William J. Bigler

EPIZOOTIC OF CANINE DISTEMPER VIRUS INFECTION AMONG URBAN RACCOONS AND GRAY FOXES

An epizootic of canine distemper (CD) virus infection is described among raccoons and gray foxes in urban Sarasota County, Florida. The epizootic persisted for 2 years with a total of 114 raccoons and 8 gray foxes being handled by Sarasota County Animal Control. Virus was isolated from clinically ill raccoons on two separate occasions, 7 months apart. CD antibodies were detected in 54.5% of a sample comprising both clinically ill and apparently normal raccoons. The incidence of CD in dogs in the county did not increase during the 2 year period.

THE ROLE OF BATS IN THE PROPAGATION AND SPREAD OF HISTOPLASMOSIS: A REVIEW

EPIZOOTIOLOGY Histoplasmosis is a mycotic infection of man and animals caused by Histop/asma capsu/atum a dimorphic fungal soil saprophyte that produces mycelium-borne infective spores. Inhalation of airborne spores invariably is the route of infection. When suitable microclimatic conditions are present and soils harboring H. capsu/atum become enriched with animal feces, the environment is favorable for proliferation of the fungus.iS Avian habitats are considered to be especially suitable for the pr&iferation of H. capsu/atum; however, infection has never been documented in birds probably because of their high body temperature.17 While the yeast form of H. capsu/atum has been found in a number of mammalian species only the Chiroptera are considered to play significant roles in the epizootiology of this mycosis. 9,2 ,26 An acute, febrile respiratory disease, referred to as cave sickness, had long been recognized in individuals who worked in or visited caves in various parts of the world. .i,7,iS Epidemiological studies demonstrated that cave sickness was histoplasmosis, with the fungus being recovered from soil, guano, and bats inhabiting many of the caves. However, caves were not the only harborhages of bats which were associated with human histoplasmosis. Bat guano and soil from in and around roosting trees, houses, bridges and other structures also have yielded H. capsu/atum. DISTRIBUTiON

ARBOVIRUS SURVEILLANCE IN FLORIDA: WILD VERTEBRATE STUDIES 1965-1974

Wildlife species from 38 of Floridas 67 counties were surveyed over a 10 year period for the presence of antibody to the five major arboviruses circulating in the state. The routine screening of 7891 sera from wild birds and mammals via the hemagglutination-inhibition (HI) test with selected reactors subjected to serum neutralization testing has 1) provided information regarding geographic distribution and seasonality of circulation of these viruses 2) identified enzootic foci of infection and those species of wildlife most commonly infected and 3) documented the potential value of certain wild mammals as indicators of St. Louis Encephalitis and Venezuelan equine encephalomyelitis virus activity prior to the detection of human cases. Limited studies of Tamiami and Tensaw virus on sera from mammals collected for other purposes provided additional baseline information on the activity of these viruses in Florida mammals. Isolations of eastern equine encephalomyelitis virus were made from the heart of a loggerhead shrike (Lanius excubitor), Tensaw virus from the brain of a gray fox (Urocyon cinereoargenteus), and Keystone virus from the heart of a bluejay (Cyanocitta cristata).

HEAVY METAL CONCENTRATIONS IN KIDNEYS OF URBAN GRAY SQUIRRELS

Concentrations of lead and zinc in the kidneys of 180 urban gray squirrels were determined by spectrophotometry and found similar for all age groups; however, concentrations of cadmium increased up to two years of age. Values for 12 rural squirrels were significantly lower than those of the urban animals. There were no differences in mean concentrations of the metals when urban squirrels were grouped by the land usage pattern of the sites in which they were captured. Grouping squirrels by human socioeconomic strata for the city revealed that squirrels in low socioeconomic areas have significantly higher levels of lead than animals residing in middle or high socioeconomic areas.

Population Characteristics of Peromyscus gossypinus and Sigmodon hispidus in Tropical Hammocks of South Florida

Population data were recorded on tagged Peromyscus gossypinus and Sigmodon hispidus trapped on study grids in two tropical hammocks of South Florida. Densities of cotton mice, the dominant species, appeared to be related to successional stages of habitat with greater numbers found in mature tropical hammocks (27 to 96 animals per hectare). Populations decreased in summer and autumn and increased in the winter and spring with recruitment of immature animals. Breeding persisted from August through May peaking in the winter and early spring. Females averaged 3.1 mice per litter with some producing three to four litters per year. Highest mortality occurred during the first 6 months. The population turned over completely every 18 to 20 months. Cotton rats, normally inhabitants of the sawgrass marsh, frequented portions of the hammocks throughout the year. It appeared as though females used the hammocks as nurseries during the summer. Period of greatest interaction between the two species in tropical hammocks is between March and November when the water levels rise. Dispersion patterns of cotton mice do not appear to be greatly influenced by the presence of cotton rats. Sex ratios, age composition, parasites, reproduction, longevity and population turnover, and movements of both species are discussed.

Salmonella infections in Florida raccoons, Procyon lotor.

Fourteen serotypes of Salmonella were isolated from 28 of 168 raccoons from Florida. These serotypes had been previously recovered from man in the state. Raccoons from state parks had an infection rate of 22% as opposed to 13% for animals from suburban and rural areas. The present role of the raccoon as a vector for human salmonellosis is discussed.

Heavy metal concentrations in kidneys of estuarine raccoons from Florida.

Concentrations of lead, zinc and cadmium in the kidneys of 14 adult raccoons from an estuarine environment were determined. The mean concentrations in ppm wet weight and standard deviation for the metals were lead—0.47 ± 0.22, zinc —75.88 ± 16.54 and cadmium—2.48 ± 1.66.

PUBLIC HEALTH AND THE URBAN GRAY SQUIRREL: MYCOLOGY

From 180 gray squirrels (Sciurus c. carolinesis), 942 isolates of fungi representing 19 genera were recovered upon culture of hair-skin scrapings and toenails. Of the isolates, 170 represented known human pathogens and 142, squirrel pathogens. A human infection of Trichophyton mentagrophytes was derived from handling the squirrels. Skin lesions of seven squirrels were attributable to T. mentagrophytes and Mucor sp.

Edwardsiella tarda Infections in Florida Raccoons, Procyon lotor

Edwardsiella tarda was isolated from the large intestine of seven (17%) of 42 racoons from Florida. The rate varied from 12% in South Florida to 25% in North Florida. In addition, 52% of the racoons examined were carrying Salmonella, with numerous serotypes represented.

Helminths of urban gray squirrels in Florida

lengths of 14 setae from so-called ear mites (P. cuniculi) that were collected from the various hosts. The lengths of the 14 setae of mites from mule deer of Colorado were similar to those of rabbits of New Mexico and goats of Texas, but were significantly different from all other P. cuniculi mites. The mites collected from bighorn sheep would be classified as P. cuniculi according to Sweatman because he first used body location (ear) and then the setal length ranges. The mean lengths of the 14 setae of these mites (137 Am) fall within the range for P. cuniculi (64-164 j,m). However, had these mites been taken from the body rather than ear locations, they would, by Sweatmans key, be classified as P. ovis (74-258 ,Am). The mites taken from the bighorn sheep in New Mexico were taken from both ear and body locations, but the predominant infestation areas were the ears of the hosts. Even though the method of Sweatman (1958, loc. cit.) for distinguishing between species of Psoroptes is widely used, our findings indicate that it is inadequate and alternate methods to identify the various species need to be found. The overlap of setal lengths mentioned by Sweatman (1958, loc. cit.) and confirmed by our data makes this point evident. Also, there are too many significant differences in lengths of the 14 setae between the same species of mites within the same host. The various species of Psoroptes are so similar morphologically that it is extremely difficult to find distinguishing characteristics. However, with the advent of the scanning electron microscope, the exoskeletons of arthropods are much easier to examine. By the use of this or different techniques, additional differences may be found to aid in the proper identification of the various species of Psoroptes. We thank the following for providing some of the psoroptic mites used in this study: Dr. Durr Bezuidenhout, Onderstepoort, Republic of South Africa; Dr. Robert L. Glaze, Kerrville, Texas; Dr. Gordon Hubell, Miami, Florida; Dr. Grant Kinzer, New Mexico State University, Las Cruces, New Mexico; Mr. Allan Kirkwood, Weybridge, England; Mr. Leonard Roundtree, Denver, Colorado; Dr. Stephen M. Schmitt, East Lansing, Michigan; and Dr. Juan Solis, Sao Paulo, Brazil.