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Biomedical subjects

N Low

Publications and source records attributed to N Low.

At least 37 records · Page 2Linked to original sources
PubMed1999

Uniform risk of clinical progression despite differences in utilization of highly active antiretroviral therapy: Swiss HIV Cohort Study.

OBJECTIVE: To compare the initiation of highly active antiretroviral therapy (HAART) in HIV-infected patients according to sex, route of HIV acquisition and education, and to assess the impact of differences in utilization on the probability of progression to AIDS. DESIGN AND SETTING: Swiss HIV Cohort Study, a national prospective multi-centre study. PARTICIPANTS: A total of 3342 patients, including 1007 (30%) women. HIV was acquired through injection drug use in 1155 (35%) cases and through sex between men in 1172 (35%). Twenty-eight per cent (957) of participants had attained only the minimum level of schooling. At baseline, the median CD4 cell count was 269x10(6)/l cells, median HIV-1 RNA was 4.3 log10 copies/ml and 2917 (87%) were free of AIDS. METHODS: Kaplan-Meier life tables and Cox proportional hazards regression. RESULTS: During 7007 person-years of follow-up 2285 (69%) patients started HAART and 318 (10%) developed a new AIDS event. In multivariable analysis controlling for CD4 cell count, viral load and disease stage at baseline, the probability of starting HAART was lower in injection drug users compared with men who have sex with men, hazard ratio 0.63 (95% confidence intervals 0.56-0.70) and in patients with minimum schooling compared with those with vocational training, hazard ratio 0.82 (0.75-0.91). The risk of progression to AIDS was similar among men and women, patients with a history of injecting drug use, and patients with lower educational attainment in both univariable and multivariable analysis. CONCLUSION: HIV-infected injecting drug users and those with lower levels of educational attainment start HAART later than other patient groups. The deferred initiation of therapy in these patients does not, however, appear to translate into an increased risk of clinical disease progression. This observation has important implications for treatment policy and the design of future clinical trials.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Bacterial vaginosis, ethnicity, and the use of genital cleaning agents: a case control study.

BACKGROUND AND OBJECTIVES: Bacterial vaginosis and vaginal douching are both reported to be more common in African-American and Caribbean than white women. It is also thought that douching alters the vaginal milieu. This study was conducted to examine associations between genital cleaning practices, bacterial vaginosis, and ethnic group. STUDY DESIGN: Case-control study of 100 women with bacterial vaginosis, diagnosed by Nugent's criteria, and 100 women without bacterial vaginosis attending a sexually transmitted diseases clinic in an ethnically heterogeneous inner-city area in London, England. RESULTS: Bacterial vaginosis was more common among black Caribbean than white women (OR, 2.1; 95% CI, 1.1-4.1). Vulval use of bubble bath or antiseptic solutions and douching with proprietary or homemade solutions were significantly more common in women with bacterial vaginosis than without. After controlling for use of vulval and vaginal antiseptics and bubble bath, douching, and a history of bacterial vaginosis, there was no ethnic difference in the occurrence of the condition (adjusted OR, 1.1; 95% CI, 0.5-2.5). CONCLUSIONS: Ethnic differences in genital hygiene behaviors can explain a twofold increase in the risk of bacterial vaginosis in black Caribbean compared with white women. The role of vulval and vaginal cleaning practices in the development of bacterial vaginosis should be examined further in longitudinal or randomized controlled studies.

Adult↗
PubMed1999

Risk factors for tuberculosis in patients with AIDS in London: a case-control study.

OBJECTIVE: To identify risk factors for the acquired immune-deficiency syndrome (AIDS) associated with tuberculosis, in patients with AIDS attending 11 of the largest human immunodeficiency virus (HIV)/AIDS Units in London. DESIGN: Case-control study nested in a retrospective cohort of 2048 HIV-1 positive patients. Cases were defined as patients with a definitive diagnosis of tuberculosis, and controls as patients with AIDS and without tuberculosis during follow-up. RESULTS: Of 627 patients diagnosed with AIDS, 121 had a definitive diagnosis of tuberculosis. Significant risk factors for tuberculosis in the univariate analysis were sex, ethnicity, age, HIV exposure category and hospital attended, and in the multiple regression analysis ethnicity, age and hospital attended. African ethnicity was the strongest risk factor for tuberculosis (adjusted odds ratio [AOR] 5.9, 95% confidence interval 3.4-10.2). The risk of tuberculosis was higher in the younger age groups (test for trend P < 0.001). The hospital-associated risk of tuberculosis was more heterogeneous in the non-African group, and non-Africans attending Hospital 1 had an increased risk of tuberculosis which was statistically significant. CONCLUSIONS: The risk factors for AIDS-associated tuberculosis in London are sub-Saharan African origin, younger age group, and, among the non-Africans only, attending one hospital in east London. Different transmission patterns and mechanisms for the development of tuberculosis may operate in different settings depending on the background risk of tuberculous infection. Screening for tuberculosis infection and disease among HIV-positive individuals in London is important for the provision of preventive or curative therapy, and prophylaxis policies need to be designed in accordance with the transmission patterns and mechanisms of disease.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Postal urine specimens: are they a feasible method for genital chlamydial infection screening?

BACKGROUND: A United Kingdom (UK) screening programme for Chlamydia trachomatis has recently been announced. Pilot projects involving the opportunistic testing of women attending health facilities are due to commence in several sites. There is a danger that this approach will fail to obtain adequate population coverage. The alternative--true systematic population screening--is generally assumed to be unfeasible. Studies in Denmark using postal urine specimens have challenged this assumption. No such studies have been reported from the UK. AIM: To assess the potential of urine specimens sent by post as the basis for a UK population screening strategy for genital chlamydial infection. METHOD: Two hundred patients (100 men, 100 women) aged 18 to 45 years were randomly sampled from the list of one urban group practice. Subjects were mailed an explanatory letter, a urine sample container, a sexual lifestyle questionnaire, and a prepaid return envelope. Non-responders were contacted by telephone; persistent non-responders were visited at home. Samples were tested for Chlamydia by DNA amplification and enzyme immunoassay. RESULTS: Sixty-four (32%) subjects were no longer living at their GP registered address. Of the remaining 136, 126 (93%) responded to the survey and 113 (83%) accepted the request for a urine sample and completed a questionnaire. Acceptance rates were similar for men and women and across age groups. Four samples (3%) were Chlamydia positive. CONCLUSION: Home mailed urine specimen collection in conjunction with a self-completed postal questionnaire is feasible. This could provide a viable basis both for determining population Chlamydia prevalence and for a UK Chlamydia population screening strategy. Overall cost effectiveness of such a strategy will depend on the cost of the test used. Comparative performance characteristics of the different currently available tests in this setting have yet to be fully determined.

Adolescent↗
PubMed1998

Disease progression and survival in HIV-1-infected Africans in London.

OBJECTIVE: To examine differences in progression to AIDS and death between HIV-1-positive Africans (most infected in sub-Saharan Africa and therefore with non-B subtypes) and HIV-1-positive non-Africans in London. DESIGN: Retrospective cohort study of 2048 HIV-1-positive individuals. SETTING: HIV-1-infected individuals attending 11 of the largest HIV/AIDS units in London. PATIENTS: Subjects were 1056 Africans and 992 non-Africans seen between 1982-1995. RESULTS: There were no differences in crude survival from presentation to death between Africans and non-Africans (median 82 and 78 months, respectively; P = 0.22). Africans progressed more rapidly to AIDS [hazard ratio (HR), 1.21; 95% confidence interval (CI), 1.02-1.45] but after adjustment for age, sex, Centers for Disease Control and Prevention category B symptoms and CD4+ lymphocyte count at presentation, year of HIV diagnosis and hospital attended, this difference was no longer significant (adjusted HR, 1.15; 95% CI, 0.93-1.43). Africans with AIDS had a reduced risk of death compared with non-Africans (HR, 0.78; 95% CI, 0.63-0.96) but not after adjustment for age, CD4+ lymphocyte count at AIDS, initial AIDS-defining conditions (ADC) and hospital attended (HR, 0.98; 95% CI, 0.76-1.27). Tuberculosis as the first ADC was associated with a 64% reduction in the risk of death. CD4+ lymphocyte decline was not significantly different between Africans and non-Africans (P = 0.18). CONCLUSIONS: Differences in progression to AIDS and death and CD4+ lymphocyte decline between HIV-1-infected Africans and non-Africans in London could not be attributed to ethnicity or different viral subtypes. Age and the clinical and immunological stage at presentation, or AIDS, were the major determinants of outcome. Compared with other diagnoses, tuberculosis as the initial ADC was associated with increased survival. Lack of access to health care and exposure to environmental pathogens are the most likely causes of reduced survival with AIDS in Africa, rather than inherently different rates of progression of immune deficiency due to racial differences or viral subtypes.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Disease progression and survival following specific AIDS-defining conditions: a retrospective cohort study of 2048 HIV-infected persons in London.

OBJECTIVE: To assess the impact of specific AIDS-defining conditions on survival in HIV-infected persons, with emphasis on the effect of tuberculosis. METHODS: A retrospective cohort analysis of HIV-infected Africans and non-Africans attending 11 specialist HIV/AIDS units in London enrolled for a comparison of the natural history of HIV/AIDS in different ethnic groups. RESULTS: A total of 2048 patients were studied of whom 627 (31%) developed 1306 different AIDS indicator diseases. Pneumocystis carinii pneumonia accounted for 159 (25%) of initial AIDS episodes and tuberculosis for 103 (16%). In patients with HIV disease, tuberculosis had the lowest risk [relative risk (RR), 1.11; 95% confidence interval (CI), 0.75-1.63], and high-grade lymphoma had the highest risk (RR, 20.56; 95% CI, 2.70-156.54) for death. For patients with a prior AIDS-defining illness, the development of subsequent AIDS indicator diseases such as Pneumocystis carinii pneumonia (RR, 1.18; 95% CI, 0.77-1.83) and tuberculosis (RR, 1.36; 95% CI, 0.76-2.47) had the best survival, and non-Hodgkin's lymphoma had the worst survival (RR, 9.67; 95% CI, 1.26-74.33). Patients with tuberculosis had a lower incidence of subsequent AIDS-defining conditions than persons with other initial AIDS diagnoses (rate ratio, 0.47; 95% CI, 0.37-0.59). CONCLUSIONS: Considerable variation exists in the relative risk of death following different AIDS-defining conditions. The development of any subsequent AIDS-defining condition is associated with an increased risk of death that differs between diseases, and this risk should be considered when evaluating the impact of specific conditions. Like other AIDS-defining conditions, incident tuberculosis was associated with adverse outcome compared with the absence of an AIDS-defining event, but we found no evidence of major acceleration of HIV disease attributable to tuberculosis.

AIDS-Related Opportunistic Infections↗
PubMed1998

Screening for chlamydial infections and the risk of ectopic pregnancy in a county in Sweden: ecological analysis.

OBJECTIVES: To analyse trends in rates of genital chlamydial infection and ectopic pregnancy between 1985 and 1995 in a county in Sweden. SETTING: Uppsala county where screening for chlamydial infection, treatment, and contact tracing has been widespread and where ectopic pregnancies are recorded. METHODS: Rates of chlamydial infections and ectopic pregnancy between 1985 and 1995 were calculated for women aged 20-39 years. Poisson and linear regression were used to examine the association between the risk of ectopic pregnancy and the current rates of chlamydial infection and rates of chlamydial infection from up to 5 years earlier. MAIN OUTCOME MEASURES: Rates of chlamydial infection per 100 examinations, rates of ectopic pregnancy per 1000 pregnancies, rate ratios and 95% confidence intervals for an increase in chlamydial infections of 5 new cases per 100 examinations. RESULTS: 103 870 cervical samples from women aged 15-39 years were analysed; 5648 (5.4%) were positive for chlamydia. 51 630 pregnancies were analysed; 930 (1.8%) were ectopic. Both rates declined over time. For women aged 20-24 years there was a strong correlation between the rate of ectopic pregnancy and the rate of chlamydial infection in the same year (r=0.93, P<0. 001); among older women correlations were stronger with rates of chlamydial infection occurring 1 or 2 years earlier. In Poisson regression ectopic pregnancy was most strongly associated with the current rate of chlamydial infection among women aged 20-24 (rate ratio 1.85, 95% confidence interval 1.44 to 2.38), with the rate of infection 1 year earlier among 25-29 year olds (rate ratio 1.72, 1. 33 to 2.22) and 30-34 year olds (rate ratio 2.27, 1.53 to 3.37); and with the rate 2 years earlier among 35 to 39 year olds (rate ratio 2. 58, 1.45 to 4.60). CONCLUSIONS: Declining rates of genital chlamydial infections have probably led to a fall in the rate of ectopic pregnancies. The timing of the decline in the rate of ectopic pregnancies varies with age. Among young women falling rates of chlamydial infection have been accompanied by an immediate reduction in the rate of ectopic pregnancy.

Adolescent↗
PubMed1998

Success and failure in gonorrhea control.

This article has shown that all the necessary components for successful control of gonorrhea are available. In developed countries, general improvements in economic conditions and advances in treatment and diagnosis have resulted in the lowest incidence rates of gonorrhea ever. Within these countries, however, control is failing, and gonorrhea is becoming hyperendemic among specific populations who tend to be disadvantaged and marginalized and who may have limited access to health care. Managing gonorrhea in individual patients and ensuring that their sexual partners receive appropriate treatment will contribute to reducing the transmission of infection in the community. Innovative school- and community-based interventions targeted to vulnerable populations will further help to reduce the incidence and contribute to improvements in the sexual health of the population.

Contact Tracing↗
PubMed1998

The role of effective diagnosis for the control of gonorrhoea in high prevalence populations.

Gonorrhoea in the UK is now a highly focal problem that is localized to certain inner city areas where it presents a significant public health concern. However, the majority of men and a proportion of women infested with Neisseria gonorrhoeae do not experience symptoms of sufficient intensity to prompt them to seek medical advice and the current strategy of treating symptomatic individuals in specialist clinics with subsequent tracing of sexual partners is therefore failing to control the spread of infection in these areas. One method for addressing this problem would be the extension of effective diagnostic services into the clinical environments most likely to be accessed by these high-risk individuals. This paper reviews the scientific literature examining the various methodologies available for the identification of N. gonorrhoeae and assesses their suitability for the diagnosis of gonorrhoea in these alternative clinical settings.

DNA Probes↗
PubMed1997

Disseminated Mycobacterium avium complex disease in the Swiss HIV Cohort Study: increasing incidence, unchanged prognosis.

OBJECTIVES: Disseminated disease due to Mycobacterium avium complex (MAC) bacteria is thought to occur less frequently in Europe than in the USA. This study investigated time trends in the occurrence of, and survival with, disseminated MAC disease in the Swiss HIV Cohort Study (SHCS). DESIGN, SETTING AND PARTICIPANTS: The SHCS participants who were free of disseminated MAC disease at registration were stratified by calendar period (1987-1989, 1990-1992, 1993-1995) in which the first recorded CD4 count was 0-49, 50-99, or 100-199 x 10(6)/l. Kaplan-Meier estimates of the probability of developing and surviving disseminated MAC disease were calculated for these nine independent groups. Multivariate analyses were performed using Cox proportional hazards regression. RESULTS: The analysis was based on 6052 participants enrolled between January 1987 and December 1995 and 202 incident episodes of disseminated MAC disease recorded during a mean follow-up time of 3.5 years. The cumulative probability of MAC disease at 2 years in individuals with CD4 counts of 0-49 x 10(6)/l in 1987-1989 was 9.8% [95% confidence interval (CI) 4.4-15.2%], increasing to 29.8% (95% CI, 20.8-38.8%) in 1993-1995. Amongst those with CD4 counts from 50-99 x 10(6)/l these probabilities were 11.9% (95% CI, 5.9-17.8%), and 21.6% (95% CI, 13.9-29.2%), respectively. After adjusting for CD4 count the relative hazard of developing disseminated MAC disease in 1993-1995, compared with 1987-1989, was 1.37 (95% CI, 0.92-2.04). Median survival following diagnosis was 7.9 months with no improvement over time. CONCLUSIONS: The incidence of disseminated MAC disease among SHCS participants has increased over time. More profound levels of immunosuppression amongst recent study entrants were found to explain this. When compared with US cohorts studied over the same calendar period the incidence of disseminated MAC disease in the SHCS appears to be lower. These findings are consistent with a secular effect of a more mature HIV epidemic in the US but direct comparison between the SHCS and a similar prospective cohort in the US should be undertaken to clarify this issue.

AIDS-Related Opportunistic Infections↗
PubMed1997

Gonorrhoea in inner London: results of a cross sectional study.

OBJECTIVES: To estimate population based incidence rates of gonorrhoea in an inner London area and examine relations with age, ethnic group, and socioeconomic deprivation. DESIGN: Cross sectional study. SETTING: 11 departments of genitourinary medicine in south and central London. SUBJECTS: 1978 first episodes of gonorrhoea diagnosed in 1994 and 1995 in residents of 73 electoral wards in the boroughs of Lambeth, Southwark, and Lewisham who attended any of the departments of genitourinary medicine. MAIN OUTCOME MEASURES: Yearly age, sex, and ethnic group specific rates of gonorrhoea per 100,000 population aged 15-59 years; rate ratios for the effects of age and ethnic group on gonorrhoea rates in women and men before and after adjustment for confounding factors. RESULTS: Overall incidence rates of gonorrhoea in residents of Lambeth, Southwark, and Lewisham were 138.3 cases yearly per 100,000 women and 291.9 cases yearly per 100,000 men aged 15-59 years. At all ages gonorrhoea rates were higher in non-white minority ethnic groups. Rate ratios for the effect of age adjusted for ethnic group and underprivilege were 15.2 (95% confidence interval 11.6 to 19.7) for women and 2.0 (1.7 to 2.5) for men aged 15-19 years compared with those over 30. After deprivation score and age were taken into account, women from black minority groups were 10.5 (8.6 to 12.8) times as likely and men 11.0 (9.7 to 12.6) times as likely as white people to experience gonorrhoea. CONCLUSIONS: Gonorrhoea rates in Lambeth, Southwark, and Lewisham in 1994-5 were six to seven times higher than for England and Wales one year earlier. The presentation of national trends thus hides the disproportionate contribution of ongoing endemic transmission in the study area. Teenage women and young adult men, particularly those from black minority ethnic groups, are the most heavily affected, even when socioeconomic underprivilege is taken into account. There is urgent need for resources for culturally appropriate research and effective intervention to prevent gonococcal infections and their long term sequelae in this population.

Adolescent↗
PubMed1997

HIV and AIDS, other sexually transmitted diseases, and tuberculosis in ethnic minorities in United Kingdom: is surveillance serving its purpose?

Experience of disease differs across ethnic groups, and ethnicity is a relevant personal characteristic for descriptive epidemiology. Information about ethnicity and country of birth is omitted from the routine notification of many diseases. HIV infection and AIDS, other sexually transmitted diseases, and tuberculosis have different incidence rates in different ethnic groups in the United Kingdom. Omission of ethnic data from surveillance activities allows such differences in incidence to go undetected and unaddressed. Surveillance data that included ethnic details could guide interventions to reduce inequalities in health between different subpopulations.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Multimodal-therapy breast salvage in the urban poor with locally advanced cancer.

OBJECTIVES: To determine whether economically disadvantaged urban women with locally advanced breast cancer (American Joint Committee on Cancer stages IIB to IIIB) have rates of response to sequential neoadjuvant chemotherapy and radiation, breast salvage rates, overall survival rates, and disease-free survival rates comparable with those previously reported in other socioeconomic groups and to compare these variables in different ethnic groups within the study population. DESIGN: Prospective, nonrandomized, case series. SETTING: Urban county hospital. PATIENTS: Thirty-seven women with locally advanced breast cancer who came to the breast clinic at Cook County Hospital, Chicago, Ill, during a 3-year interval. INTERVENTION: Sequential chemoradiation followed by surgery in selected patients. MAIN OUTCOME MEASURES: Comparison of clinical response rates, disease-free survival rates, and breast salvage rates between different ethnic groups in the study population. RESULTS: In the entire group, the overall response rate to neoadjuvant chemotherapy was 73%, with a complete response rate of 32%. Twenty-five percent of patients whose tumors responded incompletely to chemotherapy had a complete response after subsequent radiation. With a mean follow-up of 18.7 months, 65% of patients had no evidence of disease, and breast salvage without evidence of recurrent disease was achieved in 38% of patients. No differences in overall response rates, breast salvage rates, or early disease-free survival rates were observed within different ethnic groups in the study population, and these results are generally comparable with previously reported results in other socioeconomic groups. CONCLUSION: These results do not show significant differences in responses to sequential chemotherapy and irradiation, in breast salvage rates, or in survival between different ethnic groups in this study population.

Black or African American↗