Second-line drug susceptibility breakpoints for Mycobacterium tuberculosis using the MODS assay.

OBJECTIVE: To establish breakpoint concentrations for the fluoroquinolones (moxifloxacin [MFX] and ofloxacin [OFX]) and injectable second-line drugs (amikacin [AMK], kanamycin [KM] and capreomycin [CPM]) using the microscopic observation drug susceptibility (MODS) assay. SETTING: A multinational study conducted between February 2011 and August 2012 in Peru, India, Moldova and South Africa. DESIGN: In the first phase, breakpoints for the fluoroquinolones and injectable second-line drugs (n = 58) were determined. In the second phase, MODS second-line drug susceptibility testing (DST) as an indirect test was compared to MGIT™ DST (n = 89). In the third (n = 30) and fourth (n = 156) phases, we determined the reproducibility and concordance of MODS second-line DST directly from sputum. RESULTS: Breakpoints for MFX (0.5 µg/ml), OFX (1 µg/ml), AMK (2 µg/ml), KM (5 µg/ml) and CPM (2.5 µg/ml) were determined. In all phases, MODS results were highly concordant with MGIT DST. The few discrepancies suggest that the MODS breakpoint concentrations for some drugs may be too low. CONCLUSION: MODS second-line DST yielded comparable results to MGIT second-line DST, and is thus a promising alternative. Further studies are needed to confirm the accuracy of the drug breakpoints and the reliability of MODS second-line DST as a direct test.

High prevalence of latent tuberculosis infection among injection drug users in Tijuana, Mexico.

BACKGROUND: We studied prevalence and correlates of latent tuberculosis infection (LTBI) among injection drug users (IDUs) in Tijuana, Mexico, where tuberculosis (TB) is endemic. METHODS: IDUs aged > or =18 years were recruited via respondent-driven sampling (RDS) and underwent standardized interviews, human immunodeficiency virus (HIV) antibody testing and LTBI screening using Quanti-FERON((R))-TB Gold In-Tube, a whole-blood interferon-gamma release assay (IGRA). LTBI prevalence was estimated and correlates were identified using RDS-weighted logistic regression. RESULTS: Of 1020 IDUs, 681 (67%) tested IGRA-positive and 44 (4%) tested HIV-positive. Mean age was 37 years, 88% were male and 98% were Mexican-born. IGRA positivity was associated with recruitment nearest the US border (aOR 1.64, 95%CI 1.09-2.48), increasing years of injection (aOR 1.20/5 years, 95%CI 1.07-1.34), and years lived in Tijuana (aOR 1.10/5 years, 95%CI 1.03-1.18). Speaking some English (aOR 0.38, 95%CI 0.25-0.57) and injecting most often at home in the past 6 months (aOR 0.68, 95%CI 0.45-0.99) were inversely associated with IGRA positivity. DISCUSSION: Increased LTBI prevalence among IDUs in Tijuana appears to be associated with greater drug involvement. Given the high risk for HIV infection among Tijuana's IDUs, interventions are urgently needed to prevent HIV infection and treat LTBI among IDUs before these epidemics collide.

Disseminated coccidioidomycosis in children.

In an effort to define the importance of extrapulmonary coccidioidomycosis in the pediatric age group, we have studied 14 cases and reviewed the literature. The available data suggest that children are as susceptible to dissemination as are adults. Most children with disseminated coccidioidomycosis have evidence, either by history or chest radiographs, of preceding or concurrent pulmonary infection. The most common sites of dissemination are skin, subcutaneous tissue, bone, and meninges. Coccidioides immitis may be detected in tissues or body secretions by microscopic examination or by appropriate culture. Serologic tests are also useful in making the diagnosis and in following the course of the infection. Skin tests are often negative. Infection is progressive in 60% without antifungal therapy. Coccidioidomycosis of bone, skin, or subcutaneous tissue can be managed effectively with combined surgical and antifungal therapy. Meningitis is much more difficult to treat and is fatal in 50% of cases even when treated with amphotericin B.