The prevalence and demographic distribution of treated epilepsy: a community-based study in Tasmania, Australia.

OBJECTIVES: To estimate the prevalence and demographic distribution of treated epilepsy in a community-based population. MATERIALS & METHODS: We surveyed all residents in Tasmania, Australia, who were supplied at least one antiepileptic drug prescription between July 1, 2001 and June 30, 2002, recorded on the national prescription database. We adjusted for the effect of disease-related non-response bias by imputation methods. RESULTS: After three mail contacts, 54.0% (4072/7541) responded, with 1774 (43.6%) indicating treatment for epilepsy, representing 86.0% of the estimated total possible cases in Tasmania. The adjusted treated epilepsy prevalence was 4.36 per 1000 (95% CI 4.34, 4.39); lower in women (prevalence ratio 0.92 (95% CI 0.84, 1.00)); greater with increasing age (P < 0.001); similar in the three main geographic regions; and similar with socioeconomic status of postcode of residence. CONCLUSIONS: Although our estimates are likely to be affected by access to health services, overall treated epilepsy prevalence of 4.4 per 1000 is similar to previous studies. Our finding of high elderly prevalence has been reported in a few recent studies in developed countries and has important clinical and public health implications in populations with similar aging demographics.

A new value for mol percent guanine + cytosine of DNA for the salmonid fish pathogen Renibacterium salmoninarum.

The mol% G + C of DNA extracted from seven different isolates of Renibacterium salmoninarum was determined. Organisms studied were from selected geographical areas (U.S.A., Canada, England and France) and were isolated from five different species of salmonid fish. The mol% G + C was determined to be 55.5, higher than the currently reported value of 53.

Lactococcus piscium sp. nov. a new Lactococcus species from salmonid fish.

Chemical and molecular taxonomic studies were performed on a representative strain of some lactic acid bacteria of unknown taxonomic position isolated from salmonid fish. The results demonstrate that the fish bacterium represents a new species of the genus Lactococcus for which the name Lactococcus piscium sp. nov. is proposed. The type strain of Lactococcus piscium is NCFB 2778.

A phylogenetic comparison of the 16S rRNA sequence of the fish pathogen, Renibacterium salmoninarum, to gram-positive bacteria.

The 16S rRNA of Renibacterium salmoninarum, the causative agent of bacterial kidney disease in salmonids, was sequenced by reverse transcriptase to produce a nearly complete sequence (97%) of 1475 nucleotides. Phylogenetic comparisons to seventeen genera and signature sequence analysis indicated that R. salmoninarum was a member of the high G + C Gram-positive eubacterial subdivision although the reported G + C value is only 53%. A phylogenetic tree details the relationship of R. salmoninarum to ten actinomycetes from diverse environments.

Phylogenetic analysis of Piscirickettsia salmonis by 16S, internal transcribed spacer (ITS) and 23S ribosomal DNA sequencing.

Piscirickettsia salmonis, the etiologic agent of piscirickettsiosis, is a systemic disease of salmonid fish. Variations in virulence and mortality have been observed during epizootics at different geographical regions and in laboratory experiments with isolates from these different locations. This raises the possibility that biogeographical patterns of genetic variation might be a significant factor with this disease. To assess the genetic variability the 16S ribosomal DNA, the internal transcribed spacer (ITS) and the 23S ribosomal DNA of isolates from 3 different hosts and 3 geographic origins were amplified using the polymerase chain reaction (PCR). Results of this analysis confirm that P. salmonis is a member of the gamma subgroup of the Proteobacteria and show that the isolates form a tight monophyletic cluster with 16S rDNA similarities ranging from 99.7 to 98.5%. The ITS regions were 309 base pairs (bp), did not contain tRNA genes, and varied between isolates (95.2 to 99.7% similarity). Two-thirds of the 23S rRNA gene was sequenced from 5 of the isolates, yielding similarities ranging from 97.9 to 99.8%. Phylogenetic trees were constructed based on the 16S rDNA, ITS and 23S rDNA sequence data and compared. The trees were topologically similar, suggesting that the 3 types of molecules provided similar phylogenetic information. Five of the isolates are closely related (> 99.4% 16S rDNA similarity, 99.1% to 99.7% ITS and 99.3 to 99.8% 23S rDNA similarities). The sequence of one Chilean isolate, EM-90, was unique, with 16S rDNA similarities to the other isolates ranging from 98.5 to 98.9%, the ITS from 95.2 to 96.9% and the 23S rDNA from 97.6 to 98.5%.

Relative virulence of three isolates of Piscirickettsia salmonis for coho salmon Oncorhynchus kisutch.

Piscirickettsia salmonis was first recognized as the cause of mortality among pen-reared coho salmon Oncorhynchus kisutch in Chile. Since the initial isolation of this intracellular Gram-negative bacterium in 1989, similar organisms have been described from several areas of the world, but the associated outbreaks were not reported to be as serious as those that occurred in Chile. To determine if this was due to differences in virulence among isolates of P. salmonis, we conducted an experiment comparing isolates from Chile, British Columbia, Canada, and Norway (LF-89, ATL-4-91 and NOR-92, respectively). For each of the isolates, 3 replicates of 30 coho salmon were injected intraperitoneally with each of 3 concentrations of the bacterium. Negative control fish were injected with MEM-10. Mortalities were collected daily for 41 d post-injection. Piscirickettsiosis was observed in fish injected with each of the 3 isolates, and for each isolate, cumulative mortality was directly related to the concentration of bacterial cells administered. The LF-89 isolate was the most virulent, with losses reaching 97% in the 3 replicates injected with 10(5.0) TCID50, 91% in the replicates injected with 10(4.0) TCID50, and 57% in the fish injected with 10(3.0) TCID50. The ATL-4-91 isolate caused losses of 92% in the 3 replicates injected with 10(5.0) TCID50, 76% in the fish injected with 10(4.0) TCID50, and 32% in those injected with 10(3.0) TCID50. The NOR-92 isolate was the least virulent, causing 41% mortality in the replicates injected with 10(4.6) TCID50. At 41 d post-injection, 6% of the fish injected with 10(3.6) TCID50 NOR-92 had died. Mortality was only 2% in the fish injected with 10(2.6) TCID50 NOR-92, which was the same as the negative control group. Because the group injected with the highest concentration (10(4.6) TCID50) of NOR-92 was still experiencing mortality at 41 d, it was held for an additional 46 d. At 87 d post-injection, the cumulative mortality in this group had reached 70%. These differences in virulence among the isolates were statistically significant (p < 0.0001), and are important for the management of affected stocks of fish.

The life cycle of Ceratomyxa shasta, a myxosporean parasite of salmonids, requires a freshwater polychaete as an alternate host.

The actinosporean life stage of Ceratomyxa shasta, a myxozoan parasite of salmonids, and the annelid worm that serves as its alternate host were identified in laboratory transmission experiments and their roles were confirmed using molecular techniques. Infection by the parasite occurred in susceptible fish that were either exposed to or force fed the freshwater polychaete, Manayunkia speciosa, infected with the actinosporean. These observations were confirmed using the polymerase chain reaction with primers designed from the C. shasta 18S rDNA sequence. DNA was amplified from polychaetes harboring the actinosporean that caused infection in the fish but not from uninfected polychaetes. Amplified DNA from an infected polychaete was sequenced and its homology with the 18S rDNA sequence of C. shasta spores verified the proposed life cycle. Ultrastructural examination of the actinosporean in the polychaete showed developmental stages in the epidermis rather than within the intestinal epithelium as described for other myxozoans. The methods described will be useful in identifying alternate hosts and morphologically diverse life stages in the complex life cycles of other myxosporea and in understanding the relationships between these parasites and their hosts.

Predictors of smoking in pregnancy and attitudes and knowledge of risks of pregnant smokers.

This study examined the prevalence and predictors of smoking by pregnant women attending a public antenatal clinic. The prevalence of smoking in this population (n = 2577) was found to be 38.0% (95% CI 36.1-39.9%). A review of previous research investigating variables associated with smoking in pregnancy indicated that only three of 42 studies had used multivariate analysis. Using step-wise logistic regression analysis, five variables were found to be independent predictors of smoking in pregnancy: education (having 4 years or less high school), marital status (being unmarried), gravidity (being multigravida), age (being under 25 years) and language spoken at home (speaking English). The model correctly predicted 63.7% of cases. The knowledge and attitudes of pregnant smokers were also investigated using data from a sub-sample of consenting subjects. Three-quarters of the women claimed that they had reduced their smoking since discovering they were pregnant. However, their mean intake of 13.7 cigarettes daily remained at a hazardous level. Approximately half (51%) these smokers claimed to have tried to quit smoking in the current pregnancy. Most (61%) women said they believed smoking was definitely harmful to the unborn child. However, awareness and acceptance of specific risks were inadequate. Of the women in a current relationship, 72% said their partner was a regular smoker. Less than half (45%) the continuing smokers who had seen a doctor about their current pregnancy could recall being advised to stop smoking. There is a need for health care providers to adopt a more systematic and tailored approach to smoking cessation counselling. Efforts to convert quit attempts in pregnancy into sustained cessation represent a priority area of programme development and evaluation.

Serological evidence of California serogroup virus activity in Oregon.

We wished to demonstrate evidence of the presence of California serogroup viruses in Oregon and to test for the presence of certain other arboviruses in large ungulates. Blood samples from black-tailed deer (Odocoileus hemionus columbianus), mule deer (O. hemionus hemionus), and Roosevelt elk (Cervus elaphus roosevelti) from nine counties in Oregon were tested by serum-dilution plaque reduction neutralization for antibody to California serogroup viruses, including snowshoe hare, California encephalitis, and Jamestown Canyon, as well as to Cache Valley (Bunyamwera serogroup) and Klamath, an ungrouped rhabdovirus. Of 132 samples tested, 60 (46%) were found to be seropositive at a dilution of greater than or equal to 1:10 for at least one of the five different arboviruses. Forty (30%) samples contained antibody to more than one arbovirus, and 15 samples (11%) contained antibody to all five. Of these 15, 14 were from 75 black-tailed deer sera collected in Lincoln County, Oregon. Seropositivity rates for black-tailed deer ranged from 23% to 35%, with all five arboviruses represented. Positive reactions for all five arboviruses were represented among mule deer sera at rates from 5% to 29%. Elk sera were found to be positive for four of the viruses (none for Klamath virus). Although Cache Valley and Klamath viruses have been reported from Oregon, these data represent the first evidence of a California serogroup virus in the state.

Isolation of Aeromonas salmonicida from masu salmon in the Republic of Korea.

The isolation and identification of the Gram-negative fish pathogen, Aeromonas salmonicida salmonicida, from masu salmon (Oncorhynchus masou) at the Yang Yang Salmon Hatchery in the Republic of Korea is described. The bacterium possessed certain characteristics in common with isolates from fish in Japan. It is an important cause of mortality among cultured salmonids in the Republic of Korea. This is the first report of this fish pathogen from the Asian mainland.

Dual energy X-ray absorptiometry body composition and aging in a population-based older cohort.

OBJECTIVE: The aims of this cross-sectional study were (1) to examine the effect of age on body composition in older adults using dual-energy X-ray absorptiometry (DXA) and (2) to evaluate the agreement of DXA with standard indirect anthropometric measures (body mass index (BMI), waist circumference and waist-to-hip ratio (WHR)). RESEARCH METHODS AND PROCEDURES: A population-based sample of 731 adults aged between 50 and 79 years underwent measurement of BMI, waist circumference, WHR, DXA total body fat mass, DXA % total body fat, DXA % trunk fat and DXA lean body mass. Linear regression was used to test for trend in measures of body composition between age categories in men and women. Partial correlations and Bland-Altman analysis were used to examine the agreement of DXA measures with indirect measures. RESULTS: DXA lean body mass decreased significantly with increasing age in both sexes (P<0.05). In males, BMI (P=0.01) and body weight (P<0.01) decreased with age, and in females, WHR (P=0.05), DXA % total fat (P=0.02) and DXA % trunk fat (P=0.05) increased with age. There was good agreement between DXA measures of fatness and indirect anthropometric measures, except for WHR, which showed greater variability in its comparisons with DXA. CONCLUSION: Using the highly sensitive and direct DXA method of measuring body composition, a decline in lean body mass and an increase in adiposity was observed with aging. Except for WHR, indirect anthropometric measures generally showed high levels of agreement with DXA fat measures in this older cohort.

An Isolate of Piscirickettsia salmonis from White Seabass is Fully Virulent for Coho Salmon.

The virulence of the WSB-98 isolate of Piscirickettsia salmonis from white seabass Atractoscion nobilis was compared with that of the American Type Culture Collection type strain LF-89, which was originally isolated from coho salmon Oncorhynchus kisutch in Chile. In controlled laboratory challenges of juvenile coho salmon, the isolate from white seabass exhibited virulence that was equal to or greater than that of LF-89. The cumulative percent mortality (CPM) was similar between groups of coho salmon receiving an intraperitoneal injection of WSB-98 at 10(4.5) tissue culture infectious dose with 50% endpoint (TCID50)/fish (CPM = 98%) or an injection of LF-89 at 10(4.8) TCID50/fish (CPM = 95%). The mean day to death of 9.3 d for WSB-98 and 18.6 d for LF-89, however, differed significantly (P < 0.0001) between the two isolates. The virulence of an isolate of P. salmonis from white seabass for a salmonid species is consistent with the hypothesis that nonsalmonids can serve as natural marine hosts for the bacterium and potential sources for infection of salmonids.

Piscirickettsia salmonis: a Gram-negative intracellular bacterial pathogen of fish.

Piscirickettsia salmonis is the first Gram-negative, intracellular bacterial pathogen isolated from fish and is a significant cause of mortality in salmonid fish. Recent reports of P. salmonis or P. salmonis-like organisms from new fish hosts and geographic regions have increased the interest in the bacterium. In this review, the important characteristics of the bacterium including recent taxonomic changes, features of the disease caused by the bacterium including transmission, hosts, reservoirs, diagnostic procedures, and current approaches for prevention and treatment have been discussed. The reader is also directed to other reviews concerning the bacterium and the disease it causes (Fryer & Lannan 1994, 1996; Almendras & Fuentealba 1997; Lannan, Bartholomew & Fryer 1999; House & Fryer 2002; Mauel & Miller 2002).

The rickettsia: an emerging group of pathogens in fish.

Piscirickettsia salmonis is the first of the previously unrecognized rickettsial pathogens of fish to be fully characterized. Since the recognition of P. salmonis in 1989, the impact of rickettsial pathogens in fish has become increasingly apparent. Growing awareness of the emergence of these fastidious intracellular organisms has led to the discovery of rickettsial diseases among diverse species of fish from different geographic locations and aquatic environments. The source, reservoir, and mode of transmission of these agents as well as appropriate methods of disease prevention and control remain to be established.

The viral diseases of fish: a review through 1978. Part 1: Diseases of proven viral etiology.

In this review, a survey is made of the published literature on the viral diseases of fish available up to and including the year 1978. It is divided into two main sections. Part 1 describes 11 diseases where a virus has been isolated and proven to be the causative agent. Part 2 discusses 16 diseases where there is reason to suspect viral etiology because of evidence deriving from electron microscopy or transmission experiments with bacteria-free filtrates of homogenates of diseased tissue, but where final proof of a causative relationship is lacking. The review attempts to provide the most significant information on the disease process itself, in most cases including external signs, fish species susceptible, pathology, geographic distribution, existence of carriers, methods of transmission, and control. It also gives the most recent and significant data concerning the nature of the causative virus, including its cultural, biological, and physicochemical properties, where such information is available.

Characterization of anti-Aeromonas salmonicida antibodies from coho salmon.

Coho salmon (Oncorhynchus kisutch) anti-Aeromonas salmonicida agglutinins were excluded from Sephadex G-200 and their activity was lost after partial reduction and alkylation followed by exposure to 2 M urea. Immunoelectrophoretic analysis of coho antiserum revealed anodic and cathodic populations of immunoglobulin (Ig), and the anti-A. salmonicida antibodies present 12 weeks after parenteral immunization were primarily anodic Ig. Antibodies were specifically purified by dissociation of A. salmonicida cell wall agglutinates with 15% NaCl. The purified Ig was a 17S macroglobulin, and electron microscopy and sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that it was composed of four IgM-like subunits. The minimum coho antibody concentration required for visible agglutination of A. salmonicida cells was approximately 0.006 mug of Ig nitrogen/ml.