Background Despite high vaccination coverage, pertussis incidence in the Netherlands is

Background Despite high vaccination coverage, pertussis incidence in the Netherlands is amongst the highest in Europe with a shifting tendency towards adults and elderly. 2013. Socio-demographic and infrastructure-related population data were matched to the geo-coded laboratory data. The spatial scan statistic was applied to detect spatial and space-time clusters of testing, incidence and test-positivity. Geographically weighted Poisson regression (GWPR) models were then constructed to model the associations between the age-specific rates of testing and incidence and possible population-based determinants. Results Space-time clusters for pertussis incidence overlapped with space-time clusters for testing, reflecting a strong relationship between testing and incidence, irrespective of the examined age group. Testing for pertussis itself was overall associated with lower socio-economic status, multi-person-households, proximity to primary school and availability of healthcare. The current incidence in contradiction is mainly determined by testing and is not associated with a lower socioeconomic status. Discussion Testing for pertussis follows to an extent the general healthcare seeking behaviour for common respiratory infections, whereas the current pertussis incidence is largely the result of testing. More testing would thus not necessarily improve pertussis control. Detecting outbreaks using space-time cluster detection is feasible but needs to adjust for the strong impact of testing on the detection of pertussis cases. Introduction 1158838-45-9 manufacture Pertussis is a highly infectious respiratory disease caused by and is especially severe in unvaccinated and incomplete vaccinated children [1]. Despite the implementation of extensive vaccination schemes, the incidence of pertussis is increasing in many countries with a shifting tendency towards adults and elderly [2C7]. In fully vaccinated children and adults with waning immunity, the symptoms are often mild and indistinguishable from other respiratory diseases [5]. The clinical diagnosis of pertussis is challenging, not 1158838-45-9 manufacture 1158838-45-9 manufacture only because symptoms are often unspecific, but also because co-infection with respiratory diseases complicates diagnosis [5,8,9]. Additionally, sensitivity and specificity of the applied laboratory tests are influenced by vaccination coverage, frequency of mild cases within the population, exposure to pertussis and age of the patient so that no single laboratory test can be considered as gold standard for confirming pertussis cases [10]. The lack of universal standards to confirm pertussis infections thus further facilitates the spread of undiagnosed infections. This is problematic, as transmission through infected, but undiagnosed members of the same household are held responsible for most transmissions to not or incomplete vaccinated infants [11]. To further reduce transmission, several countries such as France, USA and Australia have incorporated adult booster doses in their respective vaccination schemes [12C15] and the Dutch health council recently recommended the introduction of maternal vaccination to the national vaccination program [16]. In the Netherlands, the pertussis SCA12 incidence is amongst the highest in Europe and rates have increased since 1996 [17]. The underlying reasons of this increase are not fully conclusive. Several studies attribute the increase of pertussis to a waning immunity in adults [2,17] and new emerging strains of [18,19]. Other studies suggest that an increase of detected pertussis infections occurs mainly because of an increased awareness of the population and general practitioners (GPs) [20C22] and enhanced notification systems [21C23]. Relating to current general practitioner guidelines in the Netherlands, a medical pertussis diagnosis is considered in individuals having standard symptoms such as severe coughing who had contact with a proven pertussis case. Additional screening for pertussis is only recommended for individuals in a household with an unvaccinated or incomplete vaccinated child more youthful than one year older and in households with a woman, which is more than 34 weeks pregnant [24]. For all other groups, screening is rather induced by the patient than the GP [25]. As pertussis is definitely a notifiable disease in the Netherlands [26] and many other countries, the producing monitoring data on screening and infections is used to monitor changes over space and time [27C29]. Despite earlier findings that pertussis is definitely highly heterogeneously distributed in space as well as with space-time [30,31], a substantial amount of current monitoring activities on pertussis is still restricted to a temporal analysis only [7,28,29,32], masking important regional variations and thus complicating an effective general public health response. Geographic Info Systems (GIS) and cluster detection methodsCboth, purely spatial as well as in time and space have proven useful to locate 1158838-45-9 manufacture possible outbreaks of infectious diseases [33C35], including 1158838-45-9 manufacture pertussis [30], resulting in a timely and effective response in affected areas. Such an approach might ultimately help to minimize the spread of pertussis at an early stage when the risk of transmission is definitely highest [36]. Efficient pertussis control however, requires additional background knowledge about.