Distribution and molecular characteristics of rickettsiae found in ticks across Central Mongolia.
Little is known regarding tick-borne diseases in Mongolia, despite having 26% of the population still living nomadic pastoral lifestyles. A total of 1497 adult unfed ticks: 261 Ixodes persulcatus, 795 Dermacentor nuttalli, and 441 Hyalomma asiaticum, were collected from three ecologically distinct regions in Central Mongolia. Tick pools (n = 299) containing ~5 ticks each, were tested for Rickettsia and Tick-borne encephalitis virus (TBEV) using nested polymerase chain reaction, reverse transcription-PCR, and quantitative real-time RT-PCR.



Assays yielded pooled prevalence of 92.5% (49/53) and 1.9% (1/53) for pooled I. persulcatus testing positive for "Candidatus Rickettsia tarasevichiae" and TBEV, respectively, while Rickettsia raoultii was found in 72.8% (115/158) of pooled D. nuttalli samples. When calculating a maximum likelihood estimation, an estimated 46.6% (95% CI: 35.2-63.6%) of I. persulcatus ticks in the pooled sample were infected with "Candidatus R. tarasevichiae".



Both "Candidatus R. tarasevichiae" and R. raoultii are recognized as emerging tick-borne pathogens, with this being one of the first reports of "Candidatus R. tarasevichiae" in Mongolia. Given that "Candidatus R. tarasevichiae" shares the same vector (I. persulcatus) as TBEV, and infections may present with similar symptoms, Mongolian physicians treating suspected cases of TBEV should include "Candidatus R. tarasevichiae" infection in their differential diagnosis and consider prescribing antimicrobial therapy.
Institute of Veterinary Medicine, Ulaanbaatar, Mongolia.
Bazartseren
B
Boldbaatar
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
Rui-Ruo
RR
Jiang
Division of Infectious Disease, Duke Global Health Institute, Duke University, Durham, NC, USA. mvonfric@gmu.edu.|Department of Global and Community Health, George Mason University, Fairfax, VA, USA. mvonfric@gmu.edu.
Michael E
0000-0003-2938-4549
ME
von Fricken
Institute of Veterinary Medicine, Ulaanbaatar, Mongolia.
Sukhbaatar
S
Lkhagvatseren
Mongolian Academy of Medical Sciences, Ulaanbaatar, Mongolia.
Pagbajab
P
Nymadawa
National Center for Zoonotic Diseases, Ulaanbaatar, Mongolia.
Bekhochir
B
Baigalmaa
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
Ya-Wei
YW
Wang
Division of Infectious Disease, Duke Global Health Institute, Duke University, Durham, NC, USA.
Benjamin D
BD
Anderson
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
Jia-Fu
JF
Jiang
Division of Infectious Disease, Duke Global Health Institute, Duke University, Durham, NC, USA.
Gregory C
GC
Gray
D000818:Animals; D004669:Encephalitis Viruses, Tick-Borne / Q000235:genetics / Q000302:isolation & purification; D026863:Ixodidae / Q000145:classification / Q000382:microbiology* / Q000821:virology; D008986:Mongolia; D016133:Polymerase Chain Reaction; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012287:Rickettsiaceae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*
Ixodes persulcatus; Mongolia; Rickettsia