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Several countries include medium-chain acyl- CoA dehydrogenase ( MCAD) deficiency, a rare autosomal recessive disease, in their newborn screening programmes despite prevalence uncertainty. We estimated the frequency of its most common mutation, c. 985A>G, tested for regional differences and compared screening and genotype frequencies. We identified 43 studies reporting the frequency of c. 985A>G over 10 million individuals, and pooled frequency data using a novel Bayesian approach. We found significant variation in the frequency of the mutation across regions supporting a reported founder effect. The proportion of c. 985A>G homozygotes was highest in Western Europe with 4.1 (95% CI: 2.8-5.6) per 100,000 individuals, then the New World (3.2, 95% CI: 2.0-4.7), Southern (1.2, 95% CI: 0.6-2.0) and Eastern European regions (0.9, 95% CI: 0.5-1.7). No cases with the mutation were identified in Asian and Middle Eastern regions. Significant differences were found in some countries between the genotype and screening allele frequency of c. 985A>G. Our predictions could inform the frequency of the mutation by region and our approach could apply to other genetic conditions. [ABSTRACT FROM AUTHOR]

Published studies of the duration of asymptomatic Chlamydia trachomatis infection in women have produced diverse estimates, and most reviewers have not attempted an evidence synthesis. We review the designs of duration studies, distinguishing between the incident cases presenting soon after infection in clinic-based studies and prevalent cases ascertained in population screening studies. We combine evidence from all studies under fixed-effect (single clearance rate), random-effect (study-specific clearance rate), and mixture-of-exponentials models, in which there are either two or three classes of infection that clear at different rates. We can identify classes as 'passive' infection and fast-clearing and slow-clearing infections. We estimate models by Bayesian MCMC and compared them using posterior mean residual deviance and the deviance information criterion. The single fixed-effect clearance rate model fitted very poorly. The random-effect model was adequate but inferior to the two-class and three-class mixture of exponentials. According to the two-class model, the proportion in the first class was 23% (95% CI: 16-31%), and the mean duration of C. trachomatis infection is 1.36 years (95% CI: 1.13-1.63 years). With the three-rate model, duration was similar, but identification of the proportions in each class (19%, 31%, and 49%) was poor. Although the random-effect model was descriptively adequate, the extreme degree of between-study variation in the clearance rate it predicted lacked biological plausibility. Differences in study recruitment and sampling mechanisms, acting through a mixture-of-exponentials model, better explains the apparent heterogeneity in duration. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective To determine the cost effectiveness of strategies for preventing neonatal infection with group B streptococci and other bacteria in the UK and the value of further information from research. Design Use of a decision model to compare the cost effectiveness of prenatal testing for group B streptococcal infection (by polymerase chain reaction or culture), prepartum antibiotic treatment (intravenous penicillin or oral erythromycin), and vaccination during pregnancy (not yet available) for serious bacterial infection in early infancy across 12 maternal risk groups. Model parameters were estimated using multi-parameter evidence synthesis to incorporate all relevant data inputs. Data sources 32 systematic reviews were conducted: 14 integrated results from published studies, 24 involved analyses of primary datasets, and five included expert opinion. Main outcomes measures Healthcare costs per quality adjusted life year (QALY) gained. Results Current best practice (to treat only high risk women without prior testing for infection) and universal testing by culture or polymerase chain reaction were not cost effective options. Immediate extension of current best practice to treat all women with preterm and high risk term deliveries without testing (11% treated) would result in substantial net benefits. Currently, addition of culture testing for low risk term women, while treating all preterm and high risk term women, would be the most cost effective option (21% treated). If available in the future, vaccination combined with treating all preterm and high risk term women and no testing for low risk women would probably be marginally more cost effective and would limit antibiotic exposure to 11% of women. The value of information is highest (£67m) if vaccination is included as an option. Conclusions Extension of current best practice to treat all women with preterm and high risk term deliveries is readily achievable and would be beneficial. The choice between a [ABSTRACT FROM AUTHOR]

Reports global developments related to AIDS epidemiology and seroepidemiology as of March 2000. Effect of worldwide epidemic on HIV prevalence in Great Britain; Interrelation between AIDS and cancer in Zimbabwe; Analysis on the HIV-1 gene in Italy.

Provides information on a study which assessed the cost effectiveness of universal antenatal HIV screening compared with selective screening in Great Britain. Methodology; Net benefit of antenatal diagnosis of HIV; Results and conclusion.

Presents the European Collaborative Study (ECS), a prospective study of children born to HIV-infected mothers, and reports results relating to the natural history of HIV infection and the vertical transmission rate. Background; Methods; Results; Discussion.

Presents information on a study conducted to describe the epidemiology of human immunodeficiency virus-1 (HIV-1) infection in pregnant women in the United Kingdom. Investigation of time trends in the prevalence of HIV-1 infection in mothers of newborn babies; Results obtained; Conclusions drawn from results.

Presents information on a study which interpreted time trends in vertical transmission rates for HIV using data from national obstetric and paediatric surveillance registers in British Isles. Population studied; Statistical methods; Results and conclusion.