Pediatric tuberculosis and human immunodeficiency virus infection in Palm Beach County, Florida

Pharmacokinetics of first-line antituberculosis drugs in HIV-infected children with tuberculosis treated with intermittent regimens in India

The objective of this report was to study the pharmacokinetics of rifampin (RMP), isoniazid (INH), and pyrazinamide (PZA) in HIV-infected children with tuberculosis (TB) treated with a thrice-weekly anti-TB regimen in the government program in India. Seventy-seven HIV-infected children with TB aged 1 to 15 years from six hospitals in India were recruited. During the intensive phase of TB treatment with directly observed administration of the drugs, a complete pharmacokinetic study was performed. Drug concentrations were measured by high-performance liquid chromatography. A multivariable regression analysis was done to explore the factors impacting drug levels and treatment outcomes. The proportions of children with subnormal peak concentrations (Cmax) of RMP, INH, and PZA were 97%, 28%, and 33%, respectively. Children less than 5 years old had a lower median Cmax and lower exposure (area under the time-concentration curve from 0 to 8 h [AUC0-8]) of INH (Cmax, 2.5 versus 5.1 μg/ml, respectively [P=0.016]; AUC0-8, 11.1 versus 22.0 μg/ml·h, respectively [P=0.047[) and PZA (Cmax, 34.1 versus 42.3 μg/ml, respectively [P=0.055]; AUC0-8, 177.9 versus 221.7 μg/ml·h, respectively [P=0.05]) than those more than 5 years old. In children with unfavorable versus favorable outcomes, the median Cmax of RMP (1.0 versus 2.8 μg/ml, respectively; P=0.002) and PZA (31.9 versus 44.4 μg/ml, respectively; P=0.045) were significantly lower. Among all factors studied, the PZA Cmax influenced TB treatment outcome (P=0.011; adjusted odds ratio, 1.094; 95% confidence interval, 1.021 to 1.173). A high proportion of children with HIV and TB had a subnormal RMP Cmax. The PZA Cmax significantly influenced treatment outcome. These findings have important clinical implications and emphasize that drug doses in HIV-infected children with TB have to be optimized.

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.