Predictors of latent tuberculosis treatment initiation and completion at a U.S. public health clinic: a prospective cohort study

Background Treatment of latent tuberculosis infection (LTBI) is a key component in U.S. tuberculosis control, assisted by recent improvements in LTBI diagnostics and therapeutic regimens. Effectiveness of LTBI therapy, however, is limited by patients’ willingness to both initiate and complete treatment. We aimed to evaluate the demographic, medical, behavioral, attitude-based, and geographic factors associated with LTBI treatment initiation and completion of persons presenting with LTBI to a public health tuberculosis clinic. Methods Data for this prospective cohort study were collected from structured patient interviews, self-administered questionnaires, clinic intake forms, and U.S. census data. All adults (>17 years) who met CDC guidelines for LTBI treatment between January 11, 2008 and May 6, 2009 at Wake County Health and Human Services Tuberculosis Clinic in Raleigh, North Carolina were included in the study. In addition to traditional social and behavioral factors, a three-level medical risk variable (low, moderate, high), based on risk factors for both progression to and transmission of active tuberculosis, was included for analysis. Clinic distance and neighborhood poverty level, based on percent residents living below poverty level in a person’s zip code, were also analyzed. Variables with a significance level <0.10 by univariate analysis were included in log binomial models with backward elimination. Models were used to estimate risk ratios for two primary outcomes: (1) LTBI therapy initiation (picking up one month’s medication) and (2) therapy completion (picking up nine months INH therapy or four months rifampin monthly). Results 496 persons completed medical interviews and questionnaires addressing social factors and attitudes toward LTBI treatment. 26% persons initiated LTBI therapy and 53% of those initiating completed therapy. Treatment initiation predictors included: a non-employment reason for screening (RR 1.6, 95% CI 1.0-2.5), close contact to an infectious TB case (RR 2.5, 95% CI 1.8-3.6), regular primary care(RR 1.4, 95% CI 1.0-2.0), and history of incarceration (RR 1.7, 95% CI 1.0-2.8). Persons in the “high” risk category for progression/transmission of TB disease had higher likelihood of treatment initiation (p < 0.01), but not completion, than those with lower risk. Conclusions Investment in social support and access to regular primary care may lead to increased LTBI therapy adherence in high-risk populations

Effects of Intrahypothalamic Injection of Quinolinic Acid on Anterior Pituitary Hormone Secretion in the Unanesthetized Rat

Bilateral intrahypothalamic injections of the brain metabolite quinolinic acid (QUIN) were made in an attempt to examine its effects on the secretion of LH, PRL, GH and TSH. QUIN, a neuroexcitatory amino acid with close structural similarities to glutamate, kainate and N-methylaspartate, was infused into unanesthetized male rats, the animals sacrificed 7.5 min later, and serum hormone concentrations determined by radioimmunoassay. QUIN caused surges in LH, PRL and GH release (316, 607 and 1,134% of control, respectively, at 50 µg QUIN) without affecting the serum concentrations of TSH. At lower doses, a preferential effect of QUIN on PRL release was observed. All QUIN-induced hormonal changes were inhibited by concomitant administration of the specific antagonist ()-2-amino-7-phosphonoheptanoic acid, indicating the presence of QUIN-sensitive receptors on neurons which are intimately associated with endocrine regulation. Moreover, because QUIN-treated animals exhibited behavioral signs of seizure activity and neuroendocrine dysfunction has been reported to occur in human convulsive disorders, the data are also of interest in view of a possible mechanistic link between epileptic phenomena and hormone secretion

Pairing QuantiFERON Gold In-Tube with Opt-Out HIV Testing in a Tuberculosis Contact Investigation in the Southeastern United States

Knowing one's HIV status is particularly important in the setting of recent tuberculosis (TB) exposure. Blood tests for assessment of tuberculosis infection, such as the QuantiFERON Gold in-tube test (QFT; Cellestis Limited, Carnegie, Victoria, Australia), offer the possibility of simultaneous screening for TB and HIV with a single blood draw. We performed a cross-sectional analysis of all contacts to a highly infectious TB case in a large meatpacking factory. Twenty-two percent were foreign-born and 73% were black. Contacts were tested with both tuberculin skin testing (TST) and QFT. HIV testing was offered on an opt-out basis. Persons with TST ≥10 mm, positive QFT, and/or positive HIV test were offered latent TB treatment. Three hundred twenty-six contacts were screened: TST results were available for 266 people and an additional 24 reported a prior positive TST for a total of 290 persons with any TST result (89.0%). Adequate QFT specimens were obtained for 312 (95.7%) of persons. Thirty-two persons had QFT results but did not return for TST reading. Twenty-two percent met the criteria for latent TB infection. Eighty–eight percent accepted HIV testing. Two (0.7%) were HIV seropositive; both individuals were already aware of their HIV status, but one had stopped care a year previously. None of the HIV-seropositive persons had latent TB, but all were offered latent TB treatment per standard guidelines. This demonstrates that opt-out HIV testing combined with QFT in a large TB contact investigation was feasible and useful. HIV testing was also widely accepted. Pairing QFT with opt-out HIV testing should be strongly considered when possible