Lyme disease and relapsing fever in Mexico: An overview of human and wildlife infections

Abstract

Lyme borreliosis and Relapsing fever are considered emerging and re-emerging diseases that cause major public health problems in endemic countries. Epidemiology and geographical distribution of these diseases are documented in the US and in Europe, yet in Mexico, studies are scarce and scattered. The aims of this study were (1) to present the first confirmatory evidence of an endemic case of Lyme disease in Mexico and (2) to analyze the epidemiological trend of these both diseases by compiling all the information published on Borrelia in Mexico. Two databases were compiled, one of human cases and another of wild and domestic animals in the country. The analysis included the evaluation of risk factors for the human population, the diversity of Borrelia species and their geographic distribution. Six Borrelia species were reported in a total of 1,347 reports, of which 398 were of humans. Women and children from rural communities were shown to be more susceptible for both Lyme borreliosis and Relapsing fever. The remaining reports were made in diverse mammalian species and ticks. A total of 17 mammalian species and 14 tick species were recorded as hosts for this bacterial genus. It is noteworthy that records of Borrelia were only made in 18 of the 32 states, mainly in northern and central Mexico. These results highlight the importance of performing further studies in areas where animal cases have been reported, yet no human studies have been done, in order to complete the epidemiological panorama for Lyme borreliosis and Relapsing fever. Finally, the search for Borrelia infections in other vertebrates, such as reptiles and amphibians is recommended to gain a more accurate view of Borrelia species and their distribution. The geographical approach presented herein justifies an intense sampling effort to improve epidemiological knowledge of these diseases to aid vector control and prevention programs.

Molecular Detection of Tick-Borne Pathogens in American Bison (Bison bison) at El Uno Ecological Reserve, Janos, Chihuahua, Mexico

“…This disease has previously been reported in JBR in other species, such as wild carnivores and domestic animals [7]. Colunga-Salas et al [38], reviewed cases reported in Mexico from 1930 to 2020; 29.5% were reports on humans, while 70.5% reported an animal species. They identified six Borrelia species: three responsible for Relapsing Fever (B. duguessi, B. mazzottii and B. turicatae) and three more are responsible for Lyme borreliosis (B. afzelii, B. burgdorferi s. s. and B. garini).…”

“…Wild vertebrates are associated with several enzootic cycles of tick-borne pathogens contributing to the increase of ticks and TBDs in North America, playing an important role in the maintenance and transmission of zoonoses to livestock, humans, and other wildlife [34]. A more than two-fold increase in TBDs has been observed from 2004 (>22,000 cases) to 2016 (>48,000 cases) in the USA alone [35], and up to 476,000 people per year are infected with Lyme disease [36], with reports in both Mexico and USA [37][38][39][40] involving wild animals [41][42][43][44][45]. Furthermore, ticks and TBDs have evolved, adapting themselves to new vectors and vectors have adapted to new hosts; for instance, Amblyoma immitator has recently been proposed as a RMSF vector [46].…”

“…Current research on human TBDs may be unclear and disperse; however, from Borrelia (B. afzelii, B. garrinii y B. burgdorferi s.s.) infection reports between 1939-2020, the majority were in urban environments. Mexican states with the greatest number of reports of humans are northeast of Mexico, mainly Nuevo Leon and Tamaulipas [38]. Recently, an isolated case of B. burgdorferi s. s. was reported in Sinaloa [52].…”

Borreliae Part 1: Borrelia Lyme Group and Echidna-Reptile Group

“…BYS is widespread in Brazil and in the Amazon rainforest, but also in Colombia, Peru, Venezuela, Ecuador, Bolivia, Guyana, Suriname and French Guiana [255]. In Mexico, Borrelia burgdorferi s.s. has also been described in Ambliomma cajennense, in ticks taken from the bull (Bos taurus) [256]. Cases of borreliosis have also been described in Cuba, diagnosed for the clinical picture and the positivity of anti-Borrelia antibodies and transmitted by Amblyomma cajennense, similar to BYS [257].…”

Borreliae Part 2: Borrelia Relapsing Fever Group and Unclassified Borrelia

“…Since RF is considered a forgotten and neglected tropical disease, and given the small number of cases reported by the Mexican Ministry of Health, it is conceivable that many patients who have a fever of unknown origin are suffering from RF [ 70 ]. In Mexico, the following specificities of Borrelia tick association are observed: Ornithodoros turicata with B. turicatae , Ornithodoros duguesi with B. duguesii , and Ornithodoros talaje with B. mazzottii [ 71 ]. In Brazil, Venezuela, Colombia, and Panama STBRF is caused by Borrelia venezualensis , which is transmitted by Ornithodoros rudis [ 66 ].…”