Volume 76, Issue 2
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645


Human eastern equine encephalitis (EEE) is a life-threatening mosquito-borne disease. To determine whether mosquito abundance and EEE virus infection rates are associated with human EEE disease, we evaluated retrospectively a total of 592,637 mosquitoes and onset dates for 20 confirmed human cases over 26 years in Massachusetts. Annual populations at 10 defined sites decreased over the study period ( = 0.002). Weekly infection rates and number of infected captured per trap night were positively associated EEE cases ( < 0.023 and < 0.001, respectively), whereas abundance was not ( = 0.077). The infection rate for of 0.39 per 1,000 tested mosquitoes identified human cases with a sensitivity of 0.87, a specificity of 0.82, a positive predictive value of 0.14, and a negative predictive value of 0.995. Timely mosquito testing and infection rate calculation are critical for disease risk estimation and outbreak control efforts.


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  • Received : 30 Dec 2005
  • Accepted : 13 Nov 2006

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