ObjectivesHousehold contacts (HHCs) of pulmonary tuberculosis patients are at high risk of Mycobacterium tuberculosis infection and early disease development. Identification of individuals at risk of tuberculosis disease is a desirable goal for tuberculosis control. Interferon-gamma release assays (IGRAs) using specific M. tuberculosis antigens provide an alternative to tuberculin skin testing (TST) for infection detection. Additionally, the levels of IFNγ produced in response to these antigens may have prognostic value. We estimated the prevalence of M. tuberculosis infection by IGRA and TST in HHCs and their source population (SP), and assessed whether IFNγ levels in HHCs correlate with tuberculosis development.MethodsA cohort of 2060 HHCs was followed for 2–3 years after exposure to a tuberculosis case. Besides TST, IFNγ responses to mycobacterial antigens: CFP, CFP-10, HspX and Ag85A were assessed in 7-days whole blood cultures and compared to 766 individuals from the SP in Medellín, Colombia. Isoniazid prophylaxis was not offered to child contacts because Colombian tuberculosis regulations consider it only in children under 5 years, TST positive without BCG vaccination.ResultsUsing TST 65.9% of HHCs and 42.7% subjects from the SP were positive (OR 2.60, p<0.0001). IFNγ response to CFP-10, a biomarker of M. tuberculosis infection, tested positive in 66.3% HHCs and 24.3% from the SP (OR = 6.07, p<0.0001). Tuberculosis incidence rate was 7.0/1000 person years. Children <5 years accounted for 21.6% of incident cases. No significant difference was found between positive and negative IFNγ responders to CFP-10 (HR 1.82 95% CI 0.79–4.20 p = 0.16). However, a significant trend for tuberculosis development amongst high HHC IFNγ producers was observed (trend Log rank p = 0.007).DiscussionCFP-10-induced IFNγ production is useful to establish tuberculosis infection prevalence amongst HHC and identify those at highest risk of disease. The high tuberculosis incidence amongst children supports administration of chemoprohylaxis to child contacts regardless of BCG vaccination.

Miltefosine is an oral agent used for cutaneous leishmaniasis treatment. An open-label, randomized, phase III clinical trial was carried out in the Colombian army population. Miltefosine, 50 mg capsule was taken orally three times per day for 28 days (N = 145) or meglumine antimoniate, 20 mg/kg body weight per day for 20 days by intramuscular injection (N = 143). The efficacy of miltefosine by protocol was 69.8% (85/122 patients) and 58.6% (85/145 patients) by intention to treat. For meglumine antimoniate, the efficacy by protocol was 85.1% (103/121 patients) and 72% (103/143 patients) by intention to treat. No association was found between drug efficacy and L. (V.) braziliensis or L. (V.) panamensis species of Leishmania responsible for infection. Adverse gastrointestinal events were associated with the use of miltefosine, the meglumine antimoniate treatment was associated with adverse effects on the skeletal musculature, fever, cephalea, and higher toxicity in kidney, liver, pancreas, and hematological system.

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Background Recent reports highlight the incursion of community-associated MRSA within healthcare settings. However, knowledge of this phenomenon remains limited in Latin America. The aim of this study was to evaluate the molecular epidemiology of MRSA in three tertiary-care hospitals in Medellín, Colombia. Methods An observational cross-sectional study was conducted from 2008–2010. MRSA infections were classified as either community-associated (CA-MRSA) or healthcare-associated (HA-MRSA), with HA-MRSA further classified as hospital-onset (HAHO-MRSA) or community-onset (HACO-MRSA) according to standard epidemiological definitions established by the U.S. Centers for Disease Control and Prevention (CDC). Genotypic analysis included SCC mec typing, spa typing, PFGE and MLST. Results Out of 538 total MRSA isolates, 68 (12.6%) were defined as CA-MRSA, 243 (45.2%) as HACO-MRSA and 227 (42.2%) as HAHO-MRSA. The majority harbored SCC mec type IVc (306, 58.7%), followed by SCC mec type I (174, 33.4%). The prevalence of type IVc among CA-, HACO- and HAHO-MRSA isolates was 92.4%, 65.1% and 43.6%, respectively. From 2008 to 2010, the prevalence of type IVc-bearing strains increased significantly, from 50.0% to 68.2% ( p = 0.004). Strains harboring SCC mec IVc were mainly associated with spa types t1610, t008 and t024 (MLST clonal complex 8), while PFGE confirmed that the t008 and t1610 strains were closely related to the USA300-0114 CA-MRSA clone. Notably, strains belonging to these three spa types exhibited high levels of tetracycline resistance (45.9%). Conclusion CC8 MRSA strains harboring SCC mec type IVc are becoming predominant in Medellín hospitals, displacing previously reported CC5 HA-MRSA clones. Based on shared characteristics including SCC mec IVc, absence of the ACME element and tetracycline resistance, the USA300-related isolates in this study are most likely related to USA300-LV, the recently-described ‘Latin American variant’ of USA300.