Search PubMed⌕ Search

Biomedical subjects

R E Dixon

Publications and source records attributed to R E Dixon.

At least 19 recordsLinked to original sources
PubMed1985

Economic costs of respiratory tract infections in the United States.

To evaluate one aspect of the impact of respiratory tract infections in the United States, national survey data were used to estimate direct and indirect economic costs. Overall, upper and lower respiratory tract infections are estimated to be responsible for approximately $15 billion in direct treatment costs. Physician charges account for about one half and hospital care accounts for approximately one quarter of these costs. An estimated 1.25 million patients are hospitalized yearly for community-acquired respiratory tract infections, and charges for their care are projected to exceed $4 billion. Almost 300 thousand patients acquire nosocomial respiratory infections yearly, and charges for treating these infections are approximately $470 million. Although costs associated with hospital care are substantial, approximately $10 billion (67 percent of the total estimated cost of these infections) results from treatment of patients in ambulatory settings. It is not possible to calculate the full magnitude of the indirect costs of respiratory infections, but losses in income of employed persons who miss work because of infection are calculated to be more than $9 billion per year.

Ambulatory Care↗
PubMed1985

Disk diffusion antimicrobial susceptibility testing for clinical and epidemiologic purposes.

Antimicrobial susceptibility testing is one of the most important and useful tests performed by the clinical microbiology laboratory. The value of disk susceptibility testing in epidemiology is enhanced by its simplicity of performance, reproducibility of results, and ability to indicate whether a single strain is likely to be the cause of many infections. By using a specific set of antimicrobials for either gram-positive or gram-negative bacterial susceptibility testing and by following recommended testing procedures, laboratories can reliably identify similarities and differences in strains. We propose a list of antimicrobial agents chosen specifically for their value in disk susceptibility testing for clinical and epidemiologic purposes and describe the recommended methods of testing.

Anti-Bacterial Agents↗
PubMed1981

Transmission of group B streptococci. Traced by use of multiple epidemiologic markers.

During a three-week period, septicemia caused by group B Streptococcus, serotype III, developed in four infants born at a community hospital. The first infant had early-onset disease; late-onset disease that appeared, from epidemiologic data, to be nosocomial developed in the other three infants. Bacteriophage typing and antimicrobial susceptibility testing confirmed the relatedness of the isolates. A prospective study designed to differentiate between vertical and nosocomial transmission of group B Streptococcus showed that of 82 infants, 21 (26%) were culture-positive during their hospitalization, and nine of these infants (43%) had been culture-negative at birth. Although serotype III strains were recovered from four of nine infants with apparently nosocomial acquisition, none of the isolates displayed an antibiogram or bacteriophage type similar to that of the isolates involved in the recent cluster. Bacteriophage typing and antimicrobial susceptibility testing in addition to the use of serotyping may be helpful in epidemiologic studies of group B Streptococcus.

Bacteriological Techniques↗
PubMed1981

Secular trends in nosocomial infections: 1970-1979.

Nosocomial infection data from a mean of 81 hospitals has been reported to the National Nosocomial Infections Study (NNIS) each year since 1970. Surveillance has been conducted by the hospitals on an average of 1.16 million patients annually. The median nosocomial infection rate is 341 per 10,000 patients discharged, ranging from 312 in 1970 to 358 in 1975. Since 1975, the rate has steadily declined to 329 in 1979. By category of hospital, infection rates for community-teaching and municipal hospitals have declined in recent years whereas those for community and university hospitals have not. Infection rates for patients on the surgical service have declined steadily since 1975 to the lowest levels reported, 457 per 10,000 surgical patients discharged in 1979, primarily due to a decrease in the rate of surgical wound infections. On obstetrics, infection rates have increased steadily since 1970, also primarily due to surgical wound infections. Bacteremias have increased in frequency, particularly those associated with infection at other sites. No major shifts have been noted in the relative frequency of the most common sites of infection or pathogens causing infections.

Cross Infection↗
PubMed1981

Comparison of endemic and epidemic nosocomial infections.

Epidemics account for a small proportion of preventable infections acquired in hospitals, but they have been important in defining sources, modes of spread, and methods for prevention and control of nosocomial infections. To characterize hospital-based epidemics, 265 consecutive outbreaks investigated by the Center for Disease Control between 1956 and 1979 were reviewed. Pseudoepidemics were found in 11 percent of the investigations, most often resulting from errors in processing microbiologic specimens or from surveillance artifacts. In 223 actual epidemics, the pathogens most commonly involved were Staphylococcus aureus (19 percent), tribe Klebsielleae (14 percent), Salmonella (13 percent), hepatitis B virus (8 percent), enteropathogenic Escherichia coli (5 percent), Pseudomonas (4 percent) and group A streptococci (4 percent). Sites of epidemic infection were closely linked to the responsible pathogens. Gastroenteritis (21 percent), skin infection (18 percent), bacteremia (12 percent), meningitis (11 percent) and hepatitis (10 percent), infrequent causes of endemic nosocomial infections, were frequently involved in epidemics. Over the 25-year period reviewed, staphylococcal epidemics and outbreaks of gastroenteritis due to Salmonella and Esch. coli declined in frequency and those due to gram-negative bacilli and hepatitis B virus increased. Since 1970, clusters of primary bacteremia were the most frequently investigated type of epidemic. Many epidemic strains of staphylococci obtained since 1975 or Enterobacteriaceae obtained since 1970 exhibited unusual drug resistance. Specific site-pathogen combinations were closely associated with characteristic reservoirs and modes of spread.

Cross Infection↗
PubMed1981

Epidemic nosocomial meningitis due to Citrobacter diversus in neonates.

Five infants born at one hospital over a two-year period developed meningitis due to a serotype O2 strain of Citrobacter diversus; four infants developed brain abscesses due to this organism. The initial prevalence of stool colonization in infants was 79%; eventually 140 infants (10%) and six nurses (6%) were found to be colonized. One colonized infant remained in the hospital for the entire two-year period. The strains were of two biotypes marked by the presence (biotype d) or absence (biotype a) of fermentation of sucrose and dulcitol. The biotype d strain was found in the five infants with meningitis, 110 asymptomatic infants, and five nurses. The biotype a strain, which was isolated from 30 infants and one nurse, did not cause disease. Colonized infants were distinguished by intensive care therapy (P = 10-31), gavage feeding (P = 0.036), and prenatal intrauterine monitoring (P = 0.037). These findings suggest a fecal reservoir and person-to-person transmission of C. diversus. Measures to control the outbreak cost about $110,000.

Birth Weight↗
PubMed1981

Rapid presumptive identification of Citrobacter diversus as an aid in controlling infections.

During an outbreak of neonatal meningitis caused by kanamycin-resistant Citrobacter diversus, a field procedure for presumptive identification of the organism was evaluated, and using it resulted in the early recognition of patients colonized by the epidemic strain of C. diversus. Rectal and nasopharyngeal specimens were plated and incubated on MacConkey agar containing 10 micrograms of kanamycin per ml. After 18 h of incubation, lactose-nonfermenting colonies present on the selective medium were picked and identified 8 h later with the following biochemical tests: indole, adonitol, dulcitol, citrate, and triple sugar iron agar. This presumptive identification of C. diversus was later confirmed for all cases by conventional testing with a complete set of biochemicals. In 1 week, 253 specimens from patients were processed with this technique, and 49 strains of C. diversus were identified. The rapid identification of C. diversus and transfer of carriers into appropriate cohorts resulted in a 64% reduction in the prevalence of colonization.

Bacteriological Techniques↗
PubMed1981

Cutaneous inflammation caused by inadvertent intradermal administration of DTP instead of PPD.

In 1979, 101 adults were skin-tested by a health department to evaluate tuberculin reactivity; of the 96 persons followed, 87 (91 per cent) experienced inflammation marked by swelling, erythema, arm pain, and fever. Five months later, a 5 mm to 10 mm purple macule persisted in 76 persons. The vials of PPD reportedly used for testing had been discarded, but PPD had been stored in the refrigerator with DT and DTP. The mean tetanus antitoxin titer in skin-tested persons was 0.14 units per ml (u/ml) vs 0.08 u/ml in untested control persons (p lesser than 0.03). The mean diphtheria antitoxin titer in skin-tested people was 0.90 u/ml vs 0.16 for controls (p = 10(-5)). The mean pertussis antibody in skin-tested persons was 1:169 vs 1:12 for controls (p = 10(-5)). Intradermal DTP in immune rabbits produced histologically typical Arthus reactions similar to those experienced by the humans. Seven months later, 90 persons received PPD injections. Ten had induration; none experienced persistent reactions. We concluded that the humans initially received DTP instead of PPD.

Animals↗
PubMed1979

Changing phage typing patterns of epidemic gentamicin-resistant Staphylococcus aureus. Evidence for transmission of gentamicin resistance.

In a 10-week period, infection with gentamicin resistant Staphylococcus aureus appeared in 24 adults and infants in one hospital. Medical staff were affected first, and subsequently 16 infants in the neonatal intensive-care unit. The gentamicin-resistant staphyloccal isolates showed three distinct phage susceptibility patterns in two distinct phage groups during the early, middle, and late phases of the outbreak. Although not confirmed with in-vitro or in-vivo laboratory data, this outbreak suggests that gentamicin resistance may be transferred between different strains of Staph. aureus in vivo.

Adult↗