Michael F. Iademarco

Childhood vaccinations and risk of asthma

Background. A few previous studies have suggested that childhood vaccines, particularly whole cell pertussis vaccine, may increase the risk of asthma. We evaluated the suggested association between childhood vaccinations and risk of asthma. Methods. Cohort study involving 167 240 children who were enrolled in 4 large health maintenance organizations during 1991 to 1997, with follow-up from birth until at least 18 months to a maximum of 6 years of age. Vaccinations were ascertained through computerized immunization tracking systems, and onset of asthma was identified through computerized data on medical care encounters and medication dispensings. Results. In the study 18 407 children (11.0%) developed asthma, with a median age at onset of 11 months. The relative risks (95% confidence intervals) of asthma were: 0.92 (0.83 to 1.02) for diphtheria, tetanus and whole cell pertussis vaccine; 1.09 (0.9 to 1.23) for oral polio vaccine; 0.97 (0.91 to 1.04) for measles, mumps and rubella (MMR) vaccine; 1.18 (1.02 to 1.36) for Haemophilus influenzae type b (Hib); and 1.20 (1.13 to 1.27) for hepatitis B vaccine. The Hib result was not consistent across health maintenance organizations. In a subanalysis restricted to children who had at least 2 medical care encounters during their first year, the relative risks decreased to 1.07 (0.71 to 1.60) for Hib and 1.09 (0.88 to 1.34) for hepatitis B vaccine. Conclusion. There is no association between diphtheria, tetanus and whole cell pertussis vaccine, oral polio vaccine or measles, mumps and rubella vaccine and the risk of asthma. The weak associations for Hib and hepatitis B vaccines seem to be at least partially accounted for by health care utilization or information bias.

National Survey to Measure Rates of Liver Injury, Hospitalization, and Death Associated with Rifampin and Pyrazinamide for Latent Tuberculosis Infection

BACKGROUND Cases of severe and fatal liver injury were reported after a 2-month course of rifampin-pyrazinamide therapy was recommended in 2000 as an alternative to isoniazid for treatment of latent tuberculosis infection. We estimated rates of rifampin-pyrazinamide-associated liver injury and compared these with historical rates for isoniazid. METHODS We conducted a survey of state and city tuberculosis programs and other health care settings in the United States where rifampin-pyrazinamide was prescribed. The number of rifampin-pyrazinamide therapy initiations was collected, as well as the number of occurrences of (1) asymptomatic aspartate aminotransferase serum concentration >5 times the upper limit of normal, (2) symptomatic hepatitis (in which the patient was not hospitalized), (3) hospitalization for liver injury, (4) death with liver injury, and (5) treatment completion. We also searched a national pharmacy claims database (Verispan). Rates of these events were calculated. RESULTS Among 139 programs, 110 (79%) responded; 87 (79%) had initiated rifampin-pyrazinamide therapy for a total of 8087 patients between January 2000 and June 2002. Rates per 1000 rifampin-pyrazinamide therapy initiations during this period were 25.6 (95% confidence interval [CI], 22.3-29.3) for asymptomatic aspartate aminotransferase level >5 times the upper limit of normal and 18.7 (95% CI, 15.9-21.9) for hepatitis. Seven fatalities and 23 hospitalizations occurred, with rates of 0.9 (95% CI, 0.4-1.9) and 2.8 (95% CI, 1.8-4.3) per 1000 rifampin-pyrazinamide therapy initiations, respectively. Of 8087 patients, 64% completed rifampin-pyrazinamide therapy. The Verispan search revealed 1 rifampin-pyrazinamide-associated hospitalization (2.9 hospitalizations per 1000 rifampin-pyrazinamide therapy initiations; 95% CI, 0.1-18.4) and no deaths. Articles on the use of isoniazid therapy for latent tuberculosis infection that were published after 1990 reported fatality rates of 0.0-0.3 deaths per 1000 persons. CONCLUSIONS Rates of liver injury, hospitalization, and death associated with rifampin-pyrazinamide therapy exceed rates reported for isoniazid therapy. Because earlier randomized trials of rifampin-pyrazinamide lacked adequate statistical power to detect fatal events, the Centers for Disease Control and Prevention recommends that rifampin-pyrazinamide generally should not be used for treatment of latent tuberculosis infection.

Severe or Fatal Liver Injury in 50 Patients in the United States Taking Rifampin and Pyrazinamide for Latent Tuberculosis Infection

BACKGROUND Severe liver injuries were attributed to the rifampin and pyrazinamide (RZ) regimen after it was recommended for treating latent tuberculosis infection. Implicating RZ as the likeliest cause required excluding alternative causes. METHODS US health departments reported data on patients who died or were hospitalized for liver disease within 1 month after taking RZ for latent tuberculosis infection from October 1998 through March 2004. The circumstances were investigated on site for each case. Illness characteristics, reasons for RZ treatment, doses and frequency of administration of pyrazinamide, monitoring during treatment, and causes of liver injury were determined. RESULTS Liver injury was attributable to RZ use for all 50 patients reported, 12 of whom died. For 47 patients, RZ was the likeliest cause of liver injury. The median patient age was 44 years (range, 17-73 years). Thirty-two patients (64%) were male. Seven (16%) of 43 patients tested had hepatitis C virus antibodies, 1 (2%) of 45 had chronic hepatitis B, 3 (14%) of 22 had positive results of HIV serologic tests, 34 (71%) of 48 had alcohol use noted, and 33 (66%) of 50 were taking additional hepatotoxic medications. Six patients, 2 of whom died, had no predictors for liver disease. Patients who died were older (median age, 52 vs. 42 years; P=.08) and took a greater number of other medications (median number of medications, 4 vs. 2; P=.05) than did those who recovered, but these 2 factors were correlated (P<.01). Thirty-one patients (62%) were monitored according to guidelines, 9 of whom died. CONCLUSIONS RZ was the likeliest cause of most of these liver injuries, some of which were fatal in spite of monitoring. Fatality was predicted by age or use of other medications, but none of the cofactors showed promise as a reliable clinical predictor of severe liver injury.

Leading causes of death in nonmetropolitan and metropolitan areas -- United States, 1999–2014

Problem/Condition Higher rates of death in nonmetropolitan areas (often referred to as rural areas) compared with metropolitan areas have been described but not systematically assessed. Period Covered 1999–2014 Description of System Mortality data for U.S. residents from the National Vital Statistics System were used to calculate age-adjusted death rates and potentially excess deaths for nonmetropolitan and metropolitan areas for the five leading causes of death. Age-adjusted death rates included all ages and were adjusted to the 2000 U.S. standard population by the direct method. Potentially excess deaths are defined as deaths among persons aged <80 years that exceed the numbers that would be expected if the death rates of states with the lowest rates (i.e., benchmark states) occurred across all states. (Benchmark states were the three states with the lowest rates for each cause during 2008–2010.) Potentially excess deaths were calculated separately for nonmetropolitan and metropolitan areas. Data are presented for the United States and the 10 U.S. Department of Health and Human Services public health regions. Results Across the United States, nonmetropolitan areas experienced higher age-adjusted death rates than metropolitan areas. The percentages of potentially excess deaths among persons aged <80 years from the five leading causes were higher in nonmetropolitan areas than in metropolitan areas. For example, approximately half of deaths from unintentional injury and chronic lower respiratory disease in nonmetropolitan areas were potentially excess deaths, compared with 39.2% and 30.9%, respectively, in metropolitan areas. Potentially excess deaths also differed among and within public health regions; within regions, nonmetropolitan areas tended to have higher percentages of potentially excess deaths than metropolitan areas. Interpretation Compared with metropolitan areas, nonmetropolitan areas have higher age-adjusted death rates and greater percentages of potentially excess deaths from the five leading causes of death, nationally and across public health regions. Public Health Action Routine tracking of potentially excess deaths in nonmetropolitan areas might help public health departments identify emerging health problems, monitor known problems, and focus interventions to reduce preventable deaths in these areas.

Clinical research and development of tuberculosis diagnostics: moving from silos to synergy.

The development, evaluation, and implementation of new and improved diagnostics have been identified as critical needs by human immunodeficiency virus (HIV) and tuberculosis researchers and clinicians alike. These needs exist in international and domestic settings and in adult and pediatric populations. Experts in tuberculosis and HIV care, researchers, healthcare providers, public health experts, and industry representatives, as well as representatives of pertinent US federal agencies (Centers for Disease Control and Prevention, Food and Drug Administration, National Institutes of Health, United States Agency for International Development) assembled at a workshop proposed by the Diagnostics Working Group of the Federal Tuberculosis Taskforce to review the state of tuberculosis diagnostics development in adult and pediatric populations.

Performance of Tuberculosis Drug Susceptibility Testing in U.S. Laboratories from 1994 to 2008

ABSTRACT We present a statistical summary of results from the Model Performance Evaluation Program (MPEP) for Mycobacterium tuberculosis Drug Susceptibility Testing, 1994 to 2008, implemented by the U.S. Centers for Disease Control and Prevention (CDC). During that period, a total of 57,733 test results for culture isolates were reported by 216 participating laboratories for the first-line antituberculosis drugs used in the United States—isoniazid (INH), rifampin (RMP), ethambutol (EMB), and pyrazinamide (PZA). Using Clinical Laboratory and Standards Institute (CLSI)-recommended concentrations for one or more of three methods, agar proportion (AP), BACTEC460 (Bactec), and MGIT-960 (MGIT), yielded overall agreement of 97.0% for first-line drugs. For susceptible strains, agreement was 98.4%; for resistant strains, agreement was 91.0%, with significantly lower accuracy (chi-square test, P < 0.0001). For resistant strains, overall agreement by methods was 91.3% for AP, 93.0% for Bactec, and 82.6% for MGIT and by drugs was 92.2% for INH, 91.5% for RMP, 79.0% for EMB, and 97.5% for PZA. For some strains, performance by method varied significantly. Use of duplicate strains in the same shipment and repeat strains over time revealed consistent performance even for strains with higher levels of interlaboratory discordance. No overall differences in performance between laboratories were observed based on volume of testing or type of facility (e.g., health department, hospital, independent). By all methods, decreased performance was observed for strains with low-level INH resistance, RMP resistance, and EMB-resistant strains. These results demonstrate a high level of performance in detection of drug-resistant M. tuberculosis in U.S. laboratories.

Challenges and controversies in defining totally drug-resistant tuberculosis.

In March 2012, in response to reports of tuberculosis (TB) resistant to all anti-TB drugs, the World Health Organization convened an expert consultation that identified issues to be resolved before defining a new category of highly drug-resistant TB. Proposed definitions are ambiguous, and extensive drug resistance is encompassed by the already defined extensively drug-resistant (XDR) TB. There is no evidence that proposed totally resistant TB differs from strains encompassed by XDR TB. Susceptibility tests for several drugs are poorly reproducible. Few laboratories can test all drugs, and there is no consensus list of all anti-TB drugs. Many drugs are used off-label for highly drug resistant TB, and new drugs formulated to combat resistant strains would render the proposed category obsolete. Labeling TB strains as totally drug resistant might lead providers to think infected patients are untreatable. These challenges must be addressed before defining a new category for highly drug-resistant TB.

Reducing Potentially Excess Deaths from the Five Leading Causes of Death in the Rural United States

In 2014, the all-cause age-adjusted death rate in the United States reached a historic low of 724.6 per 100,000 population (1). However, mortality in rural (nonmetropolitan) areas of the United States has decreased at a much slower pace, resulting in a widening gap between rural mortality rates (830.5) and urban mortality rates (704.3) (1). During 1999–2014, annual age-adjusted death rates for the five leading causes of death in the United States (heart disease, cancer, unintentional injury, chronic lower respiratory disease (CLRD), and stroke) were higher in rural areas than in urban (metropolitan) areas (Figure 1). In most public health regions (Figure 2), the proportion of deaths among persons aged <80 years (U.S. average life expectancy) (2) from the five leading causes that were potentially excess deaths was higher in rural areas compared with urban areas (Figure 3). Several factors probably influence the rural-urban gap in potentially excess deaths from the five leading causes, many of which are associated with sociodemographic differences between rural and urban areas. Residents of rural areas in the United States tend to be older, poorer, and sicker than their urban counterparts (3). A higher proportion of the rural U.S. population reports limited physical activity because of chronic conditions than urban populations (4). Moreover, social circumstances and behaviors have an impact on mortality and potentially contribute to approximately half of the determining causes of potentially excess deaths (5).

A new strategy for public health surveillance at CDC: improving national surveillance activities and outcomes.

472  Public Health Reports / November–December 2014 / Volume 129 The Executive Perspective column is a regular feature in Public Health Reports by leaders of offices under the Assistant Secretary for Health. In this installment, Drs. Chesley L. Richards, Michael F. Iademarco, and Tara C. Anderson describe the U.S. Centers for Disease Control and Prevention’s (CDC’s) new strategy for federally supported public health surveillance activities. The new strategy focuses on what CDC must do inside and outside the agency to encourage progress in the field, working side by side with its state, territorial, local, and tribal partners.

Potentially Preventable Deaths Among the Five Leading Causes of Death — United States, 2010 and 2014

Death rates by specific causes vary across the 50 states and the District of Columbia.* Information on differences in rates for the leading causes of death among states might help state health officials determine prevention goals, priorities, and strategies. CDC analyzed National Vital Statistics System data to provide national and state-specific estimates of potentially preventable deaths among the five leading causes of death in 2014 and compared these estimates with estimates previously published for 2010. Compared with 2010, the estimated number of potentially preventable deaths changed (supplemental material at https://stacks.cdc.gov/view/cdc/42472); cancer deaths decreased 25% (from 84,443 to 63,209), stroke deaths decreased 11% (from 16,973 to 15,175), heart disease deaths decreased 4% (from 91,757 to 87,950), chronic lower respiratory disease (CLRD) (e.g., asthma, bronchitis, and emphysema) deaths increased 1% (from 28,831 to 29,232), and deaths from unintentional injuries increased 23% (from 36,836 to 45,331). A better understanding of progress made in reducing potentially preventable deaths in the United States might inform state and regional efforts targeting the prevention of premature deaths from the five leading causes in the United States.