At the period of 1982 - 2003, morbidity rate in pseudotuberculosis and the Yersinia pseudotuberculosis culture rates in groups of servicemen (from different abiotic objects, from humans and small rodents) in different geographic zones were studied. The cases of the isolation of Y. pseudotuberculosis were most frequently registered in groups of servicemen in the Far East and the Kola Peninsula. In these regions the highest morbidity rate in pseudotuberculosis was registered among servicemen. The contamination rate of vegetables during the year was always greater than in other objects under study, including small rodents. The study demonstrated that in the Armed Forces could appear, temporary and relatively constant anthropurgic foci of pseudotuberculosis even in non endemic regions. They were formed in the objects of the food supply service due to the supply of contaminated vegetables. Synanthropic rodents played a secondary role, though they too facilitated the formation of new anthropurgic foci. Under definite conditions anthropurgic foci could exist autonomously, independently of natural foci.
Results of the analysis of the increase in the incidence of epidemic of the West Nile fever and climate conditions in the Volgograd region were presented. Certain seasonal periods and threshold values of temperature and humidity statistically associated with the epidemic rise were identified. The discussion of the probable mechanisms of indirect effects of atmospheric heat on the elements of the epidemic process was carried out.
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Methyl mercury (MeHg) is highly toxic to the developing nervous system. Human exposure is mainly from fish consumption since small amounts are present in all fish. Findings of developmental neurotoxicity following high-level prenatal exposure to MeHg raised the question of whether children whose mothers consumed fish contaminated with background levels during pregnancy are at an increased risk of impaired neurological function. Benchmark doses determined from studies in New Zealand, and the Faroese and Seychelles Islands indicate that a level of 4-25 parts per million (ppm) measured in maternal hair may carry a risk to the infant. However, there are numerous sources of uncertainty that could affect the derivation of benchmark doses, and it is crucial to continue to investigate the most appropriate derivation of safe consumption levels. Earlier, we published the findings from benchmark analyses applied to the data collected on the Seychelles main cohort at the 66-month follow-up period. Here, we expand on the main cohort analyses by determining the benchmark doses (BMD) of MeHg level in maternal hair based on 643 Seychellois children for whom 26 different neurobehavioral endpoints were measured at 9 years of age. Dose-response models applied to these continuous endpoints incorporated a variety of covariates and included the k-power model, the Weibull model, and the logistic model. The average 95% lower confidence limit of the BMD (BMDL) across all 26 endpoints varied from 20.1 ppm (range=17.2-22.5) for the logistic model to 20.4 ppm (range=17.9-23.0) for the k-power model. These estimates are somewhat lower than those obtained after 66 months of follow-up. The Seychelles Child Development Study continues to provide a firm scientific basis for the derivation of safe levels of MeHg consumption.
Study biological properties of salmonella, isolated from clinical materials and water of Don river.
Salmonella strains of various serovars were used in the study. Biochemical characteristics were studied by generally accepted methods, antigenic properties were evaluated in agglutination reactions, virulence was determined by Dlm for laboratory animals, antibiotics sensitivity was verified by disc-diffusion method.
The presence of pathogenicity factors in isolated strains was shown: hemolytic activity--in 64 and 36.8% of cases, DNAse activity--in 28 and 26%, respectively in clinical and wild strains. Microorganism dose, resulting in death of all the animals (LD100) did not depend on serovar of salmonella and varied from 10(3) to 10(10) PFU/ml.
Clinical strains were established to possess higher virulence and resistance to antibiotics compared with strains isolated from the aquatic envionment.
A possibility was examined to use a screening cytogenetic method for calculating micronuclei in frog blood cells as an indicator of the degree of environmental pollution and its hazard to human health. Data obtained correlate with an increased rate of reproductive function disorders in women and congenital malformations in children, living in regions where the cytologic studies of biological objects were carried out. The informational value of biogeochemical screening with the use of test objects for the assessment of the region ecological imbalance is stressed.
In the United States (US) and Europe, surveillance based on calls to poison control centres has identified new hazards and evolving exposure trends. In Canada, the value of poison control centre calls as a tool for health hazard surveillance is largely unrecognized.
This preliminary survey was undertaken to describe current operational characteristics and surveillance capacities at Canadian poison control centres and to determine potential for developing a Canadian poison control centre collaborative network.
A structured quantitative-qualitative survey was administered to medical directors and clinical supervisors at the five Canadian poison control centres between March and May, 2012.
All five Canadian poison control centres operate 24/7 with each serving more than one province/territory. Annual call volumes range from 10,000 to 58,000. Data analysis is limited to detection of previously unrecognized hazards and short-term event-based adverse health monitoring. Currently no centre maintains systematic ongoing collection, integration and analysis of data. Constraints on personnel, resources and funding were identified as barriers to increasing capacity to provide and analyse call data.
The potential exists to use Canadian poison control data as a novel source of public health surveillance. That they serve as sentinels for new or unexpected exposure events, have real-time electronic call-record capacity and demonstrate an interest in developing and sharing their call-record information supports their integration into existing public health networks.
Chlorophenols have contaminated the drinking water system and the local lake in the village of Järvelä in southern Finland. Local geology, ground water streams, and chemical analyses incriminated a local sawmill as the only plausible source of exposure. Cancer incidence in the municipality of Kärkölä (half of the population lives in Järvelä), compared with the rest of the local health-care district and with the greater cancer control region, indicated an excess of soft-tissue sarcomas and non-Hodgkin's lymphomas. A case-control study, which focused on cancers of the colon, bladder and soft tissues, lymphomas, and leukemia, demonstrated a significantly elevated risk ratio for non-Hodgkin's lymphomas among persons who consumed fish from the local lake, which was contaminated with chlorophenols. Probable exposure to chlorophenol-contaminated drinking water played a role in the increased incidence of non-Hodgkin's lymphomas and possibly was a factor in the development of soft-tissue sarcoma.
In Canada there is increasing concern about potential effects of industrial activities on wildlife and human health. In an interdisciplinary study concentrations of inorganic (metals, metalloids) and organic (PCBs, organochlorine pesticides) contaminants, and parasitic infections of lake whitefish (Coregonus clupeaformis) from Montreal and Reindeer lakes, Saskatchewan, were investigated to assess human health risk related to fish consumption. In both lakes contamination of fish with chemical substances and compounds, respectively, were very low and often close to detection limits. Lake whitefish parasite communities consisted of 15 (Montreal Lake) and 12 (Reindeer Lake) species most of which were found in the intestinal tract. Many parasite species showed seasonal differences in prevalence and/or mean intensity of infection. None of the identified parasites are known to be human-pathogenic and overall, whitefish from both locations can be considered safe and healthy food. Nevertheless, women of child-bearing age and young children should limit their consumption to 3 and 2 meals, respectively, of Reindeer Lake whitefish per week to minimize potentially harmful exposure to mercury. As well, intestines of Montreal Lake fish should be removed prior to fish consumption if large parasite cysts containing a yet unidentified cestode species are detected.
Extended spectrum ß-lactamase producing Escherichia coli (ESBL-EC) are excreted via effluents and sewage into the environment where they can re-contaminate humans and animals. The aim of this observational study was to detect and quantify ESBL-EC in recreational water and wastewater, and perform a genetic and phenotypic comparative analysis of the environmental strains with geographically associated human urinary ESBL-EC. Recreational fresh- and saltwater samples from four different beaches and wastewater samples from a nearby sewage plant were filtered and cultured on differential and ESBL-selective media. After antimicrobial susceptibility testing and multi-locus variable number of tandem repeats assay (MLVA), selected ESBL-EC strains from recreational water were characterized by whole genome sequencing (WGS) and compared to wastewater and human urine isolates from people living in the same area. We detected ESBL-EC in recreational water samples on 8/20 occasions (40%), representing all sites. The ratio of ESBL-EC to total number of E. coli colony forming units varied from 0 to 3.8%. ESBL-EC were present in all wastewater samples in ratios of 0.56-0.75%. ST131 was most prevalent in urine and wastewater samples, while ST10 dominated in water samples. Eight STs and identical ESBL-EC MLVA-types were detected in all compartments. Clinical ESBL-EC isolates were more likely to be multidrug-resistant (p
Cites: Environ Sci Pollut Res Int. 2015 Aug;22(15):11488-9225821088
Cites: PLoS One. 2017 Mar 7;12 (3):e017351028267783