Africa
In northern Africa, B. burgdorferi sensu lato has been identified in Morocco, Algeria, Egypt and Tunisia.Lyme disease in sub-Saharan Africa is presently unknown, but evidence indicates it may occur in humans in this region. The abundance of hosts and tick vectors would favor the establishment of Lyme infection in Africa. In East Africa, two cases of Lyme disease have been reported in Kenya. Asia
B. burgdorferi sensu lato-infested ticks are being found more frequently in Japan, as well as in northwest China, Nepal, Thailand and far eastern Russia. Borrelia has also been isolated in Mongolia. Europe
In Europe, Lyme disease is caused by infection with one or more pathogenic European genospecies of the spirochaete B. burgdorferi sensu lato, mainly transmitted by the tick Ixodes ricinus. Cases of B. burgdorferi sensu lato-infected ticks are found predominantly in central Europe, particularly in Slovenia and Austria, but have been isolated in almost every country on the continent. Number of cases in southern Europe, such as Italy and Portugal, is much lower. Diagnosed cases in some Western countries, such as Iceland, are rising. United Kingdom
In the United Kingdom the number of laboratory confirmed cases of Lyme disease has been rising steadily since voluntary reporting was introduced in 1986 when 68 cases were recorded in the UK and Ireland combined. In the UK there were 23 confirmed cases in 1988 and 19 in 1990, but 973 in 2009 and 953 in 2010.
About 94% of people have full recovery, but 5% need a permanent pacemaker and 1% end up with persistent heart block (the actual percentage may be higher because of unrecognized cases). Lyme myocardial complications usually are mild and self-limiting. However, in some cases Lyme carditis can be fatal.Recommended antibiotic treatments are effective in about 90% of Lyme arthritis cases, although it can take several months for inflammation to resolve and a second round of antibiotics is often necessary. Antibiotic-refractory Lyme arthritis also eventually resolves, typically within 9–14 months (range 4 months – 4 years); DMARDs or synovectomy can accelerate recovery.Reinfection is not uncommon. In a U.S. study, 6–11% of people treated for an EM rash had another EM rash within 30 months. The second rash typically is due to infection by a different Borrelia strain.People who have nonspecific, subjective symptoms such as fatigue, joint and muscle aches, or cognitive difficulties for more than six months after recommended treatment for Lyme disease are said to have post-treatment Lyme disease syndrome (PTLDS). As of 2016 the reason for the lingering symptoms was not known; the condition is generally managed similarly to fibromyalgia or chronic fatigue syndrome. Epidemiology
Lyme disease occurs regularly in Northern Hemisphere temperate regions. There is evidence that tick populations and Lyme disease occurrence are increasing and spreading into new areas, due in part to the warming temperatures of climate change.