiamine replete diet formulated with fish oil, (2) thiamine deplete diet formulated with fish oil, (3) thiamine replete diet formulated with soybean oil, and (4) thiamine deplete diet formulated with soybean oil, before being challenged with buffer or R. salmoninarum . We observed significantly higher mortality in the R. salmoninarum infected groups relative to the corresponding mock controls in only the thiamine replete diet groups. We also observed a significant effect of time and diet on kidney bacterial load and bacterial shedding, with a significant trend towards higher shedding and bacterial load in the fish oil &ndash; thiamine replete diet group. However, during the course of the study, unexpected mortality occurred in all groups attributed to the myxozoan parasite Ceratomyxa shasta . Since the fish were dually-infected with C. shasta , we evaluated parasite DNA levels (parasitic load) in the kidney of sampled fish. We found that parasite load varied across time points but there was no significant effect of diet. However, parasite load did differ significantly between the mock and R. salmoninarum challenge groups with a trend towards longer persistence of C. shasta DNA in fish dually-infected with R. salmoninarum . Overall, results in Aim 1 indicated: 1) that the experimental diets impacted bacterial but not parasitic infection patterns, 2) that low thiamine levels may reduce the severity of R. salmoninarum infection, and 3) that fish infected with R. salmoninarum may be less able to clear a secondary infection with a parasite. The second study (Aim 2) focused on the role that temperature plays in the progression of BKD from the asymptomatic infected state to a diseased state. Lake Michigan Chinook salmon were infected with R. salmoninarum at a common intermediate water temperature and, at 2 weeks post-infection, were split into three temperature groups (cool, intermediate and warm). Fish held at the cool temperature (8&deg;C) had significantly greater mortality following challenge, significantly higher levels of bacteria in the kidney, and shed significantly greater amounts of bacteria into the water relative to fish held at the intermediate (12&deg;C) and warm (15&deg;C) temperatures. Thus, our results support the hypothesis that, for BKD, warm temperature stress does not contribute to greater disease progression and increased bacterial shedding. Our laboratory results are consistent with field epidemiological observations that BKD mortality in the Great Lakes is commonly associated with declining water temperatures in the fall or when water temperatures begin to increase but are still cool after over-wintering.

Report↗
USGS2014

Dietary nitrate and cardiovascular health

Sep tember 17, 2014, Bethesda, Maryland The National Heart, Lung, and Blood Institute convened this workshop to discuss the results of recent research on the effects of inorganic nitrate and nitrite on the cardiovascular system, possible long term effects of these compounds in the diet and drinking water, and future research needs including population-wide effects examined through epidemiological studies.

Conference Paper↗
USGS2016

Preserving reptiles for research

What are voucher specimens and why do we collect them? Voucher specimens are animals and/or their parts that are deposited in a research museum to document the occurrence of a taxon at a specific location in space and time (Pleijel et al., 2008; Reynolds and McDiarmid, 2012). For field biologists, vouchers are the repeatable element of a field study as they allow other biologists, now and in the future, to confirm the identity of species that were studied. The scientific importance of a voucher specimen or series of specimens is that other people are afforded the opportunity to examine the entire animal and confirm or correct identifications. A photographic record is somewhat useful for recording the occurrence of a species, but such records can be insufficient for reliable confirmation of specific identity. Even if a photo shows diagnostic characters of currently recognized taxa, it may not show characters that separate taxa that may be described in the future. Substantial cryptic biodiversity is being found in even relatively well-known herpetofaunas (Crawford et al., 2010), and specimens allow researchers to retroactively evaluate the true diversity in a study as understanding of taxonomy evolves. They enable biologists to study the systematic relationships of populations by quantifying variation in different traits. Specimens are also a source of biological data such as behaviour, ecology, epidemiology, and reproduction through examination of their anatomy, reproductive and digestive tracts, and parasites (Suarez and Tsutsui, 2004). Preserving reptiles as vouchers is not difficult, although doing it properly requires care, effort, and time. Poorly preserved vouchers can invalidate the results and conclusions of your study because of the inability to confirm the identity of your study animals. Good science requires repeatability of observations, and the absence of vouchers or poorly preserved ones prevents such confirmation. Due to space restrictions, we are unable to go into as much detail as we would like in this chapter. A number of publications give more details on some topics discussed in this chapter, such as Pisani (1973), Pisani and Villa (1974), Etheridge (1996), Karns (1986), McDiarmid (1994), Cortez et al. (2006), Foster (2012) (and subchapters therein), Reynolds and McDiarmid (2012), and Simmons (2015). Although some of these works focus on amphibians, they also apply to reptiles in many aspects.

Book chapter↗
USGS2025

Perceptions and management of chronic wasting disease in Washington State: A survey of cervid hunters

Chronic wasting disease (CWD) is a fatal neurological disease caused by a misfolded protein, or prion, and is found in cervids (e.g., deer, elk, moose). It represents a serious threat to cervid populations and is one of the most important ungulate management issues facing state wildlife management agencies. Issues associated with CWD can affect many groups including hunters, tribal groups, biologists, rehabilitators, and farmers among others, and many can play an essential role in CWD management (e.g., hunters can help with cervid population control methods). In 2021, the Washington Department of Fish and Wildlife (WDFW) adopted the CWD Management Plan for Washington State, which specifically called for incorporating human dimensions of disease management with the ecological and epidemiological elements in CWD management. It is essential to develop a strong human dimensions component as management actions in other states have shown that when the public is not appropriately engaged, the probability of success is diminished. The study presented here sought to understand public preferences and perceptions of CWD and CWD management. We conducted 15 key constituent interviews and deployed a survey instrument in summer of 2023. (CWD was detected in Washington in July 2024, but this survey was completed ahead of that detection). The survey was emailed to 165,700 resident hunters in Washington State who had purchased a big game license since 2015 and the results presented below are based on interviews and completed survey responses from 7,403 individuals.

Washington↗
USGS2011

Decreasing prevalence of brucellosis in red deer through efforts to control disease in livestock

When a pathogen infects a number of different hosts, the process of determining the relative importance of each host species to the persistence of the pathogen is often complex. Removal of a host species is a potential but rarely possible way of discovering the importance of that species to the dynamics of the disease. This study presents the results of a 12-year programme aimed at controlling brucellosis in cattle, sheep and goats and the cascading impacts on brucellosis in a sympatric population of red deer (Cervus elaphus) in the Boumort National Game Reserve (BNGR; NE Spain). From February 1998 to December 2009, local veterinary agencies tested over 36 180 individual blood samples from cattle, 296 482 from sheep and goats and 1047 from red deer in the study area. All seropositive livestock were removed annually. From 2006 to 2009 brucellosis was not detected in cattle and in 2009 only one of 97 red deer tested was found to be positive. The surveillance and removal of positive domestic animals coincided with a significant decrease in the prevalence of brucellosis in red deer. Our results suggest that red deer may not be able to maintain brucellosis in this region independently of cattle, sheep or goats, and that continued efforts to control disease in livestock may lead to the eventual eradication of brucellosis in red deer in the area.

Boumort National Game Reserve↗
USGS2021

Evaluation of Indoor PM2.5 concentrations in a Native American community: A pilot study

Background Indoor air pollution is associated with adverse health effects; however, few studies exist studying indoor air pollution on the Navajo Nation in the southwest U.S., a community with high rates of respiratory disease. Methods Indoor PM 2.5 concentration was evaluated in 26 homes on the Navajo Nation using real-time PM 2.5 monitors. Household risk factors and daily activities were evaluated with three metrics of indoor PM 2.5 : time-weighted average (TWA), 90th percentile of concentration, and daily minutes exceeding 100 μg/m 3 . A questionnaire and recall sheet were used to record baseline household characteristics and daily activities. Results The median TWA, 90th percentile, and daily minutes exceeding 100 μg/m 3 were 7.9 μg/m 3 , 14.0 μg/m 3 , and 17 min, respectively. TWAs tended to be higher in autumn and in houses that used fuel the previous day. Other characteristics associated with elevated PM exposure in all metrics included overcrowded houses, nonmobile houses, and houses with current smokers, pets, and longer cooking time. Conclusions Some residents of the Navajo Nation have higher risk of exposure to indoor air pollution by Environmental Protection Agency (EPA) standards. Efforts to identify the causes and associations with adverse health effects are needed to ensure that exposure to risks and possible health impacts are mitigated.

Journal of Exposure Science and Environmental Epid↗