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McBurney SH, Kwong JC, Brown KA, Rudzicz F, Wilton A, Crowcroft NS. Improving estimates of pertussis burden in Ontario, Canada 2010-2017 by combining validation and capture-recapture methodologies. PLoS One 2023; 18:e0273205. [PMID: 38039303 PMCID: PMC10691704 DOI: 10.1371/journal.pone.0273205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 11/05/2023] [Indexed: 12/03/2023] Open
Abstract
An underestimation of pertussis burden has impeded understanding of transmission and disallows effective policy and prevention to be prioritized and enacted. Capture-recapture analyses can improve burden estimates; however, uncertainty remains around incorporating health administrative data due to accuracy limitations. The aim of this study is to explore the impact of pertussis case definitions and data accuracy on capture-recapture estimates. We used a dataset from March 7, 2010 to December 31, 2017 comprised of pertussis case report, laboratory, and health administrative data. We compared Chao capture-recapture abundance estimates using prevalence, incidence, and adjusted false positive case definitions. The latter was developed by removing the proportion of false positive physician billing code-only case episodes after validation. We calculated sensitivity by dividing the number of observed cases by abundance. Abundance estimates demonstrated that a high proportion of cases were missed by all sources. Under the primary analysis, the highest sensitivity of 78.5% (95% CI 76.2-80.9%) for those less than one year of age was obtained using all sources after adjusting for false positives, which dropped to 43.1% (95% CI 42.4-43.8%) for those one year of age or older. Most code-only episodes were false positives (91.0%), leading to considerably lower abundance estimates and improvements in laboratory testing and case report sensitivity using this definition. Accuracy limitations can be accounted for in capture-recapture analyses using different case definitions and adjustment. The latter enhanced the validity of estimates, furthering the utility of capture-recapture methods to epidemiological research. Findings demonstrated that all sources consistently fail to detect pertussis cases. This is differential by age, suggesting ascertainment and testing bias. Results demonstrate the value of incorporating real time health administrative data into public health surveillance if accuracy limitations can be addressed.
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Affiliation(s)
- Shilo H. McBurney
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
- Department of Epidemiology, Brown University School of Public Health, Providence, Rhode Island, United States of America
| | - Jeffrey C. Kwong
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
- Public Health Ontario, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
- ICES, Toronto, Ontario, Canada
- Department of Family & Community Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Kevin A. Brown
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
- Public Health Ontario, Toronto, Ontario, Canada
- ICES, Toronto, Ontario, Canada
| | - Frank Rudzicz
- Department of Computer Science, University of Toronto, Toronto, Ontario, Canada
- Faculty of Computer Science, Dalhousie University, Halifax, Nova Scotia, Canada
- Vector Institute for Artificial Intelligence, Toronto, Ontario, Canada
| | | | - Natasha S. Crowcroft
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
- Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
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McBurney SH, Kwong JC, Brown KA, Rudzicz F, Chen B, Candido E, Crowcroft NS. Validating pertussis data measures using electronic medical record data in Ontario, Canada 1986-2016. Vaccine X 2023; 15:100408. [PMID: 38161988 PMCID: PMC10755117 DOI: 10.1016/j.jvacx.2023.100408] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 09/14/2023] [Accepted: 11/13/2023] [Indexed: 01/03/2024] Open
Abstract
Background Pertussis is a reportable disease in many countries, but ascertainment bias has limited data accuracy. This study aims to validate pertussis data measures using a reference standard that incorporates different suspected case severities, allowing for the impact of case severity on accuracy and detection to be explored. Methods We evaluated 25 pertussis detection algorithms in a primary care electronic medical record database between January 1, 1986 and December 30, 2016. We estimated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). We used sensitivity analyses to explore areas of uncertainty and evaluated reasons for lack of detection. Results The algorithm including all data measures achieved the highest sensitivity at 20.6%. Sensitivity increased to 100% after reclassifying symptom-only cases as non-cases, but the PPV remained low. Age at first episode was significantly associated with detection in half of the tested scenarios, and false negatives often had some history of immunization. Conclusions Sensitivity improved by reclassifying symptom-only cases but remained low unless multiple data sources were used. Results demonstrate a trade-off between PPV and sensitivity. EMRs can enhance detection through patient history and clinical note data. It is essential to improve case identification of older individuals with vaccination history to reduce ascertainment bias.
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Affiliation(s)
- Shilo H. McBurney
- Dalla Lana School of Public Health, University of Toronto, 155 College Street, 6th Floor, Toronto, ON M5T 3M7, Canada
- Department of Epidemiology, Brown University School of Public Health, 121 South Main Street, Box G-S121-2, Providence, RI 02912, United States of America
| | - Jeffrey C. Kwong
- Dalla Lana School of Public Health, University of Toronto, 155 College Street, 6th Floor, Toronto, ON M5T 3M7, Canada
- Public Health Ontario, 661 University Avenue, Suite 1701, Toronto, ON M5G 1M1, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 1 King’s College Circle, 6th Floor, Toronto, ON M5S 1A8, Canada
- ICES, G1 06, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada
- Department of Family and Community Medicine, University of Toronto, 500 University Avenue, 5th Floor, Toronto, ON M5G 1V7, Canada
| | - Kevin A. Brown
- Dalla Lana School of Public Health, University of Toronto, 155 College Street, 6th Floor, Toronto, ON M5T 3M7, Canada
- Public Health Ontario, 661 University Avenue, Suite 1701, Toronto, ON M5G 1M1, Canada
- ICES, G1 06, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada
| | - Frank Rudzicz
- Department of Computer Science, University of Toronto, 40 St. George Street, Room 4283, Toronto, ON M5S 2E4, Canada
- Faculty of Computer Science, Dalhousie University, Halifax, Nova Scotia, Canada
- Vector Institute for Artificial Intelligence, 661 University Ave Suite 710, Toronto, ON M5G 1M1, Canada
| | - Branson Chen
- ICES, G1 06, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada
| | - Elisa Candido
- ICES, G1 06, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada
| | - Natasha S. Crowcroft
- Dalla Lana School of Public Health, University of Toronto, 155 College Street, 6th Floor, Toronto, ON M5T 3M7, Canada
- Immunization, Vaccines and Biologicals, World Health Organization, Avenue Appia 20, 1211 Geneva 27, Switzerland
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Bagordo F, Grassi T, Savio M, Rota MC, Baldovin T, Vicentini C, Napolitano F, Trombetta CM, Gabutti G. Assessment of Pertussis Underreporting in Italy. J Clin Med 2023; 12:jcm12051732. [PMID: 36902519 PMCID: PMC10003430 DOI: 10.3390/jcm12051732] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/13/2023] [Accepted: 02/18/2023] [Indexed: 02/24/2023] Open
Abstract
A study was conducted to assess the degree of pertussis underreporting in Italy. An analysis was performed to compare the frequency of pertussis infections estimated using seroprevalence data with the pertussis incidence based on reported cases among the Italian population. For this purpose, the proportion of subjects who had an anti-PT ≥ 100 IU/mL (indicative of B. pertussis infection within the last 12 months) was compared with the reported incidence rate among the Italian population ≥5 years old, divided into two age groups (6-14 and ≥15 years old), obtained from the European Centre for Disease Prevention and Control (ECDC) database. The pertussis incidence rate in the Italian population ≥5 years old reported by the ECDC in 2018 was 6.75/100,000 in the 5-14 age group and 0.28/100,000 in the ≥15 age group. The proportion of subjects recruited in the present study with an anti-PT ≥ 100 IU/mL was 0.95% in the 6-14 age group and 0.97% in the ≥15 age group. The estimated rate of pertussis infections based on seroprevalence was approximately 141-fold and 3452-fold higher than the reported incidence in the 6-14 age group and in the ≥15 age group, respectively. Quantification of underreporting can allow for the burden of pertussis, as well as the impact of ongoing vaccination, to be better evaluated.
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Affiliation(s)
- Francesco Bagordo
- Department of Pharmacy-Pharmaceutical Sciences, University of Bari, 70121 Bari, Italy
| | - Tiziana Grassi
- Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy
| | - Marta Savio
- Post-Graduate School of Hygiene and Preventive Medicine, University of Ferrara, 44121 Ferrara, Italy
| | - Maria Cristina Rota
- Department of Infectious Diseases, Italian Institute of Health (ISS), 00161 Roma, Italy
| | - Tatjana Baldovin
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, Hygiene and Public Health Unit, University of Padua, 35121 Padua, Italy
| | - Costanza Vicentini
- Department of Sciences of Public Health and Pediatrics, University of Turin, 10124 Turin, Italy
| | - Francesco Napolitano
- Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy
| | | | - Giovanni Gabutti
- National Coordinator of the Working Group “Vaccines and Immunization Policies”, Italian Society of Hygiene, Preventive Medicine and Public Health, 16030 Cogorno, Italy
- Correspondence: ; Tel.: +39-347-8889342
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Hempel K, McDonald W, Osgood ND, Fisman D, Halperin SA, Crowcroft N, Klein NP, Rohani P, Doroshenko A. Evaluation of the effectiveness of maternal immunization against pertussis in Alberta using agent-based modeling: A Canadian immunization research network study. Vaccine 2023; 41:2430-2438. [PMID: 36775775 DOI: 10.1016/j.vaccine.2022.12.071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 12/05/2022] [Accepted: 12/13/2022] [Indexed: 02/12/2023]
Abstract
INTRODUCTION The re-emergence of pertussis has occurred in the past two decades in developed countries. The highest morbidity and mortality is seen among infants. Vaccination in pregnancy is recommended to reduce the pertussis burden in infants. METHODS We developed and validated an agent-based model to characterize pertussis epidemiology in Alberta. We computed programmatic effectiveness of pertussis vaccination during pregnancy (PVE) in relation to maternal vaccine coverage and pertussis disease reporting thresholds. We estimated the population preventable fraction (PFP) of different levels of maternal vaccine coverage against counterfactual "no-vaccination" scenario. We modeled the effect of immunological blunting and measured protection through interruption of exposure pathways. RESULTS PVE was inversely related to duration of passive immunity from maternal immunization across most simulations. In the scenario of 50% maternal vaccine coverage, PVE was 87% (95% quantiles 82-91%), with PFP of 44% (95% quantiles 41-45%). For monthly age intervals of 0-2, 2-4, 4-6 and 6-12, PVE ranged between 82 and 99%, and PFP ranged between 41 and 49%. At 75% maternal vaccine coverage, PVE and PFP were 90% (95% quantiles 86-92%) and 68% (95% quantiles 65-69%), respectively. At 50% maternal vaccine coverage and 10% blunting, PVE and PFP were 86% (95% quantiles 77-87%) and 43% (95% quantiles 39-44%), respectively, while at 50% blunting, the corresponding values of PVE and PFP were 76% (95% quantiles 70-81%) and 38% (95% quantiles 35-40%). PVE attributable to interruption of exposure pathways was 54-57%. CONCLUSIONS Our model predicts significant reduction in future pertussis cases in infants due to maternal vaccination, with immunological blunting slightly moderating its effectiveness. The model is most sensitive to maternal vaccination coverage. The interruption of exposure pathways plays a role in the reduction of pertussis burden in infants due to maternal immunization. The effect of maternal immunization on population other than infants remains to be elucidated.
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Affiliation(s)
- Karsten Hempel
- Department of Medicine, Division of Preventive Medicine, College of Health Sciences, University of Alberta, Edmonton, Alberta, Canada.
| | - Wade McDonald
- Department of Computer Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
| | - Nathaniel D Osgood
- Department of Computer Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - David Fisman
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
| | - Scott A Halperin
- Departments of Pediatrics, Microbiology and Immunology, Canadian Center for Vaccinology, Dalhousie University, Halifax, Nova Scotia, Canada.
| | - Natasha Crowcroft
- World Health Organization, Geneva, Switzerland; Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
| | - Nicola P Klein
- Kaiser Permanente Vaccine Study Center, Kaiser Permanente Northern California, Oakland, CA, USA.
| | - Pejman Rohani
- Department of Infectious Diseases, University of Georgia, Athens, GA, USA; Odum School of Ecology, University of Georgia, Athens, GA, USA.
| | - Alexander Doroshenko
- Department of Medicine, Division of Preventive Medicine, College of Health Sciences, University of Alberta, Edmonton, Alberta, Canada; School of Public Health, College of Health Sciences, University of Alberta, Edmonton, Alberta, Canada.
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Nann D, Walker M, Frauenfeld L, Ferenci T, Sulyok M. Forecasting the future number of pertussis cases using data from Google Trends. Heliyon 2021; 7:e08386. [PMID: 34825092 PMCID: PMC8605298 DOI: 10.1016/j.heliyon.2021.e08386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 01/01/2021] [Accepted: 11/10/2021] [Indexed: 11/17/2022] Open
Abstract
Background Alternative methods could be used to enhance the monitoring and forecasting of re-emerging conditions such as pertussis. Here, whether data on the volume of Internet searching on pertussis could complement traditional modeling based solely on reported case numbers was assessed. Methods SARIMA models were fitted to describe reported weekly pertussis case numbers over a four-year period in Germany. Pertussis-related Google Trends data (GTD) was added as an external regressor. Predictions were made by the models, both with and without GTD, and compared with values within the validation dataset over a one-year and for a two-weeks period. Results Predictions of the traditional model using solely reported case numbers resulted in an RMSE (residual mean squared error) of 192.65 and 207.8, a mean absolute percentage error (MAPE) of 58.59 and 72.1, and a mean absolute error (MAE) 169.53 and 190.53 for the one-year and for the two-weeks period, respectively. The GTD expanded model achieved better forecasting accuracy (RMSE: 144.22 and 201.78), a MAPE 43.86, and 68.54 and a MAE of 124.46 and 178.96. Corrected Akaike Information Criteria also favored the GTD expanded model (1750.98 vs. 1746.73). The difference between the predictive performances was significant when using a two-sided Diebold-Mariano test (DM value: 6.86, p < 0.001) for the one-year period. Conclusion Internet-based surveillance data enhanced the predictive ability of a traditionally based model and should be considered as a method to enhance future disease modeling. Pertussis-related Google Trends Data (GTD) showed a weak but significant correlation with the reported weekly number of pertussis cases. We fitted a SARIMA models to estimate reported weekly pertussis case numbers The GTD-expanded models achieved significantly better predictive accuracy than the traditional model over a one-year-period. Corrected Akaike Information Criteria also favored the GTD-Expanded SARIMA model. The use of GTD should be considered as a method to enhance pertussis forecasting.
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Affiliation(s)
- Dominik Nann
- Institute of Pathology and Neuropathology, Department of Pathology, Eberhard Karls University, University Clinics Tübingen, Tübingen, Germany
| | - Mark Walker
- Department of the Natural and Built Environment, Sheffield Hallam University, Sheffield, United Kingdom
| | - Leonie Frauenfeld
- Institute of Pathology and Neuropathology, Department of Pathology, Eberhard Karls University, University Clinics Tübingen, Tübingen, Germany
| | - Tamás Ferenci
- Physiological Controls Research Center, Óbuda University, Budapest, Hungary.,Corvinus University of Budapest, Department of Statistics, Budapest, Hungary
| | - Mihály Sulyok
- Institute of Pathology and Neuropathology, Department of Pathology, Eberhard Karls University, University Clinics Tübingen, Tübingen, Germany.,Institute of Tropical Medicine, Eberhard Karls University, University Clinics Tübingen, Germany
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6
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Hughes SL, Kwong JC, Schwartz KL, Chen C, Johnson C, Li Y, Marchand-Austin A, Bolotin S, Jamieson FB, Drews SJ, Russell ML, Svenson LW, Mahmud SM, Crowcroft NS. Exploring the reasons for low pertussis vaccine effectiveness in Ontario, Canada, 2006-2008: a Canadian Immunization Research Network study. Canadian Journal of Public Health 2021; 113:155-164. [PMID: 34424508 DOI: 10.17269/s41997-021-00536-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 04/27/2021] [Indexed: 11/17/2022]
Abstract
OBJECTIVES Although pertussis vaccines have been widely used for many decades, a burden of illness persists. Resurgences in Ontario, Canada, have not been substantial in the past decade, but an outbreak of pertussis occurred in Toronto between 1 October 2005 and 31 March 2006. Previous Ontario studies found high vaccine effectiveness (VE) in the initial years post-immunization. In order to explore the impact of outbreaks and external factors on VE, we investigated pertussis VE during the period 2006-2008. METHODS We assessed pertussis VE using a frequency-matched case-control study for the period 1 March 2006 to 31 December 2008. We used logistic regression to estimate VE by age, time since last vaccination, and vaccination status according to the Ontario recommended schedule. We compared analyses including and excluding cases from Toronto, and to two recent Ontario pertussis VE studies. RESULTS We included 1797 confirmed cases and 7188 matched controls. Most cases were under 4 years of age during the study period. Pertussis VE was 3.8% (95% CI: - 21.0, 24.0) in the period 15-364 days following the last pertussis vaccine dose, and increased with increasing time since vaccination. Pertussis VE in the first 15-364 days excluding Toronto increased to 57.1% (95% CI: 26.0, 75.1), but the trend of increasing VE with time since vaccination persisted. Although VE was higher in older (6-11 years) than younger (0-5 years) children, it was lower at 12-13 years than after 14 years. CONCLUSION VE was lower in comparison with other studies conducted in Ontario, particularly in younger children. Various factors occurring during the study period may have influenced the results, including clinical testing of asymptomatic contacts, laboratory testing and methods and reporting practice, and a sensitive case definition. Further studies are needed to optimize methods for measuring VE to inform pertussis vaccine policy.
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Affiliation(s)
| | - Jeffrey C Kwong
- Public Health Ontario, Toronto, ON, Canada.,Dalla Lana School of Public Health, University of Toronto, Toronto, ON, M5T 3M7, Canada.,Department of Family & Community Medicine, University of Toronto, Toronto, ON, Canada.,ICES, Toronto, ON, Canada
| | - Kevin L Schwartz
- Public Health Ontario, Toronto, ON, Canada.,Dalla Lana School of Public Health, University of Toronto, Toronto, ON, M5T 3M7, Canada.,ICES, Toronto, ON, Canada
| | - Cynthia Chen
- Public Health Ontario, Toronto, ON, Canada.,ICES, Toronto, ON, Canada
| | | | - Ye Li
- Public Health Ontario, Toronto, ON, Canada.,Dalla Lana School of Public Health, University of Toronto, Toronto, ON, M5T 3M7, Canada
| | | | - Shelly Bolotin
- Public Health Ontario, Toronto, ON, Canada.,Dalla Lana School of Public Health, University of Toronto, Toronto, ON, M5T 3M7, Canada.,Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Frances B Jamieson
- Public Health Ontario, Toronto, ON, Canada.,Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Steven J Drews
- Canadian Blood Services, Ottawa, ON, Canada.,Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada
| | - Margaret L Russell
- Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Lawrence W Svenson
- Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Alberta Health, Edmonton, AB, Canada.,Division of Preventive Medicine, University of Alberta, Edmonton, AB, Canada.,School of Public Health, University of Alberta, Edmonton, AB, Canada
| | - Salaheddin M Mahmud
- Vaccine and Drug Evaluation Centre, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada
| | - Natasha S Crowcroft
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON, M5T 3M7, Canada.
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Crowcroft NS, Schwartz KL, Savage RD, Chen C, Johnson C, Li Y, Marchand-Austin A, Bolotin S, Deeks SL, Jamieson FB, Drews SJ, Russell ML, Svenson LW, Simmonds K, Righolt CH, Bell C, Mahmud SM, Kwong JC. A Call for Caution in Use of Pertussis Vaccine Effectiveness Studies to Estimate Waning Immunity: A Canadian Immunization Research Network Study. Clin Infect Dis 2021; 73:83-90. [PMID: 32384142 DOI: 10.1093/cid/ciaa518] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Vaccine effectiveness (VE) studies provide essential evidence on waning vaccine-derived immunity, a major threat to pertussis control. We evaluated how study design affects estimates by comparing 2 case-control studies conducted in Ontario, Canada. METHODS We compared results from a test-negative design (TND) with a frequency-matched design (FMD) case-control study using pertussis cases from 2005-2015. In the first study, we identified test-negative controls from the public health laboratory that diagnosed cases and, in the second, randomly selected controls from patients attending the same physicians that reported cases, frequency matched on age and year. We compared characteristics of cases and controls using standardized differences. RESULTS In both designs, VE estimates for the early years postimmunization were consistent with clinical trials (TND, 84%; FMD, 89% at 1-3 years postvaccination) but diverged as time since last vaccination increased (TND, 41%; FMD, 74% by 8 years postvaccination). Overall, we observed lower VE and faster waning in the TND than the FMD. In the TND but not FMD, controls differed from cases in important confounders, being younger, having more comorbidities, and higher healthcare use. Differences between the controls of each design were greater than differences between cases. TND controls were more likely to be unvaccinated or incompletely vaccinated than FMD controls (P < .001). CONCLUSIONS The FMD adjusted better for healthcare-seeking behavior than the TND. Duration of protection from pertussis vaccines is unclear because estimates vary by study design. Caution should be exercised by experts, researchers, and decision makers when evaluating evidence on optimal timing of boosters.
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Affiliation(s)
- Natasha S Crowcroft
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.,Centre for Vaccine Preventable Diseases, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.,Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
| | - Kevin L Schwartz
- Centre for Vaccine Preventable Diseases, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.,Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.,Public Health Ontario, Toronto, Ontario, Canada.,St Joseph's Health Centre, Toronto, Ontario, Canada
| | - Rachel D Savage
- Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.,Women's College Research Institute, Women's College Hospital, Toronto, Ontario, Canada
| | | | | | - Ye Li
- Centre for Vaccine Preventable Diseases, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.,Public Health Ontario, Toronto, Ontario, Canada
| | | | - Shelly Bolotin
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.,Centre for Vaccine Preventable Diseases, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.,Public Health Ontario, Toronto, Ontario, Canada
| | - Shelley L Deeks
- Centre for Vaccine Preventable Diseases, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.,Public Health Ontario, Toronto, Ontario, Canada
| | - Frances B Jamieson
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.,Public Health Ontario, Toronto, Ontario, Canada
| | - Steven J Drews
- Medical Microbiology, Canadian Blood Service, Edmonton, Alberta, Canada.,Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada
| | - Margaret L Russell
- Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Lawrence W Svenson
- Alberta Health, Edmonton, Alberta, Canada.,Division of Preventive Medicine, University of Alberta, Edmonton, Alberta, Canada.,School of Public Health, University of Alberta, Edmonton, Alberta, Canada
| | - Kimberley Simmonds
- Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Alberta Health, Edmonton, Alberta, Canada.,School of Public Health, University of Alberta, Edmonton, Alberta, Canada
| | - Christiaan H Righolt
- Vaccine and Drug Evaluation Centre, Department of Community Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Christopher Bell
- Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Salaheddin M Mahmud
- Vaccine and Drug Evaluation Centre, Department of Community Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Jeffrey C Kwong
- Centre for Vaccine Preventable Diseases, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.,Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.,Public Health Ontario, Toronto, Ontario, Canada.,Department of Family and Community Medicine, University of Toronto, Toronto, Ontario, Canada
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8
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Wilkinson K, Righolt CH, Elliott LJ, Fanella S, Mahmud SM. Pertussis vaccine effectiveness and duration of protection - A systematic review and meta-analysis. Vaccine 2021; 39:3120-3130. [PMID: 33934917 DOI: 10.1016/j.vaccine.2021.04.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 04/09/2021] [Accepted: 04/14/2021] [Indexed: 11/26/2022]
Abstract
A comprehensive review of observational pertussis vaccine effectiveness (VE) studies is needed to update gaps from previous reviews. We conducted a systematic review of VE and duration of protection studies for the whole-cell (wP) and acellular (aP) pertussis vaccines and conducted a formal meta-analysis using random effects models. Evidence continues to suggest that receipt of any pertussis vaccine confers protection in the short-term against disease although this protection wanes rapidly for aP vaccine. We detected significant heterogeneity in pooled estimates due, in part, to factors such as bias and confounding which may be mitigated by study design. Our review of possible sources of heterogeneity may help interpretation of other VE studies and aid design decisions in future pertussis VE research.
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Affiliation(s)
- Krista Wilkinson
- Vaccine and Drug Evaluation Centre, Department of Community Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Christiaan H Righolt
- Department of Medical Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Lawrence J Elliott
- Department of Medical Microbiology, University of Manitoba, Winnipeg, MB, Canada; Department of Community Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Sergio Fanella
- Department of Pediatric Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| | - Salaheddin M Mahmud
- Vaccine and Drug Evaluation Centre, Department of Community Health Sciences, University of Manitoba, Winnipeg, MB, Canada.
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A multisite study of pertussis vaccine effectiveness by time since last vaccine dose from three Canadian provinces: A Canadian Immunization Research Network study. Vaccine 2021; 39:2772-2779. [PMID: 33875270 DOI: 10.1016/j.vaccine.2021.03.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 03/04/2021] [Accepted: 03/07/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Pertussis remains poorly controlled relative to other diseases targeted by childhood vaccination programs. We combined estimates from four population-based studies of pertussis vaccine effectiveness (VE) in three Canadian provinces using a meta-analytic approach to improve precision and explore regional variation in VE and durability of protection. METHODS Studies were conducted in Alberta, Manitoba, and Ontario over periods ranging from 1996 to 2015. Adjusted log odds ratios (OR; VE = 100*[1-OR]) of the effect of vaccination on pertussis risk were estimated by time since last vaccination in each study and pooled using DerSimonian and Laird random-effects models. We used the I2 statistic to estimate between-study heterogeneity and assessed methodological and clinical heterogeneity through subgroup analyses of study design and age. RESULTS Data on 3,270 pertussis cases and 23,863 controls were available. Pertussis VE declined from 86% (95% CI 79%-90%, I2 = 81.5%) at < 1 year since last vaccination to 51% (11%-74%, I2 = 80.9%) by ≥ 8 years. Effect estimates were the most heterogeneous in the least and most elapsed time periods since last vaccine dose. This was attributable mostly to variation between provinces in the distribution of age groups and number of vaccine doses received within time periods, as well as study design and small numbers in the most elapsed time period. INTERPRETATION Consistent trends of decreasing pertussis VE with increasing time since last vaccination across three Canadian provinces indicate the need for immunization schedules and vaccine development to optimize protection for all individuals, especially for adolescents and young adults at greatest risk of infection.
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Crowcroft NS, Bolotin S, Li Y, Campbell H, Amirthalingam G. Infant pertussis and maternal immunity: The curious case of Canada. Vaccine 2021; 39:1977-1981. [PMID: 33750589 DOI: 10.1016/j.vaccine.2021.02.050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 02/20/2021] [Accepted: 02/23/2021] [Indexed: 10/22/2022]
Abstract
BACKGROUND The United Kingdom (UK) and Canada use the same acellular pertussis vaccine and both experienced large pertussis outbreaks in the past, occurring in the 1980s in the UK and 1990s in Canada, yet current epidemiology differs. A national outbreak with infant deaths occurred in the UK in 2012, yet outbreaks remain localized and death from pertussis rare in Canada. AIM We explored whether past outbreaks in children may influence future risk when those children become parents. METHODS We conducted an ecological within-country birth cohort analysis in women of childbearing age of the relative risk of ever having pertussis infection by two points in time, 2002 and 2012, comparing with 1992 as the baseline. We used notified cases of pertussis in England and Wales and Canada to compare trends in relative risk. We projected forward to 2022 in Canada assuming incidence remained stable. RESULTS In Canada, the cumulative risk of previous pertussis was similar in 2002 and 2012 and, in both periods, was higher than in 1992. In England and Wales, the cumulative risk of pertussis fell stepwise from 1992 to 2012. Projecting forwards, the pattern of risk in Canada becomes similar to England and Wales in 2022. CONCLUSIONS Widespread pertussis outbreaks in children may reduce the risk of pertussis in infants when those children become parents. Further research is needed to determine the mechanism. As birth cohorts that experienced outbreaks grow past childbearing age, pertussis burden in infants in Canada may increase, following trends observed in England and Wales.
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Affiliation(s)
- Natasha S Crowcroft
- Dalla Lana School of Public Health, University of Toronto, Canada; Laboratory Medicine and Pathobiology, University of Toronto, Canada; ICES, Toronto, Canada.
| | - Shelly Bolotin
- Dalla Lana School of Public Health, University of Toronto, Canada; Laboratory Medicine and Pathobiology, University of Toronto, Canada; Public Health Ontario, Toronto, Canada
| | - Ye Li
- Dalla Lana School of Public Health, University of Toronto, Canada; ICES, Toronto, Canada
| | - Helen Campbell
- Immunisation and Countermeasures Division, Public Health England, United Kingdom
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Assessing the Quality of Reporting to China's National TB Surveillance Systems. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18052264. [PMID: 33668804 PMCID: PMC7956775 DOI: 10.3390/ijerph18052264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/17/2021] [Accepted: 02/19/2021] [Indexed: 12/27/2022]
Abstract
(1) Background: The reliability of disease surveillance may be restricted by sensitivity or ability to capture all disease. Objective: To quantify under-reporting and concordance of recording persons with tuberculosis (TB) in national TB surveillance systems: the Infectious Disease Reporting System (IDRS) and Tuberculosis Information Management System (TBIMS). (2) Methods: This retrospective review includes 4698 patients identified in 2016 in China. County staff linked TB patients identified from facility-specific health and laboratory information systems with records in IDRS and TBIMS. Under-reporting was calculated, and timeliness, concordance, accuracy, and completeness were analyzed. Multivariable logistic regression was used to examine factors associated with under-reporting. (3) Results: We found that 505 (10.7%) patients were missing within IDRS and 1451 (30.9%) patients were missing within TBIMS. Of 171 patient records reviewed in IDRS and 170 patient records in TBIMS, 12.3% and 6.5% were found to be untimely, and 10.7% and 7.1% were found to have an inconsistent home address. The risk of under-reporting to both IDRS and TBIMS was greatest at tertiary health facilities and among non-residents; the risk of under-reporting to TBIMS was greatest with patients aged 65 or older and with extrapulmonary TB (EPTB). (4) Conclusions: It is important to improve the reporting and recording of TB patients. Local TB programs that focus on training, and mentoring high-burden hospitals, facilities that cater to EPTB, and migrant patients may improve reporting and recording.
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Craig R, Kunkel E, Crowcroft NS, Fitzpatrick MC, de Melker H, Althouse BM, Merkel T, Scarpino SV, Koelle K, Friedman L, Arnold C, Bolotin S. Asymptomatic Infection and Transmission of Pertussis in Households: A Systematic Review. Clin Infect Dis 2021; 70:152-161. [PMID: 31257450 DOI: 10.1093/cid/ciz531] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Indexed: 12/28/2022] Open
Abstract
We conducted a systematic review to describe the frequency of mild, atypical, and asymptomatic infection among household contacts of pertussis cases and to explore the published literature for evidence of asymptomatic transmission. We included studies that obtained and tested laboratory specimens from household contacts regardless of symptom presentation and reported the proportion of cases with typical, mild/atypical, or asymptomatic infection. After screening 6789 articles, we included 26 studies. Fourteen studies reported household contacts with mild/atypical pertussis. These comprised up to 46.2% of all contacts tested. Twenty-four studies reported asymptomatic contacts with laboratory-confirmed pertussis, comprising up to 55.6% of those tested. Seven studies presented evidence consistent with asymptomatic pertussis transmission between household contacts. Our results demonstrate a high prevalence of subclinical infection in household contacts of pertussis cases, which may play a substantial role in the ongoing transmission of disease. Our review reveals a gap in our understanding of pertussis transmission.
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Affiliation(s)
- Rodger Craig
- Applied Immunization Research and Evaluation, Public Health Ontario,Toronto.,Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Montreal, Canada
| | - Elizabeth Kunkel
- Applied Immunization Research and Evaluation, Public Health Ontario,Toronto.,Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Canada
| | - Natasha S Crowcroft
- Applied Immunization Research and Evaluation, Public Health Ontario,Toronto.,Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Montreal, Canada.,Department of Laboratory Medicine, University of Toronto, Toronto, Ontario, Canada.,Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
| | - Meagan C Fitzpatrick
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore
| | - Hester de Melker
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Benjamin M Althouse
- Institute for Disease Modeling, Bellevue, Washington.,Information School, University of Washington, Seattle.,Department of Biology, New Mexico State University, Las Cruces
| | - Tod Merkel
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland
| | - Samuel V Scarpino
- Network Science Institute, Northeastern University, Boston, Massachusetts.,Institute for Scientific Interchange Foundation, Torino, Italy
| | - Katia Koelle
- Department of Biology, Emory University, Atlanta, Georgia
| | - Lindsay Friedman
- Applied Immunization Research and Evaluation, Public Health Ontario,Toronto
| | - Callum Arnold
- Division of Infectious Diseases,The Hospital for Sick Children, Toronto, Canada
| | - Shelly Bolotin
- Applied Immunization Research and Evaluation, Public Health Ontario,Toronto.,Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Montreal, Canada.,Department of Laboratory Medicine, University of Toronto, Toronto, Ontario, Canada
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Luz PM, Struchiner CJ, Kim SY, Minamisava R, Andrade ALS, Sanderson C, Russell LB, Toscano CM. Modeling the cost-effectiveness of maternal acellular pertussis immunization (aP) in different socioeconomic settings: A dynamic transmission model of pertussis in three Brazilian states. Vaccine 2021; 39:125-136. [PMID: 33303180 PMCID: PMC7738757 DOI: 10.1016/j.vaccine.2020.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 07/01/2020] [Accepted: 09/01/2020] [Indexed: 01/06/2023]
Abstract
OBJECTIVES Using dynamic transmission models we evaluated the health and cost outcomes of adding acellular pertussis (aP) vaccination of pregnant women to infant vaccination in three Brazilian states that represent different socioeconomic conditions. The primary objective was to determine whether the same model structure could be used to represent pertussis disease dynamics in differing socioeconomic conditions. METHODS We tested three model structures (SIR, SIRS, SIRSIs) to represent population-level transmission in three socio-demographically distinct Brazilian states: São Paulo, Paraná and Bahia. Two strategies were evaluated: infant wP vaccination alone versus maternal aP immunization plus infant wP vaccination. Model projections for 2014-2029 include outpatient and inpatient pertussis cases, pertussis deaths, years of life lost, disability-adjusted life-years (DALYs) lost, and costs (in 2014 USD) of maternal aP vaccination, infant vaccination, and pertussis medical treatment. Incremental cost per DALY averted is presented from the perspective of the Brazilian National Health System. RESULTS Based on goodness-of-fit statistics, the SIRSIs model fit best, although it had only a modest improvement in statistical quantitative assessments relative to the SIRS model. For all three Brazilian states, maternal aP immunization led to higher costs but also saved infant lives and averted DALYs. The 2014 USD cost/DALY averted was $3068 in Sao Paulo, $2962 in Parana, and $2022 in Bahia. These results were robust in sensitivity analyses with the incremental cost-effectiveness ratios exceeding per capita gross regional product only when the probability that a pertussis case is reported was assumed higher than base case implying more overt cases and deaths and therefore more medical costs. CONCLUSIONS The same model structure fit all three states best, supporting the idea that the disease behaves similarly across different socioeconomic conditions. We also found that immunization of pregnant women with aP is cost-effective in diverse Brazilian states.
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Affiliation(s)
- Paula M Luz
- Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
| | - Claudio J Struchiner
- Escola de Matemática Aplicada, Fundação Getúlio Vargas, Praia de Botafogo, 190, Rio de Janeiro, Brazil
| | - Sun-Young Kim
- Seoul National University, Department of Healthcare Management and Policy, SNU Graduate School of Public Health, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Ruth Minamisava
- Faculdade de Enfermagem, Universidade Federal de Goiás, Goiania, Goias, Brazil
| | - Ana Lucia S Andrade
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiania, Goiás, Brazil
| | - Colin Sanderson
- London School of Hygiene and Tropical Medicine, Department of Health Services Research and Policy, 15-17 Tavistock Place, London WC1H 9SH, United Kingdom
| | - Louise B Russell
- University of Pennsylvania, Department of Medical Ethics and Health Policy, 423 Guardian Drive, Philadelphia PA 19104, USA
| | - Cristiana M Toscano
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiania, Goiás, Brazil
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Abstract
Burden of disease analyses can quantify the relative impact of different exposures on population health outcomes. Gastroenteritis where the causative pathogen was not determined and respiratory illness resulting from exposure to opportunistic pathogens transmitted by water aerosols have not always been considered in waterborne burden of disease estimates. We estimated the disease burden attributable to nine enteric pathogens, unspecified pathogens leading to gastroenteritis, and three opportunistic pathogens leading primarily to respiratory illness, in Ontario, Canada (population ~14 million). Employing a burden of disease framework, we attributed a fraction of annual (year 2016) emergency department (ED) visits, hospitalisations and deaths to waterborne transmission. Attributable fractions were developed from the literature and clinical input, and unattributed disease counts were obtained using administrative data. Our Monte Carlo simulation reflected uncertainty in the inputs. The estimated mean annual attributable rates for waterborne diseases were (per 100 000 population): 69 ED visits, 12 hospitalisations and 0.52 deaths. The corresponding 5th–95th percentile estimates were (per 100 000 population): 13–158 ED visits, 5–22 hospitalisations and 0.29–0.83 deaths. The burden of disease due to unspecified pathogens dominated these rates: 99% for ED visits, 63% for hospitalisations and 40% for deaths. However, when a causative pathogen was specified, the majority of hospitalisations (83%) and deaths (97%) resulted from exposure to the opportunistic pathogens Legionella spp., non-tuberculous mycobacteria and Pseudomonas spp. The waterborne disease burden in Ontario indicates the importance of gastroenteritis not traced back to a particular pathogen and of opportunistic pathogens transmitted primarily through contact with water aerosols.
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McGirr A, Fisman DN, Tuite AR. The health and economic burden of pertussis in Canada: A microsimulation study. Vaccine 2019; 37:7240-7247. [PMID: 31585727 DOI: 10.1016/j.vaccine.2019.09.070] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 09/18/2019] [Accepted: 09/20/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND Despite excellent vaccine coverage, pertussis persists in Canada, with high incidence during recent outbreaks and non-negligible incidence in non-outbreak years. While Canadian pertussis incidence is well-characterized, the full health and economic impact of pertussis have not been examined in Canada. We estimated age-specific life years (LYs) and quality-adjusted life years (QALYs) lost, and costs due to pertussis in Ontario, Canada, using a model-based approach. METHODS We developed a microsimulation model to simulate pertussis natural history. Daily probabilities of pertussis complications, hospitalizations, and disease sequelae as well as utilities and costs for health states were literature-derived. A healthcare payer perspective was used with a lifetime time horizon. Model outcomes were compared to those from a model with no pertussis health states. Probabilistic sensitivity analyses were used to generate distributions for estimates. Economic burden was estimated by multiplying case cost estimates by annual age-specific incidence. RESULTS Overall, LYs lost per pertussis case was low, with negligible LYs lost in those aged >4 years. Infants (<6 months) had the greatest mean QALY loss per case (0.58), while adults lost only 0.05 QALYs per case. Infants experienced the greatest mean cost per case of $22,768 (95% CI: 21,144-23,406). Case costs generally declined with age, but increased in seniors (aged 65+) with mean cost of $1920 (95% CI: 1800-2033). Based on historic age-specific incidence, pertussis costs the Ontario healthcare system approximately $7.6-$21.5 M annually. In total economic cost estimates with QALYs valued at 1xGDP (3xGDP) per capita, the net impact of pertussis in Ontario was estimated at $21.7-$66.5 M annually ($50.0-$156.3 M). For all of Canada, total economic costs were estimated at $79.6-$241.3 M ($187.5-$580.5 M) annually. CONCLUSION The health and economic consequences of pertussis persistence are substantial and highlight the need for improved control strategies.
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Affiliation(s)
- Ashleigh McGirr
- Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
| | - David N Fisman
- Dalla Lana School of Public Health, University of Toronto, Toronto, Canada; Division of Infectious Diseases, Department of Medicine, Faculty of Medicine, University of Toronto, Toronto, Canada.
| | - Ashleigh R Tuite
- Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
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Pertussis in the Association of Southeast Asian Nations: epidemiology and challenges. Int J Infect Dis 2019; 87:75-83. [PMID: 31369823 DOI: 10.1016/j.ijid.2019.07.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 07/13/2019] [Accepted: 07/20/2019] [Indexed: 12/24/2022] Open
Abstract
Pertussis is a highly infectious respiratory disease caused by Bordetella pertussis. Infants and young children are particularly at risk of severe and life-threatening disease. Infectious older individuals may transmit Bordetella pertussis to unprotected infants. Pertussis control measures have even failed in some countries with high pertussis vaccination coverage rates, leading to increased incidence rates. In 2014, this caused the World Health Organization to declare pertussis resurgent in some countries and led to recommendations regarding pertussis surveillance and national immunization programs. Despite the resurgence of pertussis, epidemiology of the disease in Southeast Asia has received little attention. In this narrative review, we describe pertussis surveillance systems, control measures, epidemiologic trends, and region-specific pertussis research in Southeast Asia. We also make recommendations for the intensification of pertussis surveillance and research in the region.
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Bell CA, Russell ML, Drews SJ, Simmonds KA, Svenson LW, Schwartz KL, Kwong JC, Mahmud SM, Crowcroft NS. Acellular pertussis vaccine effectiveness and waning immunity in Alberta, Canada: 2010–2015, a Canadian Immunization Research Network (CIRN) study. Vaccine 2019; 37:4140-4146. [DOI: 10.1016/j.vaccine.2019.05.067] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 05/19/2019] [Accepted: 05/23/2019] [Indexed: 11/15/2022]
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Crowcroft NS, Schwartz KL, Chen C, Johnson C, Li Y, Marchand-Austin A, Bolotin S, Jamieson FB, Drews SJ, Russell ML, Svenson LW, Simmonds K, Mahmud SM, Kwong JC. Pertussis vaccine effectiveness in a frequency matched population-based case-control Canadian Immunization Research Network study in Ontario, Canada 2009–2015. Vaccine 2019; 37:2617-2623. [DOI: 10.1016/j.vaccine.2019.02.047] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 02/15/2019] [Accepted: 02/18/2019] [Indexed: 11/25/2022]
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Savage RD, Rosella LC, Crowcroft NS, Horn M, Khan K, Varia M. Accuracy of health administrative data to identify cases of reportable travel or migration-related infectious diseases in Ontario, Canada. PLoS One 2018; 13:e0207030. [PMID: 30403758 PMCID: PMC6221317 DOI: 10.1371/journal.pone.0207030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 10/23/2018] [Indexed: 11/18/2022] Open
Abstract
An ongoing challenge of estimating the burden of infectious diseases known to disproportionately affect migrants (e.g. malaria, enteric fever) is that many health information systems, including reportable disease surveillance systems, do not systematically collect data on migrant status and related factors. We explored whether health administrative data linked to immigration records offered a viable alternative for accurately identifying cases of hepatitis A, malaria and enteric fever in Ontario, Canada. Using linked health care databases generated by Ontario's universal health care program, we constructed a cohort of medically-attended individuals with presumed hepatitis A, malaria or enteric fever in Peel region using diagnostic codes. Immigrant status was ascertained using linked immigration data. The sensitivity and positive predictive value (PPV) of diagnostic codes was evaluated through probabilistic linkage of the cohort to Ontario's reportable disease surveillance system (iPHIS) as the reference standard. Linkage was successful in 90.0% (289/321) of iPHIS cases. While sensitivity was high for hepatitis A and enteric fever (85.8% and 83.7%) and moderate for malaria (69.0%), PPV was poor for all diseases (0.3-41.3%). The accuracy of diagnostic codes did not vary by immigrant status. A dated coding system for outpatient physician claims and exclusion of new immigrants not yet eligible for health care were key challenges to using health administrative data to identify cases. Despite this, we show that linkages of health administrative and immigration records with reportable disease surveillance data are feasible and have the potential to bridge important gaps in estimating burden using either data source independently. .
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Affiliation(s)
- Rachel D. Savage
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
- ICES, Toronto, Ontario, Canada
- * E-mail:
| | - Laura C. Rosella
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
- ICES, Toronto, Ontario, Canada
- Public Health Ontario, Toronto, Ontario, Canada
| | - Natasha S. Crowcroft
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
- Public Health Ontario, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Maureen Horn
- Peel Public Health, Mississauga, Ontario, Canada
| | - Kamran Khan
- Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada
- Department of Medicine, Division of Infectious Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Monali Varia
- Peel Public Health, Mississauga, Ontario, Canada
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