1,975 research outputs found
Z' mass limits and the naturalness of supersymmetry
The discovery of a 125 GeV Higgs boson and rising lower bounds on the masses
of superpartners have lead to concerns that supersymmetric models are now fine
tuned. Large stop masses, required for a 125 GeV Higgs, feed into the
electroweak symmetry breaking conditions through renormalisation group
equations forcing one to fine tune these parameters to obtain the correct
electroweak vacuum expectation value. Nonetheless this fine tuning depends
crucially on our assumptions about the supersymmetry breaking scale. At the
same time extensions provide the most compelling solution to the
-problem, which is also a naturalness issue, and allow the tree level
Higgs mass to be raised substantially above . These very well motivated
supersymmetric models predict a new boson which could be discovered at the
LHC and the naturalness of the model requires that the boson mass should
not be too far above the TeV scale. Moreover this fine tuning appears at the
tree level, making it less dependent on assumptions about the supersymmetry
breaking mechanism. Here we study this fine tuning for several
supersymmetric extensions of the Standard Model and compare it to the situation
in the MSSM where the most direct tree level fine tuning can be probed through
chargino mass limits. We show that future LHC searches are extremely
important for challenging the most natural scenarios in these models.Comment: 58 pages, 5 figures; typos corrected, references added; matches
version to be published in Phys. Rev.
How health systems in sub-Saharan Africa can benefit from tuberculosis and other infectious disease programmes.
Weak and dysfunctional health systems in low-income countries, particularly in sub-Saharan Africa, are recognised as major obstacles to attaining the health-related Millennium Development Goals by 2015. Some progress is being made towards achieving the targets of Millennium Development Goal 6 for tuberculosis (TB), HIV/AIDS and malaria, with the achievements largely resulting from clearly defined strategies and intervention delivery systems combined with large amounts of external funding. This article is divided into four main sections. The first highlights the crucial elements that are needed in low-income countries in sub-Saharan Africa to deliver good quality health care through general health systems. The second discusses the main characteristics of infectious disease and TB control programmes. The third illustrates how TB control and other infectious disease programmes can help to strengthen these components, particularly in human resources; infrastructure; procurement and distribution; monitoring, evaluation and supervision; leadership and stewardship. The fourth and final section looks at progress made to date at the international level in terms of policy and guidelines, with some specific suggestions about this might be moved forward at the national level. For TB and other infectious disease programmes to drive broad improvements in health care systems and patient care, the lessons that have been learnt must be consciously applied to the broader health system, and sufficient financial input and the engagement of all players are essential
Causes of pediatric mortality and case-fatality rates in eight Médecins Sans Frontières-supported hospitals in Africa
Voluntary Counselling, HIV Testing and Sexual Behaviour Among Patients with Tuberculosis in a Rural District of Malawi.
OBJECTIVES: A study was conducted in new patients registered with tuberculosis (TB) in a rural district of Malawi in order to 1) verify the acceptability of voluntary counselling and testing for human immunodeficiency virus (HIV) infection; 2) describe sexual behaviour and condom use; and 3) identify socio-demographic and behavioural risk factors associated with 'no condom use'. DESIGN: Cross-sectional study. METHODS: Consecutive patients diagnosed with TB between January and December 2000 were offered voluntary counselling and HIV testing (VCT) and were subsequently interviewed. RESULTS: There were 1,049 new TB patients enrolled in the study. Of these, 1,007 (96%) were pre-test counselled, 955 (91%) underwent HIV testing and 912 (87%) were post-test counselled; 43 (4%) patients refused HIV testing. The overall HIV infection rate was 77%. Of all HIV-positive TB patients, 691 (94%) were put on cotrimoxazole. There were 479 (49%) TB patients who reported sexual encounters, of whom only 6% always used condoms. Unprotected sex was associated with having TB symptoms for over 1 month, having had less than 8 years of school education, being single, divorced or widowed or having sex with the same partner. CONCLUSIONS: Offering VCT to TB patients in this setting has a high acceptance rate and provides an opportunity to strengthen and integrate TB and HIV programmes
Sexually Transmitted Infections and Sexual Behaviour Among Commercial Sex Workers in a Rural District of Malawi.
In Thyolo District, Malawi, a study was conducted among commercial sex workers (CSWs) attending mobile clinics in order to; determine the prevalence and pattern of sexually transmitted infections (STIs), describe sexual behaviour among those who have an STI and identify risk factors associated with 'no condom use'. There were 1817 CSWs, of whom 448 (25%) had an STI. Of these, the commonest infections included 237 (53%) cases of abnormal vaginal discharge, 109 (24%) cases of pelvic inflammatory disease and 95 (21%) cases of genital ulcer disease (GUD). Eighty-seven per cent had sex while symptomatic, 17% without condoms. Having unprotected sex was associated with being married, being involved with commercial sex outside a known rest-house or bar, having a GUD, having fewer than two clients/day, alcohol intake and having had no prior medication for STI. The high levels of STIs, particularly GUDs, and unprotected sex underlines the importance of developing targeted interventions for CSWs and their clients
Does Antiretroviral Treatment Reduce Case Fatality Among HIV-Positive Patients with Tuberculosis in Malawi?
SETTING: Thyolo district, Malawi. OBJECTIVES: To report on 1) case fatality among human immunodeficiency virus (HIV) positive tuberculosis (TB) patients while on anti-tuberculosis treatment and 2) whether antiretroviral treatment (ART) initiated during the continuation phase of TB treatment reduces case fatality. DESIGN: Retrospective cohort analysis. METHODS: Comparative analysis of treatment outcomes for TB patients registered between January and December 2004. RESULTS: Of 983 newly registered TB patients receiving diagnostic HIV testing, 658 (67%) were HIV-positive. A total of 132 (20%) patients died during the 8-month course of anti-tuberculosis treatment, of whom 82 (62%) died within the first 2 months of treatment when ART was not provided (cumulative incidence 3.0, 95%CI 2.5-3.6 per 100 person-years). A total of 576 TB patients started the continuation phase of anti-tuberculosis treatment, 180 (31%) of whom were started on ART. The case-fatality rate per 100 person-years was not significantly different for patients on ART (1.0, 95%CI 0.6-1.7) and those without ART (1.2, 95%CI 0.9-1.7, adjusted hazard ratio 0.86, 95%CI 0.4-1.6, P = 0.6) CONCLUSIONS: ART provided in the continuation phase of TB treatment does not have a significant impact on reducing case fatality. Reasons for this and possible measures to reduce high case fatality in the initial phase of TB treatment are discussed
Cotrimoxazole prophylaxis in HIV-infected individuals after completing anti-tuberculosis treatment in Thyolo, Malawi.
SETTING: Thyolo, rural southern Malawi. OBJECTIVES: To determine 1) the proportion who continue with cotrimoxazole prophylaxis for the prevention of opportunistic infections, and 2) the reasons for continuing or stopping prophylaxis, in human immunodeficiency virus (HIV) infected individuals with tuberculosis (TB) who complete anti-tuberculosis treatment. DESIGN: A cross-sectional study. METHODS: A questionnaire study of all HIV-infected TB patients who had been registered over a 3-month period to receive anti-tuberculosis treatment and cotrimoxazole prophylaxis and who had completed antituberculosis treatment 3-6 months earlier. RESULTS: Of 82 HIV-infected individuals who were alive at the time of interview, 76 (93%) were continuing with cotrimoxazole and wished to do so indefinitely. The most common reason for continuing the drug was to prevent illness associated with HIV, while the most common reason for stopping was long distances to the health facility. Ninety-six percent of patients received cotrimoxazole free of charge from a health centre. Of those who wished to continue indefinitely, the majority (63%) could not afford to pay for the drug. CONCLUSIONS: In a rural setting, the great majority of HIV-infected individuals continued with cotrimoxazole after completing anti-tuberculosis treatment. Making the drug available and providing it free of charge is essential if it is to remain accessible for longer term prevention
Human resources for control of tuberculosis and HIV-associated tuberculosis.
The global targets for tuberculosis (TB) control were postponed from 2000 to 2005, but on current evidence a further postponement may be necessary. Of the constraints preventing these targets being met, the primary one appears to be the lack of adequately trained and qualified staff. This paper outlines: 1) the human resources and skills for global TB and human immunodeficiency virus (HIV) TB control, including the human resources for implementing the DOTS strategy, the additional human resources for implementing joint HIV-TB control strategies and what is known about human resource gaps at global level; 2) the attempts to quantify human resource gaps by focusing on a small country in sub-Saharan Africa, Malawi; and 3) the main constraints to human resources and their possible solutions, under six main headings: human resource planning; production of human resources; distribution of the work-force; motivation and staff retention; quality of existing staff; and the effect of HIV/AIDS. We recommend an urgent shift in thinking about the human resource paradigm, and exhort international policy makers and the donor community to make a concerted effort to bridge the current gaps by investing for real change
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