Biosurveillance in Central Asia: Successes and Challenges of Tick-Borne Disease Research in Kazakhstan and Kyrgyzstan

Central Asia is a vast geographic region that includes five former Soviet Union republics: Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The region has a unique infectious disease burden, and a history that includes Silk Road trade routes and networks that were part of the anti-plague and biowarfare programs in the former Soviet Union. Post Soviet Union biosurveillance research in this unique area of the world has met with several challenges, including lack of funding and resources to independently conduct hypothesis driven, peer-review quality research. Strides have been made, however, to increase scientific engagement and capability. Kazakhstan and Kyrgyzstan are examples of countries where biosurveillance research has been successfully conducted, particularly with respect to especially dangerous pathogens. In this review we describe in detail the successes, challenges and opportunities of conducting biosurveillance in Central Asia as exemplified by our recent research activities on ticks and tick-borne diseases in Kazakhstan and Kyrgyzstan

Flea-Borne Rickettsiae in Almaty Oblast, Kazakhstan

To better understand the contribution of Rickettsia spp. to prevalent flea-borne diseases in Kazakhstan, we evaluated fleas collected in the Almaty Oblast of southeastern Kazakhstan for the presence of rickettsiae by quantitative real-time PCR (qPCR). We found that fleas captured from Kazakhstan’s common Great Gerbil (Rhombomys opimus) and corresponding burrows were infected with rickettsiae. The most commonly found rickettsia-infected flea species was Xenopsylla gerbilli, and the most commonly found rickettsia was Candidatus R. asemboensis. Further studies may include testing these and other fleas samples for the presence of additional disease agents, including Bartonella spp. and Yersinia pestis

Phylogenetic Characteristics of West Nile Virus Isolated From Culex modestus Mosquitoes in West Kazakhstan

West Nile virus is widespread in southern Russia, where the fever appears annually. Since Western Kazakhstan borders on southern Russia, we examined mosquitoes in this region for the presence of West Nile virus. Virus was detected in a small proportion of Culex modestus mosquitoes (3/239 pools) and isolates are related to strains from Volgograd, Russia. A screen for West Nile virus IgG was conducted and ~5% of the local human population tested positive.</jats:p

Crimean-Congo Hemorrhagic Fever in the Zhambyl Region: Epidemiological Features of the Occurrence of Infection in 2023

Abstract Crimean-Congo hemorrhagic fever (CCHF) is an acute tick-borne viral infection with a high fatality rate. The main vector of the CCHF virus is ticks of the genus Hyalomma. Humans get infected through tick bites or by direct contact with the blood of infected humans or domestic animals. The endemic regions of CCHF in Kazakhstan are Kyzylorda, Turkestan, and Zhambyl. In the Zhambyl region, the first evidence of human cases was reported in 1982. In the following years, cases of CCHF were annually registered in two districts (Sarysu and Moiynkum) of the Zhambyl region. The study goal is twofold: 1) to provide a retrospective review of CCHF cases reported through the surveillance system in the Zhambyl region from 1991 to 2023 and 2) to analyze epidemiological features of CCHF cases in the Zhambyl region in 2023. Surveillance data on CCHF during the 1991–2023 period in the Zhambyl region were extracted from the “Report on selected infectious and parasitic diseases". Incidence (per 100,000 population) was defined as the number of annual new cases divided by the total population each year. Descriptive analysis was performed on case characteristics, time, and place of CCHF cases in the Zhambyl region in 2023. In total, 216 cases of CCHF were reported from 1991 to 2023. The incidence increased sharply with peak activity in 1995 and has declined since 2002. The natural foci of the disease have shifted from the Sarysu and Moiynkum districts to the Shu, Bayzak, and Zhambyl districts. Overall, 12 cases of CCHF were reported in the Zhambyl region in 2023, mainly in nonendemic (Shu, Bayzak, Zhambyl) districts. An analysis of epidemiological data for 2023 showed that the first peak of CCHF incidence was in March-June, with another peak from October to November. We observed dynamic distribution of CCHF in the Zhambyl region from 1991 to 2023, wherein Sarysu and Moiynkum endemic districts foci tended to increase by expanding to the Shu, Bayzak, Zhambyl districts. The disease trend is seasonal, and the life cycle of ticks can indirectly influence morbidity rates. Additional research is needed to elucidate the environmental, meteorological, and social factors associated with CCHF incidence in different decades

Crimean-Congo haemorrhagic fever virus in Kazakhstan (1948-2013)

AbstractCrimean-Congo haemorrhagic fever (CCHF) is a pathogenic and often fatal arboviral disease with a distribution spanning large areas of Africa, Europe and Asia. The causative agent is a negative-sense single-stranded RNA virus classified within the Nairovirus genus of the Bunyaviridae family.Cases of CCHF have been officially recorded in Kazakhstan since the disease was first officially reported in modern medicine. Serological surveillance of human and animal populations provide evidence that the virus was perpetually circulating in a local enzoonotic cycle involving mammals, ticks and humans in the southern regions of the country. Most cases of human disease were associated with agricultural professions such as farming, shepherding and fruit-picking; the typical route of infection was via tick-bite although several cases of contact transmission associated with caring for sick patients have been documented.In total, 704 confirmed human cases of CCHF have been registered in Kazakhstan from 1948-2013 with an overall case fatality rate of 14.8% for cases with a documented outcome.The southern regions of Kazakhstan should be considered endemic for CCHF with cases reported from these territories on an annual basis. Modern diagnostic technologies allow for rapid clinical diagnosis and for surveillance studies to monitor for potential expansion in known risk areas

First Indications of Omsk Haemorrhagic Fever Virus beyond Russia

Omsk haemorrhagic fever virus (OHFV) is the agent leading to Omsk haemorrhagic fever (OHF), a viral disease currently only known in Western Siberia in Russia. The symptoms include fever, headache, nausea, muscle pain, cough and haemorrhages. The transmission cycle of OHFV is complex. Tick bites or contact with infected small mammals are the main source of infection. The Republic of Kazakhstan is adjacent to the endemic areas of OHFV in Russia and febrile diseases with haemorrhages occur throughout the country&mdash;often with unclear aetiology. In this study, we examined human cerebrospinal fluid samples of patients with suspected meningitis or meningoencephalitis with unknown origins for the presence of OHFV RNA. Further, reservoir hosts such as rodents and ticks from four Kazakhstan regions were screened for OHFV RNA to clarify if this virus could be the causative agent for many undiagnosed cases of febrile diseases in humans in Kazakhstan. Out of 130 cerebrospinal fluid samples, two patients (1.53%) originating from Almaty city were positive for OHFV RNA. Screening of tick samples revealed positive pools from different areas in the Akmola region. Of the caught rodents, 1.1% out of 621 were positive for OHFV at four trapping areas from the West Kazakhstan region. In this paper, we present a broad investigation of the spread of OHFV in Kazakhstan in human cerebrospinal fluid samples, rodents and ticks. Our study shows for the first time that OHFV can not only be found in the area of Western Siberia in Russia, but can also be detected up to 1.600 km away in the Almaty region in patients and natural foci

First Indications of Omsk Haemorrhagic Fever Virus beyond Russia

Omsk haemorrhagic fever virus (OHFV) is the agent leading to Omsk haemorrhagic fever (OHF), a viral disease currently only known in Western Siberia in Russia. The symptoms include fever, headache, nausea, muscle pain, cough and haemorrhages. The transmission cycle of OHFV is complex. Tick bites or contact with infected small mammals are the main source of infection. The Republic of Kazakhstan is adjacent to the endemic areas of OHFV in Russia and febrile diseases with haemorrhages occur throughout the country—often with unclear aetiology. In this study, we examined human cerebrospinal fluid samples of patients with suspected meningitis or meningoencephalitis with unknown origins for the presence of OHFV RNA. Further, reservoir hosts such as rodents and ticks from four Kazakhstan regions were screened for OHFV RNA to clarify if this virus could be the causative agent for many undiagnosed cases of febrile diseases in humans in Kazakhstan. Out of 130 cerebrospinal fluid samples, two patients (1.53%) originating from Almaty city were positive for OHFV RNA. Screening of tick samples revealed positive pools from different areas in the Akmola region. Of the caught rodents, 1.1% out of 621 were positive for OHFV at four trapping areas from the West Kazakhstan region. In this paper, we present a broad investigation of the spread of OHFV in Kazakhstan in human cerebrospinal fluid samples, rodents and ticks. Our study shows for the first time that OHFV can not only be found in the area of Western Siberia in Russia, but can also be detected up to 1.600 km away in the Almaty region in patients and natural foci.</jats:p

First Indications of Omsk Haemorrhagic Fever Virus beyond Russia

Omsk haemorrhagic fever virus (OHFV) is the agent leading to Omsk haemorrhagic fever (OHF), a viral disease currently only known in Western Siberia in Russia. The symptoms include fever, headache, nausea, muscle pain, cough and haemorrhages. The transmission cycle of OHFV is complex. Tick bites or contact with infected small mammals are the main source of infection. The Republic of Kazakhstan is adjacent to the endemic areas of OHFV in Russia and febrile diseases with haemorrhages occur throughout the country—often with unclear aetiology. In this study, we examined human cerebrospinal fluid samples of patients with suspected meningitis or meningoencephalitis with unknown origins for the presence of OHFV RNA. Further, reservoir hosts such as rodents and ticks from four Kazakhstan regions were screened for OHFV RNA to clarify if this virus could be the causative agent for many undiagnosed cases of febrile diseases in humans in Kazakhstan. Out of 130 cerebrospinal fluid samples, two patients (1.53%) originating from Almaty city were positive for OHFV RNA. Screening of tick samples revealed positive pools from different areas in the Akmola region. Of the caught rodents, 1.1% out of 621 were positive for OHFV at four trapping areas from the West Kazakhstan region. In this paper, we present a broad investigation of the spread of OHFV in Kazakhstan in human cerebrospinal fluid samples, rodents and ticks. Our study shows for the first time that OHFV can not only be found in the area of Western Siberia in Russia, but can also be detected up to 1.600 km away in the Almaty region in patients and natural foci