Topic
Disease reservoir
About: Disease reservoir is a research topic. Over the lifetime, 4068 publications have been published within this topic receiving 254944 citations.
Papers published on a yearly basis
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Papers
TL;DR: It is demonstrated that intrastadial but not transovarial transmission is an efficient mode for B. equi transmission and that persistently infected horses are an important reservoir for transmission.
Abstract: Tick-borne pathogens may be transmitted intrastadially and transstadially within a single vector generation as well as vertically between generations. Understanding the mode and relative efficiency of this transmission is required for infection control. In this study, we established that adult male Rhipicephalus microplus ticks efficiently acquire the protozoal pathogen Babesia equi during acute and persistent infections and transmit it intrastadially to naive horses. Although the level of parasitemia during acquisition feeding affected the efficiency of the initial tick infection, infected ticks developed levels of > or =10(4) organisms/pair of salivary glands independent of the level of parasitemia during acquisition feeding and successfully transmitted them, indicating that replication within the tick compensated for any initial differences in infectious dose and exceeded the threshold for transmission. During the development of B. equi parasites in the salivary gland granular acini, the parasites expressed levels of paralogous surface proteins significantly different from those expressed by intraerythrocytic parasites from the mammalian host. In contrast to the successful intrastadial transmission, adult female R. microplus ticks that fed on horses with high parasitemia passed the parasite vertically into the eggs with low efficiency, and the subsequent generation (larvae, nymphs, and adults) failed to transmit B. equi parasites to naive horses. The data demonstrated that intrastadial but not transovarial transmission is an efficient mode for B. equi transmission and that persistently infected horses are an important reservoir for transmission. Consequently, R. microplus male ticks and persistently infected horses should be targeted for disease control.
94 citations
TL;DR: Hemorrhagic fever with renal syndrome (HFRS) has been reported from greater than 20 provinces in China and Lung tissues from 16 species of rodent, from two species of sorex, and from cats and weasels in the epidemic areas have been found to carry antigen.
Abstract: Hemorrhagic fever with renal syndrome (HFRS) has been reported from greater than 20 provinces in China. The number of reported cases has increased markedly in recent years and surpassed 80,000 human cases in 1983. All of the cases reported before 1981 were from rural areas and were attributed to Apodemus rats. In 1981, outbreaks of cases associated with house rats were first reported. Cases associated with Apodemus agrarius were more severe than those associated with the house rat Rattus norvegicus. The rate of inapparent infection in the rural population of areas endemic for Apodemus-associated disease was lower than that of Rattus-associated urban disease. After the onset of the disease, IgG antibody levels increase rapidly, peak after one week, and persist for as long as 25 years. Lung tissues from 16 species of rodent, from two species of sorex, and from cats and weasels in the epidemic areas have been found to carry antigen. A. agrarius, Apodemus peninsulae, and R. norvegicus serve as the main reservoirs of HFRS in rural areas, forest areas, and urban areas, respectively.
94 citations
TL;DR: The presence of rats in many urban settings and the high prevalence of Hantavirus infection in this species suggest that human exposure to this virus is occurring in the United States, although human disease from this exposure has not been recognized.
Abstract: Rats trapped from 14 locations in Baltimore, Maryland, were shown to have antibody to Hantavirus. Antibody prevalence rates were higher in residential locations than in parks. Infected rats were obtained continuously over a six-year period from 1980-1985 at five locations, indicating the enzootic nature of this infection in urban rats in the United States. Prevalence of antibody and geometric mean titers increased with rat mass and sexual maturity, suggesting that infections in rats are acquired through age-related mechanisms. Three isolates of Hantavirus were obtained from rats. One of these isolates was shown by serologic tests and monoclonal antibody reactivity patterns to be similar, if not identical, to rat virus previously obtained from Philadelphia. The presence of rats in many urban settings and the high prevalence of Hantavirus infection in this species suggest that human exposure to this virus is occurring in the United States, although human disease from this exposure has not been recognized.
94 citations
TL;DR: Recommendations for standardizing surveys of canine leishmaniasis in southern Europe would permit higher-resolution risk mapping, and the main environmental predictors of CanL seroprevalence in Portugal, Spain, France and Italy were identified.
Abstract: The domestic dog is the reservoir host of Leishmania infantum, the causative agent of zoonotic visceral leishmaniasis endemic in Mediterranean Europe. Targeted control requires predictive risk maps of canine leishmaniasis (CanL), which are now explored. We databased 2187 published and unpublished surveys of CanL in southern Europe. A total of 947 western surveys met inclusion criteria for analysis, including serological identification of infection (504, 369 dogs tested 1971-2006). Seroprevalence was 23 2% overall (median 10%). Logistic regression models within a GIS framework identified the main environmental predictors of CanL seroprevalence in Portugal, Spain, France and Italy, or in France alone. A 10-fold cross-validation approach determined model capacity to predict point-values of seroprevalence and the correct seroprevalence class ( 20%). Both the four-country and France-only models performed reasonably well for predicting correctly the 20% seroprevalence classes (AUC >0 70). However, the France-only model performed much better for France than the four-country model. The four-country model adequately predicted regions of CanL emergence in northern Italy (<5% seroprevalence). Both models poorly predicted intermediate point seroprevalences (5-20%) within regional foci, because surveys were biased towards known rural foci and Mediterranean bioclimates. Our recommendations for standardizing surveys would permit higher-resolution risk mapping.
93 citations
TL;DR: The ecosystem comprising the aquatic environment, V. cholerae, genetic elements mediating gene transfer, and the mammalian host appears to support the clustering of critical virulence genes in a proper combination leading to the origination of new V. Cholerae strains with epidemic potential.
Abstract: Toxigenic Vibrio cholerae is the etiological agent of cholera, an acute dehydrating diarrhea that occurs in epidemic form in many developing countries. Although V. cholerae is a human pathogen, aquatic ecosystems are major habitats of Vibrio species, which includes both pathogenic and nonpathogenic strains that vary in their virulence gene content. V. cholerae belonging to the 01 and 0139 serogroups is commonly known to carry a set of virulence genes necessary for pathogenesis in humans. Recent studies have indicated that virulence genes or their homologues are also dispersed among environmental strains of V. cholerae belonging to diverse serogroups, which appear to constitute an environmental reservoir of virulence genes. Although the definitive roles of the virulence-associated factors in the environment, and the environmental selection pressures for V. cholerae-carrying virulence genes or their homologues is not clear, the potential for origination of new epidemic strains from environmental progenitors seems real. It is likely that the aquatic environment harbors different virulence-associated genes scattered among environmental vibrios, which possess a lower virulence potential than the epidemic strains. The ecosystem comprising the aquatic environment, V. cholerae, genetic elements mediating gene transfer, and the mammalian host appears to support the clustering of critical virulence genes in a proper combination leading to the origination of new V. cholerae strains with epidemic potential.
93 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 1 |
| 2024 | 8 |
| 2023 | 4 |
| 2022 | 5 |
| 2021 | 51 |
| 2020 | 76 |