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Gillian A. M. Tarr
Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, Minnesota; and

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infectious disease
Enteric pathogens

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Journal article
Published: 09 April 2021 in PEDIATRICS
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ACS Style

Gillian A. M. Tarr; Phillip I. Tarr. Pediatric Enteric Diagnostic Stewardship: The Right Test in the Right Context. PEDIATRICS 2021, 147, 1 .

AMA Style

Gillian A. M. Tarr, Phillip I. Tarr. Pediatric Enteric Diagnostic Stewardship: The Right Test in the Right Context. PEDIATRICS. 2021; 147 (5):1.

Chicago/Turabian Style

Gillian A. M. Tarr; Phillip I. Tarr. 2021. "Pediatric Enteric Diagnostic Stewardship: The Right Test in the Right Context." PEDIATRICS 147, no. 5: 1.

Journal article
Published: 04 January 2021 in The Journal of Pediatrics
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To assess the performance of a hemolytic uremic syndrome (HUS) severity score among children with Shiga toxin-producing Escherichia coli (STEC) infections and HUS by stratifying them according to their risk of adverse events. The score has not been previously evaluated in a North American acute care setting. We reviewed medical records of children 13 were designated as high-risk. We assessed score performance to predict severe adverse events (ie, dialysis, neurologic complication, respiratory failure, and death) using discrimination and net benefit (ie, threshold probability), with subgroup analyses by age and day-of-illness. A total of 167 children had HUS, of whom 92.8% (155/167) had relevant data to calculate the score; 60.6% (94/155) experienced a severe adverse event. Discrimination was acceptable overall (area under the curve 0.71, 95% CI 0.63-0.79) and better among children <5 years old (area under the curve 0.77, 95% CI 0.68-0.87). For children 26%. The HUS severity score was able to discriminate between high- and low-risk children <5 years old with STEC-associated HUS at a statistically acceptable level; however, it did not appear to provide clinical benefit at a meaningful risk threshold.

ACS Style

Chu Yang Lin; Jianling Xie; Stephen B. Freedman; Ryan S. McKee; David Schnadower; Phillip I. Tarr; Yaron Finkelstein; Neil M. Desai; Roni D. Lane; Kelly R. Bergmann; Ron L. Kaplan; Selena Hariharan; Andrea T. Cruz; Daniel M. Cohen; Andrew Dixon; Sriram Ramgopal; Elizabeth C. Powell; Jennifer Kilgar; Kenneth A. Michelson; Martin Bitzan; Kenneth Yen; Garth D. Meckler; Amy C. Plint; Fran Balamuth; Stuart Bradin; Serge Gouin; April J. Kam; James A. Meltzer; Tracy E. Hunley; Usha Avva; Robert Porter; Daniel M. Fein; Jeffrey P. Louie; Gillian A.M. Tarr; Annie Rominger; Darcy Beer; Christopher M. Pruitt; Thomas J. Abramo; Abigail Schuh; John T. Kanegaye; Nicholas E. Jones. Predicting Adverse Outcomes for Shiga Toxin–Producing Escherichia coli Infections in Emergency Departments. The Journal of Pediatrics 2021, 232, 200 -206.e4.

AMA Style

Chu Yang Lin, Jianling Xie, Stephen B. Freedman, Ryan S. McKee, David Schnadower, Phillip I. Tarr, Yaron Finkelstein, Neil M. Desai, Roni D. Lane, Kelly R. Bergmann, Ron L. Kaplan, Selena Hariharan, Andrea T. Cruz, Daniel M. Cohen, Andrew Dixon, Sriram Ramgopal, Elizabeth C. Powell, Jennifer Kilgar, Kenneth A. Michelson, Martin Bitzan, Kenneth Yen, Garth D. Meckler, Amy C. Plint, Fran Balamuth, Stuart Bradin, Serge Gouin, April J. Kam, James A. Meltzer, Tracy E. Hunley, Usha Avva, Robert Porter, Daniel M. Fein, Jeffrey P. Louie, Gillian A.M. Tarr, Annie Rominger, Darcy Beer, Christopher M. Pruitt, Thomas J. Abramo, Abigail Schuh, John T. Kanegaye, Nicholas E. Jones. Predicting Adverse Outcomes for Shiga Toxin–Producing Escherichia coli Infections in Emergency Departments. The Journal of Pediatrics. 2021; 232 ():200-206.e4.

Chicago/Turabian Style

Chu Yang Lin; Jianling Xie; Stephen B. Freedman; Ryan S. McKee; David Schnadower; Phillip I. Tarr; Yaron Finkelstein; Neil M. Desai; Roni D. Lane; Kelly R. Bergmann; Ron L. Kaplan; Selena Hariharan; Andrea T. Cruz; Daniel M. Cohen; Andrew Dixon; Sriram Ramgopal; Elizabeth C. Powell; Jennifer Kilgar; Kenneth A. Michelson; Martin Bitzan; Kenneth Yen; Garth D. Meckler; Amy C. Plint; Fran Balamuth; Stuart Bradin; Serge Gouin; April J. Kam; James A. Meltzer; Tracy E. Hunley; Usha Avva; Robert Porter; Daniel M. Fein; Jeffrey P. Louie; Gillian A.M. Tarr; Annie Rominger; Darcy Beer; Christopher M. Pruitt; Thomas J. Abramo; Abigail Schuh; John T. Kanegaye; Nicholas E. Jones. 2021. "Predicting Adverse Outcomes for Shiga Toxin–Producing Escherichia coli Infections in Emergency Departments." The Journal of Pediatrics 232, no. : 200-206.e4.

Journal article
Published: 16 November 2020 in Microorganisms
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Shiga toxin-producing Escherichia coli (STEC) are associated with acute gastroenteritis worldwide, which induces a high economic burden on both healthcare and individuals. Culture-independent diagnostic tests (CIDT) in frontline microbiology laboratories have been implemented in Alberta since 2019. The objectives of this study were to determine the association between gene detection and culture positivity over time using STEC microbiological clearance samples and also to establish the frequency of specimen submission. Both stx genes’ amplification by real-time PCR was performed with DNA extracted from stool samples using the easyMAG system. Stools were inoculated onto chromogenic agar for culture. An association between gene detection and culture positivity was found to be independent of which stx gene was present. CIDT can provide rapid reporting with less hands-on time and technical expertise. However, culture is still important for surveillance and early cluster detection. In addition, stool submissions could be reduced from daily to every 3–5 days until a sample is negative by culture.

ACS Style

Michael Bording-Jorgensen; Brendon D. Parsons; Gillian A.M. Tarr; Binal Shah-Gandhi; Colin Lloyd; Linda Chui. Association of Ct Values from Real-Time PCR with Culture in Microbiological Clearance Samples for Shiga Toxin-Producing Escherichiacoli (STEC). Microorganisms 2020, 8, 1801 .

AMA Style

Michael Bording-Jorgensen, Brendon D. Parsons, Gillian A.M. Tarr, Binal Shah-Gandhi, Colin Lloyd, Linda Chui. Association of Ct Values from Real-Time PCR with Culture in Microbiological Clearance Samples for Shiga Toxin-Producing Escherichiacoli (STEC). Microorganisms. 2020; 8 (11):1801.

Chicago/Turabian Style

Michael Bording-Jorgensen; Brendon D. Parsons; Gillian A.M. Tarr; Binal Shah-Gandhi; Colin Lloyd; Linda Chui. 2020. "Association of Ct Values from Real-Time PCR with Culture in Microbiological Clearance Samples for Shiga Toxin-Producing Escherichiacoli (STEC)." Microorganisms 8, no. 11: 1801.

Journal article
Published: 29 September 2020 in One Health
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Hemolytic uremic syndrome (HUS) is a life-threatening complication of Shiga toxin-producing Escherichia coli (STEC) infection. The relationship between STEC exposure and severity of clinical outcomes is not well documented. We examined whether direct contact with farm animals increased the likelihood of HUS among Indiana residents diagnosed with STEC. Exposure data for laboratory-confirmed STEC cases among Indiana residents during 2012–2018 were retrieved. Logistic regression and mediation analysis were performed to determine the extent to which a history of direct contact with farm animals was associated with post-diarrheal HUS independent of age and mediated by stx2 gene presence. A total of 784 STEC cases were retrieved. Of these, 46 (6%) developed HUS. Complete exposure data were available for 600 (77%) cases. A total of 24 (52%) HUS patients reported direct contact with farm animals, while 114 (21%) STEC patients who did not develop HUS reported this exposure. Among all STEC cases, HUS was associated with direct farm animal contact after adjusting for age (OR = 3.40, 95% CI: 1.81, 6.40). Detection of stx2 genes mediated 12% of the association between farm animal contact and HUS. Direct farm animal contact was a risk factor for development of HUS among laboratory-confirmed STEC cases, independent of stx2 presence. Direct farm animal contact should be considered a potential predictor of progression to HUS when patients present for care and the mechanism for its effect on virulence investigated.

ACS Style

Madhura S. Vachon; Myda Khalid; Gillian A.M. Tarr; Craig Hedberg; Jennifer A. Brown. Farm animal contact is associated with progression to Hemolytic uremic syndrome in patients with Shiga toxin-producing Escherichia coli — Indiana, 2012–2018. One Health 2020, 11, 100175 .

AMA Style

Madhura S. Vachon, Myda Khalid, Gillian A.M. Tarr, Craig Hedberg, Jennifer A. Brown. Farm animal contact is associated with progression to Hemolytic uremic syndrome in patients with Shiga toxin-producing Escherichia coli — Indiana, 2012–2018. One Health. 2020; 11 ():100175.

Chicago/Turabian Style

Madhura S. Vachon; Myda Khalid; Gillian A.M. Tarr; Craig Hedberg; Jennifer A. Brown. 2020. "Farm animal contact is associated with progression to Hemolytic uremic syndrome in patients with Shiga toxin-producing Escherichia coli — Indiana, 2012–2018." One Health 11, no. : 100175.

Accepted manuscript
Published: 02 July 2020 in Journal of Infectious Diseases
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Background Norovirus is a leading cause of acute gastroenteritis. With vaccines in development, population-based estimates of norovirus burden are needed to identify target populations, quantify potential benefits, and understand disease dynamics. Methods We estimated the attributable fraction (AF) for norovirus infections in children, defined as the proportion of children testing positive for norovirus whose gastroenteritis was attributable to norovirus. We calculated the standardized incidence and emergency department (ED) visit rates attributable to norovirus using provincial gastroenteritis visit administrative data. Results From 3731 gastroenteritis case patients and 2135 controls we determined that the AFs were 67.0% (95% confidence interval [CI], 31.5%–100%) and 91.6% (88.8%–94.4%) for norovirus genogroups I (GI) and II (GII), respectively. Norovirus GII AF varied by season but not age. We attributed 116 episodes (95% CI, 103–129) and 59 (51–67) ED visits per 10 000 child-years to norovirus GII across all ages, accounting for 20% and 18% of all medically attended gastroenteritis episodes and ED visits, respectively. Conclusions In children, a large proportion of norovirus GII detections reflect causation, demonstrating significant potential for norovirus GII vaccines. Seasonal variation in the norovirus GII AF may have implications for understanding the role asymptomatic carriage plays in disease dynamics.

ACS Style

Gillian A M Tarr; Xiao-Li Pang; Ran Zhuo; Bonita E Lee; Linda Chui; Samina Ali; Otto G Vanderkooi; Christine Michaels-Igbokwe; Phillip I Tarr; Shannon E MacDonald; Gillian Currie; Judy MacDonald; Kelly Kim; Stephen B Freedman. Attribution of Pediatric Acute Gastroenteritis Episodes and Emergency Department Visits to Norovirus Genogroups I and II. Journal of Infectious Diseases 2020, 223, 452 -461.

AMA Style

Gillian A M Tarr, Xiao-Li Pang, Ran Zhuo, Bonita E Lee, Linda Chui, Samina Ali, Otto G Vanderkooi, Christine Michaels-Igbokwe, Phillip I Tarr, Shannon E MacDonald, Gillian Currie, Judy MacDonald, Kelly Kim, Stephen B Freedman. Attribution of Pediatric Acute Gastroenteritis Episodes and Emergency Department Visits to Norovirus Genogroups I and II. Journal of Infectious Diseases. 2020; 223 (3):452-461.

Chicago/Turabian Style

Gillian A M Tarr; Xiao-Li Pang; Ran Zhuo; Bonita E Lee; Linda Chui; Samina Ali; Otto G Vanderkooi; Christine Michaels-Igbokwe; Phillip I Tarr; Shannon E MacDonald; Gillian Currie; Judy MacDonald; Kelly Kim; Stephen B Freedman. 2020. "Attribution of Pediatric Acute Gastroenteritis Episodes and Emergency Department Visits to Norovirus Genogroups I and II." Journal of Infectious Diseases 223, no. 3: 452-461.

Review
Published: 29 January 2020 in Clinical Chemistry
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Background Rapid detection of Shiga toxin–producing Escherichia coli (STEC) enables appropriate monitoring and treatment. We synthesized available evidence to compare the performance of enzyme immunoassay (EIA) and PCR tests for the detection of STEC. Methods We searched published and gray literature for studies of STEC EIA and/or PCR diagnostic test accuracy relative to reference standards including at least one nucleic acid amplification test. Two reviewers independently screened studies, extracted data, and assessed quality with the second version of the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Bivariate random effects models were used to meta-analyze the clinical sensitivity and specificity of commercial EIA and PCR STEC diagnostic tests, and summary receiver operator characteristic curves were constructed. We evaluated the certainty of evidence with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Results We identified 43 articles reflecting 25 260 specimens. Meta-analysis of EIA and PCR accuracy included 25 and 22 articles, respectively. STEC EIA pooled sensitivity and specificity were 0.681 (95% CI, 0.571–0.773; very low certainty of evidence) and 1.00 (95% CI, 0.998–1.00; moderate certainty of evidence), respectively. STEC PCR pooled sensitivity and specificity were 1.00 (95% CI, 0.904–1.00; low certainty of evidence) and 0.999 (95% CI, 0.997–0.999; low certainty of evidence), respectively. Certainty of evidence was downgraded because of high risk of bias. Conclusions PCR tests to identify the presence of STEC are more sensitive than EIA tests, with no meaningful loss of specificity. However, given the low certainty of evidence, our results may overestimate the difference in performance.

ACS Style

Gillian A M Tarr; Chu Yang Lin; Ben VanderMeer; Diane L Lorenzetti; Phillip I Tarr; Linda Chui; Lisa Hartling; Stephen Freedman. Diagnostic Test Accuracy of Commercial Tests for Detection of Shiga Toxin–Producing Escherichia coli: A Systematic Review and Meta-Analysis. Clinical Chemistry 2020, 66, 302 -315.

AMA Style

Gillian A M Tarr, Chu Yang Lin, Ben VanderMeer, Diane L Lorenzetti, Phillip I Tarr, Linda Chui, Lisa Hartling, Stephen Freedman. Diagnostic Test Accuracy of Commercial Tests for Detection of Shiga Toxin–Producing Escherichia coli: A Systematic Review and Meta-Analysis. Clinical Chemistry. 2020; 66 (2):302-315.

Chicago/Turabian Style

Gillian A M Tarr; Chu Yang Lin; Ben VanderMeer; Diane L Lorenzetti; Phillip I Tarr; Linda Chui; Lisa Hartling; Stephen Freedman. 2020. "Diagnostic Test Accuracy of Commercial Tests for Detection of Shiga Toxin–Producing Escherichia coli: A Systematic Review and Meta-Analysis." Clinical Chemistry 66, no. 2: 302-315.

Journal article
Published: 18 October 2019 in Toxins
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Escherichia coli O157:H7 is the predominant cause of diarrhea-associated hemolytic uremic syndrome (HUS) worldwide. Its cardinal virulence traits are Shiga toxins, which are encoded by stx genes, the most common of which are stx1a, stx2a, and stx2c. The toxins these genes encode differ in their in vitro and experimental phenotypes, but the human population-level impact of these differences is poorly understood. Using Shiga toxin-encoding bacteriophage insertion typing and real-time polymerase chain reaction, we genotyped isolates from 936 E. coli O157:H7 cases and verified HUS status via chart review. We compared the HUS risk between isolates with stx2a and those with stx2a and another gene and estimated additive interaction of the stx genes. Adjusted for age and symptoms, the HUS incidence of E. coli O157:H7 containing stx2a alone was 4.4% greater (95% confidence interval (CI) -0.3%, 9.1%) than when it occurred with stx1a. When stx1a and stx2a occur together, the risk of HUS was 27.1% lower (95% CI -87.8%, -2.3%) than would be expected if interaction were not present. At the population level, temporal or geographic shifts toward these genotypes should be monitored, and stx genotype may be an important consideration in clinically predicting HUS among E. coli O157:H7 cases.

ACS Style

Gillian A.M. Tarr; Taryn Stokowski; Smriti Shringi; Phillip I. Tarr; Stephen B. Freedman; Hanna N. Oltean; Peter M. Rabinowitz; Linda Chui. Contribution and Interaction of Shiga Toxin Genes to Escherichia coli O157:H7 Virulence. Toxins 2019, 11, 607 .

AMA Style

Gillian A.M. Tarr, Taryn Stokowski, Smriti Shringi, Phillip I. Tarr, Stephen B. Freedman, Hanna N. Oltean, Peter M. Rabinowitz, Linda Chui. Contribution and Interaction of Shiga Toxin Genes to Escherichia coli O157:H7 Virulence. Toxins. 2019; 11 (10):607.

Chicago/Turabian Style

Gillian A.M. Tarr; Taryn Stokowski; Smriti Shringi; Phillip I. Tarr; Stephen B. Freedman; Hanna N. Oltean; Peter M. Rabinowitz; Linda Chui. 2019. "Contribution and Interaction of Shiga Toxin Genes to Escherichia coli O157:H7 Virulence." Toxins 11, no. 10: 607.

Journal article
Published: 03 September 2019 in Clinical Microbiology and Infection
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In this issue of Clinical Microbiology and Infection, Tilmanne et al. [1x[1]Tilmanne, A., Martiny, D., Quach, C., Wautier, M., Vandenberg, O., Lepage, P. et al. Enteropathogens in pediatric gastroenteritis: comparison of routine diagnostic methods to molecular ones. Clin Microbiol Infect. 2019; ([in this issue])Google ScholarSee all References][1] add to the growing body of literature comparing commercial molecular diagnostic testing platforms to conventional laboratory approaches for children with acute gastroenteritis. We commend the authors for highlighting the important issues of co-detection of definite or plausible pathogens in children with gastroenteritis and the high prevalence of such agents in controls without diarrhoea. They report, as have others, that molecular diagnostics detect enteric pathogens in more patients than do older methods (i.e. culture, microscopy and enzyme immunoassay (EIA)) [2x[2]Harrington, S.M., Buchan, B.W., Doern, C., Fader, R., Ferraro, M.J., Pillai, D.R. et al. Multicenter evaluation of the BD max enteric bacterial panel PCR assay for rapid detection of Salmonella spp., Shigella spp., Campylobacter spp. (C. jejuni and C. coli), and Shiga toxin 1 and 2 genes. J Clin Microbiol. 2015; 53: 1639–1647Crossref | PubMed | Scopus (36) | Google ScholarSee all References, 3x[3]Buchan, B.W., Olson, W.J., Pezewski, M., Marcon, M.J., Novicki, T., Uphoff, T.S. et al. Clinical evaluation of a real-time PCR assay for identification of Salmonella, Shigella, Campylobacter (Campylobacter jejuni and C. coli), and Shiga toxin-producing Escherichia coli isolates in stool specimens. J Clin Microbiol. 2013; 51: 4001–4007Crossref | PubMed | Scopus (38) | Google ScholarSee all References, 4x[4]Deng, J., Luo, X., Wang, R., Jiang, L., Ding, X., Hao, W. et al. A comparison of Luminex xTAG(R) Gastrointestinal Pathogen Panel (xTAG GPP) and routine tests for the detection of enteropathogens circulating in Southern China. Diagn Microbiol Infect Dis. 2015; 83: 325–330Crossref | PubMed | Scopus (20) | Google ScholarSee all References]. While increased sensitivity is intuitively appealing because it allows expanded attribution of illness to specific agents, thereby potentially providing diagnostic clarity, such expanded detection also poses important challenges. To advance our understanding of these issues, we believe clinical interpretation and professional guidance should focus on three questions.

ACS Style

G.A.M. Tarr; P.I. Tarr; Stephen Freedman. Clinical interpretation of enteric molecular diagnostic tests. Clinical Microbiology and Infection 2019, 25, 1454 -1456.

AMA Style

G.A.M. Tarr, P.I. Tarr, Stephen Freedman. Clinical interpretation of enteric molecular diagnostic tests. Clinical Microbiology and Infection. 2019; 25 (12):1454-1456.

Chicago/Turabian Style

G.A.M. Tarr; P.I. Tarr; Stephen Freedman. 2019. "Clinical interpretation of enteric molecular diagnostic tests." Clinical Microbiology and Infection 25, no. 12: 1454-1456.

Journal article
Published: 01 June 2019 in Journal of Clinical Microbiology
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Data are lacking regarding the impact of visible pigment on rectal swab diagnostic accuracy. We describe the test characteristics of rectal swabs with and without pigment in children with gastroenteritis.

ACS Style

Jianling Xie; Gillian A. M. Tarr; Samina Ali; Linda Chui; Xiao-Li Pang; Bonita E. Lee; Otto G. Vanderkooi; Phillip I. Tarr; Ran Zhuo; Brendon Parsons; Byron M. Berenger; Kelly Kim; Stephen B. Freedman. Pigment Visibility on Rectal Swabs Used To Detect Enteropathogens: a Prospective Cohort Study. Journal of Clinical Microbiology 2019, 57, 1 .

AMA Style

Jianling Xie, Gillian A. M. Tarr, Samina Ali, Linda Chui, Xiao-Li Pang, Bonita E. Lee, Otto G. Vanderkooi, Phillip I. Tarr, Ran Zhuo, Brendon Parsons, Byron M. Berenger, Kelly Kim, Stephen B. Freedman. Pigment Visibility on Rectal Swabs Used To Detect Enteropathogens: a Prospective Cohort Study. Journal of Clinical Microbiology. 2019; 57 (6):1.

Chicago/Turabian Style

Jianling Xie; Gillian A. M. Tarr; Samina Ali; Linda Chui; Xiao-Li Pang; Bonita E. Lee; Otto G. Vanderkooi; Phillip I. Tarr; Ran Zhuo; Brendon Parsons; Byron M. Berenger; Kelly Kim; Stephen B. Freedman. 2019. "Pigment Visibility on Rectal Swabs Used To Detect Enteropathogens: a Prospective Cohort Study." Journal of Clinical Microbiology 57, no. 6: 1.

Review
Published: 07 March 2019 in BMJ Open
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IntroductionRapid detection of Shiga toxin-producingEscherichia coli(STEC) enables appropriate treatment. Numerous commercially available molecular tests exist, but they vary in clinical performance. This systematic review aims to synthesise available evidence to compare the clinical performance of enzyme immunoassay (EIA) and nucleic acid amplification tests (NAATs) for the detection of STEC.Methods and analysisThe following databases will be searched employing a standardised search strategy: Medline, Embase, Cochrane CENTRAL Register of Controlled Trials, Cochrane Database of Systematic Reviews, PubMed, Scopus and Web of Science. Grey literature will be searched under advice from a medical librarian. Independent reviewers will screen titles, abstracts and full texts of retrieved studies for relevant studies. Data will be extracted independently by two reviewers, using a piloted template. Quality Assessment of Diagnostic Accuracy Studies-2 will be employed to assess the risk of bias of individual studies, and the quality of evidence will be assessed with the Grading of Recommendations Assessment, Development and Evaluation approach. A bivariate random-effects model will be used to meta-analyse the sensitivity and specificity of commercial STEC diagnostic tests, and a hierarchical summary receiver operator characteristic curve will be constructed. Studies of single test accuracy of EIA and NAATs and studies of comparative accuracy will be analysed separately.Ethics and disseminationEthics approval was not required for this systematic review and meta-analysis. Findings will be disseminated in conferences, through a peer-reviewed journal and via personal interactions with relevant stakeholders.PROSPERO registration numberCRD42018099119.

ACS Style

Gillian Tarr; Chu Yang Lin; Diane Lorenzetti; Linda Chui; Phillip I Tarr; Lisa Hartling; Ben VanderMeer; Stephen Freedman. Performance of commercial tests for molecular detection of Shiga toxin-producingEscherichia coli(STEC): a systematic review and meta-analysis protocol. BMJ Open 2019, 9, e025950 .

AMA Style

Gillian Tarr, Chu Yang Lin, Diane Lorenzetti, Linda Chui, Phillip I Tarr, Lisa Hartling, Ben VanderMeer, Stephen Freedman. Performance of commercial tests for molecular detection of Shiga toxin-producingEscherichia coli(STEC): a systematic review and meta-analysis protocol. BMJ Open. 2019; 9 (3):e025950.

Chicago/Turabian Style

Gillian Tarr; Chu Yang Lin; Diane Lorenzetti; Linda Chui; Phillip I Tarr; Lisa Hartling; Ben VanderMeer; Stephen Freedman. 2019. "Performance of commercial tests for molecular detection of Shiga toxin-producingEscherichia coli(STEC): a systematic review and meta-analysis protocol." BMJ Open 9, no. 3: e025950.

Journal article
Published: 04 December 2018 in Clinical Infectious Diseases
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Background The ability to identify bacterial pathogens that necessitate specific clinical management or public health action in children with acute gastroenteritis is crucial to patient care and public health. However, existing stool-testing guidelines offer inconsistent recommendations, and their performance characteristics are unknown. We evaluated 6 leading gastroenteritis guidelines (eg, those of the Centers for Disease Control and Prevention and Infectious Disease Society of America) that recommend when to test children’s stool for bacterial enteropathogens. Methods Via 2 emergency departments in Alberta, Canada, we enrolled 2447 children <18 years old who presented with ≥3 episodes of diarrhea and/or vomiting in a 24-hour period. All participants were tested for 9 bacterial enteropathogens: Aeromonas, Campylobacter, Escherichia coli O157, other Shiga toxin–producing E. coli, enterotoxigenic E. coli, Salmonella, Shigella, Vibrio, and Yersinia. Patient data gathered at the index visit were used to determine whether guidelines would recommend testing. Sensitivity and specificity to recommend testing for children with bacterial enteropathogens were calculated for each guideline. Results Outcome data were available for 2391 (97.7%) participants, and 6% (144/2391) of participants tested positive for a bacterial enteropathogen. Guideline sensitivity ranged from 25.8% (95% confidence interval [CI] 18.7–33.0%) to 66.9% (95% CI 59.3–74.6%), and varied for individual pathogens. Guideline specificity for all bacterial enteropathogens ranged from 63.6% (95% CI 61.6–65.6%) to 96.5% (95% CI 95.7–97.2%). Conclusions No guideline provided optimally balanced performance. The most sensitive guidelines missed one-third of cases and would drastically increase testing volumes. The most specific guidelines missed almost 75% of cases.

ACS Style

Gillian A M Tarr; Linda Chui; Bonita E Lee; Xiao-Li Pang; Samina Ali; Alberto Nettel-Aguirre; Otto G Vanderkooi; Byron M Berenger; James Dickinson; Phillip I Tarr; Steven Drews; Judy MacDonald; Kelly Kim; Stephen Freedman. Performance of Stool-testing Recommendations for Acute Gastroenteritis When Used to Identify Children With 9 Potential Bacterial Enteropathogens. Clinical Infectious Diseases 2018, 69, 1173 -1182.

AMA Style

Gillian A M Tarr, Linda Chui, Bonita E Lee, Xiao-Li Pang, Samina Ali, Alberto Nettel-Aguirre, Otto G Vanderkooi, Byron M Berenger, James Dickinson, Phillip I Tarr, Steven Drews, Judy MacDonald, Kelly Kim, Stephen Freedman. Performance of Stool-testing Recommendations for Acute Gastroenteritis When Used to Identify Children With 9 Potential Bacterial Enteropathogens. Clinical Infectious Diseases. 2018; 69 (7):1173-1182.

Chicago/Turabian Style

Gillian A M Tarr; Linda Chui; Bonita E Lee; Xiao-Li Pang; Samina Ali; Alberto Nettel-Aguirre; Otto G Vanderkooi; Byron M Berenger; James Dickinson; Phillip I Tarr; Steven Drews; Judy MacDonald; Kelly Kim; Stephen Freedman. 2018. "Performance of Stool-testing Recommendations for Acute Gastroenteritis When Used to Identify Children With 9 Potential Bacterial Enteropathogens." Clinical Infectious Diseases 69, no. 7: 1173-1182.

Journal article
Published: 10 October 2018 in International Journal of Medical Microbiology
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Multiple case definitions for post-diarrheal hemolytic uremic syndrome (D + HUS) associated with Shiga toxin-producing Escherichia coli (STEC) are used across public health, research, and clinical practice. To identify a single definition of D + HUS for standardized use, we evaluated the comparability and validity of four common, heterogeneous definitions: the Council of State and Territorial Epidemiologists (CSTE) definition, hematology-focused and age-focused definitions from the literature, and hospital diagnosis. We reviewed medical records from 471 hospitalized E. coli O157:H7 cases reported in Washington State, 2005-2014. We assessed 1) reliability across definitions, 2) comparability of temporal trends, and 3) sensitivity and specificity using an omnibus reference standard, developed using a combination of definition agreement and clinical outcomes. With the standard, we classified cases as definite, borderline, or unlikely/not post-diarrheal D + HUS. Reliability was highest between the age-focused definition and hospital diagnosis (κ = 0.84), and temporal trends were largely comparable across definitions. For definite D + HUS cases, the age-focused definition had the highest overall validity [100% sensitivity, 95% confidence interval (CI): 94%, 100%; 96% specificity, 95% CI: 94%, 98%]. The CSTE definition had low specificity (75%, 95% CI: 70%, 79%). In this review, the CSTE definition overestimated the burden of D + HUS, and the age-focused definition provided the best overall reliability and validity to define post-diarrheal D + HUS. Disease monitoring and research activities should consider using the age-focused D + HUS definition.

ACS Style

Gillian A.M. Tarr; Hanna N. Oltean; Amanda I. Phipps; Peter Rabinowitz; Phillip I. Tarr. Case definitions of hemolytic uremic syndrome following Escherichia coli O157:H7 infection vary in validity. International Journal of Medical Microbiology 2018, 308, 1121 -1127.

AMA Style

Gillian A.M. Tarr, Hanna N. Oltean, Amanda I. Phipps, Peter Rabinowitz, Phillip I. Tarr. Case definitions of hemolytic uremic syndrome following Escherichia coli O157:H7 infection vary in validity. International Journal of Medical Microbiology. 2018; 308 (8):1121-1127.

Chicago/Turabian Style

Gillian A.M. Tarr; Hanna N. Oltean; Amanda I. Phipps; Peter Rabinowitz; Phillip I. Tarr. 2018. "Case definitions of hemolytic uremic syndrome following Escherichia coli O157:H7 infection vary in validity." International Journal of Medical Microbiology 308, no. 8: 1121-1127.

Journal article
Published: 01 October 2018 in International Journal of Medical Microbiology
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The veracity of the association between antibiotic use and hemolytic uremic syndrome (HUS) caused by Escherichia coli O157:H7 has been a topic of debate. We postulated that criteria used to define HUS affect this association. We reviewed 471 hospitalized E. coli O157:H7 cases reported in Washington State, 2005–2014, to determine HUS status by various case definitions and antibiotic treatment. We used age-adjusted logistic regression models to estimate the effect of treatment on HUS status according to four common, but heterogeneous, definitions: the Council of State and Territorial Epidemiologists (CSTE) definition, hematology-focused and age-focused definitions from the literature, and hospital diagnosis. Inter-annual variation in antibiotic use was high, but no meaningful change in antibiotic use was observed over this ten-year period. Thirteen percent of cases <18 years-old received antibiotics, compared to 54% of cases ≥18 years-old. The CSTE, hematology-focused, age-focused, and hospital diagnosis definitions identified 149, 57, 74, and 89 cases of HUS, respectively. The association between antibiotic treatment and HUS varied by definition: CSTE odds ratio (OR) 1.57 [95% confidence interval (CI) 0.98, 2.55]; hematology-focused OR 1.73 (95% CI 0.83, 3.54); age-focused OR 2.29 (95% CI 1.20, 4.39); and hospital diagnosis OR 1.94 (95% CI 1.01, 3.72). Each definition yielded an estimate of the association in the direction of increased risk of HUS with antibiotics. While the range of OR point estimates was relatively small, confidence intervals for two HUS definitions crossed the null and two did not, potentially altering the inference an investigator makes. Discrepant reports of the association between antibiotic use and HUS in the literature might be due in part to the choice of HUS definition, and a consistent definition of HUS should be adopted for research and public health purposes.

ACS Style

Gillian A.M. Tarr; Hanna N. Oltean; Amanda I. Phipps; Peter Rabinowitz; Phillip I. Tarr. Strength of the association between antibiotic use and hemolytic uremic syndrome following Escherichia coli O157:H7 infection varies with case definition. International Journal of Medical Microbiology 2018, 308, 921 -926.

AMA Style

Gillian A.M. Tarr, Hanna N. Oltean, Amanda I. Phipps, Peter Rabinowitz, Phillip I. Tarr. Strength of the association between antibiotic use and hemolytic uremic syndrome following Escherichia coli O157:H7 infection varies with case definition. International Journal of Medical Microbiology. 2018; 308 (7):921-926.

Chicago/Turabian Style

Gillian A.M. Tarr; Hanna N. Oltean; Amanda I. Phipps; Peter Rabinowitz; Phillip I. Tarr. 2018. "Strength of the association between antibiotic use and hemolytic uremic syndrome following Escherichia coli O157:H7 infection varies with case definition." International Journal of Medical Microbiology 308, no. 7: 921-926.

Journal article
Published: 11 September 2018 in International Journal of Population Data Science
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IntroductionAcute gastroenteritis (AGE) is a major cause of morbidity in children. While viruses are known to cause the largest proportion of illnesses, slow adoption of new technology and recommendations against routine testing have blunted our ability to estimate the impact of viral AGE on the health system. Objectives and ApproachOur objective was to quantify the incidence of medically-attended norovirus and other viral AGE etiologic agents as a baseline for future norovirus vaccination programs. AGE cases were identified through the Alberta Provincial Pediatric EnTeric Infection TEam (APPETITE) study, December 2014-December 2017, which tested participants for five viruses: rotavirus, norovirus, adenovirus, astrovirus, and sapovirus. Study data was linked to provincial health registry data to identify visits associated with the AGE episode. Comparable visits for children throughout the province were identified, and a comprehensive set of potential confounders was evaluated and used to standardize APPETITE rates to the Alberta population. ResultsAPPETITE received and tested specimens from 2,358 children with AGE presenting to the emergency department (ED) for care and 513 children with AGE whose parent or guardian called the provincial health advice line Health Link (HL). Norovirus was the most commonly detected pathogen, associated with 579 (24%) ED cases and 177 (19%) HL cases. After norovirus, the most common viruses were, in descending order: adenovirus (441 ED, 97 HL), rotavirus (408 ED, 88 HL), sapovirus (211 ED, 68 HL), and astrovirus (75 ED, 21 HL). Results for the incidence of viral AGE by etiologic agent, with the associated number of hospitalizations, ED visits, and primary care visits, will be available by the date of the IPDLN conference. Conclusion/ImplicationsBy linking data from APPETITE with the visit data available because of Alberta’s single-payer system, we are able to provide population-based estimates of disease incidence for viral AGE, as well as the burden on the health care system in terms of the number of visits associated with these viral illnesses.

ACS Style

Gillian Am Tarr; Stephen Freedman. Linking Provincial and Prospective Cohort Study Data to Estimate the Incidence and Healthcare Burden of Viral Gastroenteritis. International Journal of Population Data Science 2018, 3, 1 .

AMA Style

Gillian Am Tarr, Stephen Freedman. Linking Provincial and Prospective Cohort Study Data to Estimate the Incidence and Healthcare Burden of Viral Gastroenteritis. International Journal of Population Data Science. 2018; 3 (4):1.

Chicago/Turabian Style

Gillian Am Tarr; Stephen Freedman. 2018. "Linking Provincial and Prospective Cohort Study Data to Estimate the Incidence and Healthcare Burden of Viral Gastroenteritis." International Journal of Population Data Science 3, no. 4: 1.

Journal article
Published: 19 June 2018 in Epidemiology and Infection
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Escherichia coliO157:H7 is the largest cause of hemolytic uremic syndrome (HUS). Previous studies proposed that HUS risk varies across theE. coliO157:H7 phylogenetic tree (hypervirulent clade 8), but the role of age in the association is unknown. We determined phylogenetic lineage ofE. coliO157:H7 isolates from 1160 culture-confirmedE. coliO157:H7 cases reported in Washington State, 2004–2015. Using generalised estimating equations, we tested the association between phylogenetic lineage and HUS. Age was evaluated as an effect modifier. Among 1082E. coliO157:H7 cases with both phylogenetic lineage and HUS status (HUSn= 76), stratified analysis suggested effect modification by age. Lineages IIa and IIb, relative to Ib, did not appear associated with HUS in children 0–9-years-old. For cases 10–59-years-old, lineages IIa and IIb appeared to confer increased risk of HUS, relative to lineage Ib. The association reversed in ⩾60-year-olds. Results were similar for clade 8. Phylogenetic lineage appears to be associated with HUS risk only among those ⩾10-years-old. Among children

ACS Style

G. A. M. Tarr; S. Shringi; H. N. Oltean; J. Mayer; P. Rabinowitz; J. Wakefield; P. I. Tarr; T. E. Besser; A. I. Phipps. Importance of case age in the purported association between phylogenetics and hemolytic uremic syndrome inEscherichia coliO157:H7 infections. Epidemiology and Infection 2018, 146, 1550 -1555.

AMA Style

G. A. M. Tarr, S. Shringi, H. N. Oltean, J. Mayer, P. Rabinowitz, J. Wakefield, P. I. Tarr, T. E. Besser, A. I. Phipps. Importance of case age in the purported association between phylogenetics and hemolytic uremic syndrome inEscherichia coliO157:H7 infections. Epidemiology and Infection. 2018; 146 (12):1550-1555.

Chicago/Turabian Style

G. A. M. Tarr; S. Shringi; H. N. Oltean; J. Mayer; P. Rabinowitz; J. Wakefield; P. I. Tarr; T. E. Besser; A. I. Phipps. 2018. "Importance of case age in the purported association between phylogenetics and hemolytic uremic syndrome inEscherichia coliO157:H7 infections." Epidemiology and Infection 146, no. 12: 1550-1555.

Journal article
Published: 01 January 2018 in Emerging Infectious Diseases
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The often-noted and persistent increased incidence of Escherichia coli O157:H7 infections in rural areas is not well understood. We used a cohort of E. coli O157:H7 cases reported in Washington, USA, during 2005–2014, along with phylogenomic characterization of the infecting isolates, to identify geographic segregation of and temporal trends in specific phylogenetic lineages of E. coli O157:H7. Kernel estimation and generalized additive models demonstrated that pathogen lineages were spatially segregated during the period of analysis and identified a focus of segregation spanning multiple, predominantly rural, counties for each of the main clinical lineages, Ib, IIa, and IIb. These results suggest the existence of local reservoirs from which humans are infected. We also noted a secular increase in the proportion of lineage IIa and IIb isolates. Spatial segregation by phylogenetic lineage offers the potential to identify local reservoirs and intervene to prevent continued transmission.

ACS Style

Gillian A.M. Tarr; Smriti Shringi; Amanda I. Phipps; Thomas E. Besser; Jonathan Mayer; Hanna N. Oltean; Jon Wakefield; Phillip I. Tarr; Peter Rabinowitz. Geogenomic Segregation and Temporal Trends of Human Pathogenic Escherichia coli O157:H7, Washington, USA, 2005–20141. Emerging Infectious Diseases 2018, 24, 32 -39.

AMA Style

Gillian A.M. Tarr, Smriti Shringi, Amanda I. Phipps, Thomas E. Besser, Jonathan Mayer, Hanna N. Oltean, Jon Wakefield, Phillip I. Tarr, Peter Rabinowitz. Geogenomic Segregation and Temporal Trends of Human Pathogenic Escherichia coli O157:H7, Washington, USA, 2005–20141. Emerging Infectious Diseases. 2018; 24 (1):32-39.

Chicago/Turabian Style

Gillian A.M. Tarr; Smriti Shringi; Amanda I. Phipps; Thomas E. Besser; Jonathan Mayer; Hanna N. Oltean; Jon Wakefield; Phillip I. Tarr; Peter Rabinowitz. 2018. "Geogenomic Segregation and Temporal Trends of Human Pathogenic Escherichia coli O157:H7, Washington, USA, 2005–20141." Emerging Infectious Diseases 24, no. 1: 32-39.

Journal article
Published: 10 November 2017 in Journal of Global Health
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Tobacco taxation and smoke–free workplaces reduce smoking, tobacco–related premature deaths and associated out–of–pocket health care expenditures. We examine the distributional consequences of a price increase in tobacco products through an excise tax hike, and of an implementation of smoke–free workplaces, in China. We use extended cost–effectiveness analysis (ECEA) to evaluate, across income quintiles of the male population (the large majority of Chinese smokers), the premature deaths averted, the change in tax revenues generated, and the financial risk protection procured (eg, poverty cases averted, defined as the number of individuals no longer facing tobacco–related out–of–pocket expenditures for disease treatment, that would otherwise impoverish them), that would follow a 75% increase in cigarette prices through substantial increments in excise tax fully passed onto consumers, and a nationwide total implementation of workplace smoking bans. A 75% increase in cigarette prices would avert about 24 million premature deaths among the current Chinese male population, with a third among the bottom income quintile, increase additional tax revenues by US$ 46 billion annually, and prevent around 9 million poverty cases, 19% of which among the bottom income quintile. Implementation of smoking bans in workplaces would avert about 12 million premature deaths, with a fifth among the bottom income quintile, decrease tax revenues by US$ 7 billion annually, and prevent around 4 million poverty cases, 12% of which among the bottom income quintile. Increased excise taxes on tobacco products and workplace smoking bans can procure large health and economic benefits to the Chinese population, especially among the poor.

ACS Style

Stéphane Verguet; Gillian Tarr; Cindy L Gauvreau; Sujata Mishra; Prabhat Jha; Lingrui Liu; Yue Xiao; Yingpeng Qiu; Kun Zhao. Distributional benefits of tobacco tax and smoke–free workplaces in China: A modeling study. Journal of Global Health 2017, 7, 1 .

AMA Style

Stéphane Verguet, Gillian Tarr, Cindy L Gauvreau, Sujata Mishra, Prabhat Jha, Lingrui Liu, Yue Xiao, Yingpeng Qiu, Kun Zhao. Distributional benefits of tobacco tax and smoke–free workplaces in China: A modeling study. Journal of Global Health. 2017; 7 (2):1.

Chicago/Turabian Style

Stéphane Verguet; Gillian Tarr; Cindy L Gauvreau; Sujata Mishra; Prabhat Jha; Lingrui Liu; Yue Xiao; Yingpeng Qiu; Kun Zhao. 2017. "Distributional benefits of tobacco tax and smoke–free workplaces in China: A modeling study." Journal of Global Health 7, no. 2: 1.

Research articles
Published: 06 November 2017 in Health Systems & Reform
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Abstract—The majority of Armenian adult males smoke, yet tobacco taxes in Armenia are among the lowest in Europe and Central Asia. Increasing taxes on tobacco is one of the most cost-effective public health interventions, but many opponents often cite regressivity as an argument against tobacco taxation. We use a mixed-methods approach to study the potential regressivity of tobacco taxation and the extent to which the regressivity argument hindered increases in tobacco taxation in Armenia. First, we pursued an extended cost-effectiveness analysis (ECEA) to assess the health, financial, and distributional consequences (by consumption quintile) of increases in the excise tax on cigarettes in Armenia. We simulated a hypothetical price hike leading to a tax rate of about 75% of the retail price of cigarettes, which would be fully passed on to consumers. Second, we conducted a series of stakeholder interviews to examine the importance of the regressivity argument and identify the factors that allowed tobacco tax increases to be adopted as public policy in Armenia. We show that increased excise taxes would bring large health and financial benefits to Armenian households. Half of tobacco-related premature deaths and 27% of associated poverty cases averted would be concentrated among the bottom 40% of the population. Though regressivity was raised as a concern at the initial stages of the policy adoption process, our qualitative stakeholder analysis indicates that the recent accession to the Eurasian Economic Union and the fiscal constraints faced by the government created a window of opportunity for tobacco taxation to be placed on the policy agenda and adopted as government policy, and the ECEA findings were an important input into the process.

ACS Style

Iryna Postolovska; Rouselle Lavado; Gillian Tarr; Stéphane Verguet. The Health Gains, Financial Risk Protection Benefits, and Distributional Impact of Increased Tobacco Taxes in Armenia. Health Systems & Reform 2017, 4, 30 -41.

AMA Style

Iryna Postolovska, Rouselle Lavado, Gillian Tarr, Stéphane Verguet. The Health Gains, Financial Risk Protection Benefits, and Distributional Impact of Increased Tobacco Taxes in Armenia. Health Systems & Reform. 2017; 4 (1):30-41.

Chicago/Turabian Style

Iryna Postolovska; Rouselle Lavado; Gillian Tarr; Stéphane Verguet. 2017. "The Health Gains, Financial Risk Protection Benefits, and Distributional Impact of Increased Tobacco Taxes in Armenia." Health Systems & Reform 4, no. 1: 30-41.

Book
Published: 14 April 2017 in Estimating the Distributional Impact of Increasing Taxes on Tobacco Products in Armenia
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ACS Style

Iryna Postolovska; Rouselle F. Lavado; Gillian Tarr; Stephane Verguet. Estimating the Distributional Impact of Increasing Taxes on Tobacco Products in Armenia. Estimating the Distributional Impact of Increasing Taxes on Tobacco Products in Armenia 2017, 1 .

AMA Style

Iryna Postolovska, Rouselle F. Lavado, Gillian Tarr, Stephane Verguet. Estimating the Distributional Impact of Increasing Taxes on Tobacco Products in Armenia. Estimating the Distributional Impact of Increasing Taxes on Tobacco Products in Armenia. 2017; ():1.

Chicago/Turabian Style

Iryna Postolovska; Rouselle F. Lavado; Gillian Tarr; Stephane Verguet. 2017. "Estimating the Distributional Impact of Increasing Taxes on Tobacco Products in Armenia." Estimating the Distributional Impact of Increasing Taxes on Tobacco Products in Armenia , no. : 1.

Review
Published: 01 December 2016 in Journal of Global Health
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Eva W Westley; Sharon A Greene; Gillian A M Tarr; Tove K Ryman; Sarah Skye Gilbert; Stephen E Hawes. Strengthening paper health register systems: strategies from case studies in Ethiopia, Ghana, South Africa and Uganda. Journal of Global Health 2016, 6, 020303 .

AMA Style

Eva W Westley, Sharon A Greene, Gillian A M Tarr, Tove K Ryman, Sarah Skye Gilbert, Stephen E Hawes. Strengthening paper health register systems: strategies from case studies in Ethiopia, Ghana, South Africa and Uganda. Journal of Global Health. 2016; 6 (2):020303.

Chicago/Turabian Style

Eva W Westley; Sharon A Greene; Gillian A M Tarr; Tove K Ryman; Sarah Skye Gilbert; Stephen E Hawes. 2016. "Strengthening paper health register systems: strategies from case studies in Ethiopia, Ghana, South Africa and Uganda." Journal of Global Health 6, no. 2: 020303.