Tuberculosis in the veterans healthcare system: a six-year review and evaluation of programme effectiveness.
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The Department of Veterans Affairs operates a large, centrally administered health care system consisting of 173 hospitals and 4 free standing outpatient clinics nationwide with approximately 945,115 hospital discharges, 24.2 million outpatient visits, and 2.86 million persons served annually over the time frame of the review. The purpose of the study was to define whether such a system could effect timely change in the incidence of tuberculosis (TB) using centralized programme planning and flexible field implementation. A retrospective review of the number of newly diagnosed cases of active TB treated at veterans health care facilities between 1 October 1990 and 30 September 1997 was determined by using a standardized annual case census. Intervention included implementation of the most current guidelines for the prevention of transmission of TB in the community and hospital setting, including administrative and engineering controls and a change in personal protective equipment. Centrally directed programme guidance, education, and funding were provided for field use in health care facilities of widely varying size and complexity. The numbers of total reported cases of TB decreased significantly (P < 0.001) throughout the veterans health care system (nationally and regionally), with the case rate decreasing at a rate significantly greater than that seen in the USA as a whole (P < 0.0001). TB associated with multi-drug resistance (isoniazid and rifampin) and HIV coinfection also significantly decreased over the study period. Therefore, a large, centrally administered health care system can effectively combat a re-emerging infectious disease and may also demonstrate a successful outcome greater than seen in other, perhaps less organized health care settings. (+info)
A long-term study of Rattus norvegicus in the London borough of Enfield using baiting returns as an indicator of sewer population levels.
(74/1248)
This is a long-term study that investigates the dynamics of a population of Rattus norvegicus (Berk) inhabiting a sewerage system in London. Thirteen years (1986/7-1998/9) of data from sewer baiting records were analysed (a total of 35,478 records). Manholes were baited with the anticoagulant Brodifacoum (0.005%) on a pinhead oatmeal bait base. Time series analysis was conducted on the data set to determine the underlying trend of the data and the population fluctuations about this trend. An exponential curve was found to give an accurate and realistic fit to the data and indicated that the rat population had decreased over the study period. Decomposition analysis indicated a 5-year cycle best described fluctuations around this trend. (+info)
Flavobacterium psychrophilum, invasion into and shedding by rainbow trout Oncorhynchus mykiss.
(75/1248)
The infection route of Flavobacterium psychrophilum into rainbow trout Oncorhynchus mykiss was studied using bath and cohabitation challenges as well as oral challenge with live feed as a vector. Additionally, the number of bacterial cells shed by infected fish into the surrounding water was determined in the cohabitation experiment and in challenge experiments at 3 different water temperatures. The experiments showed that skin and skin mucus abrasion dramatically enhanced the invasion of F. psychrophilum into the affected fish in bath and cohabitation challenges. Disruption of the skin is discussed as an important invasion route for F. psychrophilum into the fish. The shedding rate of F. psychrophilum by infected fish was associated with water temperature and the mortality of the infected fish. High numbers of F. psychrophilum cells were released into the water by dead rainbow trout during a long time period compared to the numbers of cells shed by live fish. The results emphasise the importance of removing dead and moribund fish from rearing tanks in order to diminish the infection pressure against uninfected fish in commercial fish farms. In immunohistochemical examinations of organs and tissues of orally infected fish, F. psychrophilum cells were detected in only 1 fish out of 31 studied. Mortality of the orally challenged fish was not observed in the experiment. (+info)
Seroepidemiology and molecular epidemiology of Kaposi's sarcoma-associated herpesvirus among Jewish population groups in Israel.
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BACKGROUND: The incidence of classic Kaposi's sarcoma among Jews in Israel is among the highest in the developed world. Kaposi's sarcoma-associated herpesvirus (KSHV or human herpesvirus 8) is causally linked to Kaposi's sarcoma. Very little is known about the prevalence of KSHV in the Middle East or about the modes of transmission in Mediterranean countries. METHODS: From 1992 through 1995, sera were obtained from 1648 adults who had tested positive for hepatitis B virus (HBV) surface antigen 20 years earlier at blood donations; sera were also obtained from 2403 of their family members. All sera were tested for anti-KSHV antibodies with the use of an indirect immunofluorescence assay. To analyze the effects of various factors on the risk of KSHV infection for both the HBV-positive cohort and their families, logistic regression for cluster data and generalized estimating equations were used. All statistical tests were two-sided. RESULTS: Among family members, the seroprevalence of antibodies against KSHV was 9.9% (95% confidence interval [CI] = 8.7% to 11.1%); among the former blood donors who had tested positive for hepatitis B, it was 22% (95% CI = 19.9% to 24.1%). Overall, the best predictor of KSHV status was the place of birth. The most important risk factors found for both husband and wife to test KSHV positive were their own places of birth and their spouse's seropositivity. For a child to test positive, the most important risk factor was maternal seropositivity. CONCLUSIONS: The crude prevalence rate of KSHV among the Jewish population in Israel is 9.9%. Important routes of KSHV transmission in the families studied are spouse to spouse and mother to child. The presence of KSHV in Jews in Israel of all ethnic origins and their high incidence of reported Kaposi's sarcoma suggest that KSHV was introduced into the Jewish population prior to the major Diaspora. (+info)
Foot care by health care providers.
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These recommendations have been provided to assist health care providers in performing foot care with the intention of decreasing the transmission of pathogens and resulting infections. It is important that providers of foot care implement these recommendations into their daily practice so that infections associated with foot care can be prevented. (+info)
Spatial targeting of interventions against malaria.
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Malaria transmission is strongly associated with location. This association has two main features. First, the disease is focused around specific mosquito breeding sites and can normally be transmitted only within certain distances from them: in Africa these are typically between a few hundred metres and a kilometre and rarely exceed 2-3 kilometres. Second, there is a marked clustering of persons with malaria parasites and clinical symptoms at particular sites, usually households. In localities of low endemicity the level of malaria risk or case incidence may vary widely between households because the specific characteristics of houses and their locations affect contact between humans and vectors. Where endemicity is high, differences in human/vector contact rates between different households may have less effect on malaria case incidences. This is because superinfection and exposure-acquired immunity blur the proportional relationship between inoculation rates and case incidences. Accurate information on the distribution of malaria on the ground permits interventions to be targeted towards the foci of transmission and the locations and households of high malaria risk within them. Such targeting greatly increases the effectiveness of control measures. On the other hand, the inadvertent exclusion of these locations causes potentially effective control measures to fail. The computerized mapping and management of location data in geographical information systems should greatly assist the targeting of interventions against malaria at the focal and household levels, leading to improved effectiveness and cost-effectiveness of control. (+info)
The pre-vaccination epidemiology of measles, mumps and rubella in Europe: implications for modelling studies.
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Data on the pre-vaccination patterns of infection for measles, mumps and rubella are collated from a number of European countries in order to compare the epidemiology of the three viruses. Key epidemiological parameters, such as the age-specific force of infection and the basic reproduction number (R0) are estimated from case notification or serological data using standard techniques. A method is described to compare force of infection estimates derived from serological data. Analysis suggests that the pre-vaccination patterns of measles and mumps infection in the different countries were similar. In contrast, the epidemiology of rubella was highly variable between countries. This suggests that it may be acceptable to use parameter values estimated from other countries to model measles and mumps transmission, but that this approach to modelling rubella transmission requires more caution. Estimates of R0 depend on underlying mixing assumptions. Constraints were placed on R0 estimates by utilising knowledge of likely mixing patterns. The estimates for R0 were highest for measles, intermediate for mumps, and generally lowest for rubella. Analysis of within- and between-age-group transmission rates suggested that mumps transmission tends to be more concentrated within young children than the other two viruses. The implications for the design of immunization programmes are that mumps may be the easiest to control via infant immunization since it is predominantly transmitted between the very young and the variability in rubella epidemiology requires that careful consideration of the possible effects of vaccination options should be made using local data when planning rubella immunization programmes. (+info)
Serological and virological evidence of non-sexual transmission of human herpesvirus type 8 (HHV8).
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To evaluate whether or not human herpesvirus 8 (HHV8) can be transmitted through a non-sexual route a serological survey was carried out in a group of 51 catholic nuns. The seroprevalence rate and the geometrical mean antibody titre to anti-latent HHV8 antigen were similar in nuns and in a group of 60 women, matched by age, in the general population (27 vs. 24%; 1028 vs. 1575, respectively). Moreover, by using nested polymerase chain reaction (PCR), HHV8 DNA sequences were detected in 7 of 16 (43.8%) saliva and peripheral blood mononuclear cells (PBMC) from patients with classical Kaposi's sarcoma (KS) and in 3 out of 7 (42%) AIDS-KS patients. None of 5 HIV positive persons who did not have KS tested positive for HHV8 DNA. HHV8 DNA sequences were also detected in 2 of 12 (17%) saliva and 1 PBMC sample out of 12 healthy HHV8 positive individuals (age range: 30-80 years old). This paper suggests that non-sexual transmission of HHV8 is operating in our geographical setting and saliva may be a potential source of HHV8 spreading in the general population. (+info)