mHealth to improve implementation of TB contact investigation: a case study from Uganda

BACKGROUND

Implementation science offers a systematic approach to adapting innovations and delivery strategies to new contexts but has yet to be widely applied in low- and middle-income countries. The Fogarty Center for Global Health Studies is sponsoring a special series, "Global Implementation Science Case Studies," to address this gap.

METHODS

We developed a case study for this series describing our approach and lessons learned while conducting a prospective, multi-modal study to design, implement, and evaluate an implementation strategy for TB contact investigation in Kampala, Uganda. The study included formative, evaluative, and summative phases that allowed us to develop and test an adapted contact investigation intervention involving home-based sample collection for TB and HIV testing. We concurrently developed a multi-component mHealth implementation strategy involving fingerprint scanning, electronic decision support, and automated reporting of test results via text message. We then conducted a household-randomized, hybrid implementation-effectiveness trial comparing the adapted intervention and implementation strategy to usual care. Our assessment included nested quantitative and qualitative studies to understand the strategy's acceptability, appropriateness, feasibility, fidelity, and costs. Reflecting on this process with a multi-disciplinary team of implementing researchers and local public health partners, we provide commentary on the previously published studies and how the results influenced the adaptation of international TB contact investigation guidelines to fit the local context.

RESULTS

While the trial did not show improvements in contact investigation delivery or public health outcomes, our multi-modal evaluation strategy helped us identify which elements of home-based, mHealth-facilitated contact investigation were feasible, acceptable, and appropriate and which elements reduced its fidelity and sustainability, including high costs. We identified a need for better tools for measuring implementation that are simple, quantitative, and repeatable and for greater attention to ethical issues in implementation science.

CONCLUSIONS

Overall, a theory-informed, community-engaged approach to implementation offered many learnings and actionable insights for delivering TB contact investigation and using implementation science in low-income countries. Future implementation trials, especially those incorporating mHealth strategies, should apply the learnings from this case study to enhance the rigor, equity, and impact of implementation research in global health settings.

Straight to test reduces time to investigation and treatment

Straight to test (STT) is a recognised pathway for improving the waiting time for red flag referrals. Electronic patient care records (ECR) provide clinicians with a greater volume of clinical information allowing virtual triage and STT. We aimed to assess if using ECR and STT can reduce delays in diagnosis and treatment. A review of 300 colorectal referrals between 2018-2019 was performed. Patients awaiting an appointment were reviewed electronically, by a single colorectal surgeon and re-triaged STT if appropriate. The delay in time from referral to initial review was removed, creating a second group for statistical comparison to demonstrate time saved if the strategy was adopted at the point of original triage. 91.3% (n= 274) were red flag referrals. 94% (n=282) were sent STT. Patients processed via traditional referral and clinic had a median time to scope of 36 days compared with 22.5 days, p < 0.001 if triaged STT via virtual clinic. Median time to management was 59 days for traditional and 35 days for STT, p < 0.001.

EP.FRI.248 The bezoar, the bowel, and the blockage: A rare case of a spontaneously passed phytobezoar

Background

Bezoar, from the Persian meaning antidote, denotes a trapped mass in the gastrointestinal system. There are several types, but here we present a case of phytobezoar.

A phytobezoar is one which is composed of undigestible plant material. While all bezoars account for less than 4% of intestinal obstruction, most occur within the stomach or small intestine. Phytobezoars causing large bowel obstruction appear to be extremely rare.

Case report

We present a case of a phytobezoar causing large bowel obstruction in a 29-year-old man. He presented with a four-day history of abdominal pain and distension with associated vomiting and no bowel opening.

An abdominal X-ray demonstrated significant dilatation of transverse colon. Subsequent CT revealed large bowel obstruction with transition point in the distal sigmoid. An intraluminal lesion, with mottled appearance, containing locules of gas – a phytobezoar – was noted as the cause.

The Patient was clinically well with no peritonism and planned for a flexible sigmoidoscopy in the first instance. However, the patient went on to pass two large, hard bowel motions leading to significant resolution of symptoms. A flexible sigmoidoscopy was carried out to exclude other pathology and demonstrated that the obstruction had been relieved. 

Conclusion

While it seems phytobezoar is an incredibly rare cause for large bowel obstruction, most of the literature suggests operative management of the problem by means of laparotomy and enterotomy. This case demonstrates the potential for conservative management and possibility for spontaneous resolution, despite emergency presentation.

Positive epistasis between disease-causing missense mutations and silent polymorphism with effect on mRNA translation velocity

Epistasis refers to the dependence of a mutation on other mutation(s) and the genetic context in general. In the context of human disorders, epistasis complicates the spectrum of disease symptoms and has been proposed as a major contributor to variations in disease outcome. The nonadditive relationship between mutations and the lack of complete understanding of the underlying physiological effects limit our ability to predict phenotypic outcome. Here, we report positive epistasis between intragenic mutations in the cystic fibrosis transmembrane conductance regulator (CFTR)-the gene responsible for cystic fibrosis (CF) pathology. We identified a synonymous single-nucleotide polymorphism (sSNP) that is invariant for the CFTR amino acid sequence but inverts translation speed at the affected codon. This sSNP in cis exhibits positive epistatic effects on some CF disease-causing missense mutations. Individually, both mutations alter CFTR structure and function, yet when combined, they lead to enhanced protein expression and activity. The most robust effect was observed when the sSNP was present in combination with missense mutations that, along with the primary amino acid change, also alter the speed of translation at the affected codon. Functional studies revealed that synergistic alteration in ribosomal velocity is the underlying mechanism; alteration of translation speed likely increases the time window for establishing crucial domain-domain interactions that are otherwise perturbed by each individual mutation.

Implementing mHealth Interventions in a Resource-Constrained Setting: Case Study From Uganda

Background

Mobile health (mHealth) interventions are becoming more common in low-income countries. Existing research often overlooks implementation challenges associated with the design and technology requirements of mHealth interventions.

Objective

We aimed to characterize the challenges that we encountered in the implementation of a complex mHealth intervention in Uganda.

Methods

We customized a commercial mobile survey app to facilitate a two-arm household-randomized, controlled trial of home-based tuberculosis (TB) contact investigation. We incorporated digital fingerprinting for patient identification in both study arms and automated SMS messages in the intervention arm only. A local research team systematically documented challenges to implementation in biweekly site visit reports, project management reports, and minutes from biweekly conference calls. We then classified these challenges using the Consolidated Framework for Implementation Research (CFIR).

Results

We identified challenges in three principal CFIR domains: (1) intervention characteristics, (2) inner setting, and (3) characteristics of implementers. The adaptability of the app to the local setting was limited by software and hardware requirements. The complexity and logistics of implementing the intervention further hindered its adaptability. Study staff reported that community health workers (CHWs) were enthusiastic regarding the use of technology to enhance TB contact investigation during training and the initial phase of implementation. After experiencing technological failures, their trust in the technology declined along with their use of it. Finally, complex data structures impeded the development and execution of a data management plan that would allow for articulation of goals and provide timely feedback to study staff, CHWs, and participants.

Conclusions

mHealth technologies have the potential to make delivery of public health interventions more direct and efficient, but we found that a lack of adaptability, excessive complexity, loss of trust among end users, and a lack of effective feedback systems can undermine implementation, especially in low-resource settings where digital services have not yet proliferated. Implementers should anticipate and strive to avoid these barriers by investing in and adapting to local human and material resources, prioritizing feedback from end users, and optimizing data management and quality assurance procedures.

Trial Registration

Pan-African Clinical Trials Registration PACTR201509000877140; https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=877

Characterisation of anti-pseudomonad activity of hyper-arid Micromonospora species

The opportunistic pathogen Pseudomonas aeruginosa is a major cause of nosocomial infections, and has been categorised by the World Health Organisation as a “Priority 1: Critical” target for research and development of novel antibiotics owing to its intrinsic multi-resistance and ability to acquire novel resistance mechanisms.

One strategy for discovering novel antibiotics is the identification and characterisation of metabolites with antimicrobial activity. Members of the bacterial phylum Actinobacteria are historic source of these metabolites, in particular the genus Streptomyces. However, other genera have not received this same level of interest despite sharing the capacity to biosynthesise a diverse array of metabolites. One such genus is Micromonospora, responsible for production of the broad-spectrum aminoglycoside antibiotic gentamicin (M. purpurea).

Here we present three Micromonospora species isolated from the Atacama Desert, Chile; that possess anti-pseudomonad bioactivity inducible by culture on International Streptomyces Project (ISP) Media. In addition, preliminary data indicates that this activity can be affected by the addition of P. aeruginosa conditioned media. In parallel, short-read Illumina sequencing was used to assemble draft genomes for these strains, enabling antiSMASH analysis of putative biosynthetic gene clusters. In addition to this, estimated Average Nucleotide Identity (ANI) as calculated by the autoMLST server indicates that these strains may all be novel Micromonospora species.

The results of this work serve to highlight the biosynthetic capacity of an understudied genus of bacteria, as well as the value of examining underexplored environments and habitats in the search for novel bioactive molecules.

Home-based tuberculosis contact investigation in Uganda: a household randomised trial

Introduction

The World Health Organization (WHO) recommends household tuberculosis (TB) contact investigation in low-income countries, but most contacts do not complete a full clinical and laboratory evaluation.

Methods

We performed a randomised trial of home-based, SMS-facilitated, household TB contact investigation in Kampala, Uganda. Community health workers (CHWs) visited homes of index patients with pulmonary TB to screen household contacts for TB. Entire households were randomly allocated to clinic (standard-of-care) or home (intervention) evaluation. In the intervention arm, CHWs offered HIV testing to adults; collected sputum from symptomatic contacts and persons living with HIV (PLWHs) if ≥5 years; and transported sputum for microbiologic testing. CHWs referred PLWHs, children <5 years, and anyone unable to complete sputum testing to clinic. Sputum testing results and/or follow-up instructions were returned by automated SMS texts. The primary outcome was completion of a full TB evaluation within 14 days; secondary outcomes were TB and HIV diagnoses and treatments among screened contacts.

Results

There were 471 contacts of 190 index patients allocated to the intervention and 448 contacts of 182 index patients allocated to the standard-of-care. CHWs identified 190/471 (40%) intervention and 213/448 (48%) standard-of-care contacts requiring TB evaluation. In the intervention arm, CHWs obtained sputum from 35/91 (39%) of sputum-eligible contacts and SMSs were sent to 95/190 (50%). Completion of TB evaluation in the intervention and standard-of-care arms at 14 days (14% versus 15%; difference −1%, 95% CI −9% to 7%, p=0.81) and yields of confirmed TB (1.5% versus 1.1%, p=0.62) and new HIV (2.0% versus 1.8%, p=0.90) diagnoses were similar.

Conclusions

Home-based, SMS-facilitated evaluation did not improve completion or yield of household TB contact investigation, likely due to challenges delivering the intervention components.

In a household randomised trial in Kampala, Uganda, home-based, SMS-facilitated evaluation did not improve completion or yield of household TB contact investigation. Future studies will evaluate user-centred design to improve intervention delivery.http://bit.ly/2xwLpDu

Patterns of usage and preferences of users for tuberculosis-related text messages and voice calls in Uganda

BACKGROUND

Little information exists about mobile phone usage or preferences for tuberculosis (TB) related health communications in Uganda.

METHODS

We surveyed household contacts of TB patients in urban Kampala, Uganda, and clinic patients in rural central Uganda. Questions addressed mobile phone access, usage, and preferences for TB-related communications. We collected qualitative data about messaging preferences.

RESULTS

We enrolled 145 contacts and 203 clinic attendees. Most contacts (58%) and clinic attendees (75%) owned a mobile phone, while 42% of contacts and 10% of clinic attendees shared one; 94% of contacts and clinic attendees knew how to receive a short messaging service (SMS) message, but only 59% of contacts aged 45 years (vs. 96% of contacts aged <45 years, P = 0.0001) did so. All contacts and 99% of clinic attendees were willing and capable of receiving personal-health communications by SMS. Among contacts, 55% preferred detailed messages disclosing test results, while 45% preferred simple messages requesting a clinic visit to disclose results.

CONCLUSIONS

Most urban household TB contacts and rural clinic attendees reported having access to a mobile phone and willingness to receive TB-related personal-health communications by voice call or SMS. However, frequent phone sharing and variable messaging abilities and preferences suggest a need to tailor the design and monitoring of mHealth interventions to target recipients.

Text Messages Sent to Household Tuberculosis Contacts in Kampala, Uganda: Process Evaluation

Background

Previous studies have reported the inconsistent effectiveness of text messaging (short message service, SMS) for improving health outcomes, but few have examined to what degree the quality, or “fidelity,” of implementation may explain study results.

Objective

The aim of this study was to determine the fidelity of a one-time text messaging (SMS) intervention to promote the uptake of tuberculosis evaluation services among household contacts of index patients with tuberculosis.

Methods

From February to June 2017, we nested a process evaluation of text message (SMS) delivery within the intervention arm of a randomized controlled trial of tuberculosis contact investigation in Kampala, Uganda. Because mobile service providers in Uganda do not provide delivery confirmations, we asked household tuberculosis contacts to confirm the receipt of a one-time tuberculosis-related text message (SMS) by sending a text message (SMS) reply through a toll-free “short code.” Two weeks later, a research officer followed up by telephone to confirm the receipt of the one-time text message (SMS) and administer a survey. We considered participants lost to follow-up after 3 unsuccessful call attempts on 3 separate days over a 1-week period.

Results

Of 206 consecutive household contacts, 119 had a text message (SMS) initiated from the server. While 33% (39/119) were children aged 5-14 years, including 20% (24/119) girls and 13% (15/119) boys, 18 % (21/119) were adolescents or young adults, including 12% (14/119) young women and 6% (7/119) young men. 50% (59/119) were adults, including 26% (31/119) women and 24% (28/119) men. Of 107 (90%) participants for whom we could ascertain text message (SMS) receipt status, 67% (72/107) confirmed text message (SMS) receipt, including 22% (24/107) by reply text message (SMS) and 45% (48/107) during the follow-up telephone survey. No significant clinical or demographic differences were observed between those who did and did not report receiving the text message (SMS). Furthermore, 52% (56/107) reported ever reading the SMS. The cumulative likelihood of a text message (SMS) reaching its target and being read and retained by a participant was 19%.

Conclusions

The fidelity of a one-time text message (SMS) intervention to increase the uptake of household tuberculosis contact investigation and linkage to care was extremely low, a fact only discoverable through detailed process evaluation. This study suggests the need for systematic process monitoring and reporting of implementation fidelity in both research studies and programmatic interventions using mobile communications to improve health.

Feasibility, Acceptability, and Adoption of Digital Fingerprinting During Contact Investigation for Tuberculosis in Kampala, Uganda: A Parallel-Convergent Mixed-Methods Analysis

Background

In resource-constrained settings, challenges with unique patient identification may limit continuity of care, monitoring and evaluation, and data integrity. Biometrics offers an appealing but understudied potential solution.

Objective

The objective of this mixed-methods study was to understand the feasibility, acceptability, and adoption of digital fingerprinting for patient identification in a study of household tuberculosis contact investigation in Kampala, Uganda.

Methods

Digital fingerprinting was performed using multispectral fingerprint scanners. We tested associations between demographic, clinical, and temporal characteristics and failure to capture a digital fingerprint. We used generalized estimating equations and a robust covariance estimator to account for clustering. In addition, we evaluated the clustering of outcomes by household and community health workers (CHWs) by calculating intraclass correlation coefficients (ICCs). To understand the determinants of intended and actual use of fingerprinting technology, we conducted 15 in-depth interviews with CHWs and applied a widely used conceptual framework, the Technology Acceptance Model 2 (TAM2).

Results

Digital fingerprints were captured for 75.5% (694/919) of participants, with extensive clustering by household (ICC=.99) arising from software (108/179, 60.3%) and hardware (65/179, 36.3%) failures. Clinical and demographic characteristics were not markedly associated with fingerprint capture. CHWs successfully fingerprinted all contacts in 70.1% (213/304) of households, with modest clustering of outcomes by CHWs (ICC=.18). The proportion of households in which all members were successfully fingerprinted declined over time (ρ=.30, P<.001). In interviews, CHWs reported that fingerprinting failures lowered their perceptions of the quality of the technology, threatened their social image as competent health workers, and made the technology more difficult to use.

Conclusions

We found that digital fingerprinting was feasible and acceptable for individual identification, but problems implementing the hardware and software lead to a high failure rate. Although CHWs found fingerprinting to be acceptable in principle, their intention to use the technology was tempered by perceptions that it was inconsistent and of questionable value. TAM2 provided a valuable framework for understanding the motivations behind CHWs’ intentions to use the technology. We emphasize the need for routine process evaluation of biometrics and other digital technologies in resource-constrained settings to assess implementation effectiveness and guide improvement of delivery.

Drop-out from the tuberculosis contact investigation cascade in a routine public health setting in urban Uganda: A prospective, multi-center study

SETTING

Seven public tuberculosis (TB) units in Kampala, Uganda, where Uganda's national TB program recently introduced household contact investigation, as recommended by 2012 guidelines from WHO.

OBJECTIVE

To apply a cascade analysis to implementation of household contact investigation in a programmatic setting.

DESIGN

Prospective, multi-center observational study.

METHODS

We constructed a cascade for household contact investigation to describe the proportions of: 1) index patient households recruited; 2) index patient households visited; 3) contacts screened for TB; and 4) contacts completing evaluation for, and diagnosed with, active TB.

RESULTS

338 (33%) of 1022 consecutive index TB patients were eligible for contact investigation. Lay health workers scheduled home visits for 207 (61%) index patients and completed 104 (50%). Among 287 eligible contacts, they screened 256 (89%) for symptoms or risk factors for TB. 131 (51%) had an indication for further TB evaluation. These included 59 (45%) with symptoms alone, 58 (44%) children <5, and 14 (11%) with HIV. Among 131 contacts found to be symptomatic or at risk, 26 (20%) contacts completed evaluation, including five (19%) diagnosed with and treated for active TB, for an overall yield of 1.7%. The cumulative conditional probability of completing the entire cascade was 5%.

CONCLUSION

Major opportunities exist for improving the effectiveness and yield of TB contact investigation by increasing the proportion of index households completing screening visits by lay health workers and the proportion of at-risk contacts completing TB evaluation.

Anomalous biliary and vascular anatomy-Potential pitfalls during cholecystectomy

Laparoscopic cholecystectomy is usually a low-risk procedure associated with a short stay and a low rate of conversion to open surgery. Complications are sometimes associated with anomalous vascular or biliary anatomy. Outlined below are the variations in vascular and biliary anatomy which may result in complications either due to involvement in the inflammatory process or inadvertent division during dissection. Clin. Anat. 30:1103-1106, 2017. © 2017 Wiley Periodicals, Inc.

Phylogenetic characterization of East African cassava mosaic begomovirus (Geminiviridae) isolated from Manihot carthaginensis subsp. glaziovii (Müll.Arg.) Allem., from a non-cassava growing region in Tanzania

Manihot carthaginensis subsp. glaziovii (Müll.Arg.) Allem., a wild relative of cassava, native to Brazil, is one of the popular agroforestry trees used for hedges and/or boundary plants surrounding homesteads and farms and also harbours cassava mosaic begomoviruses (CMBs) and cassava brown streak ipomoviruses. Sequences of the DNA-A component of East African cassava mosaic virus (EACMV) isolates from M. carthaginensis subsp. glaziovii (Müll.Arg.) Allem., collected from non-cassava growing areas of Tanzania were characterized. Thirteen full length DNA-A sequences were analysed together with 15 already reported EACMV sequences and six CMB species reference genomes. The results show 96 to 100% nucleotide sequence identity with EACMV isolates from Kenya. Phylogenetic analysis revealed that EACMV isolates from M. carthaginensis subsp. glaziovii (Müll.Arg.) Allem, belong to a single cassava mosaic begomovirus species. The EACMV monophyletic clade is distinct from all other CMB species. The presence of Cassava infecting begomoviruses in wild cassava relative growing from traditionally non cassava growing region serve as inoculum sources for cassava-infecting begomoviruses and therefore their eradication is key in the sustainable management of CMBs, especially in the non-cassava growing areas.

Identification of New ATG4B Inhibitors Based on a Novel High-Throughput Screening Platform

Autophagy is an evolutionarily conserved homeostasis process through which aggregated proteins or damaged organelles are enveloped in a double-membrane structure called an autophagosome and then digested in a lysosome-dependent manner. Growing evidence suggests that malfunction of autophagy contributes to the pathogenesis of a variety of diseases, including cancer, viral infection, and neurodegeneration. However, autophagy is a complicated process, and understanding of the relevance of autophagy to disease is limited by lack of specific and potent autophagy modulators. ATG4B, a Cys-protease that cleaves ATG8 family proteins, such as LC3B, is a key protein in autophagosome formation and maturation process. A novel time-resolved fluorescence resonance energy transfer (TR-FRET) assay measuring protease activity of ATG4B was developed, validated, and adapted into a high-throughput screening (HTS) format. HTS was then conducted with a Roche focus library of 57,000 compounds. After hit confirmation and a counterscreen to filter out fluorescence interference compounds, 267 hits were confirmed, constituting a hit rate of 0.49%. Furthermore, among 65 hits with an IC₅₀ < 50 µM, one compound mimics the LC3 peptide substrate (-TFG-). Chemistry modification based on this particular hit gave preliminary structure activity relationship (SAR) resulting in a compound with a 10-fold increase in potency. This compound forms a stable covalent bond with Cys74 of ATG4B in a 1:1 ratio as demonstrated by liquid chromatography/tandem mass spectrometry (LC/MS/MS). Furthermore, this compound displayed cellular ATG4B inhibition activity. Overall, the novel TR-FRET ATG4B protease assay plus counterscreen assay provides a robust platform to identify ATG4B inhibitors, which would help to elucidate the mechanism of the autophagy pathway and offer opportunities for drug discovery.

LabDisk with complete reagent prestorage for sample-to-answer nucleic acid based detection of respiratory pathogens verified with influenza A H3N2 virus

Portable point-of-care devices for pathogen detection require easy, minimal and user-friendly handling steps and need to have the same diagnostic performance compared to centralized laboratories. In this work we present a fully automated sample-to-answer detection of influenza A H3N2 virus in a centrifugal LabDisk with complete prestorage of reagents. Thus, the initial supply of the sample remains the only manual handling step. The self-contained LabDisk automates by centrifugal microfluidics all necessary process chains for PCR-based pathogen detection: pathogen lysis, magnetic bead based nucleic acid extraction, aliquoting of the eluate into 8 reaction cavities, and real-time reverse transcription polymerase chain reaction (RT-PCR). Prestored reagents comprise air dried specific primers and fluorescence probes, lyophilized RT-PCR mastermix and stick-packaged liquid reagents for nucleic acid extraction. Employing two different release frequencies for the stick-packaged liquid reagents enables on-demand release of highly wetting extraction buffers, such as sequential release of lysis and binding buffer. Microfluidic process-flow was successful in 54 out of 55 tested LabDisks. We demonstrate successful detection of the respiratory pathogen influenza A H3N2 virus in a total of 18 LabDisks with sample concentrations down to 2.39 × 10(4) viral RNA copies per ml, which is in the range of clinical relevance. Furthermore, we detected RNA bacteriophage MS2 acting as internal control in 3 LabDisks with a sample concentration down to 75 plaque forming units (pfu) per ml. All experiments were applied in a 2 kg portable, laptop controlled point-of-care device. The turnaround time of the complete analysis from sample-to-answer was less than 3.5 hours.

Centrifugo-pneumatic multi-liquid aliquoting - parallel aliquoting and combination of multiple liquids in centrifugal microfluidics

The generation of mixtures with precisely metered volumes is essential for reproducible automation of laboratory workflows. Splitting a given liquid into well-defined metered sub-volumes, the so-called aliquoting, has been frequently demonstrated on centrifugal microfluidics. However, so far no solution exists for assays that require simultaneous aliquoting of multiple, different liquids and the subsequent pairwise combination of aliquots with full fluidic separation before combination. Here, we introduce the centrifugo-pneumatic multi-liquid aliquoting designed for parallel aliquoting and pairwise combination of multiple liquids. All pumping and aliquoting steps are based on a combination of centrifugal forces and pneumatic forces. The pneumatic forces are thereby provided intrinsically by centrifugal transport of the assay liquids into dead end chambers to compress the enclosed air. As an example, we demonstrate simultaneous aliquoting of 1.) a common assay reagent into twenty 5 μl aliquots and 2.) five different sample liquids, each into four aliquots of 5 μl. Subsequently, the reagent and sample aliquots are simultaneously transported and combined into twenty collection chambers. All coefficients of variation for metered volumes were between 0.4%-1.0% for intra-run variations and 0.5%-1.2% for inter-run variations. The aliquoting structure is compatible to common assay reagents with a wide range of liquid and material properties, demonstrated here for contact angles between 20° and 60°, densities between 789 and 1855 kg m(-3) and viscosities between 0.89 and 4.1 mPa s. The centrifugo-pneumatic multi-liquid aliquoting is implemented as a passive fluidic structure into a single fluidic layer. Fabrication is compatible to scalable fabrication technologies such as injection molding or thermoforming and does not require any additional fabrication steps such as hydrophilic or hydrophobic coatings or integration of active valves.

Implementation of an electronic fingerprint-linked data collection system: a feasibility and acceptability study among Zambian female sex workers

Background

Patient identification within and between health services is an operational challenge in many resource-limited settings. When following HIV risk groups for service provision and in the context of vaccine trials, patient misidentification can harm patient care and bias trial outcomes. Electronic fingerprinting has been proposed to identify patients over time and link patient data between health services. The objective of this study was to determine 1) the feasibility of implementing an electronic-fingerprint linked data capture system in Zambia and 2) the acceptability of this system among a key HIV risk group: female sex workers (FSWs).

Methods

Working with Biometrac, a US-based company providing biometric-linked healthcare platforms, an electronic fingerprint-linked data capture system was developed for use by field recruiters among Zambian FSWs. We evaluated the technical feasibility of the system for use in the field in Zambia and conducted a pilot study to determine the acceptability of the system, as well as barriers to uptake, among FSWs.

Results

We found that implementation of an electronic fingerprint-linked patient tracking and data collection system was feasible in this relatively resource-limited setting (false fingerprint matching rate of 1/1000 and false rejection rate of <1/10,000) and was acceptable among FSWs in a clinic setting (2 % refusals). However, our data indicate that less than half of FSWs are comfortable providing an electronic fingerprint when recruited while they are working. The most common reasons cited for not providing a fingerprint (lack of privacy/confidentiality issues while at work, typically at bars or lodges) could be addressed by recruiting women during less busy hours, in their own homes, in the presence of “Queen Mothers” (FSW organizers), or in the presence of a FSW that has already been fingerprinted.

Conclusions

Our findings have major implications for key population research and improved health services provision. However, more work needs to be done to increase the acceptability of the electronic fingerprint-linked data capture system during field recruitment. This study indicated several potential avenues that will be explored to increase acceptability.

A microfluidic timer for timed valving and pumping in centrifugal microfluidics

Accurate timing of microfluidic operations is essential for the automation of complex laboratory workflows, in particular for the supply of sample and reagents. Here we present a new unit operation for timed valving and pumping in centrifugal microfluidics. It is based on temporary storage of pneumatic energy and time delayed sudden release of said energy. The timer is loaded at a relatively higher spinning frequency. The countdown is started by reducing to a relatively lower release frequency, at which the timer is released after a pre-defined delay time. We demonstrate timing for 1) the sequential release of 4 liquids at times of 2.7 s ± 0.2 s, 14.0 s ± 0.5 s, 43.4 s ± 1.0 s and 133.8 s ± 2.3 s, 2) timed valving of typical assay reagents (contact angles 36-78°, viscosities 0.9-5.6 mPa s) and 3) on demand valving of liquids from 4 inlet chambers in any user defined sequence controlled by the spinning protocol. The microfluidic timer is compatible to all wetting properties and viscosities of common assay reagents and does neither require assistive equipment, nor coatings. It can be monolithically integrated into a microfluidic test carrier and is compatible to scalable fabrication technologies such as thermoforming or injection molding.

An unusual cause of abdominal distension: intraperitoneal bladder perforation secondary to intermittent self-catheterisation

We report a strikingly unusual case of traumatic intraperitoneal perforation of an augmented bladder from clean intermittent self-catheterisation (CISC), which presented a unique diagnostic challenge. This case describes a 48-year-old T1 level paraplegic, who had undergone clamshell ileocystoplasty for detrusor overactivity, presenting with abdominal distension, vomiting and diarrhoea. Initial investigations were suggestive of disseminated peritoneal malignancy with ascitic fluid collections, but the ascitic fluid was found to be intraperitoneal urine from a perforation of the urinary bladder. This was associated with an inflammatory response in the surrounding structures causing an appearance of colonic thickening and omental disease. Although the diagnostic process was complex due to this patient's medical history, the treatment plan initiated was non-operative, with insertion of an indwelling urinary catheter and radiologically guided drainage of pelvic and abdominal collections. Overdistension perforations of augmented urinary bladders have been reported, but few have described perforation from CISC.

Microfluidic vapor-diffusion barrier for pressure reduction in fully closed PCR modules

Microfluidic systems for polymerase chain reaction (PCR) should be fully closed to avoid vapor loss and to exclude the risk of contaminating the laboratory environment. In closed systems however, the high temperatures of up to 95 °C associated with PCR cause high overpressures up to 100 kPa, dominated by the increase of vapor partial pressure upon evaporation. Such high overpressures pose challenges to the mechanical stability of microfluidic chips as well as to the liquid handling in integrated sample-to-answer systems. In this work, we drastically reduce the pressure increase in fully closed PCR systems by integrating a microchannel that serves as a vapor-diffusion barrier (VDB), separating the liquid-filled PCR chamber from an auxiliary air chamber. In such configurations, propagation of vapor from the PCR chamber into the auxiliary air chamber and as a consequence the increase of pressure is limited by the slow diffusion process of vapor through the VDB. At temperature increase from 23 °C to 95 °C, we demonstrate the reduction of overpressure from more than 80 kPa without the VDB to only 35 kPa with the VDB. We further demonstrate proper function of VDB and its easy integration with downstream processes for PCR based nucleic acid amplification within centrifugal microfluidics. Without integration of the VDB, malfunction due to pressure-induced delamination of the microfluidic chip occurred.

Rapid and fully automated bacterial pathogen detection on a centrifugal-microfluidic LabDisk using highly sensitive nested PCR with integrated sample preparation

Diagnosis of infectious diseases suffers from long turnaround times for gold standard culture-based identification of bacterial pathogens, therefore impeding timely specific antimicrobial treatment based on laboratory evidence. Rapid molecular diagnostics-based technologies enable detection of microorganisms within hours however cumbersome workflows and complex equipment still prevent their widespread use in the routine clinical microbiology setting. We developed a centrifugal-microfluidic "LabDisk" system for rapid and highly-sensitive pathogen detection on a point-of-care analyser. The unit-use LabDisk with pre-stored reagents features fully automated and integrated DNA extraction, consensus multiplex PCR pre-amplification and geometrically-multiplexed species-specific real-time PCR. Processing merely requires loading of the sample and DNA extraction reagents with minimal hands-on time of approximately 5 min. We demonstrate detection of as few as 3 colony-forming-units (cfu) of Staphylococcus warneri, 200 cfu of Streptococcus agalactiae, 5 cfu of Escherichia coli and 2 cfu of Haemophilus influenzae in a 200 μL serum sample. The turnaround time of the complete analysis from "sample-to-result" was 3 h and 45 min. The LabDisk consequently provides an easy-to-use molecular diagnostic platform for rapid and highly-sensitive detection of bacterial pathogens without requiring major hands-on time and complex laboratory instrumentation.

Centrifugal microfluidic platforms: advanced unit operations and applications

Review on miniaturization, integration, and automation of laboratory processes within centrifugal microfluidic platforms. For efficient implementation of applications, building blocks are categorized into unit operations and process chains.

Magnetic chemiluminescent immunoassay for human C-reactive protein on the centrifugal microfluidics platform

Schematic of the LabDisk-based hCRP MCIA. The antibody-coated dynabeads are sequentially transported through the immunoassay buffers by magnetic actuation. Finally the chemiluminescence signal is acquired from a detection cavity.

Mobile phones in clinical practice: reducing the risk of bacterial contamination

BACKGROUND

Mobile smart phones have become increasingly integrated into the practice of doctors and allied medical professionals. Recent studies suggest them to represent reservoirs for pathogens with potential to cause nosocomial infections. This study aimed to investigate the level of contamination on phones used on surgical wards and identify strategies for their safe use within clinical areas.

METHODS

Fifty mobile phones were taken from members of the multidisciplinary team working in a surgical unit. Phones were swabbed by two trained investigators using a standardised technique and samples streaked out using an automated specimen inoculator onto two types of culture media (Columbia blood agar and MacConkey agar). Colonies were identified and counted by a single trained investigator in a blinded fashion. Simultaneously a questionnaire investigating usage levels of phones was given to 150 healthcare workers.

RESULTS

Sixty per cent of phones sampled had some form of contaminant isolated from their phone. Thirty-one (62%) of phones had only three colonies or less isolated on medium. No pathogenic or drug resistant strains of bacteria were identified. A total of 88% of individuals sampled by questionnaire used their phone within the workplace of which 55% used it for clinical purposes. Sixty-three per cent expected there to be some form of contaminant on their phone with only 37% admitting to cleaning it regularly. Seventy-five per cent of people did not view a ban on phones as a practical solution was they found to be an infection risk.

CONCLUSION

Touch screen smart phones may be used safely in a clinical environment, with a low risk of cross-contamination of nosocomial bacteria to patients, in the setting of effective adherence to hand hygiene policies.

Implementation of best medical therapy for cardiovascular risk factors in vascular surgery patients treated in a tertiary referral regional unit

OBJECTIVE

Current clinical evidence reports that antiplatelet, statin, angiotensin-converting enzyme inhibitor and beta blockade therapies have advantageous effects on vascular surgery patient morbidity and mortality. Unfortunately, such patients appear to be less likely to receive optimal medical management when compared with coronary artery disease patients. This study assessed medical therapy prescribing in patients attending a regional vascular surgery unit.

METHODS

A retrospective review between February 2010 and February 2011 was performed for patients undergoing aortic aneurysm, carotid, peripheral arterial and amputation surgeries. Gender, age, smoking history, body mass index and cardiovascular risk factors were documented from inpatient charts. Current admission medications and subsequent modification by the vascular team were recorded.

RESULTS

Two hundred and forty-four patients (male = 165, mean age = 71 years) were identified. Prevalence of hypertension, hypercholesterolaemia, myocardial infarction, angina, stroke and diabetes was higher than in the general population. A total of 201 (82.3%) patients were on antiplatelets or antithrombotics upon admission to the vascular ward, which was improved to 231 (94.6%) patients on discharge. A total of 180 (73.7%) patients were on lipid-lowering therapy upon admission, which was improved to 213 (87.2%) patients on discharge. A total of 115 (47.1%) patients were on ACE-inhibitor or angiotensin 2 receptor blocker medications on admission and this was improved to 118 (48.3%) upon discharge. A total of 87 (35.6%) patients were on a beta-blocker, which was improved to 93 (38.1%) patients upon discharge.

CONCLUSION

Despite increased implementation of best medical therapy in the community with compliance rates greater than 73% for aspirin and statin therapy, further improvement is warranted. Vascular surgeons should remain vigilant for further opportunities to optimise medical therapy in this high-risk patient group particularly with antithrombotic, lipid lowering and antihypertensive therapies.

Management of a patient with autism following ingestion of a foreign body

Patients with autism often find admission to hospital an anxious time. Awareness of the condition, a speedy diagnosis and flexibility in adapting treatment plans will facilitate early discharge and return to their familiar environment. We describe a patient with severe autism who presented with an acute abdomen secondary to ingestion of a foreign body which required laparotomy. Communication directly to medical staff was greatly limited due to severe autism and close liaison with family members was essential in interpreting scant clinical signs. At the time of surgery a rubber bottle teat was found causing transection of small bowel due to erosion of the foreign body. The postoperative course was fraught with challenges and ensuring side room nursing care with family members present throughout his admission minimised postoperative stress and confusion. We recommend awareness of management strategies for patients with autism to ensure rapid recovery and early discharge home.

Adrenal sarcomatoid carcinoma: a case report and review of the literature

Adrenocortical sarcomatoid carcinoma (ASC) is an extremely rare variant of adrenocortical carcinoma (ACC). Its relative rarity and its characteristic histological pattern of both epithelioid and sarcomatoid components may pose diagnostic challenges which influence treatment. Here, we report a case of ASC in a 58 year-old man presenting with increasing abdominal pain and associated abdominal bloating with a large right adrenal mass detected by computed tomographic scan (CT). To our knowledge, only eleven prior cases of ASC have been reported in the literature. Here, we discuss the clinical, radiological and histopathological findings in our case, review the literature on ASCs and offer opinion on best management.

Twenty-one bust: a case of chemical transformation of an ingested foreign body

The majority of ingested foreign bodies pass of their own accord without causing any adverse impact on the patient, while others present a greater management dilemma. We present a case of a 36-year-old man admitted to the hospital with a 10-day history of colicky abdominal pain following voluntary ingestion of multiple pairs of vinyl gloves. The plain-film abdominal X-ray confirmed small bowel obstruction and gastric bezoar. After failed conservative management he opted for endoscopic retrieval. Following exposure to stomach acid the gloves had lost their structural integrity becoming hard, sharp and brittle. As a result endoscopic removal was abandoned due to the risk of traumatic injury to the oesophagus. A midline laparotomy was performed and the gloves were retrieved via enterotomy. While many foreign bodies are suitable for endoscopic extraction this case demonstrates that the retrieval of vinyl gloves is unlikely to be successful due to significant chemical change.

Safety, adherence and acceptability of intermittent tenofovir/emtricitabine as HIV pre-exposure prophylaxis (PrEP) among HIV-uninfected Ugandan volunteers living in HIV-serodiscordant relationships: a randomized, clinical trial

Background

Efficacy of oral pre-exposure prophylaxis (PrEP) in prevention of HIV acquisition has been evaluated using a daily regimen. However, adherence to long term daily medication is rarely perfect. Intermittent regimen may be a feasible alternative. Preclinical studies have demonstrated effectiveness of intermittent PrEP in SHIV prevention among animals. However, little is known about intermittent PrEP regimens.

Design

Seventy two HIV-uninfected volunteers in HIV serodiscordant couple relationships in Uganda were randomly assigned to receive daily oral Tenofovir/Emtricitabine (TDF/FTC-Truvada) or placebo, or intermittent (Monday, Friday and within 2 hours after sex, not to exceed one dose per day) oral TDF/FTC or placebo in a 2:1:2:1 ratio. Volunteers and study staff were blinded to drug assignment, but not to regimen assignment.

Methods

Volunteers were followed for 4 months after randomization, with monthly clinical and laboratory safety assessments and comprehensive HIV risk reduction services. Adherence was monitored using medication event monitoring system (MEMS) and self-report. Sexual activity data were collected via daily short text message (SMS) and self-report. HIV-specific immune responses were assessed by IFN-γ ELISPOT.

Results

Both daily and intermittent oral TDF/FTC regimens were well tolerated. Median MEMS adherence rates were 98% (IQR: 93-100) for daily PrEP regimen, 91% (IQR: 73-97) for fixed intermittent dosing and 45% (IQR: 20-63) for post-coital dosing. SMS response rate was 74%, but increased to 80% after excluding server outages; results may have been affected by the novelty of this measure. The majority of volunteers expressed willingness with no particular preference for either regimen.

Conclusions

Both daily and intermittent oral PrEP dosing regimens were safe. Adherence was high for daily and fixed intermittent dosing; post-coital dosing was associated with poor adherence. Fixed intermittent PrEP regimens may be feasible especially if a minimum effective drug concentration correlating with HIV prevention can be achieved with this dosing.

Registration

Clinicaltrials.gov number NCT00931346

Radiological diagnosis of a small bowel perforation secondary to toothpick ingestion

A 77-year-old edentulous man presented to the accident and emergency department with a sudden onset of sharp right-sided abdominal pain. The patient reported a change in his bowel habit with constipation over a 6 month period but did not report any significant choking event or ingestion of a foreign body in the preceding months. On examination the patient was maximally tender with guarding over McBurneys point. CT scan showed an abnormal segment of distal ileum with a 3 cm high attenuation focus which had penetrated the bowel wall. At laparotomy the patient was found to have a perforation of his distal ileum caused by an ingested toothpick. Patients wearing dental plates or dentures are at higher risk of toothpick ingestion due to impaired palatal sensation. CT scanning, in the appropriate setting, may aid diagnosis and lower operator risk of sharp related injury at the time of operation.

Introducing Bayesian thinking to high-throughput screening for false-negative rate estimation

High-throughput screening (HTS) has been widely used to identify active compounds (hits) that bind to biological targets. Because of cost concerns, the comprehensive screening of millions of compounds is typically conducted without replication. Real hits that fail to exhibit measurable activity in the primary screen due to random experimental errors will be lost as false-negatives. Conceivably, the projected false-negative rate is a parameter that reflects screening quality. Furthermore, it can be used to guide the selection of optimal numbers of compounds for hit confirmation. Therefore, a method that predicts false-negative rates from the primary screening data is extremely valuable. In this article, we describe the implementation of a pilot screen on a representative fraction (1%) of the screening library in order to obtain information about assay variability as well as a preliminary hit activity distribution profile. Using this training data set, we then developed an algorithm based on Bayesian logic and Monte Carlo simulation to estimate the number of true active compounds and potential missed hits from the full library screen. We have applied this strategy to five screening projects. The results demonstrate that this method produces useful predictions on the numbers of false negatives.

Safety and adherence to intermittent pre-exposure prophylaxis (PrEP) for HIV-1 in African men who have sex with men and female sex workers

BACKGROUND

Little is known about safety of and adherence to intermittent HIV PrEP regimens, which may be more feasible than daily dosing in some settings. We present safety and adherence data from the first trial of an intermittent PrEP regimen among Kenyan men who have sex with men (MSM) and female sex workers (FSW).

METHODS/PRINCIPAL FINDINGS

MSM and FSW were randomized to daily oral FTC/TDF or placebo, or intermittent (Monday, Friday and within 2 hours after sex, not to exceed one dose per day) oral FTC/TDF or placebo in a 2:1:2:1 ratio; volunteers were followed monthly for 4 months. Adherence was assessed with the medication event monitoring system (MEMS). Sexual activity data were collected via daily text message (SMS) queries and timeline followback interviews with a one-month recall period. Sixty-seven men and 5 women were randomized into the study. Safety was similar among all groups. Median MEMS adherence rates were 83% [IQR: 63-92] for daily dosing and 55% [IQR:28-78] for fixed intermittent dosing (p = 0.003), while adherence to any post-coital doses was 26% [IQR:14-50]. SMS response rates were low, which may have impaired measurement of post-coital dosing adherence. Acceptability of PrEP was high, regardless of dosing regimen.

CONCLUSIONS/SIGNIFICANCE

Adherence to intermittent dosing regimens, fixed doses, and in particular coitally-dependent doses, may be more difficult than adherence to daily dosing. However, intermittent dosing may still be appropriate for PrEP if intracellular drug levels, which correlate with prevention of HIV acquisition, can be attained with less than daily dosing and if barriers to adherence can be addressed. Additional drug level data, qualitative data on adherence barriers, and better methods to measure sexual activity are necessary to determine whether adherence to post-coital PrEP could be comparable to more standard regimens.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00971230.

A simple statistical test to infer the causality of target/phenotype correlation from small molecule phenotypic screens

MOTIVATION

Cell-based phenotypic screens using small molecule inhibitors is an important technology for early drug discovery if the relationship between the disease-related cellular phenotype and inhibitors' biological targets can be determined. However, chemical inhibitors are rightfully believed to be less specific than perturbation by biological agents, such as antibody and small inference RNA. Therefore, it is often a challenge in small molecule phenotypic screening to infer the causality between a particular cellular phenotype and the inactivation of the responsible protein due to the off-target effect of the inhibitors.

RESULTS

In this article, we present a Roche in-house effort of screening 746 structurally diverse compounds for their cytotoxicity in HeLa cells measured by high content imaging technology. These compounds were also systematically profiled for the targeted and off-target binding affinity to a panel of 25 pre-selected protein kinases in a cell-free system. In an effort to search for the kinases whose activities are crucial for cell survival, we found that the simple association method such as the chi-square test yields a large number of false positives because the observed cytotoxic phenotype is likely to be the result of promiscuous action of less specific inhibitors instead of true consequence of inactivation of single relevant target. We demonstrated that a stratified categorical data analysis technique such as the Cochran-Mantel-Haenszel test is an effective approach to extract the meaningful biological connection from the spurious correlation resulted from confounding covariates. This study indicates that, empowered by appropriate statistical adjustment, small molecule inhibitor perturbation remains a powerful tool to pin down the relevant biomarker for drug safety and efficacy research.

CONTACT

xin.wei@roche.com

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

A qualitative assessment of perspectives on the inclusion of adolescents in HIV vaccine trials in South Africa

Adolescents are at high risk for HIV acquisition, and thus need to be included in HIV vaccine trials. In preparation for inclusion of adolescents in HIV vaccine trials in an urban community in Cape Town with a high antenatal HIV prevalence, the study assessed the attitudes towards the inclusion of adolescents in HIV vaccine trials. A total of 18 focus group discussions were conducted using a semistructured interview guide. The participants (n = 200) were adolescents, young adults, parents and other key informants. Participants from all groups welcomed the inclusion of adolescents in HIV vaccine trials due to their high-risk status. There were, however, concerns about sexual disinhibition, fear of side-effects, fear of HIV testing and disclosure of HIV status, mistrust of nurses and clinics. The study highlighted a number of ethical and social issues that need to be addressed before the trials.