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James E Childs

Publications and source records attributed to James E Childs.

At least 19 recordsLinked to original sources
PubMed2006

Bats: important reservoir hosts of emerging viruses.

Bats (order Chiroptera, suborders Megachiroptera ["flying foxes"] and Microchiroptera) are abundant, diverse, and geographically widespread. These mammals provide us with resources, but their importance is minimized and many of their populations and species are at risk, even threatened or endangered. Some of their characteristics (food choices, colonial or solitary nature, population structure, ability to fly, seasonal migration and daily movement patterns, torpor and hibernation, life span, roosting behaviors, ability to echolocate, virus susceptibility) make them exquisitely suitable hosts of viruses and other disease agents. Bats of certain species are well recognized as being capable of transmitting rabies virus, but recent observations of outbreaks and epidemics of newly recognized human and livestock diseases caused by viruses transmitted by various megachiropteran and microchiropteran bats have drawn attention anew to these remarkable mammals. This paper summarizes information regarding chiropteran characteristics and information regarding 66 viruses that have been isolated from bats. From these summaries, it is clear that we do not know enough about bat biology; we are doing too little in terms of bat conservation; and there remain a multitude of questions regarding the role of bats in disease emergence.

Animals↗
PubMed2006

National surveillance and the epidemiology of human Q fever in the United States, 1978-2004.

Although Q fever is considered enzootic in the United States, surveillance for human Q fever has been historically limited. From 1978 through 1999, 436 cases (average = 20 per year) of human Q fever were reported. After Q fever became nationally reportable in 1999, 255 human Q fever cases (average = 51 per year) were reported with illness onset during 2000 through 2004. The median age of cases was 51 years, and most cases were male (77%). The average annual incidence of Q fever was 0.28 cases per million persons, and was highest in persons 50-59 years of age (0.39 cases per million). State-specific incidence ranged from a high of 2.40 cases per million persons in Wyoming, to 0 cases in some states. Since Q fever became reportable, case reports have increased by more than 250%. Surveillance for Q fever is essential to establish the distribution and magnitude of disease and to complement U.S. bioterrorism preparedness activities.

Adolescent↗
PubMed2005

Unifying the spatial population dynamics and molecular evolution of epidemic rabies virus.

Infectious disease emergence is under the simultaneous influence of both genetic and ecological factors. Yet, we lack a general framework for linking ecological dynamics of infectious disease with underlying molecular and evolutionary change. As a model, we illustrate the linkage between ecological and evolutionary dynamics in rabies virus during its epidemic expansion into eastern and southern Ontario. We characterized the phylogeographic relationships among 83 isolates of fox rabies virus variant using nucleotide sequences from the glycoprotein-encoding glycoprotein gene. The fox rabies virus variant descended as an irregular wave with two arms invading from northern Ontario into southern Ontario over the 1980s and 1990s. Correlations between genetic and geographic distance suggest an isolation by distance population structure for the virus. The divergence among viral lineages since the most recent common ancestor correlates with position along the advancing wave front with more divergent lineages near the origin of the epidemic. Based on divergence from the most recent common ancestor, the regional population can be partitioned into two subpopulations, each corresponding to an arm of the advancing wave. Subpopulation A (southern Ontario) showed reduced isolation by distance relative to subpopulation B (eastern Ontario). The temporal dynamics of subpopulation A suggests that the subregional viral population may have undergone several smaller waves that reduced isolation by distance. The use of integrated approaches, such as the geographical analysis of sequence variants, coupled with information on spatial dynamics will become indispensable aids in understanding patterns of disease emergence.

Animals↗
PubMed2005

Predictive spatial dynamics and strategic planning for raccoon rabies emergence in Ohio.

Rabies is an important public health concern in North America because of recent epidemics of a rabies virus variant associated with raccoons. The costs associated with surveillance, diagnostic testing, and post-exposure treatment of humans exposed to rabies have fostered coordinated efforts to control rabies spread by distributing an oral rabies vaccine to wild raccoons. Authorities have tried to contain westward expansion of the epidemic front of raccoon-associated rabies via a vaccine corridor established in counties of eastern Ohio, western Pennsylvania, and West Virginia. Although sporadic cases of rabies have been identified in Ohio since oral rabies vaccine distribution in 1998, the first evidence of a significant breach in this vaccine corridor was not detected until 2004 in Lake County, Ohio. Herein, we forecast the spatial spread of rabies in Ohio from this breach using a stochastic spatial model that was first developed for exploratory data analysis in Connecticut and next used to successfully hind-cast wave-front dynamics of rabies spread across New York. The projections, based on expansion from the Lake County breach, are strongly affected by the spread of rabies by rare, but unpredictable long-distance translocation of rabid raccoons; rabies may traverse central Ohio at a rate 2.5-fold greater than previously analyzed wildlife epidemics. Using prior estimates of the impact of local heterogeneities on wave-front propagation and of the time lag between surveillance-based detection of an initial rabies case to full-blown epidemic, specific regions within the state are identified for vaccine delivery and expanded surveillance effort.

Animals↗
PubMed2004

A priori prediction of disease invasion dynamics in a novel environment.

Directly transmitted infectious diseases spread through wildlife populations as travelling waves away from the sites of original introduction. These waves often become distorted through their interaction with environmental and population heterogeneities and by long-distance translocation of infected individuals. Accurate a priori predictions of travelling waves of infection depend upon understanding and quantifying these distorting factors. We assess the effects of anisotropies arising from the orientation of rivers in relation to the direction of disease-front propagation and the damming effect of mountains on disease movement in natural populations. The model successfully predicts the local and large-scale prevaccination spread of raccoon rabies through New York State, based on a previous spatially heterogeneous model of raccoon-rabies invasion across the state of Connecticut. Use of this model provides a rare example of a priori prediction of an epidemic invasion over a naturally heterogeneous landscape. Model predictions matched to data can also be used to evaluate the most likely points of disease introduction. These results have general implications for predicting future pathogen invasions and evaluating potential containment strategies.

Animals↗
PubMed2004

Pseudoepidemic of Q fever at an animal research facility.

Serum samples from people exposed to sheep at a research facility were evaluated by a commercial laboratory and resulted in an overall Coxiella burnetii seroprevalence of 75%. We interviewed individuals to determine exposure history and compatible illness, and retested their sera. Analysis indicated that the commercial laboratory was misinterpreting its results; when corrected, the seroprevalence dropped to 27%. Test kits of the brand used by the commercial laboratory gave equivalent results to the in-house CDC assay when tested in parallel at CDC. Upon final analysis, only the attending veterinarian was confirmed as a Q fever case. This event resulted in increased risk reduction protocols at the research facility and improved public health communication among health authorities. This pseudoepidemic resulted from a lapse in laboratory quality control for testing. Similar errors can be avoided through standardization and improved review of laboratory procedures.

Animals↗
PubMed2004

Imported spotted fever rickettsioses in United States travelers returning from Africa: a summary of cases confirmed by laboratory testing at the Centers for Disease Control and Prevention, 1999-2002.

The increasing popularity of foreign travel and ecotourism places travelers at increased risk for certain tick-borne diseases. From 1999 through 2002, 31 cases of imported spotted fever-group rickettsioses (SFGR) in United States residents reporting travel to Africa were confirmed by laboratory testing at the Centers for Disease Control and Prevention. Nineteen patients (61%) reported visiting South Africa prior to illness onset. Most patients reported fever and one or more eschars; rash was reported for only 26% of the patients. Twelve patients had an initial non-reactive acute-phase serum sample obtained a median of three days after illness onset, and were confirmed by testing a second convalescent-phase serum sample obtained a median of 32 days after illness onset. Five patients were confirmed positive through immunohistochemical staining of skin biopsies, including three patients with acute-phase serum samples that tested negative for SFGR. This study emphasizes the importance of evaluating convalescent-phase serum specimens 28 days or more after illness onset or examining skin biopsies by immunohistochemical staining during early infection to confirm a diagnosis of imported SFGR.

Africa↗
PubMed2003

Rabies surveillance in the United States during 2002.

During 2002, 49 states and Puerto Rico reported 7,967 cases of rabies in nonhuman animals and 3 cases in human beings to the Centers for Disease Control and Prevention, an increase of 7.2% from the 7,436 cases in non-human animals and 1 case in a human being reported in 2001. More than 92% (7,375 cases) were in wild animals, whereas 7.4% (592) were in domestic species (compared with 93.3% in wild animals and 6.7% in domestic species in 2001). Compared with cases reported in 2001, the numbers of cases reported in 2002 increased among all major reporting groups with the exception of swine and rodents and lagomorphs. The relative contributions of the major groups of animals were as follows: raccoons (36.3%; 2,891 cases), skunks (30.5%; 2,433), bats (17.2%; 1,373), foxes (6.4%; 508), cats (3.8%; 299), dogs (1.2%; 99), and cattle (1.5%; 116). Thirteen of the 19 states in which the raccoon-associated variant of the rabies virus has been enzootic reported increases in the numbers of rabid raccoons during 2002. Among those states that have engaged in wildlife rabies control programs, Ohio reported 1 case of raccoon rabies associated with the epizootic of rabies in raccoons and 1 case in an equid that was infected with a bat variant of the rabies virus, compared with 2 cases reported in terrestrial animals during 2001. Texas reported no cases of rabies associated with the dog/coyote variant of the rabies virus (compared with 1 case in 2001) and 65 cases associated with the gray fox variant of the virus (an increase of 225% from 20 cases reported in 2001). In Massachusetts and Rhode Island, states with enzootic raccoon rabies, reports of rabid skunks again exceeded those of rabid raccoons (the sixth consecutive year, although in Rhode Island, this difference decreased to only 7 more skunks than raccoons [38/31]). Tennessee reported a single case of raccoon rabies in a pet raccoon from the central part of the state; the captive animal had been transported toTennessee from northern Georgia. Nationally, the number of rabies cases in skunks during 2002 increased by 6.6% over those reported in 2001. Texas reported the greatest number (740) of rabid skunks and the greatest overall state total of rabies cases (1,049) during 2002. The 1,373 cases of rabies reported in bats during 2002 surpassed the previous year's record (1,281 cases) as the largest number of reported cases ever recorded for this group of mammals. Cases of rabies reported in cats (299), cattle (116), and dogs (99) increased by 10.7%, 41.5%, and 11.24%, respectively, from 2001 to 2002. Rabies among sheep and goats increased 400% from 3 cases in 2001 to 15 in 2002, and cases among horses and mules increased 13.7% (51 cases in 2001 to 58 in 2002). Reported cases of rabies in mongooses in Puerto Rico decreased 4.3% from the previous year (70 cases in 2001 to 67 cases in 2002), while cases of rabies in dogs increased 77% (13 to 14). California, Tennessee, and Iowa each reported a case of rabies in a human being during 2002. All cases of rabies in humans were the result of infection with bat variants of the rabies virus.

Animals↗
PubMed2003

Trends in national surveillance for rabies among bats in the United States (1993-2000).

OBJECTIVE: To describe surveillance trends and epidemiologic features of rabies in bats in the United States, focusing on 3 bat species primarily associated with variants of the rabies virus that affect humans. DESIGN: Retrospective study. ANIMALS: 31,380 bats. PROCEDURE: Data on rabies for bats identified to species and reported by state laboratories from 1993 to 2000 were analyzed, focusing on silver-haired, eastern pipistrelle, and Brazilian free-tailed bats. Categoric variables were derived from other provided information. RESULTS: Data were reported from 37 states during the study interval; complete species-specific data were not reported by any state for the entire interval. Bats primarily associated with rabies virus variants affecting humans were more likely to yield positive test results for rabies (22.7%), compared with all other bats (5.5%) in most seasons and from most regions of the United States. However, certain other bat species had higher percentages of positive results. Risk of positive results was highest in the fall and highest among bats originating in the southwestern United States. CONCLUSIONS AND CLINICAL RELEVANCE: Increased risk of rabies among certain groups of bat species was consistently found across seasons and most geographic regions of the United States. Results were in general agreement with those of previous studies conducted within smaller geographic regions. There are ongoing efforts to improve surveillance of rabies in bats, although surveillance is incomplete in some regions.

Animals↗
PubMed2003

Rickettsialpox in New York City: a persistent urban zoonosis.

Rickettsialpox, a spotted fever rickettsiosis, was first identified in New York City (NYC) in 1946. During the next five years, approximately 540 additional cases were identified in NYC. However, during the subsequent five decades, rickettsialpox received relatively little attention from clinicians and public health professionals, and reporting of the disease diminished markedly. During February 2001 through August 2002, 34 cases of rickettsialpox in NYC were confirmed at CDC from cutaneous biopsy specimens tested by using immunohistochemical (IHC) staining, PCR analysis, and isolation of Rickettsia akari in cell culture, as well as an indirect immunofluorescence assay of serum specimens. Samples were collected from patients with febrile illnesses accompanied by an eschar, a papulovesicular rash, or both. Patients originated predominantly from two boroughs (Manhattan and the Bronx). Only 8 (24%) of the cases were identified prior to the reports of bioterrorism-associated anthrax in the United States during October 2001, and lesions of several patients evaluated during and subsequent to this episode were suspected initially to be cutaneous anthrax. IHC staining of biopsy specimens of eschars and papular lesions were positive for spotted fever group rickettsiae for 32 patients. Of the eleven patients for whom paired serum samples were obtained, all demonstrated fourfold or greater increases in antibody titers reactive with R. akari. The 17-kDa protein gene sequence of R. akari was amplified from eschars of five patients. Four isolates of R. akari were obtained from cutaneous lesions. Possible factors responsible for the increase in clinical samples evaluated for rickettsialpox during this interval include renewed clinical interest in the disease, improved diagnostic methods, epizootiological influences, and factors associated with the recent specter of bioterrorism.

Animals↗
PubMed2003

National surveillance for the human ehrlichioses in the United States, 1997-2001, and proposed methods for evaluation of data quality.

This report describes the data accumulated during the first 5 years of national surveillance for the human ehrlichioses in the United States and territories, from its initiation in 1997 through 2001. Reported cases of human monocytic and granulocytic ehrlichiosis (HME and HGE) and cases of "other ehrlichiosis" (OE), where the agent was unspecified, originated from 30 states. As anticipated, most HME cases were from the south-central and southeastern United States, while HGE was most commonly reported from the northeastern and upper-Midwestern region. State-level incident reports of 487 HME, 1,091 HGE, and 11 OE cases were evaluated. The average annual incidences of HME, HGE, and OE per million persons residing in states reporting disease were 0.7, 1.6, and 0.2, respectively. The median ages of HME (53 yr) and HGE cases (51 yr) were consistent with published patient series. Most (> 57%) ehrlichiosis patients were male. The results suggest that national surveillance for the ehrlichioses, although imperfect in coverage, will help define endemic regions and may be useful for monitoring long-term trends. Although the data appear representative of the demographic profiles established for HME and HGE, rigorous evaluation of the system is required. Methods are proposed for evaluating the quality and representativeness of HME and HGE surveillance data, using well-established surveillance systems for Rocky Mountain spotted fever and Lyme disease.

Ehrlichiosis↗
PubMed2003

Ehrlichia chaffeensis: a prototypical emerging pathogen.

Ehrlichia chaffeensis is an obligately intracellular, tick-transmitted bacterium that is maintained in nature in a cycle involving at least one and perhaps several vertebrate reservoir hosts. The moderate to severe disease caused by E. chaffeensis in humans, first identified in 1986 and reported for more than 1,000 patients through 2000, represents a prototypical "emerging infection." Knowledge of the biology and natural history of E. chaffeensis, and of the epidemiology, clinical features, and laboratory diagnosis of the zoonotic disease it causes (commonly referred to as human monocytic ehrlichiosis [HME]) has expanded considerably in the period since its discovery. In this review, we summarize briefly the current understanding of the microbiology, pathogenesis, and clinical manifestations associated with this pathogen but focus primarily on discussing various ecological factors responsible for the recent recognition of this important and potentially life-threatening tick-borne disease. Perhaps the most pivotal element in the emergence of HME has been the staggering increases in white-tailed deer populations in the eastern United States during the 20th century. This animal serves as a keystone host for all life stages of the principal tick vector (Amblyomma americanum) and is perhaps the most important vertebrate reservoir host for E. chaffeensis. The contributions of other components, including expansion of susceptible human populations, growth and broadening geographical distributions of other potential reservoir species and A. americanum, and improvements in confirmatory diagnostic methods, are also explored.

Animals↗
PubMed2003

Skunk and raccoon rabies in the eastern United States: temporal and spatial analysis.

Since 1981, an epizootic of raccoon rabies has spread throughout the eastern United States. A concomitant increase in reported rabies cases in skunks has raised concerns that an independent maintenance cycle of rabies virus in skunks could become established, affecting current strategies of wildlife rabies control programs. Rabies surveillance data from 1981 through 2000 obtained from the health departments of 11 eastern states were used to analyze temporal and spatial characteristics of rabies epizootics in each species. Spatial analysis indicated that epizootics in raccoons and skunks moved in a similar direction from 1990 to 2000. Temporal regression analysis showed that the number of rabid raccoons predicted the number of rabid skunks through time, with a 1-month lag. In areas where the raccoon rabies virus variant is enzootic, spatio-temporal analysis does not provide evidence that this rabies virus variant is currently cycling independently among skunks.

Animals↗
PubMed2003

Rabies among infrequently reported mammalian carnivores in the United States, 1960-2000.

Most cases of rabies reported annually in the United States occur among three groups of carnivores--raccoons (Procyon lotor), skunks (Mephitis, Spilogale, and Putorius), foxes (Vulpes, Urocyon, and Alopex)--and among bats (numerous species). However, between 1960 and 2000, a total of 2,851 cases of rabies in 17 other carnivore taxa were reported to the Centers for Disease Control and Prevention, Atlanta, Georgia (USA), from 49 states, the District of Columbia, and Puerto Rico. Three species of these other carnivores (mongooses [Herpestes javanicus], coyotes [Canis latrans], and bobcats [Lynx rufus]) accounted for 92% (2,624/2,851) of the cases reported among other canivorous mammals (OCMs). Most OCMs demonstrated temporal or spatial variation in numbers of reported cases. Tests of specimens from OCMs infected in the United States identified variants of the rabies virus that corresponded with variants associated with the major terrestrial reservoirs within their respective regions of origin. Variants of the rabies virus in samples from mongooses in Puerto Rico could not be distinguished from those in samples from dogs in Puerto Rico by virus typing methods.

Animals↗
PubMed2003

Environmental and human demographic features associated with epizootic raccoon rabies in Maryland, Pennsylvania, and Virginia.

We assessed land use and demographic data as predictors discriminating between counties experiencing large or small first epizootics of rabies among raccoons (Procyon lotor). Monthly county reports of raccoons testing positive for rabies were obtained from rabies surveillance databases from Maryland, Pennsylvania, and Virginia (USA). Environmental and demographic data for the three states were obtained from public sources. On the basis of total reports of raccoon rabies during the first defined epizootic period, the 203 counties were dichotomized at the 75th percentile as having a large epizootic (> or = 24 rabid raccoons in the first epizootic) (51 counties) or a small epizootic or no epizootic (152 counties). A high percentage of agricultural land use [OR = 9.1, 95% CI (3.6-23.1)], high water coverage in combination with low human population density [OR = 8.8, 95% CI (2.9-27.0)], and low water coverage with high human population density [OR = 11.7, 95% CI (4.0-34.1)] were positively associated with large rabies epizootics. Counties with more than 15% of mixed forest were less likely to experience large epizootics than were counties with < or = 15% of mixed forest [OR = 0.3, 95% CI (0.1, 0.9)]. A combination of land use and human population density measures provided the best model for determining epizootic size and may be important predictors of epizootic behavior and risk of exposure to this reservoir species.

Animals↗