RESUMEN

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. Sera (n = 1,635) from 18 communities were screened using an ELISA. All age groups were tested for antibodies to Jamestown Canyon (JC), Inkoo (INK), snowshoe hare (SSH), and Northway (NOR) viruses; persons > or = 45 years old (n = 90) from six communities were additionally tested for antibodies to Tahyna (TAH), Batai (BAT), Cache Valley (CV), and Sindbis (SIN) viruses. Thirty free-ranging mammals were tested by a plaque reduction neutralization test (PRNT) for antibodies to all eight viruses and to Getah (GET) virus. In Natives, overall antibody prevalence was 24.9% (JC = 17.6%, monotypic JC = 6.5%, INK = 11.1%, monotypic INK = 0.6%, SSH = 6.8%, monotypic SSH = 3.5%, and NOR = 6.2%). Five TAH, CV, and BAT virus exposures may be serologic cross-reactions, and no SIN virus antibodies were detected. Sindbis-like virus antibodies were found in 30% of the mammals. Most mammals had antibodies to NOR (83.3%) and California serogroup (70.0%) viruses; no GET virus exposures were found. Significant risk factors for human bunyavirus exposures were age group, ethnic-linguistic group, biotic province, climate zone, terrestrial vegetation, and presence of some ungulates and small mammals in communities. Sex was not a significant risk factor.

Asunto(s)

RESUMEN

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 (ELISA) 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, Jerry Slough, La-Crosse, San Angelo, and trivittatus viruses. We conclude from this investigation and previous isolations of JC virus from mosquitoes in the state that JC virus occurs enzootically in Connecticut.

Asunto(s)

RESUMEN

A surveillance program for mosquito-borne arboviruses was conducted in Connecticut following an epizootic of eastern equine encephalitis (EEE) in horses and domestic birds during 1990. Mosquito trapping was done weekly using CO2-baited miniature light traps at 12 freshwater swamp sites that were located mostly in the southeastern portion of the state. Trapping was conducted from June 27 to October 11, 1991 and from June 2 to September 30, 1992. Totals of 7,435 (1991) and 13,912 (1992) adult female mosquitoes representing 21 species in 7 genera were collected and assayed for arboviruses. Virus isolates were identified by ELISA using reference antibody of California encephalitis, EEE, Highlands J (HJ), Jamestown Canyon (JC), LaCrosse, and St. Louis encephalitis viruses. Culiseta melanura was the most common species trapped each year, followed by Aedes canadensis, Aedes cinereus, and Coquillettidia perturbans. The most abundant univoltine snowmelt species was Aedes abserratus. Three isolates positive for JC virus were obtained from Ae. abserratus, Ae. canadensis (new state record), and Ae. cinereus (new state record) that were collected from 2 different sites in June (1992) and July (1991 and 1992). Six isolates positive for HJ virus were made from Cs. melanura and one isolate from Ae. cinereus (new host record) collected in mid- to late September, 1992 from 3 locations. Based on repeated virus isolations in this and other studies, high field infection rates, and its relative abundance, Ae. abserratus appears to be a principal vector of JC in Connecticut. However, the prevalence and importance of JC as a human disease in the state are unknown.(ABSTRACT TRUNCATED AT 250 WORDS)

Asunto(s)

Asunto(s)

RESUMEN

As the hair follicle is one of the most rapidly growing tissues in the body, it must be nourished by a rich blood supply. Histological studies have indicated that the number of vessels about a growing follicle exceeds that about a resting follicle, so we postulated that the hair follicle might provide its own angiogenic stimulus during certain phases of its growth. Reported here are experiments testing the angiogenic properties of the growing (anagen) hair follicle. Using the rabbit corneal pocket angiogenesis assay and cycled anagen rat vibrissae hair follicles, we found that the mesenchymal dermal papilla had no angiogenic properties, but the anagen bulb was angiogenic. These findings suggest a mechanism for the cycling of hair follicles and an example of normal epithelium to mesenchyme interactions.

Asunto(s)