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Ongoing transmission of hepatitis B virus in rural parts of the Netherlands, 2009-2013.

Soetens LC, van Benthem BH, Urbanus A, Cremer J, Benschop KS, Rietveld A, van Dijk EI, Hahné SJ - PLoS ONE (2015)

Bottom Line: Cluster analysis identified two significant clusters (p<0.000) in the South-western and North-eastern regions.Rural border regions showed higher incidences and more ongoing transmission, mainly among MSM, than the more urban inland areas.Therefore, preventive measures should be enhanced in these regions.

View Article: PubMed Central - PubMed

Affiliation: Epidemiology and Surveillance Unit, Centre of Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, The Netherlands.

ABSTRACT

Background: Reported acute hepatitis B incidence in the Netherlands reached its nadir in 2013. However, regional signals about increased number of hepatitis B cases raised the question how hepatitis B incidence was distributed over the country. In this study, regional differences in hepatitis B epidemiology were investigated using epidemiological and molecular data.

Methods: Acute hepatitis B virus (HBV) infections, reported between 2009-2013, were included. If serum was available, a fragment of S and C gene of the HBV was amplified and sequenced. Regional differences in incidence were studied by geographical mapping of cases and cluster analysis. Regional differences in transmission were studied by constructing regional maximum parsimony trees based on the C gene to assess genetic clustering of cases.

Results: Between 2009 and 2013, 881 cases were notified, of which respectively 431 and 400 cases had serum available for S and C gene sequencing. Geographical mapping of notified cases revealed that incidences in rural border areas of the Netherlands were highest. Cluster analysis identified two significant clusters (p<0.000) in the South-western and North-eastern regions. Genetic cluster analysis showed that rural border areas had relatively large clusters of cases with indistinguishable sequences, while other regions showed more single introductions.

Conclusion: This study showed that regional differences in HBV epidemiology were present in the Netherlands. Rural border regions showed higher incidences and more ongoing transmission, mainly among MSM, than the more urban inland areas. Therefore, preventive measures should be enhanced in these regions.

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Related in: MedlinePlus

Regions for sexual health care in the Netherlands.Purple areas indicate the more rural regions, green areas indicate the more urban regions.
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pone.0117703.g001: Regions for sexual health care in the Netherlands.Purple areas indicate the more rural regions, green areas indicate the more urban regions.

Mentions: To study regional differences in epidemiology of acute hepatitis B, we stratified statistical analyses by region (Fig. 1). Furthermore, all cases were mapped using the geographic information system ArcGIS software, version 10.1. The postal code was used to identify the geographic location of cases, but data were aggregated and analysed on municipality level for privacy reasons. Incidences per municipality were calculated per 100,000 population. To identify geographic clusters of cases in the period 2009–2013, cluster analysis on municipality level was performed using the SaTScan software version 9.0 [9]. We used a discrete Poisson model, which assumes that the number of cases in each location is Poisson-distributed, and analysed the data with the space-time scan statistic to identify clusters in space and time. The space-time scan statistic uses cylindrical search windows in a space-time cube in order to seek significant spatio-temporal clusters. We set SaTScan to scan only for areas with high rates, that is for clusters.


Ongoing transmission of hepatitis B virus in rural parts of the Netherlands, 2009-2013.

Soetens LC, van Benthem BH, Urbanus A, Cremer J, Benschop KS, Rietveld A, van Dijk EI, Hahné SJ - PLoS ONE (2015)

Regions for sexual health care in the Netherlands.Purple areas indicate the more rural regions, green areas indicate the more urban regions.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4338044&req=5

pone.0117703.g001: Regions for sexual health care in the Netherlands.Purple areas indicate the more rural regions, green areas indicate the more urban regions.
Mentions: To study regional differences in epidemiology of acute hepatitis B, we stratified statistical analyses by region (Fig. 1). Furthermore, all cases were mapped using the geographic information system ArcGIS software, version 10.1. The postal code was used to identify the geographic location of cases, but data were aggregated and analysed on municipality level for privacy reasons. Incidences per municipality were calculated per 100,000 population. To identify geographic clusters of cases in the period 2009–2013, cluster analysis on municipality level was performed using the SaTScan software version 9.0 [9]. We used a discrete Poisson model, which assumes that the number of cases in each location is Poisson-distributed, and analysed the data with the space-time scan statistic to identify clusters in space and time. The space-time scan statistic uses cylindrical search windows in a space-time cube in order to seek significant spatio-temporal clusters. We set SaTScan to scan only for areas with high rates, that is for clusters.

Bottom Line: Cluster analysis identified two significant clusters (p<0.000) in the South-western and North-eastern regions.Rural border regions showed higher incidences and more ongoing transmission, mainly among MSM, than the more urban inland areas.Therefore, preventive measures should be enhanced in these regions.

View Article: PubMed Central - PubMed

Affiliation: Epidemiology and Surveillance Unit, Centre of Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, The Netherlands.

ABSTRACT

Background: Reported acute hepatitis B incidence in the Netherlands reached its nadir in 2013. However, regional signals about increased number of hepatitis B cases raised the question how hepatitis B incidence was distributed over the country. In this study, regional differences in hepatitis B epidemiology were investigated using epidemiological and molecular data.

Methods: Acute hepatitis B virus (HBV) infections, reported between 2009-2013, were included. If serum was available, a fragment of S and C gene of the HBV was amplified and sequenced. Regional differences in incidence were studied by geographical mapping of cases and cluster analysis. Regional differences in transmission were studied by constructing regional maximum parsimony trees based on the C gene to assess genetic clustering of cases.

Results: Between 2009 and 2013, 881 cases were notified, of which respectively 431 and 400 cases had serum available for S and C gene sequencing. Geographical mapping of notified cases revealed that incidences in rural border areas of the Netherlands were highest. Cluster analysis identified two significant clusters (p<0.000) in the South-western and North-eastern regions. Genetic cluster analysis showed that rural border areas had relatively large clusters of cases with indistinguishable sequences, while other regions showed more single introductions.

Conclusion: This study showed that regional differences in HBV epidemiology were present in the Netherlands. Rural border regions showed higher incidences and more ongoing transmission, mainly among MSM, than the more urban inland areas. Therefore, preventive measures should be enhanced in these regions.

Show MeSH
Related in: MedlinePlus