The virus is maintained in a cycle in nature which involves mosquitoes and 

 wild birds. One mosquito species typically feeds on birds and is important in 

 the amplification of the virus among wild bird populations. In order to bring 

 about an episode of transmission of the disease to people and/or horses, a 

 "bridge mosquito" is needed to bridge the virus from birds to humans and horses. 

 This different type of mosquito feeds on a variety of hosts and several species 

 and are thought to be able to spread the disease to humans and horses. 



GROUND SPRAYING AUTHORIZED TO PROTECT PUBLIC HEALTH 



This year the regional mosquito control projects were alerted and 

 authorized to intensify ground spraying in high risk areas to protect the public 

 health. Mosquito control activities were concentrated in areas where virus iso- 

 lations or human and horse cases were documented, as well as in high risk areas 

 delineated by the Department of Public Health. All available equipment was 

 mobilized to focus immediate attention on the EE risk areas. 



The pace of the mosquito control efforts began to outstrip local resources 

 and consequently. Governor Dukakis made available emergency monies in the 

 sum of $150,000 dollars to the State Reclamation and Mosquito Control Board. 

 These funds addressed the threat of EE to the public health in specific areas. 

 The EE threat caused a strain on the budgets of organized mosqutio control pro- 

 jects and on budgets of individual municipalities not in organized mosquito 

 control projects and located in the areas of risk. These funds enabled orga- 

 nized mosquito control projects and local municipalities in the high risk areas 

 to continue the intensified ground spraying to reduce the likelihood of EE 

 transmission to the public. Operations continued until weather conditions 

 greatly reduced the contact between mosquitoes and humans. 



Massachusetts statistics relative to the 1983 season are as follows: 

 six (6) confirmed human cases with one death; and five (5) horse cases, all fatal. 

 Since 1938, there have been sixty-five (65) human cases with thirty-six (36) deaths 

 as the result of the sporadic appearance of Eastern Encephalitis in Massachusetts. 



Looking ahead to 1984, it appears likely that 1984 will also be a year of 

 higher than average risk from EE. This event will depend on environmental con- 

 ditions (such as a relatively warm winter and wet spring) which would be 

 favorable to the maintenance of virus in the environment and also would 

 influence the survival and flourishing of mosquitoes. 



MOSQUTIO CONTROL PROGRAMS APPROVED 



This year the State Reclamation and Mosquito Control Board forwarded 

 mosquito control information cards to those municipalities not currently members 

 of a regional mosquito control project. The Board received one hundred (100) 

 responses from various municipalities. Seventy-three (73) municipalities 

 reported that no mosqutio control program would be implimented in 1983. Twenty- 

 seven (27) municipalities reported that a local mosquito control program would 

 be carried out in 1983. All mosquito control programs received by the State 

 Reclamation and Mosquito Control Board were reviewed and approved, some as 

 modified to meet Board requirements. 



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