Mosquito-borne disease, worldwide, is one of the greatest threats to human health. Malaria alone kills over one million people every year. Additionally, other mosquito-borne diseases can, or have, wreaked havoc through epidemics and other disease events. Although some mosquito-borne diseases are spread by parasites, such as malaria and filiarsis, most of them are viral. These kinds of disease are classified as arboviruses, which stands for arthropod-borne disease. Ticks, for example, are another arthropod that carry arboviruses. Worldwide, malaria is the most important mosquito-borne disease, however, yellow fever, Dengue fever, filiarsis, and various encephalitises are also of concern. Malaria has been nearly eradicated in the US, and Dengue fever and filiarsis are not found here. Yellow fever, an important disease in this country at one time, has not occurred for over a hundred years. The diseases of greatest concern in the United States at this time are five encephalitises:

• St. Louis Encephalitis
• Eastern Equine Encephalitis
• Western Equine Encephalitis
• La Crosse Encephalitis
• West Nile Virus

Other than West Nile virus, these diseases appear to be cyclical in nature. There are indications that particular weather patterns foster more cases. Another suggestion is that these diseases are not native to many areas where they occur; the process of re-introduction of the disease to an area may require several years to cause an outbreak, and may be require particular weather conditions to become especially virulent. Typically, an outbreak of the non-West Nile virus encephalitises may account for hundreds of cases nationwide during an outbreak. West Nile virus is a novel disease to this country, being first diagnosed in 1999. In comparison to the hundreds of cases associated with the other four encephalitises, West Nile virus accounted for nearly 10,000 cases in 2003. Research is being conducted in weather-dependent causation of West Nile virus, but, to date, there is little suggestion that is the case.

Suffolk County has declared public health emergencies due to mosquito-borne diseases in seven years of the decade from 1994 to 2003. Eastern equine encephalitis was responsible for the concerns in 1994 and 1996; malaria was a problem in 1999 - two cases apparently initiated in the county; and the outbreak of West Nile virus, beginning in 1999, has led to declared public health threats from 1999 through 2003.

Factors associated with the greater mobility of people, animals, and goods, and stresses leading to failures in formerly well-established public health services appear to be responsible for the greater number and wider range of mosquito-borne diseases afflicting people in this century. It is unlikely that the Unites States and, perhaps, Suffolk County has experienced its last novel arbovirus event.

For detailed information see Task 3 - Literature Review (Book2)