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At least 397 records · Page 22Linked to original sources
PubMed2006

A large community outbreak of waterborne giardiasis-delayed detection in a non-endemic urban area.

BACKGROUND: Giardia is not endemic in Norway, and more than 90% of reported cases acquire the infection abroad. In late October 2004, an increase in laboratory confirmed cases of giardiasis was reported in the city of Bergen. An investigation was started to determine the source and extent of the outbreak in order to implement control measures. METHODS: Cases were identified through the laboratory conducting giardia diagnostics in the area. All laboratory-confirmed cases were mapped based on address of residence, and attack rates and relative risks were calculated for each water supply zone. A case control study was conducted among people living in the central area of Bergen using age- and sex matched controls randomly selected from the population register. RESULTS: The outbreak investigation showed that the outbreak started in late August and peaked in early October. A total of 1300 laboratory-confirmed cases were reported. Data from the Norwegian Prescription Database gave an estimate of 2500 cases treated for giardiasis probably linked to the outbreak. There was a predominance of women aged 20-29 years, with few children or elderly. The risk of infection for persons receiving water from the water supply serving Bergen city centre was significantly higher than for those receiving water from other supplies. Leaking sewage pipes combined with insufficient water treatment was the likely cause of the outbreak. CONCLUSION: Late detection contributed to the large public health impact of this outbreak. Passive surveillance of laboratory-confirmed cases is not sufficient for timely detection of outbreaks with non-endemic infections.

Adolescent↗
PubMed1999

Lower pulmonary function and cerebral subclinical abnormalities detected by MRI: the Atherosclerosis Risk in Communities study.

STUDY OBJECTIVES: To investigate the association between pulmonary function and (1) cerebral infarction and (2) white matter lesions (WMLs), identified by MRI and believed to represent subclinical lesions of arteriosclerosis, generalized hypoperfusion, or ischemia of the brain. DESIGN: Population-based, cross-sectional study. SETTING: Two communities in the United States. PARTICIPANTS: A sample of 1,917 African-American and white men and women 55 to 72 years old who were selected from the second follow-up examination of the Atherosclerosis Risk in Communities Study cohort. INTERVENTIONS: Observational study. MEASUREMENTS AND RESULTS: The lung function indexes, FEV1 and FVC, were assessed according to American Thoracic Society criteria. Subclinical cerebral infarction and WMLs were assessed by MRI. After adjusting for age, ethnicity, gender, height, and height squared, a 1-SD decrease of FEV1 in nonsmokers was associated with odds ratios (95% confidence interval [CI], 1.31 to 2.03) of 1.63 for infarction and 1.35 (95% CI, 1.08 to 1.69) for WMLs. Of those in the lowest quartile of FEV1, 15% had infarction and WMLs, in contrast to 6% of the individuals in the uppermost quartile of FEV1. Consistent associations were also observed by using FVC as an index of pulmonary function. Similar patterns of association were found among current smokers. The associations were not altered by additional adjustment of conventional risk factors of cardiovascular disease, comorbidity, or cognitive function. CONCLUSION: The results from this population-based study suggest that lower pulmonary function is associated with subclinical cerebral abnormalities.

Brain↗
PubMed1980

Education in early detection of oral squamous cell carcinoma: a community outreach program.

An educational program consisting of a slide presentation and lecture, a demonstration of how to examine the oral soft tissues, and handout materials was presented to practitioners, hygienists, assistants, and other personnel in their office. A pretest, a critique by the participants, and a follow-up questionnaire were used to determine the value of the program.

Audiovisual Aids↗
PubMed2000

Detection of Fasciola hepatica infection in a community located in the Ecuadorian Andes.

The presence of fascioliasis was assessed in four Andean communities using an enzyme-linked immunosorbent assay (ELISA) test to measure antibodies against Fasciola hepatica excretion-secretion antigens. Six percent (9 out of 150) of the individuals in one community were ELISA-positive for these antibodies. Fecal samples from two of the ELISA-positive individuals contained F. hepatica ova. All of the ELISA-positive cases, except for one, were children within the ages of 9 to 12 years.

Adult↗
PubMed2000

Comparison of acid mine drainage microbial communities in physically and geochemically distinct ecosystems.

This study presents population analyses of microbial communities inhabiting a site of extreme acid mine drainage (AMD) production. The site is the inactive underground Richmond mine at Iron Mountain, Calif., where the weathering of a massive sulfide ore body (mostly pyrite) produces solutions with pHs of approximately 0.5 to approximately 1.0. Here we used a suite of oligonucleotide probes, designed from molecular data recently acquired from the site, to analyze a number of microbial environments by fluorescent in situ hybridization. Microbial-community analyses were correlated with geochemical and mineralogical data from those environments. The environments investigated were within the ore body and thus at the site of pyrite dissolution, as opposed to environments that occur downstream of the dissolution. Few organism types, as defined by the specificities of the oligonucleotide probes, dominated the microbial communities. The majority of the dominant organisms detected were newly discovered or organisms only recently associated with acid-leaching environments. "Ferroplasma" spp. were detected in many of the communities and were particularly dominant in environments of lowest pH and highest ionic strength. Leptospirillum spp. were also detected in many slime and pyrite-dominated environments. In samples of an unusual subaerial slime, a new uncultured Leptospirillum sp. dominated. Sulfobacillus spp. were detected as a prominent inhabitant in warmer ( approximately 43 degrees C) environments. The information gathered here is critical for determining organisms important to AMD production at Iron Mountain and for directing future studies of this process. The findings presented here also have relevance to the microbiology of industrial bioleaching and to the understanding of geochemical iron and sulfur cycles.

Bacteria↗
PubMed1992

Effectiveness, costs, and cost-effectiveness of recruitment strategies for a mammographic screening program to detect breast cancer.

BACKGROUND AND PURPOSE: Since effective and affordable recruitment methods are essential for the widespread implementation of mammographic screening for detection of breast cancer, we studied the effectiveness, the costs, and the cost-effectiveness of various recruitment strategies in the population targeted by a pilot Australian program that offered free mammography screening between 1988 and 1990. METHODS: We evaluated three public recruitment strategies--local newspaper articles, community promotion, and promotion to physicians--and five personal strategies--invitation letters with or without specified appointment times, either alone or with a follow-up letter, or telephone call to nonattenders. The effectiveness of public recruitment strategies was estimated from monthly attendance rates by Poisson regression analysis, while the probability of attendance in response to personal strategies was calculated using logistic regression analysis. Costs were determined by resource usage studies. The cost-effectiveness ratios for personal strategies were determined using decision analysis. RESULTS: The costs in 1988-1989 Australian dollars per woman recruited were $22 for local newspaper articles and $106 for community promotion. No detectable increase in attendance resulted from promotion to physicians. When the cost of reserving an appointment was considered, the most cost-effective personal recruitment strategy was an invitation letter without a specified appointment time, followed by a second letter to nonattenders. This strategy recruited 35.6% of women in the sample targeted and cost $10.52 per attendee. In comparison, the most effective personal recruitment strategy was a letter with a specified appointment time followed by a second letter to nonattenders, which recruited 44.1% of women at an average cost of $19.99 and a marginal cost of $59.71 per additional attendee. CONCLUSIONS: Personal recruitment strategies were more cost-effective than public strategies. The most cost-effective personal strategy was an invitation letter without a specified appointment time, followed by a second letter to nonattenders.

Australia↗
PubMed2003

Virioplankton community structure along a salinity gradient in a solar saltern.

The virioplankton community structure along a salinity gradient from near seawater (40 per thousand ) to saturated sodium chloride brine (370 per thousand ) in a solar saltern was investigated by pulsed-field gel electrophoresis. Viral populations with genome sizes varying from 10 kb to 533 kb were detected. The viral community structure changed along the salinity gradient. Cluster analysis of the viral genome-banding pattern resulted in two main clusters. The virioplankton diversity within the samples with salinity from 40 per thousand to 150 per thousand was on the same cluster of a cladogram. The other group consisted of virioplankton from samples with salinity above 220 per thousand. The virioplankton diversity in the different samples was calculated using the Shannon index. The diversity index demonstrated an increase in diversity in the samples along the gradient from 40 per thousand to 150 per thousand salinity, followed by a decrease in the diversity index along the rest of the salinity gradient. These results demonstrate how viral diversity changes from habitats that are considered one of the most common (seawater) to habitats that are extreme in salt concentrations (saturated sodium brine). The diversity index was highest in the environments that lie in between the most extreme and the most common.

Electrophoresis, Gel, Pulsed-Field↗
PubMed1980

Use of Moore swabs for isolating Vibrio cholerae from sewage.

The Moore swab method was shown to be a practical and sensitive technique for the isolation of Vibrio cholerae from sewage. In each of three instances in which cholera patients lived in homes connected to municipal sewers, V. cholerae was isolated from the community sewage plant intake at the time of the patients illness. Sewer systems became negative within 1 day after patients were treated with tetracycline. Sewer surveillance using the Moore swab also found evidence of infections occurring in areas where surveillance of diarrheal illness failed to detect cholera. Culturing community sewage by the Moore swab method proved to be an economical and effective way of determining areas where V. cholerae infections were occurring.

Bacteriological Techniques↗
PubMed2006

Increased abundance of IncP-1beta plasmids and mercury resistance genes in mercury-polluted river sediments: first discovery of IncP-1beta plasmids with a complex mer transposon as the sole accessory element.

Although it is generally assumed that mobile genetic elements facilitate the adaptation of microbial communities to environmental stresses, environmental data supporting this assumption are rare. In this study, river sediment samples taken from two mercury-polluted (A and B) and two nonpolluted or less-polluted (C and D) areas of the river Nura (Kazakhstan) were analyzed by PCR for the presence and abundance of mercury resistance genes and of broad-host-range plasmids. PCR-based detection revealed that mercury pollution corresponded to an increased abundance of mercury resistance genes and of IncP-1beta replicon-specific sequences detected in total community DNA. The isolation of IncP-1beta plasmids from contaminated sediments was attempted in order to determine whether they carry mercury resistance genes and thus contribute to an adaptation of bacterial populations to Hg pollution. We failed to detect IncP-1beta plasmids in the genomic DNA of the cultured Hg-resistant bacterial isolates. However, without selection for mercury resistance, three different IncP-1beta plasmids (pTP6, pTP7, and pTP8) were captured directly from contaminated sediment slurry in Cupriavidus necator JMP228 based on their ability to mobilize the IncQ plasmid pIE723. These plasmids hybridized with the merRTDeltaP probe and conferred Hg resistance to their host. A broad host range and high stability under conditions of nonselective growth were observed for pTP6 and pTP7. The full sequence of plasmid pTP6 was determined and revealed a backbone almost identical to that of the IncP-1beta plasmids R751 and pB8. However, this is the first example of an IncP-1beta plasmid which had acquired only a mercury resistance transposon but no antibiotic resistance or biodegradation genes. This transposon carries a rather complex set of mer genes and is inserted between Tra1 and Tra2.

Bacteria↗
PubMed2006

Typhoid fever in children: some epidemiological considerations from Karachi, Pakistan.

BACKGROUND: The morbidity of typhoid fever is highest in Asia with 93% of global episodes occurring in this region. Southeast Asia has an estimated incidence of 110 cases/100,000 population, which is the third highest incidence rate for any region. Pakistan falls into this region. There is also a considerable seasonal variation of typhoid fever, carrying significant public health importance. Children are worst affected. Population-based data from Pakistan are scarce. METHODS: From June 1999 to December 2001 a fortnightly surveillance system was established in two squatter settlements in Karachi, Pakistan, with two study centers, each staffed by a doctor and five community health workers. Cases of continuous high-grade fever for three or more days were referred to these centers and screened clinically. Blood culture and Typhidot tests were done. RESULTS: One-third of the 4198 cases with febrile episodes of three or more days detected in the community were screened at the centers; 341 were clinically suspected of having typhoid fever. Forty-nine were positive by culture whereas 161 were positive by serology. Ten cases were multi-drug resistant. Incidence of culture-proven typhoid was estimated to be 170 (95% CI: 120, 220)/100,000 population, whereas serology-based incidence was 710 (95% CI: 620, 810)/100,000 population. Peak incidence was noted in October followed by May and June. CONCLUSION: Passive surveillance, even when augmented by household visits, misses a significant portion of suspected cases. Morbidity of typhoid is quite high in Pakistan and needs public health intervention. Hot months have higher incidence of typhoid. Healthcare behavior studies will help to develop a better surveillance system.

Adolescent↗
PubMedDate not supplied

Prevalence of bacterial vaginosis in a community setting and role of the pap smear in its detection.

OBJECTIVE: To study the revalence of bacterial vaginosis (BV) in symptomatic and asymptomatic women in a community setting, to assess the validiy of the Pap smear in the detection of BV and to determine the sensitivity and specificity of clinical criteria for the diagnosis of BV. STUDY DESIGN: Gram staining was performed on vaginal secretions collected from 301 women to determine the prevalence of BV. Each smear was assigned a score on the basis of the bacterial morphotypes identified. The bacterial pattern was also studied on 270 adequate, Pap-stained cervical smears and compared with the gold standard, the morphotypes on gram stain, to derive the validity of the Pap smear in diagnosing BV. Also each clinical criterion defined for diagnosis of BV was independently evaluated to determine their sensitivity and specificity. RESULTS: The overall prevalence of BV was 41.5% in the study subjects using Amsel's and Nugent's criteria. The Pap smear was 78.3% sensitive and 86.9% specific in detection of BV. Among the clinical criteria, the presence of clue cells on wet mounts was both highly sensitive (76.7%) and specific (92.4%) for diagnosing BV, while a positive whiff test had a specificity of 86.9% with sensitivity of 33.9%. Vaginal pH > 4.5 was sensitive (88.3%) but less specific (58.6%). The presence of a thin, homogeneous discharge clinging to vaginal mucosa had low sensitivity (56.3%) and specificity (48.9%). In this study, BV was prevalent in both symptomatic and asymptomatic women. The routine Pap smear was able to detect BV in the majority of women. Its utility can be greater in asymptomatic women, in whom this infection may go undetected otherwise, resulting in future complications related to reproductive health. Among Amsel's clinical criteria, the most sensitive and specific was the presence of clue cells in wet mounts. They can be detected easily by laboratory staff with little training in primary health care seting

Adolescent↗