B. afzelii, B. bavariensis and B. garinii; www.eucalb. com) are important in terms of infections for humans and animals, particularly for dogs, cats and horses. The other Borrelia species of the B. burgdorferi complex (e.g. B. valaisiana, B. lusitaniae) are not of great veterinary clinical importance. A second group of Borrelia species is the cause of relapsing fever in humans and animals. For example, B. recurrentis is a louse-borne agent, while B. hermsii is transmitted by soft ticks of the genus Ornithodorus. Both can cause relapsing fever in man. Likewise, B. persica is transmitted by Ornithodorus tholozani and causes relapsing fever in humans, cats and dogs. It seems that a third group of Borrelia species is emerging from the vast diversity of spiral-shaped bacteria; Borrelia transmitted by hard-shelled ticks, but exhibiting characteristics of relapsing fever-causing spirochaetes (e.g. B. miyamotoi transmitted by Ixodes ticks; B. theileri transmitted by Boophilus/Rhipicephalus tick species)
Epidemiology of the Borrelia burgdorferi complex Many wild mammals and birds are known reservoirs for B. burgdorferi species. The range of these is discussed fully in Chapter 2 and summarized in Figure 10.2.