Survey of tick-borne relapsing fever borreliae in southern and southeastern Kazakhstan

Abstract

Tick-borne relapsing fever group borreliae (TBRFGB) are spirochetes that cause disease in humans and animals. Little is known about the prevalence of TBRFGB infections in ticks and humans in Kazakhstan. A total of 846 ticks belonging to ten species of the family Ixodidae and three species of the family Argasidae were collected from the vegetation, poultry shelters, domestic ruminants, bitten humans, pigeons, dogs and house walls in four oblasts of the southern and southeastern regions of Kazakhstan. The ticks were subjected to DNA extraction and identification of TBRFGB by conventional PCR using primers targeting flagella subunit B (flaB), glycerophosphodiester phosphodiesterase (glpQ) and P66 porin (P66) genes. The overall infection rate of TBRFGB in the ticks was 6.2 % (46/846). TBRFGB DNA was identified in Ixodes persulcatus (5.5 %; 26/477), Ornithodoros tartakovskyi (6 %; 2/36) and Argas persicus (13.4 %; 18/134) ticks. Partial sequencing of flaB, glpQ and P66 genes identified Borrelia miyamotoi in I. persulcatus and Borrelia anserina in A. persicus. To detect the presence of B. miyamotoi infection in people in the study region, we performed serological analysis of samples collected from 42 patients admitted to hospital with fever of unknown etiology or with a history of a tick bite. The analysis revealed IgM and IgG antibodies against one or several B. miyamotoi antigens in 10 % and 5 % of patients, respectively. The data obtained provide strong evidence of the presence of B. miyamotoi and B. anserina in the southern and southeastern regions of Kazakhstan, underscoring the need for increased awareness of potential infections caused by these borreliae in these regions.

Keywords: Argasid ticks; Borrelia anserina; Borrelia miyamotoi; Ixodid ticks; Kazakhstan; Relapsing fever group borreliae.