Public Health Perspectives on the Rising Incidence of Pertussis

Pertussis-like syndrome often not associated with Bordetella pertussis: 5-year study in a large children's hospital

Background: Recently, a resurgence of pertussis has been observed worldwide despite broad vaccination coverage. The purpose of this study was to identify the clinical characteristics and the aetiological agent of pertussis-like syndrome (PLS) in Eastern China.Methods: 1168 patients who were diagnosed with a suspected Bordetella pertussis in Shanghai Children's Hospital from 2013 to 2017 were included in the study. Clinical features and aetiologies were analysed. Aetiological analyses in sub-cohorts of age, seasons and years were also investigated.Results: 96.0% (1121) of the patients were less than 12 months old. 59.0% (689) of the patients were male. The Top 5 pathogens were respiratory syncytial virus (RSV; n = 125; 10.7%), Streptococcus pneumonia (SP; n = 109; 9.3%), Haemophilus influenzae type b (HIB; n = 86; 7.4%), Bordetella pertussis (B. pertussis; n = 84; 7.2%), and Mycoplasma pneumonia (MP; n = 80; 6.9%), respectively. The percentage of SP in the age group of 0-3 months was significantly lower than that in other age groups. The percentage of B. pertussis in the age group of 3-6 months was significantly lower than that in the group of 6-12 months. The percentage of MP in 0-3 months' group was significantly lower than that in >12 months group. RSV peaked in winter (n = 52), while HIB peaked in spring (n = 38).Conclusion: PLS occurred most often in infants. RSV, SP, HIB, B. pertussis, and MP were the most prevalent pathogens. Since patients with B. pertussis and other pathogens have similar clinical manifestations, diagnosis of pertussis should be based on both clinical symptoms and laboratory confirmation.

Prevention of pertussis through adult vaccination

Pertussis is a vaccine preventable respiratory infection. Young infants are at high risk of developing severe complications from infection. Despite high rates of pediatric vaccine uptake, there continues to be increases in pertussis cases, likely due to waning immunity from childhood vaccine and increased transmission through adults. Currently, pertussis booster vaccine (Tdap) is recommended for unimmunized adults and for women in the third trimester of each pregnancy; yet adult Tdap coverage remains low. Administering Tdap vaccine at non-traditional vaccination clinics and at sites where adults are accessing care for their children are effective in improving adult Tdap uptake. While most are willing to receive vaccine when recommended by their provider, lack of provider recommendation is a major obstacle to immunization. Future studies to understand barriers to provider vaccine recommendations need to be undertaken to develop interventions to improve adult Tdap vaccine uptake and reduce pertussis infection in the susceptible population.

Report of a pertussis outbreak in a low coverage booster vaccination group of otherwise healthy children in Italy

Background

The introduction of universal pertussis immunization and the high coverage achieved in most developed countries have largely changed the epidemiology of the disease. Although vaccination rates are high in the first year of life, the rates of booster doses are unsatisfactory and lead to the onset of outbreaks. This report describes an outbreak of pertussis affecting school students already immunized in a town of Puglia (Italy), detected at the end of April 2009.

Methods

Vaccine effectiveness is measured by calculating the incidence rates (attack rates- AR) of disease among vaccinated (ARV) and unvaccinated (ARU) people and determining the percentage reduction in the incidence rate of disease among vaccinated people compared to unvaccinated people.

Results

The index case was a healthy child, female, 9-years-old who attended a local elementary school and developed pertussis on 27 April 2009. The secondary cases were the aunt and the cousin of the index case who developed a cough on 10 May 2009. In the elementary class of the index case, a cluster occurred. The overall AR was 15.8%, in particular 20% in children who did not receive the booster doses at 5–6 years old (ARU) and 14.3% in children receiving the booster (ARV). The VE of booster dose in this setting was 28.5%. Moreover, only the index case developed a persistent cough; the VE against moderate to severe pertussis was 100%. A cluster was detected in the middle school class that the cousin of the index case attended; AR was 44.4% (12/27); ARU was 50% (10/20) and ARV 28.6% (2/7). VE in this setting was 42.8%.

Conclusions

Our results confirm the need to administer booster doses; failure the booster is the principal determinant for the outbreak onset.

Relationship between the population incidence of pertussis in children in New South Wales, Australia and emergency department visits with cough: a time series analysis

Background

Little is known about the potential of syndromic surveillance to provide early warning of pertussis outbreaks. We conducted a time series analysis to assess whether an emergency department (ED) cough syndrome would respond to changes in the incidence of pertussis in children aged under 10 years in New South Wales (NSW), Australia, and to evaluate the timing of any association. A further aim was to assess the lag between the onset of pertussis symptoms and case notification in the infectious diseases surveillance system in NSW.

Methods

Using routinely collected data, we prepared a daily count time series of visits to NSW EDs assigned a provisional diagnosis of cough. Separate daily series were prepared for three independent variables: notifications of cases of pertussis and influenza and ED visits with bronchiolitis (a proxy measure of respiratory syncytial virus (RSV) infection). The study period was 1/1/2007-31/12/2010. A negative binomial multivariate model was used to assess associations between the outcome and independent variables. We also evaluated the median delay in days between the estimated onset of a case of pertussis and the date the local public health authority was notified of that case.

Results

When notified pertussis increased by 10 cases in one day, ED visits with cough increased by 5.2% (95% confidence interval (CI): 0.5%-10.0%) seven days later. Daily increases in the other independent variables had a smaller impact on cough visits. When notified influenza increased by 10 cases in one day, ED visits with cough increased by 0.8% (95% CI: 0%-1.7%) seven days later. When ED visits with bronchiolitis increased by 10 visits in one day, ED visits with cough increased by 4.8% (95% CI: 1.2%-8.6%) one day earlier. The median interval between estimated onset of pertussis and case notification was seven days.

Conclusions

Pertussis appears to be an important driver of ED visits with cough in children aged under 10 years. However, the median delay in notification of cases of pertussis was similar to the lag in the pertussis-associated short-term increases in ED visits with cough. Elevations in RSV and influenza activity may also explain increases in the ED cough syndrome. Real time monitoring of ED visits with cough in children is therefore unlikely to consistently detect a potential outbreak of pertussis before passive surveillance.

Protecting infants against pertussis: the cocooning strategy in practice

Cocooning is a strategy to protect infants from pertussis. This study explored the postpartum Tdap status of close newborn contacts during a primary care visit. The findings include a summary of the results and the implications for nurse practitioner practice to decrease the incidence of pertussis in the young infant.

Trends in Michigan early adolescent immunization: 2006-2008

OBJECTIVES

We have described vaccine coverage of Michigan young adolescents immunized with tetanus, diphtheria, and pertussis; meningococcal conjugate; and human papillomavirus vaccines during 2006-2008.

METHODS

We obtained data from the Michigan Care Improvement Registry, a state-based immunization information system that included more than 57 million vaccination records. We examined 3 overlapping cohorts of 11- and 12-year-old children (n > 350 000 in each) to assess temporal trends in vaccination coverage, characteristics of those immunized, funding sources, and vaccination sites.

RESULTS

Vaccine uptake increased during 2006 through 2008, peaking in the summer months. More than half of children receiving more than 1 vaccine received the vaccines simultaneously. Older age, receipt of Medicaid, and prior completion of early childhood immunizations were associated with greater odds of vaccination.

CONCLUSIONS

Vaccine coverage among Michigan young adolescents is increasing but continues to be relatively low. Coverage of 11- and 12-year-old children may improve with efforts to encourage vaccination at all health care visits, an increase in public funding in support of adolescent vaccination, and continued monitoring of adolescent vaccination levels through school-based assessments.

Pertussis-the case for universal vaccination

PURPOSE

Does the literature support universal vaccination of adolescents and adults, reducing disease incidence in infants and young children?

DESIGN & METHODS

An extensive literature review and a meta-analysis of four case-control studies, evaluating effects of missed or late vaccine doses, was conducted.

RESULTS

The literature confirms (a) increasing pertussis rates; (b) adults and adolescents are the primary carriers; (c) vaccine effectiveness wanes over time; and (d) pertussis persists despite disease control efforts.

PRACTICE IMPLICATIONS

Missed or late doses mean an increase in likelihood of contracting pertussis, supporting full vaccination for children and boosters for adolescents/adults.

Registry research in dermatology

A medical "registry" is a systematic collection of information from cases of a particular disease or other health relevant condition. Hospital-based registries primarily address prognosis, whereas population-based registries provide estimates of disease incidence. Opportunities to establish and investigate dermatology hospital- and population-based registries abound.