Spatial-temporal variation and primary ecological drivers of Anopheles sinensis human biting rates in malaria epidemic-prone regions of China

Zhoupeng Ren; Duoquan Wang; Jimee Hwang; Adam Bennett; Hugh J W Sturrock; Aimin Ma; Jixia Huang; Zhigui Xia; Xinyu Feng; Jinfeng Wang

doi:10.1371/journal.pone.0116932

Spatial-temporal variation and primary ecological drivers of Anopheles sinensis human biting rates in malaria epidemic-prone regions of China

PLoS One. 2015 Jan 22;10(1):e0116932. doi: 10.1371/journal.pone.0116932. eCollection 2015.

Authors

Zhoupeng Ren¹, Duoquan Wang², Jimee Hwang³, Adam Bennett⁴, Hugh J W Sturrock⁴, Aimin Ma⁵, Jixia Huang⁶, Zhigui Xia², Xinyu Feng², Jinfeng Wang⁷

Affiliations

¹ State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Science and Natural Resource Research, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China; Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China.
² National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, People's Republic of China.
³ Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, California, United States of America; Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
⁴ Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, California, United States of America.
⁵ State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Science and Natural Resource Research, Chinese Academy of Sciences, Beijing, China; Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China; College of Geoscience and Surveying Engineering, China University of Mining and Technology, Beijing, China.
⁶ State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Science and Natural Resource Research, Chinese Academy of Sciences, Beijing, China; Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China; Center of 3S Technology and Mapping, Beijing Forestry University, Beijing, China.
⁷ State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Science and Natural Resource Research, Chinese Academy of Sciences, Beijing, China; Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China.

Abstract

Background: Robust malaria vector surveillance is essential for optimally selecting and targeting vector control measures. Sixty-two vector surveillance sites were established between 2005 and 2008 by the national malaria surveillance program in China to measure Anopheles sinensis human biting rates. Using these data to determine the primary ecological drivers of malaria vector human biting rates in malaria epidemic-prone regions of China will allow better targeting of vector control resources in space and time as the country aims to eliminate malaria.

Methods: We analyzed data from 62 malaria surveillance sentinel sites from 2005 to 2008. Linear mixed effects models were used to identify the primary ecological drivers for Anopheles sinensis human biting rates as well as to explore the spatial-temporal variation of relevant factors at surveillance sites throughout China.

Results: Minimum semimonthly temperature (β = 2.99; 95% confidence interval (CI) 2.07- 3.92), enhanced vegetation index (β =1.07; 95% CI 0.11-2.03), and paddy index (the percentage of rice paddy field in the total cultivated land area of each site) (β = 0.86; 95% CI 0.17-1.56) were associated with greater An. Sinensis human biting rates, while increasing distance to the nearest river was associated with lower An. Sinensis human biting rates (β = -1.47; 95% CI -2.88, -0.06). The temporal variation (σ(s0)(2) = 0.83) in biting rates was much larger than the spatial variation (σ(t)(2) = 1.35), with 19.3% of temporal variation attributable to differences in minimum temperature and enhanced vegetation index and 16.9% of spatial variance due to distance to the nearest river and the paddy index.

Discussion: Substantial spatial-temporal variation in An. Sinensis human biting rates exists in malaria epidemic-prone regions of China, with minimum temperature and enhanced vegetation index accounting for the greatest proportion of temporal variation and distance to nearest river and paddy index accounting for the greatest proportion of spatial variation amongst observed ecological drivers.

Conclusions: Targeted vector control measures based on these findings can support the ongoing malaria elimination efforts in China more effectively.

Publication types

Multicenter Study
Research Support, Non-U.S. Gov't

MeSH terms

Animals
Anopheles*
China / epidemiology
Ecosystem*
Epidemiological Monitoring*
Female
Humans
Insect Bites and Stings / epidemiology*
Insect Vectors*
Malaria / epidemiology
Malaria / transmission
Male

Grants and funding

This study was supported by the National S & T Major Program (Grant No. 2012ZX10004-220, 2012CB955503 and 2012 ZX10004-201). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.