Heterosexual outbreak of infectious syphilis: epidemiological and ethnographic analysis and implications for control.
(73/718)
This study describes the epidemiology and ethnography of an outbreak of infectious syphilis in Vancouver, British Columbia. Between 1996 and 1999, British Columbias's rate of infectious syphilis rose from 0.5 to 3.4 per 100,000, with a dense concentration of cases among sex trade workers, their clients, and street-involved people in the downtown eastside area of Vancouver. Sexual networks were imported cases with secondary spread (dyads and triads), large densely connected dendritic networks of sex trade workers and clients, or occasional starburst networks among gay men. Only 232 of 429 partners were documented as having been treated (54% of those named, or 0.9 per case). The geographical and demographic concentration of this outbreak led to consideration of a programme of focused mass treatment with single dose azithromycin. (+info)
Determinants of STD epidemics: implications for phase appropriate intervention strategies.
(74/718)
Determinants of evolving epidemics of sexually transmitted diseases (STD) are equally influenced by the evolution of the STD epidemics themselves and by the evolution of human societies. A temporal approach to STD transmission dynamics suggests the need to monitor infectivity, rate of exposure between infected and susceptible individuals, and duration of infectiousness in societies. Different indicators may be used to monitor rate of exposure in the general population and in core groups. In addition, underlying determinants of STD epidemics such as poverty, inequality, racial/ethnic discrimination, unemployment, sex ratio, volume of migration, and health care coverage and quality are important variables to monitor through a surveillance system focused on social context. Ongoing large scale societal changes including urbanisation, globalisation, increasing inequality, and increasing volume of migrant populations may affect the evolution of STD epidemics. Globalised STD epidemics could pose a major challenge to local public health systems. (+info)
Hepatitis B vaccination in prisons.
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The opportunities and problems for hepatitis B vaccination programmes in prison settings are discussed. In particular, the advantages of modelling are stressed and an active case-finding approach is advocated. Measures for maintaining good case-holding are also discussed, and a 0, 1, 2 months vaccination regimen with 20 microg doses of vaccine is advocated for prison settings. A higher reference level for inferring adequate immunization is also recommended, with booster injections for inmates who do not meet the higher reference after a primary course of vaccination. (+info)
Partner notification among asymptomatic Chlamydia trachomatis cases, by means of mailed specimens.
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The objective of the study was to evaluate the prevalence of Chlamydia trachomatis infection and the participation, among partners of asymptomatic cases in general practice. Index cases were requested to invite partners for testing by mailed urine samples. One or more partners of 62% of the index cases participated, and the prevalence of infection among partners was 48%. A steady relationship was a determinant of both participation and prevalence. In conclusion, the mailing strategy is an effective strategy for partner notification. A high prevalence wasfound among partners. (+info)
Chlamydia trachomatis in non-gonococcal urethritis patients and their heterosexual partners: routine testing by polymerase chain reaction.
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OBJECTIVES: To identify the proportion of cases of non-gonococcal urethritis (NGU) in which Chlamydia trachomatis was detected in patients and their partners, using DNA amplification testing; and to relate the importance of age and symptoms to the presence of chlamydial infection and so clarify the aetiology and epidemiology of NGU, with a view to reducing the prevalence of chlamydial infection in general. METHODS: A 6 month cohort of all newly registered heterosexual men diagnosed with NGU, shortly after the introduction of polymerase chain reaction (PCR) chlamydial testing in 1997, was reviewed, with particular reference to their age and presence of symptoms; where possible, their women partners' data were traced. RESULTS: Of 283 NGU patients, 35% were chlamydia positive and significantly younger than the chlamydia negative cases (mean ages 25 and 29 years respectively). 51% NGU patients were symptomatic, of whom 40% were chlamydia positive. 43% of all chlamydia positive NGU patients were asymptomatic. 36 men had had chlamydia positive index partners. 26% of the 97 secondary female contacts were chlamydia positive; three had had a negative male partner. From 155 men (28% chlamydia positive) no contacts were traceable. CONCLUSIONS: In comparison with a previous similar study in 1987-90, using less sensitive diagnostic methods, a higher rate of chlamydial infection in NGU was detected. Young age and the presence of symptoms were confirmed as important factors for chlamydial positivity. (+info)
West Nile virus infection in organ donor and transplant recipients--Georgia and Florida, 2002.
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On August 23, 2002, the Georgia Division of Public Health (GDPH) and CDC were notified of two cases of unexplained fever and encephalitis in recipients of organ transplants from a common donor. An investigation has identified illness in two other recipients from the same donor: one with encephalopathy and the other with febrile illness. CDC, the Food and Drug Administration, GDPH, and the Florida Department of Health are conducting the investigation. This duster could possibly represent the first recognized transmission of West Nile virus (WNV) by organ donation. (+info)
Cytokine profiles of patients infected with Mycobacterium ulcerans and unaffected household contacts.
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Mycobacterium ulcerans, the cause of Buruli ulcer, is an environmental mycobacterium with a distinct geographic distribution. The reasons why only some individuals who are exposed to M. ulcerans develop ulcers are not known but are likely to reflect individual differences in the immune response to infections with this bacterium. In this study, we investigated cytokine profiles of peripheral blood mononuclear cells (PBMC) from 23 Buruli ulcer patients and 25 household contacts in a region of Australia where Buruli ulcer is endemic. The results showed that following stimulation with M. ulcerans or Mycobacterium bovis BCG, PBMC from Buruli ulcer patients mounted a Th2-type response, which was manifested by the production of mRNA for interleukin 4 (IL-4), IL-5, IL-6, and IL-10, whereas unaffected contacts responded mainly with the Th1 cytokines gamma interferon (IFN-gamma) and IL-12. For example, mRNA for IL-4 was detected in 18 of 23 patients but in only 3 of 25 control subjects (P < 0.0001). By contrast, PBMC from 21 of 25 unaffected individuals produced IFN-gamma compared with 3 of 23 patients (P < 0.0001). IFN-gamma release following stimulation with mycobacteria was markedly reduced in affected subjects. Frequencies of antibodies to M. ulcerans in serum samples from affected and unaffected subjects were similar, indicating that many of the control subjects had been exposed to this bacterium. Together, these findings suggest that a Th1-type immune response to M. ulcerans may prevent the development of Buruli ulcer in people exposed to M. ulcerans, but a Th-2 response does not. (+info)
Investigation of blood transfusion recipients with West Nile virus infections.
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An investigation conducted by CDC, the Food and Drug Administration (FDA), the American Red Cross, and state health departments in Georgia and Florida has confirmed transmission of West Nile virus (WNV) from a single organ donor to four organ recipients. During treatment for injuries that eventually proved fatal, the organ donor received numerous transfusions of blood products. However, the source of the organ donor's infection remains unknown. (+info)