Persistence of pertussis in an immunized population: Results of the Nova Scotia Enhanced Pertussis Surveillance Program

doi:10.1016/S0022-3476(89)80643-2

The Journal of Pediatrics

Volume 115, Issue 5, Part 1, November 1989, Pages 686-693

https://doi.org/10.1016/S0022-3476(89)80643-2 Get rights and content

An enhanced pertussis surveillance and laboratory diagnosis program was initiated in the Halifax metropolitan area of Nova Scotia to better delineate the epidemiology of pertussis. During the 28 months of the study, 526 cases of pertussis were identified (overall yearly incidence: 74 cases per 100,000 population). Laboratory confirmation was obtained in 168 (32%) cases, including 111 (21%) by culture. Peak incidence occurred among children 2 to 5 years of age; the highest morbidity rate was seen in children less than 1 year of age. Hospitalization was required for 22 (4.2%) patients; 14 (64%) of those hospitalized were less than 1 year of age. Most (91%) patients had received at least three doses of pertussis vaccine; vaccine efficacy was estimated at 45%. The surveillance program demonstrated that the incidence of pertussis in Nova Scotia, although among the highest in North America, is still underestimated. A ninefold increase in cases was identified over the comparable period of the previous year, largely because patients meeting clinical criteria were reported. By supplementing culture techniques with immunofluorescent staining and serologic methods, we increased the rate of laboratory confirmation from 17% to 65%, suggesting that strict clinical criteria accurately reflect incidence. We conclude that pertussis remains a significant health problem in Nova Scotia, despite nearly universal vaccination.

References (27)

BroomeCV et al.
Epidemiology of pertussis, Atlanta, 1977
J Pediatr
(1981)
GellerRJ
The pertussis syndrome: a persistent problem
Pediatr Infect Dis J
(1984)
BassJW et al.
The return of pertussis
Pediatr Infect Dis J
(1987)
Centers for Disease Control
Summary of Notifiable Diseases, United States, 1986
MMWR
(1986)
VarugheseP
Incidence of pertussis in Canada
Can Med Assoc J
(1985)
FieldLH et al.
Pertussis outbreak in Austin and Travis County, Texas, 1975
J Clin Microbiol
(1977)
WassilakS et al.
Pertussis outbreak in Colorado: use of a newly-developed diagnostic test
SteketeeRW et al.
Evidence for a high attack rate and efficacy of erythromycin prophylaxis in a pertussis outbreak in a facility for the developmentally disabled
J Infect Dis
(1988)
BiellikRJ et al.
Risk factors for community- and household-acquired pertussis during a large-scale outbreak in central Wisconsin
J Infect Dis
(1988)
Statistics Canada
Notifiable Diseases Summary
Can Dis Weekly Rep
(1988)

CherryJD et al.

Report of the Task Force on Pertussis and Pertussis Immunization—1988

Pediatrics

(1988)

OnoratoIM et al.

Laboratory diagnosis of pertussis: the state of the art

Pediatr Infect Dis J

(1987)

SteketeeRW et al.

A comparison of laboratory and clinical methods for diagnosing pertussis in an outbreak in a facility for the developmentally disabled

J Infect Dis

(1988)

Cited by (82)

Pertussis vaccine effectiveness and duration of protection – A systematic review and meta-analysis
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Citation Excerpt :
Due to concerns about vaccine safety and efficacy, aP vaccine replaced wP vaccine in the vaccine programs of most developed and many middle-income countries in the late 1990′s [1]. Neither infection nor vaccination provides life-long immunity; outbreaks in older, vaccinated individuals in the 2000 s [4-6] highlighted concerns about the effectiveness of pertussis vaccines over time [6-9]. Previous systematic reviews and meta-analyses (SRMA) estimating pertussis vaccine effectiveness (VE) and waning immunity varied in both inclusion criteria and measured outcomes.
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.
Assessing adolescent immunization options for pertussis in Canada: A cost-utility analysis
2020, Vaccine
Citation Excerpt :
Age-related infection probabilities (10–14, 15–19, 20–24 years) were obtained from national incidence rates prior to introduction of the adolescent Tdap program (0.523%, 0.115%, and 0.028% for respective age groups) [15]. A correction factor (CF = 9) was applied to baseline probabilities to adjust for under-diagnosis implicit with reportable disease data [16,17]. Immunization uptake (63.2%) was obtained from a provincial report regarding immunization coverage of Ontario students [18].
Adolescent tetanus, diphtheria and pertussis (Tdap) immunization helps prevent pertussis infection. Timing of Tdap receipt represents an important facet of successful adolescent pertussis immunization. Potential strategies for timing of vaccine administration are each associated with different benefits – including disease prevention – and costs. The objective of this study was to assess the cost-utility of adolescent pertussis immunization strategies in Canada.
A cost-utility analysis was conducted using a pertussis disease history-simulating Markov model, with adolescents (beginning at age 10 years) as the cohort of interest. The model assessed three Tdap vaccination strategies: (1) immunization of 10 year olds, (2) removal of adolescent vaccination, and (3) immunization of 14 year olds (status quo). The analysis was conducted from a healthcare payer perspective and used a lifetime time horizon. Primary outcomes included life years, quality-adjusted life years (QALYs), health system costs, and an incremental cost-effectiveness ratio (ICER). Costs and outcomes were discounted at 1.5 percent annually. Deterministic and probabilistic sensitivity analyses were performed to assess parameter uncertainty.
The current recommended adolescent immunization strategy (at age 14) resulted in an average of 40.4432 expected QALYs and $26.28 per individual. This strategy was dominated by immunization at 10 years and no immunization. Compared to no immunization, immunizing adolescents at age 10 had an ICER of $74,899 per QALY. Results were most sensitive to the incidence of pertussis and the utility of moderate or severe pertussis. At a cost-effectiveness threshold of $50,000/QALY, removal of adolescent vaccination represented the most cost-effective strategy in 78% of simulations.
Analysis assumes a policy context where immunization of pregnant women is recommended. Findings suggest that alternate adolescent Tdap vaccine strategies – either immunization of 10 year olds, or removal of the adolescent vaccine – are more cost-effective than the current practice of immunizing 14 year olds.
A nested case-control study measuring pertussis vaccine effectiveness and duration of protection in Manitoba, Canada, 1992–2015: A Canadian Immunization Research Network Study
2019, Vaccine
Citation Excerpt :
Disease incidence rose from 1.2 cases per 100,000 people in 2008 to 9.4 cases per 100,000 people in 2012 [5]. Pertussis incidence increased elsewhere around the same time and patients were older and more likely to be fully-vaccinated against pertussis compared to earlier outbreaks [6–8], raising concerns that the immunity conferred by the acellular pertussis (aP) vaccine may wane over time [8–11]. To better understand the limitations of current and past pertussis vaccine programs, we measured the vaccine effectiveness (VE) and duration of protection of both the wP and aP vaccines in Manitoba.
Pertussis persists in Manitoba despite the universal availability of pertussis vaccines. Recent cases have included previously vaccinated individuals, raising concerns about declining vaccine effectiveness (VE). We measured pertussis VE and duration of protection using Manitoba’s provincial immunization and communicable disease registries.
Using a nested case-control design, individuals with laboratory-confirmed pertussis in Manitoba diagnosed between April 1, 1992, and March 31, 2015, were matched to up to five population-based controls on age, gender, geography, and case physician or number of physician visits. Conditional logistic regression was used to estimate VE against pertussis for both the whole-cell (wP) and acellular (aP) pertussis vaccines. Duration of protection was assessed using time since last dose.
Data on 534 eligible cases and 2614 controls were available for analysis. The adjusted VE estimate for aP-containing vaccines was 85% (95%CI: 74–91%); VE was 89% (66–96%) one to three years after the last vaccination. The adjusted VE of wP-containing vaccines was –15% (–91–31%) during a large outbreak in 1994 and 1995 compared to 35% (–26–66%) during non-outbreak years.
Our estimates suggest that the aP vaccine was effective in preventing pertussis since its introduction in Manitoba. VE was lower during a large outbreak, highlighting the importance of separately analyzing outbreak periods when estimating pertussis VE over time.
Bordetella pertussis (Pertussis) and Other Bordetella Species
2018, Principles and Practice of Pediatric Infectious Diseases
Pertussis Vaccines
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Genetic analysis of Bordetella pertussis in Ontario, Canada reveals one predominant clone
2013, International Journal of Infectious Diseases
To characterize Bordetella pertussis isolates in Ontario, Canada in order to understand the clonal diversity of strains present in this province.
A total of 521 isolates from the period 1998–2006 were analyzed by serotyping, pulsed-field gel electrophoresis (PFGE), and DNA sequencing of their virulence factors of pertactin, fimbriae 3, pertussis toxin subunit 1, and pertussis toxin gene promoter. Characteristics of the Ontario isolates were compared to those described for isolates from Europe and Australia.
A single predominant clone was identified in Ontario, Canada, represented by 83.5% of the 521 isolates analyzed. This clone was characterized by the genotype fim3B, prn2, ptxS1A, and ptxP3 (sequence type (ST)-1), and 72.9% of this clone displayed three closely related PFGE profiles of BpSR11, BpSR5, and BpSR12. Pertussis isolates in Europe with these PFGE profiles and virulence factor genotype are reported as common. The Australian epidemic clone was previously reported to have the genotype prn2 and ptxP3.
The finding of one predominant B. pertussis clone in Ontario, Canada, with characteristics identical to strains involved in epidemics in Europe and Australia, suggests a potential link of this strain to the resurgence of pertussis in this province.

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⁺: Supported in part by National Health Research and Development Program grants Nos. 6603-1244-54 and 6603-1245-54 from Health and Welfare, Canada.

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Original articlePersistence of pertussis in an immunized population: Results of the Nova Scotia Enhanced Pertussis Surveillance Program+

J Pediatr

The pertussis syndrome: a persistent problem

Pediatr Infect Dis J

The return of pertussis

Pediatr Infect Dis J

Summary of Notifiable Diseases, United States, 1986

MMWR

Incidence of pertussis in Canada

Can Med Assoc J

Pertussis outbreak in Austin and Travis County, Texas, 1975

J Clin Microbiol

Pertussis outbreak in Colorado: use of a newly-developed diagnostic test

Evidence for a high attack rate and efficacy of erythromycin prophylaxis in a pertussis outbreak in a facility for the developmentally disabled

J Infect Dis

Risk factors for community- and household-acquired pertussis during a large-scale outbreak in central Wisconsin

J Infect Dis

Notifiable Diseases Summary

Can Dis Weekly Rep

Report of the Task Force on Pertussis and Pertussis Immunization—1988

Pediatrics

Laboratory diagnosis of pertussis: the state of the art

Pediatr Infect Dis J

A comparison of laboratory and clinical methods for diagnosing pertussis in an outbreak in a facility for the developmentally disabled

J Infect Dis

Original article
Persistence of pertussis in an immunized population: Results of the Nova Scotia Enhanced Pertussis Surveillance Program+