Answer: The town in Connecticut where it was discovered.

Lyme disease is named after the town, Old Lyme, Connecticut in the Northeastern United States. In the 1970's, two mother's reported to the US government that there was an unusually high rate of juvenile rheumatoid arthritis in their neighborhood. 10 years later, it was discovered that the cause of this arthritis was bacteria that was transmitted by ticks to the children in their neighborhood.

Answer: Bacteria

Lyme disease is the general name for the symptoms that result in humans who are infected with "Lyme disease bacteria." These bacteria are called spirochetes because of their corkscrew shape (see photo). Specifically, Lyme disease is caused by many closely related species that are referred to as Borrelia burgdorferi sensu lato. Roughly, this means "Borrelia burgdorferi in the loose sense." The first species to be named in this group is called Borrelia burgdorferi sensu stricto ("in the strict sense").

Answer: 20+

The Borrelia burgdorferi sensu lato (s.l.) species complex has 23 genospecies, at least 5 of which result in Lyme disease symptoms in humans. A species complex is a term used for a group of species that are very similar, and that used to be considered one species. In the 1980's, all 23 species of Borrelia burgdorferi s.l. Were called one species. By the 1990's there were ~10 accepted species, and since the 2000's there are now ~20 accepted species.

Answer: North America, South America, Africa, Asia, and Europe

Borrelia burgdorferi s.l. Has been found on almost all continents of the world! In particular, it is most commonly considered a disease of the Northern Hemisphere. Most species are found at temperate latitudes in North America, Europe, and/or Asia.

Answer: Erythema Migrans, Lyme carditis, Lyme arthritis, Neuroborreliosis, and Acrodermatitis Chronica Atrophicans

Different genospecies of B. Burgdorferi s.l. Are responsible for different clinical manifestations of Lyme disease in humans. It is possible that a person with Lyme arthritis in the United States is infected with a different species than a person who has Lyme arthritis in Europe. This can result in confusion when diagnosing Lyme disease, as the symptoms and treatment depend on the species a patient is infected with.

References: Lyme arthritis - from Fig 6B, Eckland et al. 2005, AJR; Neuroborreliosis - Fig 1, Haene & Troeger 2009, Neurology; Acrodermatitis Chronica Atrophicans - derm101.com/therapeutic/borreliosis-lyme-disease-2/

Answer: Rabbits, Mice, Hedgehogs & Shrews, Birds, and Lizards

Different species of B. Burgdorferi s.l. Are specialized to survive and be transmitted between different species of hosts and ticks. The only host types shown which are not competent for any species of B. Burgdorferi s.l. Are deer. It is a common misconception that Lyme disease comes from deer due to the fact that it is transmitted by "deer ticks" in the United States. Deer actually kill any B. Burgdorferi s.l. Transmitted to them by ticks. The role of domestic dogs and humans has not been confirmed in Lyme disease, but it is assumed that they are dead-end hosts.

Answer: All of the methods listed

Many lines of experimental evidence are currently used to support a host as being competent for a given species of B. Burgdorferi s.l. Testing the host's ability to transmit and receive Borrelia from a feeding tick is particularly important, because it cannot spread in an ecosystem without its tick vectors.

Answer: Borrelia prevalence would decrease in the system

By removing a host which kills and stops the spread of B. Burgdorferi s.l., we would expect that the prevalence of Borrelia in the ecosystem would increase. Swei et al. 2011, Proc R Soc B, found that the opposite happened. This was because the lizards are also an important host for Western black-legged ticks, the main vectors for Borrelia in this ecosystem. The tick population decreased because they had fewer lizards to feed on, and thus the Borrelia population also decreased. When studying vector-borne diseases, it is important to consider ecology when predicting disease dynamics.

Answer: A host that CAN become infected with Borrelia and CAN transmit it to other hosts

A competent host must be able to 1) be infected with Borrelia and 2) transmit Borrelia to new feeding ticks. If it only fulfills one of these requirements, it will not allow Borrelia to spread in the ecosystem.

Answer: A host that CAN become infected with Borrelia, CAN transmit it to other hosts in the LABORATORY & ECOSYSTEM, and IS regularly fed on by vector ticks in the ecosystem.

In addition to fulfilling requirements 1 & 2 for host competence, a reservoir host must also 3) play an active role in natural transmission cycles in the ecosystem. This means that a reservoir must be fed on regularly by ticks in the ecosystem which are able to transmit Borrelia to new hosts. Although the most meaningful information about this would be found from transmission studies in the ecosystem, it is not possible to tell where the infection in the hosts came from. Thus the best information currently comes from experimental transmission studies in the laboratory.