12 research outputs found

    Male circumcision and penile cancer: a systematic review and meta-analysis

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    OBJECTIVE: We systematically reviewed the evidence of an association between male circumcision and penile cancer. METHODS: Databases were searched using keywords and text terms for the epidemiology of penile cancer. Random effects meta-analyses were used to calculate summary odds ratios (ORs) and 95% confidence intervals (CI). RESULTS: We identified eight papers which evaluated the association of circumcision with penile cancer, of which seven were case-control studies. There was a strong protective effect of childhood/adolescent circumcision on invasive penile cancer (OR = 0.33; 95% CI 0.13-0.83; 3 studies). In two studies, the protective effect of childhood/adolescent circumcision on invasive cancer no longer persisted when analyses were restricted to boys with no history of phimosis. In contrast, there was some evidence that circumcision in adulthood was associated with an increased risk of invasive penile cancer (summary OR = 2.71; 95% CI 0.93-7.94; 3 studies). There was little evidence for an association of penile intra-epithelial neoplasia and in situ penile cancer with circumcision performed at any age. CONCLUSIONS: Men circumcised in childhood/adolescence are at substantially reduced risk of invasive penile cancer, and this effect could be mediated partly through an effect on phimosis. Expansion of circumcision services in sub-Saharan Africa as an HIV prevention strategy may additionally reduce penile cancer risk

    Causes of Acute Hospitalization in Adolescence: Burden and Spectrum of HIV-Related Morbidity in a Country with an Early-Onset and Severe HIV Epidemic: A Prospective Survey

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    Background: Survival to older childhood with untreated, vertically acquired HIV infection, which was previously considered extremely unusual, is increasingly well described. However, the overall impact on adolescent health in settings with high HIV seroprevalence has not previously been investigated.Methods and Findings: Adolescents (aged 10-18 y) systematically recruited from acute admissions to the two public hospitals in Harare, Zimbabwe, answered a questionnaire and underwent standard investigations including HIV testing, with consent. Pre-set case-definitions defined cause of admission and underlying chronic conditions. Participation was 94%. 139 (46%) of 301 participants were HIV-positive (median age of diagnosis 12 y: interquartile range [IQR] 11-14 y), median CD4 count = 151; IQR 57-328 cells/mu l), but only four (1.3%) were herpes simplex virus-2 (HSV-2) positive. Age (median 13 y: IQR 11-16 y) and sex (57% male) did not differ by HIV status, but HIV-infected participants were significantly more likely to be stunted (z-score < -2: 52% versus 23%, p<0.001), have pubertal delay (15% versus 2%, p<0.001), and be maternal orphans or have an HIV-infected mother (73% versus 17%, p<0.001). 69% of HIV-positive and 19% of HIV-negative admissions were for infections, most commonly tuberculosis and pneumonia. 84 (28%) participants had underlying heart, lung, or other chronic diseases. Case fatality rates were significantly higher for HIV-related admissions (22% versus 7%, p<0.001), and significantly associated with advanced HIV, pubertal immaturity, and chronic conditions.Conclusion: HIV is the commonest cause of adolescent hospitalisation in Harare, mainly due to adult-spectrum opportunistic infections plus a high burden of chronic complications of paediatric HIV/AIDS. Low HSV-2 prevalence and high maternal orphanhood rates provide further evidence of long-term survival following mother-to-child transmission. Better recognition of this growing phenomenon is needed to promote earlier HIV diagnosis and care

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Impact of the MEMA kwa Vijana adolescent sexual and reproductive health interventions on use of health services by young people in rural Mwanza, Tanzania: results of a cluster randomized trial.

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    PURPOSE: To assess the impact of an adolescent sexual health intervention on the use of health services by young people in Tanzania. METHODS: Twenty communities, including 39 health facilities, were randomly allocated to the intervention or comparison arm. Health workers from the intervention arm were trained in the provision of youth-friendly health services, as part of a package of interventions. Independent process evaluations were conducted in health facilities, and simulated patients visited clinics using sexual and reproductive health problem scenarios. The impact on health facility attendances were assessed in 1998 (baseline) and 1999-2001. Reported sexually transmitted infection (STI) symptoms and use of health services were evaluated in young people in the trial cohort. RESULTS: The mean monthly attendance for STI symptoms per health facility, per month was .5 for young males and 1.0 for young females at baseline. Attendance by young males was greater in the intervention communities in 1999-2000 after adjustment for baseline differences (p = .005), and this difference increased over time (p-trend = .022). The mean difference in attendance was however relatively modest, at 1.1 per month in 2001 after adjustment for baseline (95% CI: .5, 1.7). There was weaker evidence of an intervention effect on attendance by young women (p = .087). Few condoms were distributed, although a greater number were distributed in intervention facilities (p = .008). Generally, intervention health workers tended to be less judgmental and provided more comprehensive information. CONCLUSIONS: Training staff to provide more youth-friendly health services can increase the utilization of health services for suspected STIs by young people, especially among young men

    Human papillomavirus infection and increased risk of HIV acquisition. A systematic review and meta-analysis.

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    OBJECTIVES: Human papillomavirus (HPV), one of the commonest sexually transmitted infections, may be a cofactor in HIV acquisition. We systematically reviewed the evidence for an association of HPV infection with HIV acquisition in women, heterosexual men and men who have sex with men (MSM). DESIGN: : Systematic review and meta-analysis. METHODS: Studies meeting inclusion criteria in Pubmed, Embase and conference abstracts up to 29 July 2011 were identified. Random effects meta-analyses were performed to calculate summary hazard ratios (HR). Publication bias and statistical heterogeneity were evaluated and population attributable fractions (PAFs) calculated. RESULTS: Eight articles were included, with previously unpublished data from five authors. Seven studies found an association between prevalent HPV and HIV acquisition. Risk of HIV acquisition in women doubled with prevalent HPV infection with any genotype [HR = 2.06 (95% CI = 1.44-2.94), I = 0%], although adjustment for confounders was often inadequate. The effect was similar for high-risk [HR = 1.99 (95% CI = 1.54-2.56), I = 8.4%] and low-risk [HR = 2.01 (95% CI = 1.27-3.20), I = 0%] HPV genotypes with weak evidence of publication bias (P = 0.06). Two studies in men were identified: both showed an association between HPV infection and HIV acquisition. Unpublished data from one of two studies in women indicated an association between genotypes targeted by HPV vaccines and HIV acquisition. PAFs for HIV attributable to infection with any HPV genotype ranged between 21 and 37%. CONCLUSION: If further studies validate the association between HPV infection and HIV acquisition, HPV vaccines may reduce HIV incidence in high HPV prevalence populations, in addition to preventing cervical cancer. HIV surveillance studies during implementation of HPV vaccine programmes are warranted

    Male circumcision and human papillomavirus infection in men: a systematic review and meta-analysis.

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    BACKGROUND: We systematically reviewed the evidence for an association between male circumcision and Human Papillomavirus (HPV) infection and genital warts in men. METHODS: PubMed and Embase were searched to 15 September 2010. The measure of effect was the adjusted odds ratio (OR) or rate ratio (RR) when present and the crude estimate otherwise. Random effects meta-analyses were used to calculate summary measures of effect. RESULTS: We identified 23 papers about the association between circumcision and HPV DNA. Circumcised men were less likely to have prevalent genital HPV infection than uncircumcised men (summary OR, 0.57, 95% confidence interval [CI], 0.45-0.71) with between-study heterogeneity (P-heterogeneity = 0.006; I(2) = 50.5%; 19 studies). Similar summary associations were seen in clinical and methodological subgroups. The effect of circumcision was stronger at the glans/corona (OR, 0.47; 95% CI, 0.37-0.60) and urethra (OR, 0.35; 95% CI, 0.12-1.05) compared with sites more distal to the foreskin. There was weak evidence that circumcision was associated with decreased HPV incidence (summary RR, 0.75, 95% CI, 0.57-0.99; 3 studies) and increased HPV clearance (summary RR, 1.33; 95% CI, 0.89-1.98; 3 studies) but no evidence of an association with prevalent genital warts (OR, 0.93, 95% CI, 0.65-1.33; 15 studies). CONCLUSIONS: Several countries are expanding access to voluntary medical male circumcision to reduce HIV prevalence. This could provide additional benefit in reducing HPV prevalence

    Prospective Study of the Diagnostic Accuracy of the In Vivo Laser Scanning Confocal Microscope for Severe Microbial Keratitis

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    PurposeTo determine the diagnostic accuracy of in vivo confocal microscopy (IVCM) for moderate to severe microbial keratitis (MK).DesignDouble-masked prospective cohort study.ParticipantsConsecutive patients presenting to Aravind Eye Hospital, Madurai, India, between February 2012 and February 2013 with MK (diameter ≥3 mm, excluding descemetocele, perforation, or herpetic keratitis).MethodsFollowing examination, the corneal ulcer was scanned by IVCM (HRT3/RCM, Heidelberg Engineering, Heidelberg, Germany). Images were graded for the presence or absence of fungal hyphae or Acanthamoeba cysts by the confocal microscopist who performed the scan (masked to microbial diagnosis) and 4 other experienced confocal graders (masked to clinical features and microbiology). The regrading of the shuffled image set was performed by 3 graders, 3 weeks later. Corneal-scrape samples were collected for microscopy and culture.Main Outcome MeasuresThe main outcome measures were sensitivity, specificity, and positive and negative predictive values of IVCM compared with those of a reference standard of positive culture or light microscopy. Sensitivities and specificities for multiple graders were pooled and 95% confidence intervals calculated using a bivariate random-effects regression model.ResultsThe study enrolled 239 patients with MK. Fungal infection was detected in 176 (74%) and Acanthamoeba in 17 (7%) by microbiological methods. IVCM had an overall pooled (5 graders) sensitivity of 85.7% (95% confidence interval [CI]: 82.2%–88.6%) and pooled specificity of 81.4% (95% CI: 76.0%–85.9%) for fungal filament detection. For Acanthamoeba, the pooled sensitivity was 88.2% (95% CI: 76.2%–94.6%) and pooled specificity was 98.2% (95% CI: 94.9%–99.3%). Intergrader agreement was good: κ was 0.88 for definite fungus; κ was 0.72 for definite Acanthamoeba. Intragrader repeatability was high for both definite fungus (κ: 0.88–0.95) and definite Acanthamoeba classification (κ: 0.63–0.90). IVCM images from 11 patients were considered by all 5 graders to have a specific organism present (10 fungus, 1 Acanthamoeba) but had negative results via culture and light microscopy.ConclusionsLaser scanning IVCM performed with experienced confocal graders has high sensitivity, specificity, and test reproducibility for detecting fungal filaments and Acanthamoeba cysts in moderate to large corneal ulcers in India. This imaging modality was particularly useful for detecting organisms in deep ulcers in which culture and light microscopy results were negative

    Diagnostic accuracy of the Xpert MTB/RIF assay for extrapulmonary and pulmonary tuberculosis when testing non-respiratory samples: a systematic review.

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    BACKGROUND: Although the evidence base regarding the use of the Xpert MTB/RIF assay for diagnosis of pulmonary tuberculosis (TB) when testing respiratory samples is well established, the evidence base for its diagnostic accuracy for extrapulmonary and sputum-scarce pulmonary TB when testing non-respiratory samples is less clearly defined. METHODS: A systematic literature search of 7 electronic databases (Medline, EMBASE, ISI Web of Science, BIOSIS, Global Health Database, Scopus and Cochrane Database) was conducted to identify studies of the diagnostic accuracy of the Xpert assay when testing non-respiratory samples compared with a culture-based reference standard. Data were extracted and study quality was assessed using the QUADAS-2 tool. Sensitivities and specificities were calculated on a per-sample basis, stratified by sample type and smear microscopy status and summarised using forest plots. Pooled estimates were calculated for groups with sufficient data. RESULTS: Twenty-seven studies with a total of 6,026 non-respiratory samples were included. Among the 23 studies comparing Xpert and culture done on the same samples, sensitivity was very heterogeneous with a median sensitivity of 0.83 (IQR, 0.68-0.94) whereas specificities were typically very high (median, 0.98; IQR, 0.89-1.00). The pooled summary estimates of sensitivity when testing smear-positive and smear-negative samples were 0.95 (95% CI 0.91-1.00) and 0.69 (95% CI 0.60-0.80), respectively. Pooled summary estimates of sensitivity varied substantially between sample types: lymph node tissue, 0.96 (95% CI, 0.72-0.99); tissue samples of all types, 0.88 (95% CI, 0.76-0.94); pleural fluid, 0.34 (95% CI, 0.24-0.44); gastric aspirates for diagnosis of sputum-scarce pulmonary TB, 0.78 (IQR, 0.68 - 0.85). Median sensitivities when testing cerebrospinal fluid and non-pleural serous fluid samples were 0.85 (IQR, 0.75-1.00) and 0.67 (IQR, 0.00-1.00), respectively. CONCLUSION: Xpert detects with high specificity the vast majority of EPTB cases with smear-positive non-respiratory samples and approximately two-thirds of those with smear-negative samples. Xpert is a useful rule-in diagnostic test for EPTB, especially when testing cerebrospinal fluid and tissue samples. In addition, it has a high sensitivity for detecting pulmonary TB when using gastric aspirate samples. These findings support recent WHO guidelines regarding the use of Xpert for TB diagnosis from non-respiratory samples

    The genome of the simian and human malaria parasite Plasmodium knowlesi

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    Plasmodium knowlesi is an intracellular malaria parasite whose natural vertebrate host is Macaca fascicularis (the ‘kra’ monkey); however, it is now increasingly recognized as a significant cause of human malaria, particularly in southeast Asia1,2. Plasmodium knowlesi was the first malaria parasite species in which antigenic variation was demonstrated3, and it has a close phylogenetic relationship to Plasmodium vivax4, the second most important species of human malaria parasite (reviewed in ref. 4). Despite their relatedness, there are important phenotypic differences between them, such as host blood cell preference, absence of a dormant liver stage or ‘hypnozoite’ in P. knowlesi, and length of the asexual cycle (reviewed in ref. 4). Here we present an analysis of the P. knowlesi (H strain, Pk1(A+) clone5) nuclear genome sequence. This is the first monkey malaria parasite genome to be described, and it provides an opportunity for comparison with the recently completed P. vivax genome4 and other sequenced Plasmodium genomes6,7,8. In contrast to other Plasmodium genomes, putative variant antigen families are dispersed throughout the genome and are associated with intrachromosomal telomere repeats. One of these families, the KIRs9, contains sequences that collectively match over one-half of the host CD99 extracellular domain, which may represent an unusual form of molecular mimicry.ISSN:0028-0836ISSN:1476-468
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