Seroepidemiologic studies of hantavirus infection among wild rodents in California.

A total of 4,626 mammals were serologically tested for antibodies to Sin Nombre virus. All nonrodent species were antibody negative. Among wild rodents, antibody prevalence was 8.5% in murids, 1.4% in heteromyids, and < 0.1% in sciurids. Of 1,921 Peromyscus maniculatus (deer mice), 226 (11.8%) were antibody positive, including one collected in 1975. The highest antibody prevalence (71.4% of 35) was found among P. maniculatus on Santa Cruz Island, off the southern California coast. Prevalence of antibodies among deer mice trapped near sites of human cases (26.8% of 164) was significantly higher than that of mice from other sites (odds ratio = 4.5; 95% confidence interval = 1.7, 11.6). Antibody prevalence increased with rising elevation (> 1,200 meters) and correlated with a spatial cluster of hantavirus pulmonary syndrome cases in the Sierra Nevada.

Short report: prevalence of hantavirus infection in rodents associated with two fatal human infections in California.

Rodents living near two fatal human cases of hantavirus pulmonary syndrome in California were surveyed for evidence of hantavirus infection. Seventeen (15%) (14 Peromyscus maniculatus and one each of P. truei, Eutamias minimus, and Microtus californicus) of 114 rodents tested had evidence (enzyme-linked immunosorbent assay or polymerase chain reaction) of hantavirus infection. This suggests that Peromyscus mice, and P. maniculatus in particular, may be the reservoir for the virus causing this newly recognized disease in California, as previously reported for New Mexico and Arizona.

Irritative and systemic symptoms following exposure to Microban disinfectant through a school ventilation system.

Microban, a pesticide not registered in California, was sprayed into an operating heating/ventilation/air conditioning (HVAC) unit at an elementary school in San Francisco, California. This incident occurred on Monday, September 28, 1992, while 396 students and 67 staff members were in the school. The Microban formulation used contains ortho-phenylphenol (0.21%), a quaternary ammonium complex (di-isobutylphenoxy-ethoxy-ethyldimethylbenzyl-ammonium chloride, 0.69%), and bromine (0.04%). This study of the health effects of Microban mist exposure on the school staff was conducted as a result of legal and toxicological concerns. California registration for this formulation had been denied because of inadequate data and because there were concerns about inhalation toxicity in test animals. Predicted health effects from short-duration exposure to Microban are primarily skin and mucous membrane irritation. A self-administered health symptom questionnaire that covered the work week following the evacuation was used to determine a pattern of higher symptom risks for those who were at work on Monday and who reported that they felt they were exposed to a chemical. Symptoms, which were generally consistent with exposure to an irritating chemical, were elevated on Monday and Tuesday; the symptoms normalized by the end of the work week. No additional health effects were detected following application of chlorpyrifos to cracks and crevices for ant control 2 d following the Microban incident. Strict supervision and coordination of pesticide use in public schools are recommended to prevent adverse health effects and emotional trauma in students and staff.

Neonatal deaths in bonnet monkeys born to dams with rudimentary papillae mammae.

Deaths due to dehydration and starvation occurred in the early neonatal period in bonnet monkey (Macaca radiata) infants housed with their dams in an outdoor half-acre corral. Dams were found to have small, rudimentary papillae mammae of insufficient size to permit suckling. Both papillary and breast tissue of affected dams were histologically normal; the nipples differed macroscopically from those of normal females only in size. This abnormality accounted for half of the neonatal mortality experienced in this breeding colony over a 5-year period.

Dysgerminoma in a rhesus monkey: morphologic and biological features.

A female Macaca mulatta was observed for 31 months after the initial surgical removal of an ovarian tumor. Solitary metastatic lesions were surgically removed 26 and 28 months after excision of the primary tumor. The animal was killed after 31 months because of additional metastatic lesions. Histological evaluation by light microscopy was not conclusive in determining the origin of neoplasm. Transmission electron microscopy, lymphocyte marker studies, and hormone assays were utilized to confirm the diagnosis of dysgerminoma.

Mycobacterium avium infection in three rhesus monkeys.

Naturally occurring Mycobacterium avium infection in 3 rhesus monkeys was characterized clinically and pathologically by intestinal and lymphoreticular involvement. Blood lymphocyte rosette formation and phytomitogen responses were depressed, whereas serum beta and gamma globulin concentrations were increased. Slow-growing, acid-fast, nonchromogenic bacilli isolated from lymph nodes taken at necropsy were identified as M avium serotypes 4, 18, and double types 1 and 8.