Endemic Tularemia, Sweden, 2003
ABSTRACT Tularemia cases have been reported in Sweden since 1931, but no cyclical patterns can be identified. In 2003, the largest outbreak of tularemia since 1967 occurred, involving 698 cases. Increased reports were received from tularemia-nonendemic areas. Causal factors for an outbreak year and associated geographic distribution are not yet understood.
Full-textDOI: · Available from: Anders Tegnell, Aug 03, 2015
- SourceAvailable from: Patrik Rydén
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- "Since the first description in Sweden in the 1930s (1), tularaemia has occurred predominantly in some northern and central areas of the country but, recently, the disease has extended southwards resulting in a considerable number of human cases in emerging areas. In 2003, for example, 700 individuals were diagnosed with tularaemia and half of them were affected in areas south of the river Dalälven cutting across central Sweden from the mountains in the west to its draining areas in the Botnian Sea in the east (2). The large majority of humans that contract tularaemia get infected in late summer and autumn (3, 4). "
ABSTRACT: Tularaemia is a vector-borne infectious disease. A large majority of cases transmitted to humans by blood-feeding arthropods occur during the summer season and is linked to increased temperatures. Therefore, the effect of climate change is likely to have an effect on tularaemia transmission patterns in highly endemic areas of Sweden. In this report, we use simulated climate change scenario data and empirical data of temperatures critical to tularaemia transmission to forecast tularaemia outbreak activity. The five high-endemic counties: Dalarna, Gävleborg, Norrbotten, Värmland and Orebro represent only 14.6% of the total population of Sweden, but have recorded 40.1-81.1% of the number of annual human tularaemia in Sweden from 1997 until 2008. We project here earlier starts and a later termination of future tularaemia outbreaks for the time period 2010-2100. For five localised outbreak areas; Gagnef (Dalarna), Ljusdal (Gävleborg), Harads (Norrbotten), Karlstad (Värmland) and Orebro municipality (Orebro), the climate scenario suggests an approximately 2 degrees C increase in monthly average summer temperatures leading to increases in outbreak durations ranging from 3.5 weeks (Harads) to 6.6 weeks (Karlstad) between 2010 and 2100. In contrast, an analysis of precipitation scenarios indicates fairly stable projected levels of precipitation during the summer months. Thus, there should not be an increased abundance of late summer mosquitoes that are believed to be main vectors for transmission to humans in these areas. In conclusion, the results indicate that the future climate changes will lead to an increased burden of tularaemia in high-endemic areas of Sweden during the coming decades.Global Health Action 11/2009; 2. DOI:10.3402/gha.v2i0.2063 · 1.65 Impact Factor
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ABSTRACT: We live in an era of emerging infectious diseases and the threat of bioterrorism. Most of the infectious agents of modern concern, from plague to avian influenza H5N1, are zoonotic diseases: infectious agents that reside in quiet animal reservoir cycles that are transmitted occasionally to humans. The public health, health care, and veterinary communities have an enormous challenge in the early recognition, reporting, treatment, and prevention of zoonotic diseases. An intimate understanding of the natural ecology, geographic distribution, clinical signs, lesions, and diagnosis of these diseases is essential for the early recognition and control of these diseases.Clinics in Laboratory Medicine 07/2006; 26(2):445-89, x. DOI:10.1016/j.cll.2006.03.010 · 1.35 Impact Factor
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ABSTRACT: Four subspecies of the zoonotic bacterium F tularensis have been described to date, with F t tularensis and F t holarctica being the subspecies causing most human tularemia cases. F t holarctica causes tularemia type B, a milder form of tularemia that appears over almost the entire Northern Hemisphere and that seems dependent on an aquatic life cycle. F t tularensis, the agent of the more severe tularemia type A that occurs in North America, has been divided into two major subpopulations. Each of the subpopulations occurs in different areas of North America and seems to be connected to different vectors. Despite more recent findings, several aspects of the ecology and epidemiology of tularemia still need to be clarified. Tularemia has emerged, or re-emerged, in new areas, showing the potential of Francisella for geographic propagation. There are few, if any, zoonotic diseases with an epidemiology as complex as is the case with tularemia. Transmission to humans can occur by several routes, including vectors, direct contact, aerosol, food, and water. The clinical manifestations depend on the subspecies involved and on the route of acquisition. Different clinical forms of tularemia are recognized: ulceroglandular or glandular, oropharyngeal, oculoglandular, typhoidal, and respiratory. Laboratory diagnostics are based mainly on serology, culture, and molecular methods. More recent studies of tularemia have shed new light on the pathogenesis of this intracellular parasite, including its ability to minimize inflammatory response through different mechanisms. Treatment of tularemia in North America traditionally has been based on aminoglycosides and in Europe on tetracyclines. Today, increasing experience with fluoroquinolones in the treatment of tularemia makes these agents alternatives in treatment of children and adults with tularemia. The low infective dose of Francisella, the high attack rate via the respiratory route, and the relative ease of production cause concern over its use in possible bioterrorism scenarios. Molecular typing methods will prove crucial tools in future research on the epidemiology of tularemia and in the event of bioterrorism. Today there are no commercially available vaccines, and prevention of tularemia has to be based on physical protection. The development of a new, highly protective vaccine is a high-priority research field.Infectious Disease Clinics of North America 07/2006; 20(2):289-311, ix. DOI:10.1016/j.idc.2006.03.002 · 2.31 Impact Factor