Incidence of pertussis in persons ≤15 years of age in Valencia, Spain: seroprevalence of antibodies to pertussis toxin (PT) in children, adolescents and adults
Introduction
Bordetella pertussis continues to be a cause of childhood morbidity, specially in developing countries. An estimated 50 million cases and 300 000 deaths occur every year worldwide; case fatality rates in developing countries may be as high as 4% in infants.1 Widespread immunization of infants and children has resulted in changes in the epidemiology of B. pertussis in the developed countries. The frequency of the disease has declined overall, but the circulation of B. pertussis had not been eliminated and a change in the clinical spectrum and age-related incidence of the disease has been observed.2 Furthermore, the vaccine-induced immunity is not long lasting and it is known to wane in the decade following the last dose of vaccine.3 The whole-cell pertussis vaccine was introduced in Spain in 1965 and the high coverage achieved with DTP vaccine resulted in a marked decline in the incidence of whooping cough. Incidence was 133 cases per 100 000 population in 1982, when pertussis became a national reportable disease, whereas the annual incidence reported in 2000 and 2001 was 2.3 and 0.9 cases per 100 000 population, respectively.4., 5. However, the real incidence will be highly underestimated, as surveillance of pertussis basically relies on notifications of clinically diagnosed cases from general practitioners and paediatricians.6., 7. Pertussis is rarely considered or diagnosed in older children, adolescents or adults, however, it appears to be epidemiologically significant since it represents a reservoir for infection of unprotected individuals. Serological methods using antigen-specific enzyme linked immunoassays (ELISAs) have been developed to increase the sensitivity of the laboratory diagnostic method.8., 9. These serologic methods have been used in studies to estimate the incidence of pertussis, as well as in seroepidemiological surveys to assess the prevalence of pertussis antibodies in different population groups.10., 11., 12., 13., 14., 15., 16., 17., 18., 19. This paper reports the results of a study conducted in Valencia, a Mediterranean region of Spain, to determine the population-based incidence of pertussis in persons ≤15 years in age, and to assess the prevalence of IgG antibodies to pertussis toxin (PT) in children, adolescents and adults.
Section snippets
Material and methods
This prospective active-surveillance study was conducted during 1-year period (from February 1st, 2001 to January 31st, 2002) by a network of 10 paediatric primary care centres in Valencia, Spain. These centres have a total of 10 848 registered patients aged 0–15 years. All parents or tutors signed a written consent form.
Incidence of pertussis
A total of 61 patients ≤15 years in age (mean age 5.7±3.6 years and 55% females) presented with symptoms leading to a clinical diagnosis of pertussis (cough that lasted for more than 2 weeks) we detected during the 1-year study period. Of these, 57 subjects provided serum specimens. Blood samples were taken at a mean of 18.2±4.1 days after the onset of cough. Serological evidence of recent pertussis infection was found in 9% (5/57) of these patients. The mean duration of cough in these patients
Discussion
Sixty-one clinical cases of prolonged cough were reported during the 1-year study period in a follow-up population of about 10 000 persons ≤15 years in age. But elevated absorbance value of IgG to PT ≥2.0, indicative of current or recent infection, was only detected in five cases, that were considered confirmed cases for the study. These cases represent an annual incidence of about 46.0 per 100 000 persons ≤15 years in age, being of 76.1 and 59.8 per 100 000 children 2–5 and 6–10 years in age,
References (38)
- et al.
Serological correlates in whooping cough
Vaccine
(1993) - et al.
Seroepidemiology or Bordetella pertussis infections in the Spanish population: a cross-sectional study
Vaccine
(2000) - et al.
Pertussis vaccination: is there a need for a booster dose?
Lancet
(1994) - et al.
Pertussis vaccination
Lancet
(1994) - National Institute of Health, National Institute of Allergy and Infectious Diseases. Respiratory infections. In: The...
- et al.
Mass vaccination of children with pertussis toxoid decreased incidence in both vaccinated and nonvaccinated persons
Clin Infect Dis
(2001) Duration of effectiveness of pertussis vaccine: evidence form a 10 year community study
BMJ
(1988)Incidencia de las enfermedades transmisibles de declaración obligatoria. Casos y tasas por 100.000 habitantes a nivel provincial/CC.AA
Bol Epidemiol Sem
(2000)Incidencia de las enfermedades transmisibles de declaración obligatoria. Casos y tasas por 100.000 habitantes a nivel provincial/CC.AA. España
Bol Epidemiol Sem
(2001)Epidemiology of pertussis
Pediatr Infect Dis
(1997)
Whooping cough diagnosis: a clinical evaluation of complementing culture and immunofluorescence with enzyme-linked immunosorbent assay of pertussis immunoglobulin A in nasopharyngeal secretions
J Med Microbiol
A controlled trial of a two-component acellular, a five-component acellular and a whole-cell pertussis vaccine
N Engl J Med
A controlled trial of two acellular and one whole-cell bacines against pertussis
N Engl J Med
Comparación de tres técnicas ELISA para evaluar la seroprevalencia de IgG frente a Bordetella pertussis en niños vacunados con tres dosis de DTPe
Enferm Infecc Microbiol Clin
Widespread silent transmission of pertussis in families: antibody correlates of infection and symptomatology
J Infect Dis
A search for Bordetella pertussis infection in university students
Clin Infect Dis
Bordetella pertussis infection
Med J Aust
A comparison of laboratory and clinical methods for diagnosing pertussis in an outbreak in a facility for the development disabled
J Infect Dis
Sensitivity and specificity of clinical case definitions for pertussis
Am J Public Health
Cited by (16)
Underdetection and underreporting of pertussis in children attended in primary health care centers: Do surveillance systems require improvement?
2016, American Journal of Infection ControlCitation Excerpt :During the same period, the incidence in adolescents aged 15-20 years increased from 0.37 cases per 100,000 person-years in 2010 to 7.93 in 2012.24 In Valencia, Spain, a prospective study using serologic evidence of recent pertussis infection was conducted between 2001 and 2002 in children from 10 PHCCs; the incidence was 46.0 per 100,000 person-years, showing that, despite of high pediatric vaccination coverages, B pertussis continues to circulate in Spain and 8% of children younger than age 2 years were undetected.18 In a retrospective study in 11 hospitals in Catalonia carried out in 1997-2001 to estimate hospitalizations due to pertussis in infants younger than age 12 months,25 there was underreporting in 36.4% of hospitalizations and, therefore, the real incidence was probably greatly underestimated.
Prevalence of atypical pathogens in patients with cough and community-acquired pneumonia: A meta-analysis
2016, Annals of Family MedicineCitation Excerpt :In a large, multi-country, European prospective study of adults presenting to primary care with cough of up to 28 days duration,17 prevalence was 3% (95% CI, 2.4%-3.6%). The prevalence was higher in studies of children (17.6%; 95% CI, 3.4%-31.8%) than in those of adults and children (8.9%; 95% CI, 6.7%-11.2%), but there was significant heterogeneity in the studies of children, with a range from 4.6% to 37.2%.67–70 Of the 26 countries to report data on B pertussis, Australia had the highest incidence rate of 105.0 cases per 100,000 persons per year.
Epidemiological features of pertussis resurgence based on community populations with high vaccination coverage in China
2015, Epidemiology and InfectionResurgence of pertussis in Europe
2005, Pediatric Infectious Disease JournalBordetella pertussis in School-Age Children, Adolescents and Adults: A Systematic Review of Epidemiology and Mortality in Europe
2021, Infectious Diseases and TherapySeroprevalence studies of pertussis: What have we learned from different immunized populations
2020, Pathogens and Disease