West Nile (WN) virus, a mosquito-transmitted virus native to Africa, Asia, and Europe, was isolated from two species of mosquitoes, Culex pipiens and Aedes vexans, and from brain tissues of 28 American crows, Corvus brachyrhynchos, and one Cooper's hawk, Accipiter cooperii, in Connecticut. A portion of the genome of virus isolates from four different hosts was sequenced and analyzed by comparative phylogenetic analysis. Our isolates from Connecticut were similar to one another and most closely related to two WN isolates from Romania (2.8 and 3.6 percent difference). If established in North America, WN virus will likely have severe effects on human health and on the health of populations of birds.

Abstract. This study investigated the geographic distribution and prevalence of antibodies to California and Bunyamwera serogroup viruses in Native populations of Alaska, and demographic and ecologic risk factors associated with exposure.

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Abstract. The safety and immunogenicity of Japanese encephalitis (JE) vaccine (Nakayama strain, monovalent / BIKEN) was studied in 538 U.S. soldiers in 1990. Three doses of vaccine from three consecutively manufactured lots were given on days 0, 7, and either 14 or 30. Serum for antibody determination was drawn at months 0, 2, and 6. Japanese encephalitis plaque reduction neutralization tests were performed by three laboratories on each specimen. Five hundred twenty-eight (98%) participants completed the immunization series. All recipients without antibody before immunization developed neutralizing antibody against JE virus. There were no differences in geometric mean titer among the three test lots at months 2 and 6. Soldiers who received the third dose on day 30 had higher titers at both time points. Antibody to yellow fever had no significant effect on immune response to vaccine. Conclusions drawn from analysis of serologic data from the three labs were nearly identical. Symptoms were generally limited to mild local effects and were reduced in frequency with each subsequent does in the series (21% to 11%; P Ͻ 0.0001). Generalized symptoms were rare (e.g., fever ϭ 5%) with no reported cases of anaphylaxis.

Arboviral encephalitis in domestic animals in the United States is rare with the exception of equine encephalomyelitis in horses. 8 This report describes 2 cases in which La Crosse virus (LACV) was isolated from canine littermates with acute clinical encephalitis or sudden death. Both cases occurred in the southern region of the state of Georgia and were submitted as cadavers for necropsy to the Veterinary Diagnostic and Investigational Laboratory (VDIL) in Tifton, Georgia. On May 9, 1988, 4 2-week-old mixed-breed littermate puppies exhibited acute signs of central nervous system disease and were taken to a veterinarian. Three of the puppies had repeated seizures during the clinical examination. Because the clinical signs were compatible with a diagnosis of canine distemper virus encephalitis, the veterinarian issued a poor prognosis; the 3 puppies were euthanized and submitted to the VDIL for necropsy. The fourth puppy was mildly affected and was sent home without follow-up. On May 28, 1991, illness and deaths occurred in a litter of 7 8-day-old Brittany spaniel puppies. Two puppies were found dead and were taken to a veterinarian, who submitted the cadavers to the VDIL for necropsy. A third puppy was moribund and experienced breathing difficulty and died within the following hour. The veterinarian examined the 4 remaining puppies later that day and found them to be healthy. The same veterinarian had examined the entire litter 5 days previously. At that time, the animals appeared healthy, and tail docking was performed. A necropsy was performed on each of the 3 mixed-breed and 2 Brittany spaniel puppies submitted to the VDIL. Macroscopically, the brain of each puppy was severely and diffusely malacic. Other tissues appeared normal. Representative sections of lung, heart, liver, kidney, urinary bladder,

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We determined the prevalence and distribution of Jamestown Canyon (JC) virus antibody in white-tailed deer (Odocoileus virginianus) populations in Connecticut, USA. Sera were collected from hunter-killed deer during 1993. Antibody to JC virus was detected by enzyme-linked immunosorbent assay (ELI-SA) in 92 (21%) of 446 deer sera, and was uniformly distributed among geographic sites. Twenty-one ELISA-positive sera were tested and confirmed positive by plaque reduction neutralization testing. This represents the first serologic evidence of JC virus in a reservoir host population from the northeastern United States. No cross-reactivity was seen with California encephalitis, Keystone, or snowshoe hare viruses, but a varying degree of cross-reactivity was obtained with Guaroa,