RESUMO
OBJECTIVES: Source case finding in San Diego, California, rarely detects the source for children with tuberculosis (TB) infection or disease. One third of all pediatric TB isolates in San Diego are Mycobacterium bovis, a strain associated with raw dairy products. This study was conducted to determine risk factors for TB infection in San Diego. DESIGN: Case-control study of children /=10 mm) Mantoux skin test (TST) were matched by age to 1 to 2 children with negative TST from the same clinic. We assessed risk factors for TB infection through parental interview and chart review. RESULTS: A total of 62 cases and 97 controls were enrolled. Eleven cases and 25 controls were excluded from analysis because of previous positive skin tests. Compared with controls, cases were more likely to have received BCG vaccine (73% vs 7%, odds ratio [OR] 44), to be foreign born (35% vs 11%, OR 4.3), and to have eaten raw milk or cheese (21% vs 8%, OR 3.76). The median time between the most recent previous TST and the current test was 12 months for cases and 25 months for controls. Other factors associated with a positive TST included foreign travel, staying in a home while out of the country, and having a relative with a positive TST. There was no association between contact with a known TB case. In a multivariable model, receipt of BCG, contact with a relative with a positive TST, and having a previous TST within the past year were independently associated with TB infection. CONCLUSIONS: We identified several new or reemerging associations with positive TST including cross border travel, staying in a foreign home, and eating raw dairy products. The strong associations with BCG receipt and more recent previous TST may represent falsely positive reactions, booster phenomena, or may be markers for a population that is truly at greater risk for TB infection. Unlike studies conducted in nonborder areas, we found no association between positive TB skin tests and contact with a TB case or a foreign visitor. Efforts to control pediatric TB in San Diego need to address local risk factors including consumption of unpasteurized dairy products and cross-border travel. The interpretation of a positive TST in a young child in San Diego who has received BCG is problematic.
Assuntos
Vacina BCG/imunologia , Teste Tuberculínico/estatística & dados numéricos , Tuberculose/imunologia , Vacina BCG/uso terapêutico , California/epidemiologia , Estudos de Casos e Controles , Pré-Escolar , Controle de Doenças Transmissíveis/métodos , Busca de Comunicante/estatística & dados numéricos , Laticínios/efeitos adversos , Laticínios/microbiologia , Reações Falso-Positivas , Humanos , Hipersensibilidade Tardia/diagnóstico , Hipersensibilidade Tardia/imunologia , México , Mycobacterium bovis/imunologia , Mycobacterium bovis/isolamento & purificação , Fatores de Risco , Viagem/estatística & dados numéricos , Tuberculose/epidemiologia , Tuberculose/transmissãoRESUMO
SETTING: The prevalence of substandard anti-tuberculosis drugs is unknown. To maximize the effectiveness of tuberculosis (TB) control efforts, simple, inexpensive drug quality screening methods are needed. DESIGN: Isoniazid (INH) and rifampin (RMP) single- and fixed-dose combination (FDC) formulations were collected from selected TB programs and pharmacies in Colombia, Estonia, India, Latvia, Russia and Vietnam. Samples were screened using a recently developed thin-layer chromatography (TLC) kit. All abnormal samples and a 40% random sample of normal formulations were further analyzed using confirmatory techniques. Samples outside of 85% to 115% of stated content, and/or containing compounds other than the stated drug, were defined as being substandard. RESULTS: Overall, 10% (4/40) of all samples, including 13% (4/30) RMP samples, contained <85% of stated content. More FDCs (5/24, 21%) than single-drug samples (2/16, 13%) were substandard. A comparison of TLC with the confirmatory analysis for RMP analysis showed a sensitivity of 100% (4/4), a specificity of 92% (24/26), a positive predictive value (PPV) of 67% (4/6), and a negative predictive value (NPV) of 100% (24/24). An analysis of INH showed a specificity of 90% (9/10). However, sensitivity, PPV, and NVP could not be determined. CONCLUSION: A substantial number of anti-tuberculosis drugs from several countries, in particular FDCs, were found to be substandard. Such drugs may contribute to the creation of drug-resistant TB. TLC is an effective, convenient, and inexpensive method for the detection of substandard drugs.
Assuntos
Antituberculosos/análise , Cromatografia em Camada Fina/métodos , Isoniazida/análise , Rifampina/análise , Tuberculose/tratamento farmacológico , Antituberculosos/normas , Ásia , Colômbia , Combinação de Medicamentos , Europa Oriental , Humanos , Isoniazida/normas , Valor Preditivo dos Testes , Controle de Qualidade , Padrões de Referência , Rifampina/normas , Sensibilidade e EspecificidadeRESUMO
OBJECTIVE: To identify factors contributing to a 400% increase in tuberculosis among children in San Diego County, California, from 1985 to 1993. DESIGN: Review of medical records of reported cases in 1989, 1991, and 1993 and their source case. RESULTS: Of 192 children with tuberculosis, the largest increase was observed in children younger than 5 years old, of whom 77.4% were born in the United States, 67.8% had a foreign-born parent, 73.1% came from a non-English-speaking household, and 46.2% were known to visit Mexico. Of 28 source cases, 82.1% were born outside the United States, primarily in Mexico (67.9%). Resistance to at least one first-line antituberculous drug was identified in 27.5% of isolates from children and in 33.3% of isolates from source cases. CONCLUSIONS: The increase in tuberculosis and high level of drug-resistance among children born in the United States may be attributed to transmission outside of the United States or within the United States from household contacts born in countries in which tuberculosis is highly endemic.