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Introduction and persistence of tularemia in Bulgaria.

ABSTRACT: INTRODUCTION:Outbreaks of the zoonotic disease tularemia occurred in north-east Bulgaria in the 1960s. Then came 30 years of epidemiological silence until new outbreaks occurred in west Bulgaria in the 1990s. To investigate how bacterial strains of Francisella tularensis causing tularemia in wildlife and humans in the 1960s and the 1990s were related, we explored their genetic diversity. MATERIAL AND METHODS:Ten F. tularensis genomes from the 1960s (n=3) and the 1990s (n=7) were sequenced, assigned to canonical single-nucleotide polymorphism (canSNP) clades, and compared to reference genomes. We developed four new canSNP polymerase chain reaction (PCR) assays based on the genome sequence information. RESULTS AND DISCUSSION:The genetic analysis showed that the outbreaks in the 1960s as well as in the 1990s involved multiple clones and new genetic diversity. The smallest genetic difference found between any of the Bulgarian strains was five SNPs between the strains L2 and 81 isolated 43 years apart, indicating that F. tularensis may persist locally over long time periods without causing outbreaks. The existence of genetically highly similar strain-pairs isolated the same year in the same area from different hosts supports a hypothesis of local expansion of clones during outbreaks. Close relationship (two SNPs) was found between one strain isolated 1961 in northeast Bulgaria and one strain isolated 5 years before in USSR. Historical data coinciding with the actual time point describe the introduction of water rats from USSR into the Bulgarian outbreak area, which may explain the close genetic relationship and the origin of the outbreak. CONCLUSION:Genome analysis of strains from two outbreaks in the 1960s and the 1990s provided valuable information on the genetic diversity and persistence of F. tularensis in Bulgaria.

SUBMITTER: Myrtennas K

PROVIDER: S-EPMC5084392 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

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Introduction and persistence of tularemia in Bulgaria.

Myrtennäs Kerstin K Marinov Krustyu K Johansson Anders A Niemcewicz Marcin M Karlsson Edvin E Byström Mona M Forsman Mats M

Infection ecology & epidemiology 20161026

<h4>Introduction</h4>Outbreaks of the zoonotic disease tularemia occurred in north-east Bulgaria in the 1960s. Then came 30 years of epidemiological silence until new outbreaks occurred in west Bulgaria in the 1990s. To investigate how bacterial strains of <i>Francisella tularensis</i> causing tularemia in wildlife and humans in the 1960s and the 1990s were related, we explored their genetic diversity.<h4>Material and methods</h4>Ten <i>F. tularensis</i> genomes from the 1960s (<i>n</i>=3) and t ...[more]

PMID: 27790972

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Project description:IntroductionPost-menopausal women with osteoporosis > 70 years of age at high risk of fracture urgently require treatment for fracture prevention. Moreover, persistence with osteoporosis therapy is critical for real-world effectiveness. We estimated persistence with denosumab in older women at high fracture risk in clinical practice in Bulgaria.MethodsEligible participants were post-menopausal women, > 70 years of age, diagnosed with osteoporosis (T-score ≤ - 2.5) and at high risk of fracture (≥ 3% for hip and ≥ 20% for major osteoporotic fracture) who received at least one denosumab injection before enrollment. Planned follow-up was 24 months. The primary endpoint was persistence to denosumab at 12, 18, and 24 months (defined as receiving all denosumab injections within 6 months ± 60 days of the previous injection).Results250 women were enrolled across 12 Bulgarian endocrinology/rheumatology practices; median follow up, 736 days. Mean (SD) age was 75.8 (4.2) years; mean (SD) FRAX® was 13.1 (8.6) for hip and 26.1 (9.5) for major osteoporotic fracture; 47 (18.8%) women had prior osteoporosis therapy and 104 (41.6%) had prior fracture. Denosumab persistence was high: 98.0%, 92.4%, and 84.4% at 12, 18, and 24 months, respectively. A total of 42 (16.8%) women discontinued denosumab during follow-up, mostly for financial reasons [25/42 (59.5%)] or loss to follow-up [8/42 (19.0%)]. After 24 months of denosumab treatment, BMD T-score improvement to the range of osteopenia (- 2.5 ≤ T < - 1.5) was achieved by 42.4% at the femoral neck, 23.6% at the lumbar spine, and 49.2% at the total hip; complete recovery (T-score ≥ - 1.5) was observed in 9.0%, 26.4%, and 23.0% respectively. New fracture was reported in 5 patients (2%).ConclusionsEven in an elderly population, persistence with denosumab was high despite the challenge imposed by the 50% co-pay in Bulgaria.Trial registrationBulgarian Drug Agency, №HИП-0009 (registered 28.06.2017); Central Ethics Commission: №КИ-41 (registered 16.05.2017).

Project description:Avian influenza virus (AIV) surveillance in Antarctica during 2013 revealed the prevalence of evolutionarily distinct influenza viruses of the H11N2 subtype in Adélie penguins. Here we present results from the continued surveillance of AIV on the Antarctic Peninsula during 2014 and 2015. In addition to the continued detection of H11 subtype viruses in a snowy sheathbill during 2014, we isolated a novel H5N5 subtype virus from a chinstrap penguin during 2015. Gene sequencing and phylogenetic analysis revealed that the H11 virus detected in 2014 had a >99.1% nucleotide similarity to the H11N2 viruses isolated in 2013, suggesting the continued prevalence of this virus in Antarctica over multiple years. However, phylogenetic analysis of the H5N5 virus showed that the genome segments were recently introduced to the continent, except for the NP gene, which was similar to that in the endemic H11N2 viruses. Our analysis indicates geographically diverse origins for the H5N5 virus genes, with the majority of its genome segments derived from North American lineage viruses but the neuraminidase gene derived from a Eurasian lineage virus. In summary, we show the persistence of AIV lineages in Antarctica over multiple years, the recent introduction of gene segments from diverse regions, and reassortment between different AIV lineages in Antarctica, which together significantly increase our understanding of AIV ecology in this fragile and pristine environment. IMPORTANCE:Analysis of avian influenza viruses (AIVs) detected in Antarctica reveals both the relatively recent introduction of an H5N5 AIV, predominantly of North American-like origin, and the persistence of an evolutionarily divergent H11 AIV. These data demonstrate that the flow of viruses from North America may be more common than initially thought and that, once introduced, these AIVs have the potential to be maintained within Antarctica. The future introduction of AIVs from North America into the Antarctic Peninsula is of particular concern given that highly pathogenic H5Nx viruses have recently been circulating among wild birds in parts of Canada and the Unites States following the movement of these viruses from Eurasia via migratory birds. The introduction of a highly pathogenic influenza virus in penguin colonies within Antarctica might have devastating consequences.

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Introduction and persistence of tularemia in Bulgaria.

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Introduction and persistence of tularemia in Bulgaria.

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