Site migration in seeking care services from multiple providers is associated with worse clinical outcomes among HIV-infected individuals in Washington, DC.

Washington, DC, is a metropolitan city with a severe HIV epidemic and faces challenges in retaining people living with HIV (PLWH) in quality care. This study assessed site migration in seeking care services and its correlates among PLWH in DC. PLWH diagnosed before 2008 and living through the end of 2010 were analyzed. Six scenarios of site migration were examined as patients visited =2, =3, and =4 different providers for their CD4 cell count and/or viral load (VL) tests in the past 3 years from 2008 to 2010 and 2 years from 2009 to 2010, respectively. Of 6480 patients analyzed from 2008 to 2010, 18.4% had CD4 < 200 cells/mm(3), 30.5% had VL > 400 copies/mL, and 76.6% were retained in same care sites; 23.4%, 5.0%, and 0.9% visited =2, =3, and =4 sites in the past 3 years from 2008 to 2010, respectively. Of 5954 patients analyzed from 2009 to 2010, 16.8% had CD4 < 200 cells/mm(3), 29.4% had VL > 400 copies/mL, and 81.9% were retained in same care sites; 18.1%, 3.1%, and 0.6% visited =2, =3, and =4 sites in the past 2 years from 2009 to 2010, respectively. Multivariable logistic regression analyses revealed that migration across six scenarios are consistently associated with CD4 < 200 cells/mm(3) and VL > 400 copies/mL. Site migration was common and associated with lower CD4 and higher VL among PLWH in DC. Frequent migration might be a factor in achieving optimal health outcomes for a subset of patients. Site migration might potentially limit effective delivery of high quality care and treatment services. The preliminary findings underscore the need for further research to assess the predictors of migration and its impact on stage of care.

Temporal association between expanded HIV testing and improvements in population-based HIV/AIDS clinical outcomes, District of Columbia.

In 2006, the District of Columbia Department of Health (DC DOH) launched initiatives promoting routine HIV testing and improved linkage to care in support of revised the Centers for Disease Control and Prevention (CDC) HIV-testing guidelines. An ecological analysis was conducted using population-based surveillance data to determine whether these efforts were temporally associated with increased and earlier identification of HIV/AIDS cases and improved linkages to care. Publically funded HIV-testing data and HIV/AIDS surveillance data from 2005 to 2009 were used to measure the number of persons tested, new diagnoses, timing of entry into care, CD4 at diagnosis and rates of progression to AIDS. Tests for trend were used to determine whether statistically significant changes in these indicators were observed over the five-year period. Results indicated that from 2005 to 2009, publically funded testing increased 4.5-fold; the number of newly diagnosed HIV/AIDS cases remained relatively constant. Statistically significant increases in the proportion of cases entering care within three months of diagnosis were observed (p < 0.0001). Median CD4 counts at diagnosis increased over the five-year time period from 346 to 379 cells/µL. The proportion of cases progressing from HIV to AIDS and diagnosed with AIDS initially, decreased significantly (both p < 0.0001). Routine HIV testing and linkage to care efforts in the District of Columbia were temporally associated with earlier diagnoses of cases, more timely entry into HIV-specialized care, and a slowing of HIV disease progression. The continued use of surveillance data to measure the community-level impact of other programmatic initiatives including test and treat strategies will be critical in monitoring the response to the District's HIV epidemic.

Drug therapy of experimental tuberculosis (TB): improved outcome by combining SQ109, a new diamine antibiotic, with existing TB drugs.

Substitution of the new diamine antibiotic SQ109 for ethambutol in a mouse model of chronic tuberculosis (TB) improved efficacy of combination drug therapy with first-line TB drugs rifampin and isoniazid, with or without pyrazinamide: at 8 weeks, lung bacteria were 1.5 log10 lower in SQ109-containing regimens.

The American cotton rat: a novel model for pulmonary tuberculosis.

Several animal models are used to study Mycobacterium tuberculosis (MTB) infections, but none is a fully ideal model of human disease. The American cotton rat is an excellent model for the study of several human viral and bacterial respiratory infectious diseases, but until now has not been reported to be a model with MTB infection. Preliminary experiments were designed in which two species of cotton rats (Sigmodon hispidus and Sigmodon fulviventer) received respiratory challenges with M. tuberculosis via either intranasal or aerosol inoculation. Granulomatous disease, often with central necrosis, developed in the lungs, spleen, and lymph nodes of infected animals. The number of MTB bacilli in the lungs increased logarithmically until reaching a plateau in the second month after aerosol inoculation. There were differences in response to infection between the two species, with S. fulviventer demonstrating greater mortality than S. hispidus. Cytokine gene expression analysis by reverse transcriptase polymerase chain reaction (RT-PCR) was performed on both normal appearing and granulomatous lung tissue from infected animals. Many cytokine genes were more highly expressed in the focal areas of inflammation. Cotton rats provide another valuable tool in future research with tuberculosis.

Identification of new diamine scaffolds with activity against Mycobacterium tuberculosis.

A diverse 5000-compound library was synthesized from commercially available diamines and screened for activity against Mycobacterium tuberculosis in vitro, revealing 143 hits with minimum inhibitory concentration (MIC) equal to or less than 12.5 microM. New prospective scaffolds with antitubercular activity derived from homo-piperazine, phenyl- and benzyl-substituted piperazines, 4-aminomethylpiperidine, 4-aminophenylethylamine, and 4,4'-methylenebiscyclohexylamine were identified. Compound SQ775 derived from homopiperazine and compound SQ786 derived from benzylpiperazine had potent antimicrobial activity against M. tuberculosis in experimental animals in vivo.

Design and optimization of a recombinant system for large-scale production of the MPT64 antigen from Mycobacterium tuberculosis.

Early clinical trials of a potential new tuberculosis (TB) diagnostic, the Patch Test for Active TB (PTAT), used MPB64 protein that was purified from the spent medium of Bacillus Calmette-Guérin (BCG) Tokyo 172 vaccine production. The yield was poor, 0.05 mg/L, and the process for purification of the protein was complex, requiring four chromatographic steps. The combination of yield and purification complexity compromised the ability to produce the PTAT diagnostic in quantities sufficient for larger clinical trials and commercialization. We report here a highly efficient method for the overexpression and purification of recombinant MPT64 from Escherichia coli (rMPT64) based upon a mild insolubility of rMPT64 following induction, and scalable anion-exchange and gel filtration chromatographies. Yields of protein were improved substantially to approximately 250 mg/L, and resulted in a preparation greater than 98% pure. Quantitative release assays were developed and used with MALDI-TOF mass spectrometry to confirm the identity of rMPT64. Using a guinea pig model of active TB, we found that rMPT64 elicited a specific immune response indistinguishable from that of MPB64 purified from BCG Tokyo culture filtrates. These results describe the first efficient and scalable protocol for production of rMPT64, demonstrate its activity in an animal model of active TB, and lay the foundation of ongoing and future use of the PTAT in clinical settings.

Identification of a new antitubercular drug candidate, SQ109, from a combinatorial library of 1,2-ethylenediamines.

OBJECTIVES: The aim of this study was to identify a candidate drug for clinical development from a previously synthesized combinatorial library based on the 1,2-ethylenediamine structure of ethambutol. METHODS: Sixty-nine of the most potent hits against Mycobacterium tuberculosis from the original studies were subjected to a sequential set of tests in vitro and in vivo--determination of MIC for M. tuberculosis H37Rv, cytotoxicity, intracellular antimycobacterial activity, permeability evaluation and in vivo efficacy testing. RESULTS: Twenty-seven compounds with MICs of < or = 15.6 microM were tested on Vero cells to determine in vitro cytotoxicity (IC50) and to establish a selectivity index (SI) (SI = IC50/MIC). Ten compounds with acceptable SI were tested for activity against intracellular bacteria--all were equivalent (within 1%) or superior to ethambutol and several demonstrated cidal activity. Five of the most potent compounds were tested for in vivo efficacy in a murine model of chronic tuberculosis infection. CONCLUSION: Compound SQ109 with an MIC of 0.7-1.56 microM (H37Rv, Erdman and drug-resistant strains of M. tuberculosis), an SI of 16.7 and 99% inhibition activity against intracellular bacteria, demonstrated potency in vivo and limited toxicity in vitro and in vivo, and was selected for further development.

Rapid, simple in vivo screen for new drugs active against Mycobacterium tuberculosis.

We evaluated the use of a simple and easy-to-obtain potential marker of tuberculosis (TB) drug efficacy, body weight, and correlated weight loss or gain with the number of CFU of Mycobacterium tuberculosis in lungs and spleens of infected mice. C3H mice were infected intravenously with 10(6) CFU of virulent M. tuberculosis H37Rv, and body weight was evaluated for several weeks after infection. At day 20, infected untreated mice consistently lost more than 25% of their body weight. Chemotherapy with selected orally active anti-TB drugs was initiated 7 days following infection and continued for 13 days. Drugs that were administered daily by gavage included isoniazid (INH), ethambutol (EMB), rifampin (RIF), and moxifloxacin (MXF). At the most effective doses, each of these drugs inhibited bacterial growth and abolished infection-induced body weight loss. Chemotherapy with 1/10 the standard dose of INH determined in accepted long-term murine models of TB also prevented body weight loss, while chemotherapy with 1/10 the standard dose of RIF did not. With only 2 weeks of chemotherapy, we observed a good reverse correlation between CFU in lung or spleen and body weight of mice. The simple measurement of weight in TB-infected drug-treated mice required only a weight balance, and go/no-go drug efficacy data was available on day 20 without the necessity of prolonged drug treatment and long (3 weeks or more) in vitro culture times to obtain organ CFU values.