Public Health Efforts Can Impact Adoption of Current Susceptibility Breakpoints, but Closer Attention from Regulatory Bodies Is Needed.

Microbiological testing, including interpretation of antimicrobial susceptibility testing results using current breakpoints, is crucial for clinical care and infection control. Continued use of obsolete Enterobacteriaceae carbapenem breakpoints is common in clinical laboratories. The purposes of this study were (i) to determine why laboratories failed to update breakpoints and (ii) to provide support for breakpoint updates. The Los Angeles County Department of Public Health conducted a 1-year outreach program for 41 hospitals in Los Angeles County that had reported, in a prior survey of California laboratories, using obsolete Enterobacteriaceae carbapenem breakpoints. In-person interviews with hospital stakeholders and customized expert guidance and resources were provided to aid laboratories in updating breakpoints, including support from technical representatives from antimicrobial susceptibility testing device manufacturers. Forty-one hospitals were targeted, 7 of which had updated breakpoints since the prior survey. Of the 34 remaining hospitals, 27 (79%) assumed that their instruments applied current breakpoints, 17 (50%) were uncertain how to change breakpoints, and 10 (29%) lacked resources to perform a validation study for off-label use of the breakpoints on their systems. Only 7 hospitals (21%) were familiar with the FDA/CDC Antibiotic Resistance Isolate Bank. All hospitals launched a breakpoint update process; 16 (47%) successfully updated breakpoints, 12 (35%) received isolates from the CDC in order to validate breakpoints on their systems, and 6 (18%) were planning to update within 1 year. The public health intervention was moderately successful in identifying and overcoming barriers to updating Enterobacteriaceae carbapenem breakpoints in Los Angeles hospitals. However, the majority of targeted hospitals continued to use obsolete breakpoints despite 1 year of effort. These findings have important implications for the quality of patient care and patient safety. Other public health jurisdictions may want to utilize similar resources to bridge the patient safety gap, while manufacturers, the FDA, and others determine how best to address this growing public health issue.

Body mass index and asthma in the military population of the northwestern United States.

BACKGROUND: Patients with asthma commonly have other medical problems such as obesity, but it is unclear if obesity independently relates to asthma occurrence. OBJECTIVE: To examine the association between asthma and obesity. METHODS: We studied enrollees aged 17 to 96 years in region 11 of TRICARE, a military managed health care program encompassing Washington, Oregon, and northern Idaho, using an enrollment questionnaire from January 1997 to December 1998. We performed case-control analyses on 2788 asthma cases and 39 637 controls. From these cases and controls, we selected a random sample of 1000 asthma cases and 1000 controls, linking them to a computerized military health record system to verify if medications indicated for asthma therapy were prescribed. After excluding cases not prescribed bronchodilator medications and excluding controls prescribed bronchodilator medications or steroids, we used logistic regression to estimate associations among asthma, body mass index, and demographic, lifestyle, and comorbid risk factors in 386 verified cases and 744 verified controls. RESULTS: Increasing body mass index, younger age, female sex, non-active duty beneficiary status, and arthritis were significant independent predictors of asthma prevalence in both our larger analysis and our verified substudy, whereas stomach ulcer, depression, hypertension, and white race are also independent predictors of asthma prevalence in our larger analysis. CONCLUSIONS: Increasing body mass index is a key factor predicting prevalence of asthma and, if determined to be etiologically related to asthma incidence, is a potentially modifiable risk factor for asthma.

Epidemiology and control of acute respiratory diseases with emphasis on group A beta-hemolytic streptococcus: a decade of U.S. Army experience.

OBJECTIVE: To summarize the experiences of the U.S. Army regarding prevention and control, and frequencies, rates, trends, and determinants of febrile acute respiratory diseases (ARDs), particularly Group A beta-hemolytic streptococcus (GABHS). METHODOLOGY: Since 1966, the U.S. Army has conducted routine surveillance of ARDs among basic trainees. Since 1985, all trainees with fever and respiratory tract symptoms have been cultured for GABHS: Field investigations were conducted when outbreaks of acute respiratory or GABHS-associated illnesses were detected. Mass plus tandem benzathine penicillin prophylaxis were used to interdict and control training center GABHS outbreaks. RESULTS: During the period 1985 to 1994, there were 65,184 hospitalizations for acute febrile respiratory illnesses among Army trainees. The crude hospitalization rate was 0.45 per 100 trainees per week. The rate consistently declined over the period. Incremental declines were temporally associated with increased use of adenovirus immunizations and broader use of benzathine penicillin prophylaxis. During the period, 10,789 of 59,818 (18%) pharyngeal cultures were positive for GABHS: GABHS outbreaks were associated with diverse clinical manifestations including streptococcal toxic shock, acute rheumatic fever, and pneumonia. The emergence of mucoid colony morphology in clinical isolates was a consistent indicator of circulating virulent strains with epidemic potential. Outbreak-associated M types were M1, M3, M5, and M18. In response to six GABHS outbreaks, mass plus tandem benzathine penicillin chemoprophylaxis produced rapid and sustained GABHS control. ARD and GABHS recovery rates were lowest when benzathine penicillin prophylaxis was widely used. CONCLUSIONS: ARD rates among Army trainees have consistently declined to unprecedented levels. GABHS has reemerged as an important threat to military trainees. Benzathine penicillin chemoprophylaxis is safe and effective for interdicting and preventing GABHS outbreaks in closed, healthy young adult populations.

Broad and persistent effects of benzathine penicillin G in the prevention of febrile, acute respiratory disease.

After an outbreak of acute rheumatic fever at a US Army training installation, a benzathine penicillin G prophylaxis program was instituted. Surveillance data were analyzed to measure rates of febrile, acute respiratory disease (ARD) among trainees before and after prophylaxis was begun. Annual admissions for ARD decreased from 1927 to 690 (-64.2%) after benzathine penicillin G prophylaxis was begun. Admissions with throat cultures positive for Streptococcus pyogenes fell from 595 to 63 (-89.4%), a reduction that accounted only for a minority (43%) of the total 1237 "prevented" admissions. Temporal changes in disease rates at other installations where drug was not administered were also analyzed. Only a small decrease in the number of annual ARD admissions (-6.3%) was observed at other training installations. These findings support a hypothesis that benzathine penicillin G has a broad effect in the prevention of ARD that extends beyond the simple elimination of group A streptococcal infection.

Epidemic streptococcal disease among Army trainees, July 1989 through June 1991.

Outbreaks of group A streptococcal infection occurred at four of seven US Army basic training installations between 1 July 1989 and 30 June 1991. Study data were collected through a respiratory disease surveillance program and on-site epidemiologic investigations. Although hospitalizations were frequent (range, 191-334) during each outbreak, average rates of hospitalization were low (2.4-4.8 hospitalizations/1000 trainees/week). Outbreak-associated morbidity included streptococcal toxic shock syndrome (2 cases, 1 fatal), acute rheumatic fever (6), acute glomerulonephritis (1), scarlet fever (1), and numerous other invasive sequelae. Four serotypes of Streptococcus pyogenes (M-1, -3, -5, and -18) were identified; M-18 caused significant disease at 2 installations. Disease control was rapidly achieved through prophylaxis programs using benzathine penicillin G in nonallergic trainees. These outbreaks extend other reports that document an evolution of the nature and severity of circulating S. pyogenes in the United States.

Human immunodeficiency virus infections among civilian applicants for United States military service, October 1985 to March 1986. Demographic factors associated with seropositivity.

During the six months from October 1985 through March 1986, blood samples from 306,061 civilian applicants for military service from the United States were tested for antibody to the human immunodeficiency virus (HIV). Four hundred sixty subjects were positive for the antibody as determined by Western (immune) blot reactivity. The mean prevalence of HIV infection in this population of teenagers and young adults was thus 1.50 per 1000. According to multivariate analysis, the following demographic factors were found to be significant independent predictors of a positive HIV-antibody test: age (adjusted odds ratio = 1.10 per year), black race (adjusted odds ratio = 2.04), male sex (adjusted odds ratio = 1.84), residence in a densely populated county (adjusted odds ratio = 1.05 per 1000 per square mile), and residence in a metropolitan area with a high incidence of the acquired immunodeficiency syndrome (adjusted odds ratio = 1.53). Antibody-positive applicants were identified in 43 of the 50 states. Counties with high prevalence rates for HIV (greater than 5 per 1000) were located in New York State (four counties), New Jersey (three counties), California (two counties), Maryland (two counties), and Texas, Colorado, and Washington, D.C.