Search

Undifferentiated febrile illness still represents a demanding medical problem all over the world, but primarily in low- and middle-income countries. Scientific and clinical investigations related to undifferentiated febrile illness and rickettsial diseases in Kazakhstan are lacking. This study reflects the investigation of antibodies against spotted fever group (SFG) and typhus group (TG) rickettsiae in patients with undifferentiated febrile illness in the southern region of Kazakhstan (Almaty and Kyzylorda oblasts). Paired serum samples were gathered from 13 hospitals in these two oblasts and explored for the presence of IgM and IgG antibodies against typhus group and IgG antibodies against spotted fever group rickettsiae using ELISA. Patient’s questionnaires were statistically analyzed. In total, 802 inpatients from Almaty (N = 9) and Kyzylorda (N = 4) hospitals were included in this research. Based on ELISA results, 250 patients out of 802 (31.2%) from both oblasts had IgG antibodies against SFG rickettsiae. Results from 11 (1.4%) patients indicated acute infection with tick-borne rickettsiosis. Regarding TG rickettsiae (R. typhi), a past infection was detected in 248 (30.9%) febrile patients and acute infection in 22 (2.7%) patients in the two selected oblasts. The data indicated that SFG and TG rickettsioses are present in Kazakhstan. Kazakh physicians should be aware of these emerging diseases in both investigated oblasts because the occurrence of these diseases is not suspected during day-to-day clinical practice. The identification of rickettsial pathogens and implementation of modern laboratory methods for the diagnostics of rickettsioses are in need throughout Kazakhstan.

Lyme borreliosis (LB) is one of the most common vector-borne diseases transmitted by ticks. It is caused by the Borrelia burgdorferi sensu lato (s.l.) genospecies. The Almaty oblast of Kazakhstan is considered endemic for LB. Nevertheless, there are significant gaps in the tick surveillance for LB agents in the region. We evaluated B. burgdorferi s.l. prevalence in 413 ixodid ticks collected from bitten people and the seroprevalence of antibodies to B. burgdorferi s.l. in 589 residents of the Almaty oblast, Kazakhstan. All samples were collected between 2018 and 2020. Borrelia burgdorferi s.l. DNA was detected in 24 % (9/38) of I. persulcatus ticks that attacked humans in the city of Almaty and the Talgar and Karasay districts. Multilocus sequence typing identified two novel B. afzelii sequence types in I. persulcatus. The seroprevalence of IgG antibodies against B. burgdorferi s.l. in the analyzed population was detected to be 5.8 %. The obtained results confirm active circulation of B. burgdorferi s.l. in the Almaty oblast of Kazakhstan and raise concern regarding LB preventive measures in the region.

Background In the South of Kazakhstan, Almaty Oblastʼ (region) is endemic for tick-borne encephalitis, with 0.16–0.32 cases/100,000 population between 2016–2018. The purpose of this study was to determine the prevalence and circulating subtypes of tick-borne encephalitis virus (TBEV) in Almaty Oblastʼ and Kyzylorda Oblastʼ. Methods In 2015 we investigated 2341 ticks from 7 sampling sites for the presence of TBEV. Ticks were pooled in 501 pools and isolated RNA was tested for the presence of TBEV by RT-qPCR. For the positive samples, the E gene was amplified, sequenced and a phylogenetic analysis was carried out. Results A total of 48 pools were TBEV-positive by the RT-qPCR. TBEV-positive ticks were only detected in three districts of Almaty Oblastʼ and not in Kyzylorda Oblastʼ. The positive TBEV pools were found within Ixodes persulcatus, Haemaphysalis punctata and Dermacentor marginatus. These tick species prevailed only in Almaty Oblastʼ whereas in Kyzylorda Oblastʼ Hyalomma asiaticum and D. marginatus are endemic. The minimum infection rates (MIR) in the sampling sites were 4.4% in Talgar, 2.8% in Tekeli and 1.1% in Yenbekshikazakh, respectively. The phylogenetic analysis of the generated sequences indicates that TBEV strains found in Almaty Oblastʼ clusters in the Siberian subtype within two different clades. Conclusions We provided new data about the TBEV MIR in ticks in Almaty Oblastʼ and showed that TBEV clusters in the Siberian Subtype in two different clusters at the nucleotide level. These results indicate that there are different influences on the circulating TBEV strains in south-eastern Kazakhstan. These influences might be caused by different routes of the virus spread in ticks which might bring different genetic TBEV lineages to Kazakhstan. The new data about the virus distribution and vectors provided here will contribute to an improvement of monitoring of tick-borne infections and timely anti-epidemic measures in Kazakhstan.

Tick-borne diseases (TBDs), in particular Crimean-Congo hemorrhagic fever (CCHF) and tick-borne encephalitis (TBE), have been found to be expanding beyond their traditional geographic locations in Kazakhstan, which led to increased awareness and concern against TBDs in recent years. The tick fauna of Kazakhstan includes more than 30 species of human-biting ixodid ticks, recognized as carriers of a number of dangerous infectious pathogens that cause CCHF, TBE, tularemia, tick-borne rickettsioses and Lyme borreliosis. This paper presents the current knowledge of the main vectors of tick-borne pathogens (TBP) occurring in Kazakhstan, as well as a review of recent studies of ticks performed with the use of molecular methods being currently developed and widely utilized by Kazakh epidemiologists.

Highlights • Population screening has confirmed circulation of West Nile virus in the southern region of Kazakhstan (Almaty region). • We report two cases of meningoencephalitis of unknown etiology occurred in the rural area near Tekeli city, Kazakhstan, in August 2019. • Retrospective analysis showed high titers of anti-WNV IgG in both patients’ serum specimens obtained on day 9 after the onset of symptoms. • These are the first reports of West Nile virus infection in Kazakhstan., Background West Nile virus (WNV) is a member of the genus Flavivirus, which transmitted to humans mainly by mosquitoes. Recent pilot serosurveillance data from the Almaty region, Kazakhstan, suggest widespread WNV circulation in this area. This report includes two cases of neuroinvasive WNV infection in the same family living in a rural area near Tekeli city, Eskeldinsky district, Almaty region, Kazakhstan. Occurring concurrently and manifesting as WNV infection with febrile illness and symptoms of meningoencephalitis. Methods The study performed retrospective analysis of clinical histories and achieved serum samples obtained from patients with febrile and meningoencephalitic syndromes of unknown origin in the Almaty region spanning from April 1 to October 31, 2019. All sera samples obtained from patients with clinically suspected cases of acute WNV infection were retrospectively tested for WNV and tick-borne encephalitis virus by commercial immunoassays. Two cases were selected. Cases presentation We report two cases that occurred in August 2019 in a rural area near Tekeli city. Previously healthy 28- and 19-year-old husband and wife with febrile illness and neurological manifestations were hospitalized with the diagnosis of meningoencephalitis of unknown etiology and treated empirically. Retrospective serological analysis showed the presence of high titers of IgG against WNV on day 9 after onset of symptoms in cases. Conclusions This is the first report of aseptic meningitis with WNV infection in the background in Kazakhstan. The obtained data suggest circulation of WNV in the Almaty region and emphasize importance of laboratory testing for WNV in suspicious cases occurring in the region.