The epidemiology of pertussis in Germany: past and present

Abstract

BackgroundCurrent and past pertussis epidemiology in the two parts of Germany is compared in the context of different histories of vaccination recommendations and coverage to better understand patterns of disease transmission.MethodsAvailable regional pertussis surveillance and vaccination coverage data, supplemented by a literature search for published surveys as well as official national hospital and mortality statistics, were analyzed in the context of respective vaccination recommendations from 1964 onwards.ResultsRoutine childhood pertussis vaccination was recommended in the German Democratic Republic (GDR) from 1964 and in former West German states (FWG) from 1969, but withdrawn from 1974–1991 in FWG. Pertussis incidence declined to <1 case/100.000 inhabitants in GDR prior to reunification in 1991, while in FWG, where pertussis was not notifiable after 1961, incidence was estimated at 160–180 cases/100.000 inhabitants in the 1970s-1980s. Despite recommendations for universal childhood immunization in 1991, vaccination coverage decreased in former East German States (FEG) and increased only slowly in FWG. After introduction of acellular pertussis vaccines in 1995, vaccination coverage increased markedly among younger children, but remains low in adolescents, especially in FWG, despite introduction of a booster vaccination for 9–17 year olds in 2000. Reported pertussis incidence increased in FEG to 39.3 cases/100.000 inhabitants in 2007, with the proportion of adults increasing from 20% in 1995 to 68% in 2007. From 2004–2007, incidence was highest among 5–14 year-old children, with a high proportion fully vaccinated according to official recommendations, which did not include a preschool booster until 2006. Hospital discharge statistics revealed a ~2-fold higher pertussis morbidity among infants in FWG than FEG.ConclusionThe shift in pertussis morbidity to older age groups observed in FEG is similar to reports from other countries with longstanding vaccination programs and suggests that additional booster vaccination may be necessary beyond adolescence. The high proportion of fully vaccinated cases in older children in FEG suggests waning immunity 5–10 years after primary immunisation in infancy. The higher incidence of pertussis hospitalisations in infants suggests a stronger force of infection in FWG than FEG. Nationwide pertussis reporting is required for better evaluation of transmission patterns and vaccination policy in both parts of Germany.

Surveillance of hospitalized and outpatient cases of pertussis in Catalonia from 2003 to 2009

“…However, the incidence of pertussis has increased in recent years, both in Catalonia and other countries. [10][11][12][13] The rate of hospitalized cases < 1 y was 39 per 100,000 persons/y, compared with the 196 per 100,000 persons/y found by Somerville et al 14 or the 56 per 100,000 persons/y found by Elliot et al 15 In our study, 38.7% of hospitalized cases were correctly vaccinated, compared with the 66% found in an Australian study, 15 although another Australian study in New South Wales found that only 3% of hospitalized cases were correctly vaccinated, 16 and a German study found a rate of 4.5%. 17 A higher percentage of unvaccinated cases than vaccinated cases may be expected to be found in hospitalized cases, as vaccination should prevent both infection and the severity of cases.…”

Characteristics of pertussis outbreaks in Catalonia, Spain, 1997 to 2010

“…These results are in agreement with other studies performed in the last decade. [11][12][13][14][15][16][17] Changes in the pertussis vaccination schedule in Catalonia occurred during the study period, similar to those occurring in other countries, such as Sweden, Italy and Finland. [18][19][20][21] These changes and changes introduced in the pertussis surveillance system in Catalonia make it difficult to interpret the data.…”

Pertussis

“…88 An epidemiological study carried out in Germany before re-unification showed similar results; the lack of booster dose at school age was clearly associated with a high incidence in the >5-y-age-group. 89 In the light of these data, it is clear that a booster dose at pre-school or school age should be included in pertussis vaccination schedules and that efforts should be made to achieve vaccine coverage in this age group.…”