689 research outputs found
Understanding the gender disparity in HIV infection across countries in sub-Saharan Africa: Evidence from the Demographic and Health Surveys
Women in sub-SaharanAfrica bear a disproportionate burden of human immunodeficiency virus (HIV) infections, which is exacerbated by their role in society and biological vulnerability. The specific objectives of this article are to (i) determine the extent of gender disparity in HIV infection; (ii) examine the role of HIV behaviour factors on the gender disparity and (iii) establish how the gender disparity varies between individuals of different characteristics and across countries. The analysis involves multilevel logistic regression analysis applied to pooledDemographic andHealth Surveys data from 20 countries in sub-Saharan Africa conducted during 2003–2008. The findings suggest that women in sub- Saharan Africa have on average a 60%higher risk of HIV infection than their male counterparts. The risk for women is 70%higher than their male counterparts of similar sexual behaviour, suggesting that the observed gender disparity cannot be attributed to sexual behaviour. The results suggest that the risk ofHIV infection among women (compared to men) across countries in sub-Saharan Africa is further aggravated among those who are younger, in female-headed households, not in stable unions or marital partnerships or had an earlier sexual debut.⁄ acquired immune deficiency syndrome (AIDS) awareness and sexua
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Male circumcision for HIV prevention in high HIV prevalence settings: what can mathematical modelling contribute to informed decision making?
Experts from UNAIDS, WHO, and the South African Centre for Epidemiological Modelling report their review of mathematical models estimating the impact of male circumcision on HIV incidence in high HIV prevalence settings
Guidelines for using HIV testing technologies in surveillance: selection, evaluation, and implementation
[UNAIDS/WHO Working Group on Global HIV/AIDS and STI Surveillance]."WHO/CDS/CSR/EDC/2001.16.""UNAIDS/01.22E.""Global surveillance of HIV/AIDS and sexually transmitted infections (STIs) is a joint effort of the World Health Organization (WHO) and the Joint United Nations Programme on HIV/AIDS (UNAIDS). The UNAIDS/WHO Working Group on Global HIV/AIDS and STI Surveillance, initiated in November 1996, is the main coordination and implementation mechanism for UNAIDS and WHO to compile the best information available and to improve the quality of data needed for informed decision-making and planning at national, regional and global levels. ... The Centers for Disease Control and Prevention (CDC), Atlanta, USA, deserves special credit for having prepared these Guidelines. The key professional staff, Dr. Christopher Murrill and Dr. Rebecca Martin, should be congratulated for their efforts in producing this document, with editorial assistance from Ms. Sadhna Patel and Ms. Beatrice Divine." - p. iiAlso available via the World Wide Web.Includes bibliographical references (p. 37-38)
The comparison of teen clubs vs. standard care on treatment outcomes for adolescents on antiretroviral therapy in Windhoek, Namibia
Adolescents living with HIV (ALHIV) are challenged to adhere to antiretroviral therapy (ART) and achieve and maintain virologic suppression. Group-based adherence support interventions, such as adherence clubs, have been shown to improve long-term adherence in ART patients. The teen club intervention was introduced in 2010 in Namibia to improve treatment outcomes for ALHIV by providing adherence support in a peer-group environment. Adolescents who have completed the full HIV disclosure process can voluntarily join the teen clubs. The current study compared treatment outcomes of ALHIV receiving ART at a specialized paediatric HIV clinic between 1 July 2015 and 30 June 2017 in Windhoek, Namibia. Methods. A retrospective cohort analysis was conducted on routine patient data extracted from the electronic Patient Monitoring System, individual Patient Care Booklets, and teen club attendance registers. A sample of 385 adolescents were analysed: 78 in teen clubs and 307 in standard care. Virologic suppression was determined at 6, 12, and 18 months from study start date, and compared by model of care, age, sex, disclosure status, and ART regimen. Comparisons between adolescents in teen clubs and those receiving standard care were performed using the chi-square test, and risk ratios were calculated to analyze differences in ART adherence and virologic suppression
ANALYSIS OF SLG GENE – THE MOLECULAR MARKER IN HYBRID BREEDING OF OIL SEED RAPE
Oil seed rape (Brassica napus L.) cultivars, donors of quality (SC) and self-incompatible (SI) lines have been analysed using identification of S-locus. In several Brassica napus cultivars one S-locus SLG gene was detected as dominant and the second S-locus as recessive. Amplification class II SLG gene screened recessive gene in all analysed samples (SC and SI). The DNA fragment of recessive gene corresponded to SLG gene W found in cv. Westar. S-haplotypes
were analysed by PCR-RFLP. Different Brassica napus cultivars had an identical electrophoretic profile conforming with nonfunctional A10 allele in B. campestris. In B. napus A10 allele is localised in genome A. The functional recessive SLG gene is probably localised in genome C. Model of their segregation was suggested. SC and SI plants
segregated in F2 generation at the ratio of approximately 3:1. This indicates a recessive monogenic disposition of SI in the experimental population.Autoinkompatibilita u odrůd, donorů kvality a autoinkompatibilních linií Brassica napus byla analyzována použitím identifikace S lokusu. U několika odrůd B. napus jeden S lokus genu SLG byl detekován jako dominantní a druhý S lokus jako recesivní. Amplifikací SLG genu třídy II byl odhalen recesivní gen ve všech analyzovaných vzorcích (autokompatibilních i autoinkomatibilních). DNA fragment recesivního genu sekvenčně souhlasil s SLG genem W, který byl objeven u odrůdy Westar. S haplotypy byly analyzovány metodou PCR-RFLP. Různé odrůdy B. napus měly identická elektroforetická spektra, která odpovídala nefunkční A10 alele v B. campestris. V B. napus A10 alela je lokalizována v genomu A, který pochází z B. campestris. Funkční recesivní alela SLG genu je pravděpodobně
lokalizována v genomu C. Byl navržen model segregace. Autokompatibilní a autoinkompatibilní rostliny segregovaly v F2 generaci v poměru přibližně 3:1. To potvrzuje recesivní monogenní založení autoinkomaptibility v experimentálních populacích
How fast could HIV change gene frequencies in the human population?
Infectious diseases have the potential to act as strong forces for genetic selection on the populations they affect. Human immunodeficiency virus (HIV) is a prime candidate to impose such genetic selection owing to the vast number of people it infects and the varying susceptibility of different human leucocyte antigen (HLA) types to HIV disease progression. We have constructed a model of HIV infection that differentiates between these HLA types, and have used reported estimates of the number of people infected with HIV and the different rates of progression to acquired immunodeficiency syndrome (AIDS) to provide a lower bound estimate on the length of time it would take for HIV to impose major genetic change in humans. We find that an HIV infection similar to that currently affecting sub-Saharan Africa could not yet have caused more than a 3 per cent decrease in the proportion of individuals who progress quickly to disease. Such an infection is unlikely to cause major genetic change (defined as a decrease in the proportion of quickly progressing individuals to under 50 per cent of their starting proportion) until 400 years have passed since HIV emergence. However, in very severely affected populations, there is a chance of observing such major genetic changes after another 50 years
How much can we gain from improved efficiency? An examination of performance of national HIV/AIDS programs and its determinants in low- and middle-income countries
<p>Abstract</p> <p>Background</p> <p>The economic downturn exacerbates the inadequacy of resources for combating the worldwide HIV/AIDS pandemic and amplifies the need to improve the efficiency of HIV/AIDS programs.</p> <p>Methods</p> <p>We used data envelopment analysis (DEA) to evaluate efficiency of national HIV/AIDS programs in transforming funding into services and implemented a Tobit model to identify determinants of the efficiency in 68 low- and middle-income countries. We considered the change from the lowest quartile to the average value of a variable a "notable" increase.</p> <p>Results</p> <p>Overall, the average efficiency in implementing HIV/AIDS programs was moderate (49.8%). Program efficiency varied enormously among countries with means by quartile of efficiency of 13.0%, 36.4%, 54.4% and 96.5%. A country's governance, financing mechanisms, and economic and demographic characteristics influence the program efficiency. For example, if countries achieved a notable increase in "voice and accountability" (e.g., greater participation of civil society in policy making), the efficiency of their HIV/AIDS programs would increase by 40.8%. For countries in the lowest quartile of per capita gross national income (GNI), a notable increase in per capita GNI would increase the efficiency of AIDS programs by 45.0%.</p> <p>Conclusions</p> <p>There may be substantial opportunity for improving the efficiency of AIDS services, by providing more services with existing resources. Actions beyond the health sector could be important factors affecting HIV/AIDS service delivery.</p
Direct microscopy versus sputum cytology analysis and bleach sedimentation for diagnosis of tuberculosis: a prospective diagnostic study.
ABSTRACT: BACKGROUND: Diagnostic options for pulmonary tuberculosis in resource-poor settings are commonly limited to smear microscopy. We investigated whether bleach concentration by sedimentation and sputum cytology analysis (SCA) increased the positivity rate of smear microscopy for smear-positive tuberculosis. METHODS: We did a prospective diagnostic study in a Medecins Sans Frontieres-supported hospital in Mindouli, Republic of Congo. Three sputum samples were obtained from 280 consecutive pulmonary tuberculosis suspects, and were processed according to WHO guidelines for direct smear microscopy. The remainder of each sputum sample was homogenised with 2.6% bleach, sedimented overnight, smeared, and examined blinded to the direct smear result for acid-fast bacilli (AFB). All direct smears were assessed for quality by SCA. If a patient produced fewer than three good-quality sputum samples, further samples were requested. Sediment smear examination was performed independently of SCA result on the corresponding direct smear. Positivity rates were compared using McNemar's test. RESULTS: Excluding SCA, 43.2% of all patients were diagnosed as positive on direct microscopy of up to three samples. 47.9% were diagnosed on sediment microscopy, with 48.2% being diagnosed on direct microscopy, sediment microscopy, or both. The positivity rate increased from 43.2% to 47.9% with a case definition of one positive smear ([greater than or equal to]1 AFB/100 high power fields) of three, and from 42.1% to 43.9% with two positive smears. SCA resulted in 87.9% of patients producing at least two good-quality sputum samples, with 75.7% producing three or more. Using a case definition of one positive smear, the incremental yield of bleach sedimentation was 14/121, or 11.6% (95% CI 6.5-18.6, p=0.001) and in combination with SCA was 15/121, or 12.4% (95% CI 7.1-19.6, p=0.002). Incremental yields with two positive smears were 5/118, or 4.2% (95% CI 1.4-9.6, p=0.062) and 7/118, or 5.9% (95% CI 2.4-11.8, p=0.016), respectively. CONCLUSIONS: The combination of bleach sedimentation and SCA resulted in significantly increased microscopy positivity rates with a case definition of either one or two positive smears. Implementation of bleach sedimentation led to a significant increase in the diagnosis of smear-positive patients. Implementation of SCA did not result in significantly increased diagnosis of tuberculosis, but did result in improved sample quality. Requesting extra sputum samples based on SCA results, combined with bleach sedimentation, could significantly increase the detection of smear-positive patients if routinely implemented in resource-limited settings where gold standard techniques are not available. We recommend that a pilot phase is undertaken before routine implementation to determine the impact in a particular context
Global trends in molecular epidemiology of HIV-1 during 2000-2007
Objective
To estimate the global and regional distribution of HIV-1 subtypes and recombinants between 2000 and 2007.
Design
Country-specific HIV-1 molecular epidemiology data were combined with estimates of the number of HIV-infected people in each country.
Method
Cross-sectional HIV-1 subtyping data were collected from 65913 samples in 109 countries between 2000 and 2007. The distribution of HIV-1 subtypes in individual countries was weighted according to the number of HIV-infected people in each country to generate estimates of regional and global HIV-1 subtype distribution for the periods 2000–2003 and 2004–2007.
Results
Analysis of the global distribution of HIV-1 subtypes and recombinants in the two time periods indicated a broadly stable distribution of HIV-1 subtypes worldwide with a notable increase in the proportion of circulating recombinant forms (CRFs), a decrease in unique recombinant forms (URFs), and an overall increase in recombinants. In 2004–2007, subtype C accounted for nearly half (48%) of all global infections, followed by subtypes A (12%) and B (11%), CRF02_AG (8%), CRF01_AE (5%), subtype G (5%) and D(2%). Subtypes F, H, J and K together cause fewer than 1% of infections worldwide. Other CRFs and URFs are each responsible for 4% of global infections, bringing the combined total of worldwide CRFs to 16% and all recombinants (CRFs plus URFs) to 20%.
Conclusions
The global and regional distributions of individual subtypes and recombinants are broadly stable, although CRFs may play an increasing role in the HIV pandemic. The global diversity of HIV-1 poses a formidable challenge to HIV vaccine development.Fil: Hemelaar, Joris. University of Oxford; Reino UnidoFil: Gouwsb, Eleanor. UNAIDS; SuizaFil: Ghysb, Peter D.. UNAIDS; SuizaFil: Osmanov, Saladin. WHO-UNAIDS HIV Vaccine Initiative; SuizaFil: WHO-UNAIDS Network for HIV Isolation and Characterisation.Fil: Salomon, Horacio Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin
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