Vincenti-Gonzalez Maria F, Grillet María-Eugenia, Velasco-Salas Zoraida I, Lizarazo Erley F, Amarista Manuel A, Sierra Gloria M, Comach Guillermo, Tami Adriana
Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
Laboratorio de Biología de Vectores y Parásitos, Instituto de Zoología y Ecología Tropical, Facultad de Ciencias, Universidad Central de Venezuela, Caracas, Venezuela.
PLoS Negl Trop Dis. 2017 Jan 23;11(1):e0005317. doi: 10.1371/journal.pntd.0005317. eCollection 2017 Jan.
Dengue virus (DENV) transmission is spatially heterogeneous. Hence, to stratify dengue prevalence in space may be an efficacious strategy to target surveillance and control efforts in a cost-effective manner particularly in Venezuela where dengue is hyperendemic and public health resources are scarce. Here, we determine hot spots of dengue seroprevalence and the risk factors associated with these clusters using local spatial statistics and a regression modeling approach.
METHODOLOGY/PRINCIPAL FINDINGS: From August 2010 to January 2011, a community-based cross-sectional study of 2012 individuals in 840 households was performed in high incidence neighborhoods of a dengue hyperendemic city in Venezuela. Local spatial statistics conducted at household- and block-level identified clusters of recent dengue seroprevalence (39 hot spot households and 9 hot spot blocks) in all neighborhoods. However, no clusters were found for past dengue seroprevalence. Clustering of infection was detected at a very small scale (20-110m) suggesting a high disease focal aggregation. Factors associated with living in a hot spot household were occupation (being a domestic worker/housewife (P = 0.002), lower socio-economic status (living in a shack (P<0.001), sharing a household with <7 people (P = 0.004), promoting potential vector breeding sites (storing water in containers (P = 0.024), having litter outdoors (P = 0.002) and mosquito preventive measures (such as using repellent, P = 0.011). Similarly, low socio-economic status (living in crowded conditions, P<0.001), having an occupation of domestic worker/housewife (P = 0.012) and not using certain preventive measures against mosquitoes (P<0.05) were directly associated with living in a hot spot block.
CONCLUSIONS/SIGNIFICANCE: Our findings contribute to a better comprehension of the spatial dynamics of dengue by assessing the relationship between disease clusters and their risk factors. These results can inform health authorities in the design of surveillance and control activities. Focalizing dengue control measures during epidemic and inter-epidemic periods to disease high risk zones at household and neighborhood-level may significantly reduce virus transmission in comparison to random interventions.
登革热病毒（DENV）的传播在空间上是异质的。因此，对登革热流行情况进行空间分层，可能是一种以具有成本效益的方式确定监测和控制工作目标的有效策略，特别是在登革热高度流行且公共卫生资源稀缺的委内瑞拉。在此，我们使用局部空间统计和回归建模方法，确定登革热血清流行率的热点区域以及与这些聚集区相关的风险因素。
方法/主要发现：2010年8月至2011年1月，在委内瑞拉一个登革热高度流行城市的高发病率社区，对840户家庭中的2012名个体进行了一项基于社区的横断面研究。在家庭和街区层面进行的局部空间统计，在所有社区中识别出近期登革热血清流行率的聚集区（39个热点家庭和9个热点街区）。然而，未发现既往登革热血清流行率的聚集区。感染聚集在非常小的尺度（20 - 110米）上被检测到，表明疾病具有高度的局部聚集性。与居住在热点家庭相关的因素包括职业（家政工人/家庭主妇，P = 0.002）、社会经济地位较低（居住在棚屋，P < 0.001）、家庭人口少于7人（P = 0.004）、存在潜在的病媒滋生场所（在容器中储水，P = 0.024）、户外有垃圾（P = 0.002）以及采取蚊虫预防措施（如使用驱蚊剂，P = 0.011）。同样，社会经济地位较低（居住在拥挤环境，P < 0.001）、职业为家政工人/家庭主妇（P = 0.012）以及未采取某些防蚊措施（P < 0.05）与居住在热点街区直接相关。
结论/意义：我们的研究结果通过评估疾病聚集区与其风险因素之间的关系，有助于更好地理解登革热的空间动态。这些结果可为卫生当局设计监测和控制活动提供参考。与随机干预相比，在流行期和非流行期将登革热控制措施集中在家庭和社区层面的疾病高风险区域，可能会显著减少病毒传播。
