1921
Volume 68, Issue 5
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645

Abstract

The California Mosquito-Borne Virus Surveillance and Response Plan recently was developed to provide a semi-quantitative means for assessing risk for western equine encephalomyelitis (WEE) or St. Louis encephalitis (SLE) viruses and to provide intervention guidelines for mosquito control and public health agencies during periods of heightened risk for human infection. West Nile virus recently has arrived in California, and the response plan also will provide a baseline for assessing the risk for human and equine infection with this virus. In the response plan, overall risk is calculated by averaging risk due to 1) environmental conditions, 2) adult mosquito vector abundance, 3) vector infection rates, 4) sentinel chicken seroconversion rates, 5) equine cases (for WEE), 6) human cases, and 7) the proximity of virus activity to populated areas. Overall risk is categorized into three levels: normal season, emergency planning, or epidemic conditions. We evaluated this response plan using historical data from years with no, enzootic, and epidemic activity of WEE and SLE in several areas of California to determine whether calculated risk levels approximated actual conditions. Multiple methods of risk calculation were considered for both viruses. Assessed risk based on cumulative temperature, rainfall, and runoff levels over the entire season provided more or equally accurate assessments than biweekly assessments based solely on the previous half-month. For WEE, during years with enzootic activity or early-season periods of years with WEE epidemic activity, combining horse and human cases as a single risk factor improved the model’s ability to forecast pending WEE activity, but separating the two factors allowed a better indication of WEE activity during epidemics and periods with no activity. For SLE, assignment of higher risk to drier conditions as measured by rainfall and runoff yielded the most accurate representation of actual virus activity during all recent study periods.

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2003-05-01
2017-09-21
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References

  1. Barker CM, Reisen WK, Kramer VL, 2002. Evaluation of the California encephalitis epidemic risk scheme using conditional simulations with historical data. Proc Mosq Vector Control Assoc Calif 70 : 31–34.
  2. Olson JG, Reeves WC, Emmons RW, Milby MM, 1979. Correlation of Culex tarsalis indices with the incidence of St. Louis encephalitis and western equine encephalomyelitis in California. Am J Trop Med Hyg 28 : 335–343.
  3. California Department of Health Services, Mosquito and Vector Control Association of California, University of California, 2002. California State Mosquito-borne Virus Surveillance and Response Plan. URL: http://westnile.ca.gov/CA%20Mosquito%20Response%20Plan%2010-17.doc. Last accessed: 4/1/2003.
  4. Reeves WC, 1990. Epidemiology and Control of Mosquito-Borne Arboviruses in California, 1943–1987. Sacramento, CA: California Mosquito and Vector Control Association.
  5. Reeves WC, Hammon WM, 1962. The Role of Arthropod Vectors. Smith CE, Griffiths W, Reeves WC, eds. Epidemiology of the Arthropod-Borne Viral Encephalitides in Kern County, California, 1943–1952. Berkeley, CA: University of California Press, 75–108.
  6. Kuno G, 2001. Persistence of arboviruses and antiviral antibodies in vertebrate hosts: its occurrence and impacts. Rev Med Virol 11 : 165–190.
  7. Walsh JD, 1987. California’s Mosquito Encephalitis Virus Surveillance and Control Program. Sacramento, CA: California Department of Health Services. 1987.
  8. Reisen WK, 1995. Guidelines for surveillance and control of arboviral encephalitis in California. Interagency Guidelines for the Surveillance and Control of Selected Vector-Borne Pathogens in California. Sacramento, CA: California Mosquito and Vector Control Association, 1–34.
  9. Gubler DJ, Campbell GL, Nasci R, Komar N, Petersen L, Roehrig JT, 2000. West Nile virus in the United States: guidelines for detection, prevention, and control. Viral Immunol 13 : 469–475.
  10. Reeves WC, 1990. Clinical and subclinical disease in man. Reeves WC, ed. Epidemiology and Control of Mosquito-Borne Arboviruses in California, 1943–1987. Sacramento, CA: California Mosquito and Vector Control Association, 1–25.
  11. Longshore WAJ, Stevens IM, Hollister AC Jr, Gittelsohn A, Lennette EH, 1956. Epidemiologic observations on acute infectious encephalitis in California, with special reference to the 1952 outbreak. Am J Hyg 63 : 69–86.
  12. Reisen WK, Meyer RP, Milby MM, Presser SB, Emmons RW, Hardy JL, Reeves WC, 1992. Ecological observations on the 1989 outbreak of St. Louis encephalitis virus in the southern San Joaquin Valley of California. J Med Entomol 29 : 472–482.
  13. Tueller JE, 1990. An outbreak of illness due to St. Louis encephalitis virus in the southern San Joaquin Valley, California, 1989. Proc Calif Mosq Vector Control Assoc 58 : 12.
  14. Reisen WK, 1984. Observations on arbovirus ecology in Kern County, California. Bull Soc Vector Ecol 9 : 6–16.
  15. Reisen WK, Lundstrom JO, Scott TW, Eldridge BF, Chiles RE, Cusack R, Martinez VM, Lothrop HD, Gutierrez D, Wright S, Boyce K, Hill BR, 2000. Patterns of avian seroprevalence to western equine encephalomyelitis and St. Louis encephalitis viruses in California, USA. J Med Entomol 37 : 507–527.
  16. Reisen WK, Boyce K, Yoshimura G, Lemenager D, Emmons RW, 1995. Enzootic transmission of western equine encephalomyelitis virus in the Sacramento Valley of California during 1993 and 1994. J Vector Ecol 20 : 153–163.
  17. Murray RA, Habel LA, Mackey KJ, Wallace HG, Peck BA, Mora SJ, Ginsberg MM, Emmons RW, 1985. Epidemiological aspects of the 1984 St Louis encephalitis epidemic in southern California. Proc Calif Mosq Vector Control Assoc 53 : 5–9.
  18. University of California Statewide Integrated Pest Management Program, 2002. UC IPM Online. URL: http://www.ipm.ucdavis.edu. Last accessed: 1/29/2003.
  19. California Department of Water Resources, 2002. California Data Exchange Center. URL: http://cdec.water.ca.gov. Last accessed: 1/29/2003.
  20. United States Geological Survey, 2002. NWISWeb Data for the Nation. URL: http://waterdata.usgs.gov/nwis/. Last accessed: 1/29/2003.
  21. Emmons RW, Milby MM, Gillies PA, Reeves WC, Bayer EV, White K, Woodie JD, Murray RA, 1984. Surveillance for arthropod-borne viral activity and disease in California during 1983. Proc Calif Mosq Vector Control Assoc 52 : 1–6.
  22. Emmons RW, Milby MM, Walsh JD, Reeves WC, Bayer EV, White K, Woodie JD, Murray RA, 1985. Surveillance for arthropod-borne viral activity and disease in California during 1984. Proc Calif Mosq Vector Control Assoc 53 : 1–4.
  23. Emmons RW, Dondero DV, Milby MM, Hui LT, Murray RA, Tueller JE, Ennik F, Wilson BA, Pitstick L, Hardy JL, Presser SB, Reeves WC, Barrett L, Ascher MS, 1990. Surveillance for arthropod-borne viral activity and disease in California during 1989. Proc Calif Mosq Vector Control Assoc 58 : 1–11.
  24. Emmons RW, Ascher MS, Dondero DV, Enge B, Reisen WK, Milby MM, Eliason DA, Murray RA, Lin J, Ennik F, Hui LT, Hardy JL, Presser SB, Reeves WC, Reilly K, 1994. Surveillance for arthropod-borne viral activity and disease in California during 1993. Proc Calif Mosq Vector Control Assoc 62 : 13–17.
  25. Kramer VL, Ascher MS, Enge B, Hui LT, Ball S, Ennik F, Reilly K, Reisen WK, Eliason DA, Lin J, Murray RA, Milby MM, Hardy JL, Presser SB, Chiles RE, Reeves WC, 1996. Surveillance for mosquito-borne encephalitis virus activity and human disease in California, 1995. Proc Mosq Vector Control Assoc Calif 64 : 3–7.
  26. Kramer VL, Ascher MS, Enge B, Hui LT, Reisen WK, Eliason DA, Lin J, Murray RA, Chiles RE, 1997. Surveillance for mosquito-borne encephalitis virus activity and human disease in California, 1996. Proc Mosq Vector Control Assoc Calif 65 : 16–23.
  27. Kramer VL, Husted SR, Ascher MS, Baylis E, Reisen WK, Eldridge BF, Chiles RE, Eliason DA, 1999. Surveillance for mosquito-borne encephalitis virus activity and human disease in California, 1998. Proc Mosq Vector Control Assoc Calif 67 : 32–37.
  28. Husted SR, Kramer VL, Cornelius A, Ascher MS, Rogers C, Chiles RE, Reisen WK, Eldridge BF, Glaser C, Gilliam S, Eliason DA, 2001. Surveillance for mosquito-borne encephalitis virus activity and human disease in California, including West Nile virus, 2000. Proc Mosq Vector Control Assoc Calif 69 : 2–8.
  29. Reeves WC, Hammon WM, 1962. Infection in other vertebrate hosts. Smith CE, Griffiths W, Reeves WC, eds. Epidemiology of the Arthropod-Borne Viral Encephalitides in Kern County, California, 1943–1952. Berkeley, CA: University of California Press, 46–74.
  30. Reeves WC, Geib AF, Hammon WM, 1962. Evaluation of the Vector Control Program. Smith CE, Griffiths W, Reeves WC, eds. Epidemiology of the Arthropod Borne Viral Encephalitides in Kern County, California, 1943–1952. Berkeley, CA: University of California Press, 155–178.
  31. Reeves WC, Hammon WM, 1962. Appendix. Smith CE, Griffiths W, Reeves WC, eds. Epidemiology of the Arthropod-Borne Viral Encephalitides in Kern County, California, 1943–1952 Berkeley, CA: University of California Press, 217–240.
  32. National Oceanic and Atmospheric Administration, 2002. National Climatic Data Center: Most Popular Questions. URL: http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?wwAW~MP~Q. Last accessed: 1/29/2003.
  33. Reisen WK, 1995. Effect of temperature on Culex tarsalis (Diptera: Culicidae) from the Coachella and San Joaquin Valleys of California. J Med Entomol 32 : 636–645.
  34. Reisen WK, Meyer RP, Presser SB, Hardy JL, 1993. Effect of temperature on the transmission of western equine encephalomyelitis and St. Louis encephalitis viruses by Culex tarsalis (Diptera: Culicidae). J Med Entomol 30 : 151–160.
  35. Monath TP, 1980. Epidemiology. Monath TP, ed. St. Louis Encephalitis. Washington, DC: American Public Health Association, 239–312.
  36. Reeves WC, Hammon WM, 1962. 4. Epidemiology of the arthropod-borne viral encephalitides in Kern County, California, 1943–1952. Smith CE, Griffiths W, Reeves WC, eds. University of California Publications in Public Health. Berkeley, CA: University of California Press, 1–257.
  37. Reeves WC, Milby MM, Reisen WK, 1990. Development of a statewide arbovirus surveillance program and models of vector populations and virus transmission. Reeves WC, ed. Epidemiology and Control of Mosquito-Borne Arboviruses in California, 1943–1987. Sacramento, CA: California Mosquito and Vector Control Association, 431–458.
  38. Monath TP, Tsai TF, 1987. St. Louis encephalitis: lessons from the last decade. Am J Trop Med Hyg 37 (Suppl): 40S–59S.
  39. Day JF, 2001. Predicting St. Louis Encephalitis virus epidemics: lessons from recent, and not so recent, outbreaks. Annu Rev Entomol 46 : 111–138.
  40. Reisen WK, Lothrop HD, Chiles RE, Cusack R, Green EG, Fang Y, Kensington M, 2002. Persistence and amplification of St. Louis encephalitis virus in the Coachella Valley of California, 2000—2001. J Med Entomol 39 : 793–805.
  41. Hess AD, Cherubin CE, LaMotte LC, 1963. Relation of temperature to activity of western and St. Louis encephalitis viruses. Am J Trop Med Hyg 12 : 657–667.
  42. Lumsden LL, 1958. St. Louis encephalitis in 1933. Observations on epidemiological features. Public Health Rep 73 : 340–353.
  43. Reisen WK, Monath TP, 1989. Western equine encephalomyelitis. Monath TP, ed. The Arboviruses: Epidemiology and Ecology. Boca Raton, FL: CRC Press, 89–138.
  44. Reisen WK, Chiles RE, 1997. Prevalence of antibodies to western equine encephalomyelitis and St. Louis encephalitis viruses in residents of California exposed to sporadic and consistent enzootic transmission. Am J Trop Med Hyg 57 : 526–529.
  45. Gahlinger PM, Reeves WC, Milby MM, 1986. Air conditioning and television as protective factors in arboviral encephalitis risk. Am J Trop Med Hyg 35 : 601–610.
  46. Eidson M, Miller J, Kramer L, Cherry B, Hagiwara Y, Ostlund EN, Crom RL, Pedersen DD, Johnson DJ, Williams WO, Schmitt BJ, 2001. Dead crow densities and human cases of West Nile virus, New York state, 2000. Emerg Infect Dis 7 : 662–669.
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  • Received : 17 Sep 2002
  • Accepted : 13 Feb 2003

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