Impact of Community Treatment With Ivermectin for the Control of Scabies on the Prevalence of Antibodies to Strongyloides stercoralis in Children.

The prevalence of antibodies to Strongyloides stercoralis was measured in 0-12-year-olds using a bead-based immunoassay before and after ivermectin mass drug administration (MDA) for scabies in the Solomon Islands. Seroprevalence was 9.3% before and 5.1% after MDA (P = .019), demonstrating collateral benefits of ivermectin MDA in this setting

Defining Seropositivity Thresholds for Use in Trachoma Elimination Studies.

BACKGROUND: Efforts are underway to eliminate trachoma as a public health problem by 2020. Programmatic guidelines are based on clinical signs that correlate poorly with Chlamydia trachomatis (Ct) infection in post-treatment and low-endemicity settings. Age-specific seroprevalence of anti Ct Pgp3 antibodies has been proposed as an alternative indicator of the need for intervention. To standardise the use of these tools, it is necessary to develop an analytical approach that performs reproducibly both within and between studies. METHODOLOGY: Dried blood spots were collected in 2014 from children aged 1-9 years in Laos (n = 952) and Uganda (n = 2700) and from people aged 1-90 years in The Gambia (n = 1868). Anti-Pgp3 antibodies were detected by ELISA. A number of visual and statistical analytical approaches for defining serological status were compared. PRINCIPAL FINDINGS: Seroprevalence was estimated at 11.3% (Laos), 13.4% (Uganda) and 29.3% (The Gambia) by visual inspection of the inflection point. The expectation-maximisation algorithm estimated seroprevalence at 10.4% (Laos), 24.3% (Uganda) and 29.3% (The Gambia). Finite mixture model estimates were 15.6% (Laos), 17.1% (Uganda) and 26.2% (The Gambia). Receiver operating characteristic (ROC) curve analysis using a threshold calibrated against external reference specimens estimated the seroprevalence at 6.7% (Laos), 6.8% (Uganda) and 20.9% (The Gambia) when the threshold was set to optimise Youden's J index. The ROC curve analysis was found to estimate seroprevalence at lower levels than estimates based on thresholds established using internal reference data. Thresholds defined using internal reference threshold methods did not vary substantially between population samples. CONCLUSIONS: Internally calibrated approaches to threshold specification are reproducible and consistent and thus have advantages over methods that require external calibrators. We propose that future serological analyses in trachoma use a finite mixture model or expectation-maximisation algorithm as a means of setting the threshold for ELISA data. This will facilitate standardisation and harmonisation between studies and eliminate the need to establish and maintain a global calibration standard

How communication affects prescription decisions in consultations for acute illness in children:a systematic review and meta-ethnography

BACKGROUND: Communication within primary care consultations for children with acute illness can be problematic for parents and clinicians, with potential misunderstandings contributing to over–prescription of antibiotics. This review aimed to synthesise the evidence in relation to communication and decision making in consultations for children with common acute illness. METHODS: A systematic search of MEDLINE, EMBASE, CINAHL, PsycINFO, SSCI, SIGLE, Dissertation Express and NHS economic evaluation databases was conducted. Studies of primary care settings in high income countries which made direct observations of consultations and reported qualitative data were included. Included studies were appraised using the process recommended by the Cochrane Qualitative Methods Group. Credibility was assessed as high for most studies but transferability was usually assessed low or unclear. Data were synthesised using a meta–ethnographic approach. RESULTS: Thirty–five papers and 2 theses reporting on 13 studies were included, 7 of these focussed on children with respiratory tract infections (RTI) and the remaining 6 included children with any presenting illness. Parent communication focussed on their concerns and information needs, whereas clinician communication focussed on diagnosis and treatment decisions. During information exchanges, parents often sought to justify the need for the consultation, while clinicians frequently used problem minimising language, resulting in parents and clinicians sometimes talking at cross–purposes. In the context of RTIs, a range of parent communication behaviours were interpreted by clinicians as indicating an expectation for antibiotics; however, most were ambiguous and could also be interpreted as raising concerns or requests for further information. The perceived expectation for antibiotics often changed clinician decision making into clinician–parent negotiation. CONCLUSIONS: Misunderstandings occurred due to parents and clinicians talking at cross purposes about the ‘seriousness’ of the illness and because parents’ expressions of concern or requests for additional information were sometimes perceived as a challenge to the clinicians’ diagnosis or treatment decision. This modifiable problem may be an important contribution to the unnecessary and unwanted prescribing of antibiotics. Primary care clinicians should be offered training to understand parent communication primarily as expressions of concern or attempts at understanding and always to check rather than infer parental expectations

The utility of serology for elimination surveillance of trachoma.

Robust surveillance methods are needed for trachoma control and recrudescence monitoring, but existing methods have limitations. Here, we analyse data from nine trachoma-endemic populations and provide operational thresholds for interpretation of serological data in low-transmission and post-elimination settings. Analyses with sero-catalytic and antibody acquisition models provide insights into transmission history within each population. To accurately estimate sero-conversion rates (SCR) for trachoma in populations with high-seroprevalence in adults, the model accounts for secondary exposure to Chlamydia trachomatis due to urogenital infection. We estimate the population half-life of sero-reversion for anti-Pgp3 antibodies to be 26 (95% credible interval (CrI): 21-34) years. We show SCRs below 0.015 (95% confidence interval (CI): 0.0-0.049) per year correspond to a prevalence of trachomatous inflammation-follicular below 5%, the current threshold for elimination of active trachoma as a public health problem. As global trachoma prevalence declines, we may need cross-sectional serological survey data to inform programmatic decisions

Sub-10 nm feature chromium photomasks for contact lithography patterning of square metal ring arrays

Advances in photolithographic processes have allowed semiconductor industries to manufacture smaller and denser chips. As the feature size of integrated circuits becomes smaller, there has been a growing need for a photomask embedded with ever narrower patterns. However, it is challenging for electron beam lithography to obtain <10 nm linewidths with wafer scale uniformity and a necessary speed. Here, we introduce a photolithography-based, cost-effective mask fabrication method based on atomic layer deposition and overhang structures for sacrificial layers. Using this method, we obtained sub-10 nm square ring arrays of side length 50 mu m, and periodicity 100 mu m on chromium film, on 1 cm by 1 cm quartz substrate. These patterns were then used as a contact-lithography photomask using 365 nm I-line, to generate metal ring arrays on silicon substrate