An encephalomyocarditis virus epizootic in a baboon colony.

Approximately 80 baboon deaths were caused by encephalomyocarditis virus (EMCV) infection in a 3060 member research and production colony. The epizootic extended over a 9-month period and occurred in baboons ranging from 1 day to 22 years of age. Acute death was the most common history. When clinical disease was detected, it was characterized by labored respiration associated with acute congestive heart failure. The salient necropsy findings were pulmonary congestion and edema, hydropericardium, hydrothorax, ascites, lymph node and splenic hypertrophy, and pale white-to-tan mottled hearts. The most significant histologic lesion was nonsuppurative necrotizing myocarditis. Placental infection with fetal loss occurred. Diagnosis was confirmed by light microscopy, transmission electron microscopy, virus culture, and serology. Rarely, EMCV-induced antibody persisted in surviving baboons for more than 24 months. EMCV-infected feral rats were the probable source of the virus and their control stopped the epizootic. No EMCV neutralizing antibody was detected in colony support personnel or chimpanzees.     

An epizootic Staphylococcus infection in a nude mouse colony

An epizootic of Staphylococcus infection causing abscesses was encountered in a small-scale breeding colony of nude mice of BALB/c background. The incidence of abscess was sporadic and mostly nude (nu/nu) mice aged over 3 months were affected. Staphylococcus aureus was isolated from the face, oral cavity, and feces of almost all nu/nu and heterozygous (nu/+) mice in the colony. After a prolonged time period, up to 10 to 14 months of age, almost all the S. aureus-carrying nu/nu mice produced abscesses and eventually died. Athymicity of the host seemed to be a prerequisite for the abscess formation since nu/+ mice were spared from the lesions. Also, transfer of immunocompetent spleen cells cured the abscesses of the affected nude mice.     

An epizootic form of Tyzzer's disease in a rat colony

An epizootic form of Tyzzer's disease was experienced in a rearing facility of laboratory rats with an infectivity and morbidity of 36 to 80% and 5 to 30%, respectively. With liver tissue from an affected rat, a spore-forming causative agent was successfully transmitted to other rats by oral inoculation in association with cortisone, producing 10(6) to 10(7) spores/g liver tissue.     

An epizootic outbreak of ringworm in a guinea-pig colony caused by Trichophyton mentagrophytes.

The disease was characterized by loss of hair, initially occurring at the tip of the nose and spreading throughout the body. Lesions appeared as circular, scaley alopecia with occasional scarring. Although spread of the infection in the colony was random, the most severe infection occurred in an inbred line with light coat colour. The unusually high temperature and humidity, and the open type of outdoor management, appear to have contributed to the high incidence and severity of infection. Electron microscopic observation indicated that the organism multiplied in the keratin layer of the skin. The hyphae as well as chlamydospores were readily demonstrable by electron microscopy.     

An epizootic infection of Citrobacter freundii in a guineapig colony: short communication

An epizootic infection of Citrobacter freundii in a guineapig colony is reported. From 1300 guineapigs maintained in a colony, a total of 115 guineapigs died. Lesions found postmortem were suggestive of acute pneumonia and enteritis. Citrobacter freundii was consistently isolated from necropsy specimens of lung, liver, spleen and intestines of the animals. The source of infection was not ascertained.     

Viral infections of the captive Kenya baboon (Papio cynocephalus): a five-year epidemiologic study of an outdoor colony.

Rectal swabs, throat swabs, fecal samples, tissues, and sera were collected from 334 adult and infant Kenya baboons (Papio cynocephalus) in captivity at this institution over a 5-year period. A total of 4,893 specimens were collected, resulting in the isolation of 582 viral isolates (11.9%). The month of November yielded the lowest isolation rate, while the month of January produced the highest rate. The most commonly isolated viruses in adults and infants were SV6 and SV23, followed by N125, SV15, and SV17 in that order in adults, and SA7, N125, SV15, V340, and SV17 in that order in infants. Nine serotypes, namely enteroviruses SV19, SV42, SA5, A13, and N203, as well as adenoviruses SV15, SV20, SV31, and SV37, were isolated only from adults. Two adenovirus serotypes, SA7 and V340, were recovered predominantly from infants.     

A naturally occurring epizootic of simian agent 8 in the baboon

An epizootic of genital lesions was observed on baboons (four Papio sub-species) housed in two different outdoor breeding corrals. Serological analysis revealed strong prevalence of antibodies to Simian Agent 8 (SA8). This herpesvirus was subsequently recovered from skin lesions and identified by restriction endonuclease digestion of infected cell DNA. Observations of lesion type, frequency and location were suggestive of venereal transmission. The remarkable similarity between infection resulting from SA8 in baboons and herpes simplex virus in man suggests that the baboon is an excellent model in which to study genital herpes virus transmission and infection.     

Genetics of primate lymphomas in a baboon (Papio hamadryas) colony of Sukhumi,USSR

A lymphoma outbreak occurred at the Sukhumi Center in the Late 1960's, when 12 baboons were inoculated with blood from human leukemia patients. Out of a total of 3219 animals, 218 contracted lymphoma and died. This outbreak appears to be primarily horizontal in transmission. Genetic investigations reveal that: (1) inbreeding does not increase risk of lymphoma; (2) there is a weak association between the PGM₂ locus and lymphoma; (3) based upon path analysis, there is evidence of a significant transmissible component (genetic predisposition) passed from the parental to the next generation.     

An outbreak of Caparinia tripilis in a colony of African pygmy hedgehogs (Atelerix albiventris) from Korea

In February 2010, dermatitis characterized by scale and self-trauma due to puritis was recognized in a group of 22 four-toed hedgehogs (Atelerix albiventris Wagner, 1841) from a local pet shop in Gwangju, Korea. Microscopic examinations of skin scraping samples showed numerous mites of all developmental stages. Morphologically, pedicels of adult mites were short and unjointed. Tarsal caruncles were bell-shaped on all legs of males while they were absent on legs III and IV of females. Three long setae on the third pair of legs in both sexes were present. Adult males had posterior end of the abdomen with trilobate projection on each side, each lobe with a long seta. Based on these features, the mites were identified as Caparinia tripilis. This is the first report of caparinic mite infestation in hedgehogs from Korea. Identification keys for the family Psoroptidae and the genus Caparinia are provided.     

An epizootic model of an insect-fungal pathogen system

A system of integro-differential equations is derived to describe epizootics of a fungal pathogen in an insect population. Because of piecewise continuous behavior under some parametric conditions, it is concluded that standard phase orbits can be misleading. Using a different analytic approach yields a simple system of finite difference equations. Both the continuous and discrete versions are compared to classical forms. The continuous version differs from a classical one in possessing a second derivative dependent on population density. The discrete version differs in maintaining positive, non-zero populations of both infectives and susceptibles in finite time. Scientific paper No. 81-7-129 of the Kentucky Agricultural Experiment Station, Lexington. This research has been financed (in part) with Federal funds from the Environmental Protection Agency under grant number CR-806277-020. The contents do not necessarily reflect the views and policies of the Environmental Protection Agency, nor does mention of trade name or commercial products constitute endorsement or recommendation for use.     

An epizootic of fibromatosis in gray squirrels (Sciurus carolinensis) in Florida

Beginning in the fall of 1998 and extending into the spring and early summer of 1999 there was a large epizootic of squirrel fibromatosis in squirrels in seven counties in peninsular Florida. Hundreds of gray squirrels (Sciurus carolinensis) with multiple cutaneous tumors were submitted or reported to biologists, veterinary hospitals, and private wildlife rehabilitators. Most squirrels died or were euthanized soon after submission. Twenty squirrels were submitted for necropsy. The majority of the squirrels examined were adults (12/20) and male (15/20). The number and location of tumors varied widely among the affected squirrels; however, a consistent finding was involvement of the eyelids (20/20). Histopathology revealed a proliferative population of mesenchymal cells within the dermis and marked ballooning degeneration of keratinocytes in the overlying epidermis. Intracytoplasmic viral inclusions were present in the neoplastic mesenchymal cell population and the degenerating keratinocytes. Ulceration and necrosis of the surface of the tumors or associated tissues was present in 14 of the 20 squirrels. Virions consistent with poxvirus were observed via electron microscopy in samples collected from a representative tumor. Death of the squirrels was attributed to emaciation, tissue damage, and severe negative energy balance associated with poxvirus infection and massive tumor growth. The underlying cause of this unusual epizootic of fibromatosis in gray squirrels remains unknown.     

Trichuris sp. and Strongyloides sp. infections in a free-ranging baboon colony

We conducted cross-sectional surveys of parasites infecting a large free-living colony of baboons at the Southwest National Primate Research Center in San Antonio in October 2003 and April 2004, immediately before, and 6 mo after, treatment with ivermectin. Trichuris sp. was the predominant species present, infecting 79 and 69% of individual animals in the 2 surveys, with fecal egg counts (FEC) of up to 60,200 eggs per g (epg) (mean = 1,235 in October 2003 and 1,256 in April 2004). Prevalence remained fairly stable across age groups, and intensity was highest in animals <1 or >15 yr old, in contrast to patterns observed in humans, where school-age children show the heaviest infections. Strongyloides sp. was also identified, but the species identity remains uncertain. Small subunit ribosomal DNA sequences differed from published sequences of Strongyloides fuelleborni at multiple sites, but resided in a monophyletic group with other Strongyloides species with 92% bootstrap support. This may reflect a recent acquisition from a local host, or that the published sequence of S. fuelleborni is incorrect. Widespread infections with 2 nematode genera in a free-ranging baboon colony that are an important source of morbidity in human populations provide a useful model system for work on the epidemiology, control, pathology, and genetics of these parasites in a host species that is physiologically, immunologically, and genetically similar to humans.