Pertussis outbreak in a basic school in Estonia: Description, contributing factors and vaccine effectiveness

Abstract

The aim of the current study was to assess the epidemiological situation concerning the emergence of a pertussis outbreak, as well as potential contributing factors and vaccine effectiveness. A retrospective epidemiological description and an analysis of the outbreak among students were performed. The basic school in Adavere had a total of 150 students in 2003. Of these, 54 cases of pertussis, with median age 12 y, all corresponding to clinical case definition, were identified with an attack rate of 36%. Regarding confirmation of the diagnosis, out of all clinical cases, 18 were confirmed by laboratory testing (2 by isolation of B. pertussis and 16 serologically based on single sera) and 36 with epidemiological linkage only. Of all the students with pertussis, 35 (65%) had received 4 doses and 6 (11%) 3 doses of DTwP vaccine; 13 (24%) students had received fewer than 3 doses or were unvaccinated. The contributing factors in generating this outbreak were close epidemiological contacts, late identification of pertussis diagnosis in the primary, secondary and later cases, as well as a too late initiated active surveillance. In this outbreak, low vaccine effectiveness and low vaccination coverage also played an important role.

Evidence of increased circulation of Bordetella pertussis in the Italian adult population from seroprevalence data (2012–2013)

“…Tuttavia, nonostante il raggiungimento di una copertura vaccinale estesa, la pertosse è ancora endemica (1,2,4). Questa infezione è fortemente riemersa negli ultimi dieci anni nei Paesi industrializzati e rimane la malattia meno controllata tra quelle prevenibili da vaccino nel mondo e rappresenta un problema importante nell'ambito delle malattie prevenibili da vaccinazione in diversi Paesi europei (5)(6)(7)(8)(9)(10)(11)(12)(13).…”

Epidemiological characteristics of pertussis in Estonia, Lithuania, Romania, the Czech Republic, Poland and Turkey—1945 to 2005

“…A comparison of pertussis surveillance systems in European countries has recommended that the World Health Organization (WHO) case definition, the standardisation of laboratory diagnosis and the integration of information on deaths from alternative sources should be supported [16]. However, the epidemiology of pertussis in Eastern Europe has, thus far, been reported only on an individual country basis [7,15].…”

High heterogeneity in methods used for the laboratory confirmation of pertussis diagnosis among European countries, 2010: integration of epidemiological and laboratory surveillance must include standardisation of methodologies and quality assurance

“…However, despite the extensive vaccination, pertussis has remained endemic [1][2][3][4]. The disease has resurged in the last decade and remains the least controlled of vaccine-preventable disease worldwide [5][6][7][8][9][10][11][12][13].…”