Lukas Fenner

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BACKGROUND Smear-positive pulmonary TB is the most infectious form of TB. Previous studies on the effect of HIV and antiretroviral therapy on TB treatment outcomes among these highly infectious patients demonstrated conflicting results, reducing understanding of important issues. METHODS All adult smear-positive pulmonary TB patients diagnosed between(More)
Immigrants from high-burden countries and HIV-coinfected individuals are risk groups for tuberculosis (TB) in countries with low TB incidence. Therefore, we studied their role in transmission of Mycobacterium tuberculosis in Switzerland. We included all TB patients from the Swiss HIV Cohort and a sample of patients from the national TB registry. We(More)
BACKGROUND Many HIV-infected children in Southern Africa have been started on antiretroviral therapy (ART), but loss to follow up (LTFU) can be substantial. We analyzed mortality in children retained in care and in all children starting ART, taking LTFU into account. PATIENTS AND METHODS Children who started ART before the age of 16 years in 10 ART(More)
We evaluated a two-step algorithm for detection of Clostridium difficile in 1,468 stool specimens. First, specimens were screened by an immunoassay for C. difficile glutamate dehydrogenase antigen (C.DIFF CHEK-60). Second, screen-positive specimens underwent toxin testing by a rapid toxin A/B assay (TOX A/B QUIK CHEK); toxin-negative specimens were(More)
There is increasing evidence that strain variation in Mycobacterium tuberculosis complex (MTBC) might influence the outcome of tuberculosis infection and disease. To assess genotype-phenotype associations, phylogenetically robust molecular markers and appropriate genotyping tools are required. Most current genotyping methods for MTBC are based on mobile or(More)
BACKGROUND Mycobacterium tuberculosis has a global population structure consisting of six main phylogenetic lineages associated with specific geographic regions and human populations. One particular M. tuberculosis genotype known as "Beijing" has repeatedly been associated with drug resistance and has been emerging in some parts of the world. "Beijing"(More)
This study describes the distribution and frequencies of strain types by protein A-encoding gene (spa) typing among a total of 200 meticillin-resistant Staphylococcus aureus (MRSA) single-patient isolates collected between 2000 and 2005 at the University Hospital Basel, Switzerland. Nine frequent spa types accounted for 49.5 % of MRSA isolates, whereas spa(More)
BACKGROUND Whole-genome sequencing (WGS) is increasingly used in molecular-epidemiological investigations of bacterial pathogens, despite cost- and time-intensive analyses. We combined strain-specific single-nucleotide polymorphism (SNP) typing and targeted WGS to investigate a tuberculosis cluster spanning 21 years in Bern, Switzerland. METHODS On the(More)
The phylogeographic population structure of Mycobacterium tuberculosis suggests local adaptation to sympatric human populations. We hypothesized that HIV infection, which induces immunodeficiency, will alter the sympatric relationship between M. tuberculosis and its human host. To test this hypothesis, we performed a nine-year nation-wide(More)
The number of positive anaerobic blood culture results per 1,000 blood cultures performed decreased from 12.6 in the period from 1997 to 2001 to 7.0 in the period from 2002 to 2006 (P < 0.001), as did the proportion of isolated anaerobic organisms compared to the number of all organisms isolated from blood cultures (7.6% to 4.3% [P < 0.001]), while positive(More)