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Biomedical subjects

Charles D Wells

Publications and source records attributed to Charles D Wells.

9 recordsLinked to original sources
PubMed2006

Tuberculosis among foreign-born persons in the United States: achieving tuberculosis elimination.

RATIONALE: In the United States, the number of annual reported cases of tuberculosis (TB) among U.S.-born persons declined by 62% from 1993 to 2004, but increased by 5% among foreign-born persons. Over half of all reported cases of TB in the United States occur among foreign-born persons, most of these due to activation of latent TB infection (LTBI). Current guidelines recommend targeting only foreign-born persons who entered the United States within the previous 5 yr for LTBI testing. OBJECTIVE: We sought to assess the epidemiologic basis for this guideline. METHODS: We calculated TB case rates among foreign-born persons, stratified by duration of United States residence and world region of origin. We determined the number of cases using 2004 U.S. TB surveillance data, and calculated case rates using population data from the 2004 American Community Survey. MEASUREMENTS AND MAIN RESULTS: In 2004, a total of 14,517 cases of TB were reported; 3,444 (24%) of these were among foreign-born persons who had entered the United States more than 5 yr previously. The rate of TB disease among foreign-born persons was 21.5/100,000, compared with 2.7/100,000 for U.S.-born persons, and varied by duration of residence and world region of origin. CONCLUSIONS: Almost one-quarter of all TB cases in the United States occur among foreign-born persons who have resided in the United States for longer than 5 yr; case rates for such persons from selected regions of origin remain substantially elevated. To eliminate TB, we must address the burden of LTBI in this high-risk group.

Communicable Disease Control↗
PubMed2006

Time to sputum culture conversion in multidrug-resistant tuberculosis: predictors and relationship to treatment outcome.

BACKGROUND: Conversion of sputum mycobacterial cultures from positive growth to negative growth of Mycobacterium tuberculosis in patients with pulmonary tuberculosis (TB) is considered the most important interim indicator of the efficacy of anti-TB pharmacologic treatment for multidrug-resistant disease. OBJECTIVE: To evaluate and compare time to and predictors of initial sputum culture conversion with predictors of treatment outcome for patients with multidrug-resistant TB. DESIGN: Retrospective cohort study. SETTING: Latvia. PATIENTS: All civilian patients with multidrug-resistant TB treated with the DOTS-Plus strategy between 1 January and 31 December 2000. INTERVENTION: Individualized treatment for confirmed sputum culture-positive pulmonary multidrug-resistant TB. MEASUREMENTS: Time to initial sputum culture conversion and treatment outcome. RESULTS: Among 167 patients who were sputum culture-positive at initiation of second-line therapy, 129 (77%) converted in a median time of 60 days (range, 4 to 462 days) and 38 (23%) did not convert. Independent predictors of a longer sputum culture conversion time, using an accelerated failure time regression model, included previous treatment for multidrug-resistant TB, high initial sputum culture colony count, bilateral cavitations on chest radiography, and the number of drugs the initial isolate was resistant to at treatment initiation. Treatment outcomes were statistically significantly worse for patients who did not convert their sputum culture within 2 months. LIMITATIONS: Twenty-five percent of patients missed 5 or more monthly sputum collections. CONCLUSIONS: Under program conditions in Latvia, most patients with multidrug-resistant TB achieved sputum culture conversion within 12 weeks of starting treatment. Chest radiography and sputum culture drug susceptibility testing can assist physicians in predicting which patients will convert more slowly. Sputum culture conversion is a useful and appropriate interim indicator of treatment outcome in patients with multidrug-resistant TB.

Adolescent↗
PubMed2005

Multidrug-resistant tuberculosis detection, Latvia.

To improve multidrug-resistant tuberculosis (MDR-TB) detection, we successfully introduced the rpoB gene mutation line probe assay into the national laboratory in Latvia, a country with epidemic MDR-TB. The assay detected rifampin resistance with 91% sensitivity and 96% specificity within 1 to 5 days (vs. 12-47 days for BACTEC).

Antitubercular Agents↗
PubMed2004

Tuberculosis serodiagnosis in a predominantly HIV-infected population of hospitalized patients with cough, Botswana, 2002.

A sensitive and accurate tuberculosis (TB) serodiagnostic test would aid in the control of TB, but results of current tests are relatively unreliable for persons infected with human immunodeficiency virus (HIV). We evaluated a new prototype immunochromatographic strip test and 5 commercially available serodiagnostic TB tests in a prospective study comprised of 465 consecutively enrolled patients with suspected TB from 2 hospitals in Botswana. Consenting adults underwent HIV testing, >/=2 sputum smears and cultures, and mycobacterial blood culture. Patients were defined as having TB on the basis of any positive smear or culture. Between January and September 2002, 465 of 498 consecutive patients consented to enrollment. A total of 384 patients (83%) were infected with HIV, and 175 (38%) had TB; the mycobacterial blood culture was the sole source of diagnosis for 26 patients (15%) with TB. Among the tests evaluated, the sensitivity was 0%-63%, the specificity was 39%-99%, the positive predictive value was 0%-39%, and the negative predictive value was 63%-65%. We conclude that the serodiagnostic tests evaluated in this study lacked sufficient sensitivity as sole tests for TB in this population.

AIDS-Related Opportunistic Infections↗
PubMed2004

Tuberculosis in children: considerations for children from developing countries.

Although accurate data are scarce for children, tuberculosis (TB) represents one of the most common infectious causes of morbidity and mortality worldwide. TB case rates have declined among children in the United States in the last decade, but they remain high among children from low-income countries and racial or ethnic minorities. Establishing the definitive diagnosis of TB in a child remains difficult and frequently relies on a constellation of history, clinical findings, and bacteriology. Recently, updated national and international treatment recommendations have been published. Contact investigation and treatment using directly observed therapy are important components of the optimal case detection and management of TB in children.

Adolescent↗
PubMed2004

Epidemiology of childhood tuberculosis in the United States, 1993-2001: the need for continued vigilance.

OBJECTIVE: To describe trends and highlight epidemiologic and clinical characteristics of childhood tuberculosis (TB) in the United States. METHODS: All verified TB cases reported to the national TB surveillance system from 1993 to 2001 were included. A child was defined as a person younger than 15 years. RESULTS: A total of 11,480 childhood TB cases were reported. Case rates (TB cases/100,000 population) in all children declined from 2.9 (n = 1663) in 1993 to 1.5 (n = 931) in 2001. Among children, those who were younger than 5 years had the highest rate. California, Texas, and New York accounted for 48% of all childhood TB cases. In 2001, TB case rates were higher for foreign-born (12.2) than US-born children (1.1). Hispanic and non-Hispanic black children accounted for nearly three quarters of all cases. Twenty-four percent of children with TB were foreign-born children, with the largest number originating from Mexico (39.8%), the Philippines (8.6%), and Vietnam (5.7%). Most children had evidence of pulmonary TB disease (78.9%). Among culture-positive cases without previous TB, drug resistance to at least isoniazid was 7.3% and to isoniazid and rifampin was 1.6%. In 1999, 82.9% of children received directly observed therapy for at least part of their treatment and 94.8% completed treatment. CONCLUSIONS: Although the overall TB case number among children is declining in the United States, certain groups of children (eg, younger children, racial and ethnic minorities, foreign-born) are at higher risk for TB. As the United States moves toward the elimination of TB, future efforts should endeavor to prevent all cases of childhood TB.

Adolescent↗
PubMed2004

Tuberculosis along the United States-Mexico border, 1993-2001.

OBJECTIVES: Tuberculosis (TB) is a leading public health problem and a recognized priority for the federal Governments of both Mexico and the United States of America. The objectives of this research, primarily for the four states in the United States that are along the border with Mexico, were to: (1) describe the epidemiological situation of TB, (2) identify TB risk factors, and (3) discuss tuberculosis program strategies. METHODS: We analyzed tuberculosis case reports collected from 1993 through 2001 by the tuberculosis surveillance system of the United States. We used those data to compare TB cases mainly among three groups: (1) Mexican-born persons in the four United States border states (Arizona, California, New Mexico, and Texas), (2) persons in those four border states who had been born in the United States, and (3) Mexican-born persons in the 46 other states of the United States, which do not border Mexico. RESULTS: For the period from 1993 through 2001, of the 16 223 TB cases reported for Mexican-born persons in the United States, 12 450 of them (76.7%) were reported by Arizona, California, New Mexico, and Texas. In those four border states overall in 2001, tuberculosis case rates for Mexican-born persons were 5.0 times as high as the rates for persons born in the United States; those four states have 23 counties that directly border on Mexico, and the ratio in those counties was 5.8. HIV seropositivity, drug and alcohol use, unemployment, and incarceration were significantly less likely to be reported in Mexican-born TB patients from the four border states and the nonborder states than in patients born in the United States from the four border states (P < 0.001). Multivariate analysis revealed that among pulmonary tuberculosis patients who were 18-64 years of age and residing in the four border states, the Mexican-born patients were 3.6 times as likely as the United States-born patients were to have resistance to at least isoniazid and rifampin (i. e., to have multidrug-resistant TB) and twice as likely to have isoniazid resistance. Mexican-born TB patients from the four border states and the nonborder states were significantly more likely to have moved or to be lost to follow-up than were the TB patients born in the United States from the four border states (P < 0.001). CONCLUSIONS: Increased collaborative tuberculosis control efforts by the federal Governments of both Mexico and the United States along the border that they share are needed if tuberculosis is to be eliminated in the United States.

Adolescent↗
PubMedDate not supplied

Clinical outcome of individualised treatment of multidrug-resistant tuberculosis in Latvia: a retrospective cohort study.

BACKGROUND: Latvia has one of the highest rates of multidrug-resistant tuberculosis (MDRTB). Our aim was to assess treatment outcomes for the first full cohort of MDRTB patients treated under Latvia's DOTS-Plus strategy following WHO guidelines. METHODS: We retrospectively reviewed all civilian patients who began treatment with individualised treatment regimens for pulmonary MDRTB in Latvia between Jan 1, and Dec 31, 2000. We applied treatment outcome definitions for MDRTB, developed by an international expert consensus group, and assessed treatment effectiveness and risk factors associated with poor outcome. FINDINGS: Of the 204 patients assessed, 55 (27%) had been newly diagnosed with MDRTB, and 149 (73%) had earlier been treated with first-line or second-line drugs for this disease. Assessment of treatment outcomes showed that 135 (66%) patients were cured or completed therapy, 14 (7%) died, 26 (13%) defaulted, and treatment failed in 29 (14%). Of the 178 adherent patients, 135 (76%) achieved cure or treatment completion. In a multivariate Cox proportional-hazards model of these patients, independent predictors of poor outcome (death and treatment failure) included having previously received treatment for MDRTB (hazard ratio 5.7, 95% CI 1.9-16.6), the use of five or fewer drugs for 3 months or more (3.2, 1.1-9.6), resistance to ofloxacin (2.6, 1.2-5.4), and body-mass index less than 18.5 at start of treatment (2.3, 1.1-4.9). INTERPRETATION: The DOTS-Plus strategy of identifying and treating patients with MDRTB can be effectively implemented on a nationwide scale in a setting of limited resources.

Adolescent↗