Sun, 27 Jul 2008 07:22:09 BST CiteULike: neteler's change http://www.citeulike.org/user/neteler/tag/change CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/neteler/article/276951 <i>Proc Biol Sci, Vol. 267, No. 1454. (7 September 2000), pp. 1741-1744.</i><br /><br />Repeated predictions that vector-borne disease prevalence will increase with global warming are usually based on univariate models. To accommodate the full range of constraints, the present-day distribution of tick-borne encephalitis virus (TBEv) was matched statistically to current climatic variables, to provide a multivariate description of present-day areas of disease risk. This was then applied to outputs of a general circulation model that predicts how climatic variables may change in the future, and future distributions of TBEv were predicted for them. The expected summer rise in temperature and decrease in moisture appears to drive the distribution of TBEv into higher-latitude and higher-altitude regions progressively through the 2020s, 2050s and 2080s. The final toe-hold in the 2080s may be confined to a small part of Scandinavia, including new foci in southern Finland. The reason for this apparent contraction of the range of TBEv is that its transmission cycles depend on a particular pattern of tick seasonal dynamics, which may be disrupted by climate change. The observed marked increase in incidence of tick-borne encephalitis in most parts of Europe since 1993 may be due to non-biological causes, such as political and sociological changes. Fragile transmission cycles of tick-borne encephalitis virus may be disrupted by predicted climate change. SE Randolph DJ Rogers Proc Biol Sci, Vol. 267, No. 1454. (7 September 2000), pp. 1741-1744. 2005-08-08T19:09:34-00:00 2000 Proc Biol Sci 0962-8452 267 1454 1741 1744 change climate disease encephalitis tick-borne http://www.citeulike.org/user/neteler/article/262332 <i>Int J Med Microbiol, Vol. 293 Suppl 37 (April 2004), pp. 5-15.</i><br /><br />Even though tick-borne disease systems are highly susceptible to climatic influences, climate change to date is not necessarily the cause of the marked increased incidence of a variety of tick-borne diseases in many parts of Europe over the past two decades. To test for causality, rather than coincidence, we need to examine whether the right sorts of climate change have occurred at the right time and in the right places to account for the observed heterogeneous temporal and spatial patterns of tick-borne disease 'emergence'. Tick-borne encephalitis (TBE) incidence, for example, showed a 3-fold step increase from 1983 to 1986 in Sweden, doubled in 1993 in the Czech Republic, increased even more dramatically in the same year in Lithuania and Poland, but declined markedly in 1997 in Hungary, Croatia and Slovenia. Within each country, TBE incidence has changed to different degrees in different regions. Because other tick-borne diseases, notably Lyme borreliosis, has commonly 'emerged' in parallel with TBE, we should first examine climate variables predicted to have a general effect on tick abundance, which has indeed increased in the past decade. These include temperature and moisture stress, which have seasonally differential impacts. Monthly mean records for 1960-2000 from the UK Climate Research Unit's interpolated global climate surface reveal that mean spring, spring-autumn and winter temperatures have all increased gradually over the past 40 years, but apparently most sharply in the late 1980s, when moisture stress also increased. These climate data do not reveal any obvious differences between sites where TBE did or did not 'emerge', and in Sweden increases in TBE pre-dated the onset of warmer springs and winters. If recorded climate changes cannot yet satisfactorily explain the temporal and spatial patterns of tick-borne disease change in Europe, the impact of biotic factors, such as increases in deer abundance and changing habitat structure, and of socio-political changes following the end of communist rule, demand more detailed quantitative analyses. Evidence that climate change has caused 'emergence' of tick-borne diseases in Europe? SE Randolph Int J Med Microbiol, Vol. 293 Suppl 37 (April 2004), pp. 5-15. 2005-07-22T08:59:38-00:00 2004 Int J Med Microbiol 1438-4221 293 Suppl 37 5 15 change climate disease ticks