Risk for Tuberculosis Disease Among Contacts with Prior Positive Tuberculin Skin Test: A retrospective Cohort Study, New York City.

BACKGROUND: Patients with prior positive tuberculin skin test (TST) results may benefit from prophylaxis after repeat exposure to infectious tuberculosis (TB). OBJECTIVE: To evaluate factors associated with active TB disease among persons with prior positive TST results named as contacts of persons with infectious TB. DESIGN: Population-based retrospective cohort study. PARTICIPANTS: A total of 2,933 contacts with prior positive TST results recently exposed to infectious TB identified in New York City's TB registry during the period from January 1, 1997 through December 31, 2003. MAIN MEASUREMENTS: Contacts developing active TB disease ≤ 4 years after exposure were identified and compared with those who did not, using Poisson regression analysis. Genotyping was performed on selected Mycobacterium tuberculosis-positive isolates. KEY RESULTS: Among contacts with prior positive TST results, 39 (1.3 %) developed active TB disease ≤ 4 years after exposure (≤ 2 years: 34). Risk factors for contacts that were independently associated with TB were age < 5 years (adjusted prevalence ratio [aPR] = 19.48; 95 % confidence interval [CI] = 7.15-53.09), household exposure (aPR = 2.60;CI = 1.30-5.21), exposure to infectious patients (i.e., cavities on chest radiograph, acid-fast bacilli on sputum smear; aPR = 1.9 3; CI = 1.01-3.71), and exposure to a U.S.-born index patient (aPR = 4.04; CI = 1.95-8.38). Receipt of more than 1 month of treatment for latent TB infection following the current contact investigation was found to be protective (aPR = 0.27; CI = .08-0.93). Genotype results were concordant with the index patients among 14 of 15 contacts who developed active TB disease and had genotyping results available. CONCLUSIONS: Concordant genotype results and a high proportion of contacts developing active TB disease within 2 years of exposure indicate that those with prior positive TST results likely developed active TB disease from recent rather than remote infection. Healthcare providers should consider prophylaxis for contacts with prior TB infection, especially young children and close contacts of TB patients (e.g., those with household exposure).

Severe Mpox Among People With Advanced Human Immunodeficiency Virus Receiving Prolonged Tecovirimat in New York City.

Severe mpox has been observed in people with advanced human immunodeficiency virus (HIV). We describe clinical outcomes of 13 patients with advanced HIV (CD4 <200 cells/µL), severe mpox, and multiorgan involvement. Despite extended tecovirimat courses and additional agents, including vaccinia immune globulin, cidofovir, and brincidofovir, this group experienced prolonged hospitalizations and high mortality.

Towards better prediction of Mycobacterium tuberculosis lineages from MIRU-VNTR data.

The determination of lineages from strain-based molecular genotyping information is an important problem in tuberculosis. Mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) typing is a commonly used molecular genotyping approach that uses counts of the number of times pre-specified loci repeat in a strain. There are three main approaches for determining lineage based on MIRU-VNTR data - one based on a direct comparison to the strains in a curated database, and two others, on machine learning algorithms trained on a large collection of labeled data. All existing methods have limitations. The direct approach imposes an arbitrary threshold on how much a database strain can differ from a given one to be informative. On the other hand, the machine learning-based approaches require a substantial amount of labeled data. Notably, all three methods exhibit suboptimal classification accuracy without additional data. We explore several computational approaches to address these limitations. First, we show that eliminating the arbitrary threshold improves the performance of the direct approach. Second, we introduce RuleTB, an alternative direct method that proposes a concise set of rules for determining lineages. Lastly, we propose StackTB, a machine learning approach that requires only a fraction of the training data to outperform the accuracy of both existing machine learning methods. Our approaches demonstrate superior performance on a training dataset collected in New York City over 10 years, and the improvement in performance translates to a held-out testing set. We conclude that our methods provide opportunities for improving the determination of pathogenic lineages based on MIRU-VNTR data.

Confirming Mycobacterium tuberculosis transmission from a cadaver to an embalmer using molecular epidemiology.

Genotyping results and epidemiologic investigation were used to confirm tuberculosis transmission from a cadaver to an embalmer. This investigation highlights the utility of genotyping in identifying unsuspected epidemiologic links and unusual transmission settings. In addition, the investigation provides additional evidence for the occupational risk of tuberculosis among funeral service workers and indicates a need for education about tuberculosis risk and the importance of adhering to appropriate infection control measures among funeral service workers.