Epidemiologic patterns of nosocomial infections in 10 Oklahoma hospitals.

The epidemiology of nosocomial infections was studied for 5 years in 10 Oklahoma hospitals. These were categorized into small and large hospitals. The seven small hospitals averaged 47 beds and the three large hospitals averaged 266 beds. Overall, most of the infected patients were < 5 years of > 60 years of age. Females accounted for the majority of the infections. In general, the three most common sites of infection were the urinary tract, surgical wounds, and the lower respiratory tract. Escherichia coli was the single most frequently identified agent followed by Staphylococcus aureus and Staphylococcus epidermidis. The most frequently reported risk factors among patients acquiring a nosocomial infection were the use of prior antibiotics, indwelling urinary catheters, and intravenous catheters or cut-down. The specific problems associated with nosocomial infections, such as sites of infection, risks of infection, and the types of organisms isolated, essentially had not changed much since the 1960s, the 1970s, and for most of the 1980s.

Human ehrlichiosis--an overview.

Canine ehrlichiosis, previously thought to be restricted to dogs, has gained prominence in the human population since 1986. In the United States, human ehrlichiosis is a newly recognized disease ranging from a mild infection to a severe life threatening or fatal disease. Since antibody titers were found to be highest to E. canis in human ehrlichiosis patients, it was believed that E. canis or a closely related species was the etiologic agent. Investigators from the Centers for Disease Control recently have isolated a bacterium believed to be the etiologic agent of human ehrlichiosis and proposed the name Ehrlichia chaffeensis. Human cases of the disease have been identified primarily in the southeastern and south-central areas of the United States. Although relatively few cases are diagnosed, Oklahoma, according to one source, has been found to have the highest incidence rate. The human disease could be misdiagnosed as Rocky Mountain spotted fever, murine typhus fever, or Q fever.

Prevalence of Lyme disease infection in Oklahoma.

Even though Lyme disease probably existed in Oklahoma prior to 1975 when the disease was first reported in Connecticut and even though ecological conditions favor a high prevalence, an unexpectedly low rate was evidenced in both a serological survey and the number of cases reported to the Oklahoma State Department of Health. Lyme disease does not appear to pose a significant public health threat in Oklahoma at the present time; however, the the presence of all the necessary factors for transmission and the rapidly increasing number of cases reported in nearby areas merits continued surveillance in this state. The need for consistent case definition is discussed.

Incidence of Legionella pneumophila infections among Oklahoma pulmonary disease patients.

Prior studies by the authors suggested high levels of Legionella pneumophila in the recreational and water supply reservoirs in central Oklahoma. This high exposure potential was supported by a relatively high prevalence of seropositive, asymptomatic infections among healthy blood donors in the area. In contrast, the present 9-month laboratory-based study confirmed only one clinical Legionella infection among 117 unidentified pulmonary disease patients admitted to the Oklahoma City Veterans Administration Medical Center. Comparison with the reports of others and with reported legionellosis in Oklahoma indicates that differences in cohort definition and variations in utilization and interpretation of clinical analyses leads to wide variations in the reported incidence of legionellosis.

Screening media for detection of methicillin-resistant Staphylococcus aureus from non-sterile body sites.

Four hundred and forty clinical isolates were tested on Baird-Parker and Vogel-Johnson agars with 6 micrograms/ml of oxacillin, to determine their growth characteristics on these potential screening media for methicillin-resistant Staphylococcus aureus (MRSA). While both media performed well individually, a combination biplate with each medium may be the most useful in screening patients for MRSA from normally non-sterile sites.

False positive Legionella pneumophila direct immunofluorescent monoclonal antibody test caused by Bacillus cereus spores.

Direct immunofluorescent monoclonal antibody stain testing for Legionella pneumophila in Oklahoma lake water yielded an unknown bacillus with fluorescence intensity equal to that of L. pneumophila stock strains. The organism in question was identified as Bacillus cereus, a ubiquitous bacterium. When B. cereus cultures were studied, fluorescence was seen in spores but not in vegetative cells. Since a positive immunofluorescent monoclonal antibody test (alone) might be considered by some individuals as unequivocal to very good evidence for the presence of L. pneumophila, this finding emphasizes the importance of confirming positive stain results with cultures whenever possible.

Transplacental transfer of Legionella pneumophila antibodies.

In order to determine the extent to which Legionella pneumophila antibodies are passively transferred transplacentally into the fetal circulation, 199 matched serums of mothers and their newborn infants were tested using the indirect fluorescent polyclonal antibody technique. Considering L. pneumophila antibody titers of greater than or equal to 1:64 as evidence of inapparent infection, the overall prevalence rate was 35.7% for the mothers and 14.1% for their newborns. Among the mothers who were seropositive at greater than or equal to 1:64, 36.6% of their matched infants acquired antibodies transplacentally. With only two exceptions there were no newborns with an antibody titer greater than or equal to 1:64 whose mothers did not also evidence at least the same titer.

Lead absorption in children of employees in a lead-related industry.

Children can be exposed to lead from a variety of environmental sources. It has been repeatedly reported that children of employees in a lead-related industry are at increased risk of lead absorption because of the high levels of lead found in the household dust of these workers. A case-control study was done in Oklahoma in 1978 to determine whether children of employees in battery manufacturing plant had a higher prevalence of high levels of blood lead than children whose parents were not employed in a lead-related industry. The data obtained indicated that the blood lead levels of the study children were significantly greater than those of the control children. None of the control children had blood lead levels greater than 30 micrograms/dl, while 53% of the exposed children had blood lead levels of greater than 30 micrograms/dl. Trends indicated that the children whose fathers had higher lead exposure at work also had higher blood lead levels. However, the study children whose fathers had good personal hygiene had blood lead levels comparable to the control children. It appeared that only good personal hygiene, i.e., showering, shampooing and changing clothes and shoes before leaving work, was effective for lead containment. The mere changing of clothes and shoes appeared to be inadequate for lead containment.

Relationship between spray adhesives and congenital malformations.

Evidence from clinical impressions and laboratory slides that spray adhesive products could have a potentially dangerous mutagenic or teratogenic effect was first reported in 1973. However, similar laboratory slides observed by others revealed no significant difference between chromosomal slides of malformed infants and those of normal children in households whose members were exposed to spray adhesives. Because of opposing opinions, a pilot epidemiologic study was initiated to investigate the association between the use of spray adhesives and congenital malformations. All congenital malformations reported on birth certificates from 1971 through 1974 in Oklahoma County, Oklahoma were used. A normal birth was selected as a matching control for each case. Complete and usable questionnaires regarding 112 malformed subjects and 116 controls, including 56 matched controls, were received. There was a statistical association between malformed subjects and household members using spray adhesives. There appears to be sufficient epidemiologic evidence to reopen the controversy with the appeal for further studies.

Frequency of canine and feline tumors in a defined population.

The Tulsa Registry of Canine and Feline Neoplasms was the second animal tumor registry in the United States concerned with a defined population in a delimited geographic area. Only tumors histologically confirmed by registry pathologists were included in frequency statistics based on the annual dog and cat population presented to veterinarians. During the first registry year, about 1% of the 63,504 dogs and 0.5% of the 11,909 cats had one or more primary tumors. While the incidence rate for malignant tumors in dogs was similar to that in cats, the incidence of benign tumors of dogs was over 10 times that of cats. The most common tumors were sebaceous adenoma in dogs and lymphosarcoma in cats. Mammary cancer was the most common malignant tumor in dogs. Mammary tumors of female dogs were significantly more frequent in Pointers, Poodles and Boston Terriers, in that order, than in other breeds. A greater incidence of mammary tumors among intact compared to spayed female dogs was seen for virtually every age group except in the Pointer breed.

Epidemiologic aspects of nosocomial infections.

In a currently ongoing surveillance of hospital-associated infections in two metropolitan hospitals in Oklahoma, the results over a four-month period suggest at least tentative principles of host-agent relationships in hospital-associated infections. Within the urinary tract, the site with the highest number of total isolations, Escherichia coli and Klebsiella pneumoniae were the most common pathogens. By age, the under 5 and over 60 year age groups had the highest number of isolations. Staphylococcus aureus and E coli were isolated more frequently in the younger group, while K pneumoniae, Serratia marcescens, and Proteus mirabilis occurred more frequently in infections among the older group. A higher frequency of Enterobacter sp and S aureus were isolated among male patients, while Candida albicans and E coli apparently had a greater affinity for females; however, none of these differences by sex were statistically significant. Over 50% of the infections were manifest within the first ten days of hospitalization.

Seroepidemiological investigation of Brucella canis antibodies in different human population groups.

A study was conducted to determine the prevalence of Brucella canis antibodies in specified groups based on their exposure to dogs. The method used was a microtiter technique, and the presence of antibodies at a 1:12 or greater dilution of serum was considered a positive test. Eleven (5.7%) of the newborn infants had evidence of maternal antibodies, and 67.8% of the persons with an average exposure to dogs had B. canis antibodies, with a 62.1% prevalence in males and a 72.4% prevalence in females (P less than or equal to 0.001). Veterinarians had a much higher rate of infection (72.6%) than male blood donors (56.9%) (P less than or equal to 0.01). Patients with fevers of undetermined origin had significantly higher antibody titers to B. canis than all other patients (P less than or equal to 0.001). This study presents evidence that the prevalence of B. canis antibodies in humans is high, and that the incidence of brucellosis may increase when physicians consider B. canis as a possible etiological agent in febrile illnesses.