The distribution of medically significant ticks in Vietnam requires ongoing monitoring. This study presents data on tick distribution and molecular screening for Borrelia spp. and Coxiella burnetii DNA. Ticks were collected from domestic animals and vegetation in four provinces over the period of 2024-2025. Species identification was performed based on morphology and confirmed by sequencing mitochondrial COI and 16S rRNA genes. A total of 2347 ticks were collected, representing eight species from the genera Haemaphysalis, Rhipicephalus, and Amblyomma. The study provides new distribution records for H. bispinosa, H. cornigera, A. integrum, and several rarely reported species (H. lagrangei, H. hystricus, and H. wellingtoni). PCR screening revealed a relatively high detection rate of Borrelia DNA in H. cornigera from Cao Bang province. Sequencing identified the pathogen as B. theileri, the agent of bovine borreliosis. Borrelia theileri was also detected in R. microplus in other regions, indicating wider circulation. PCR screening for Coxiella burnetii was positive for 13 ticks from cattle in Cao Bang province. To rule out false-positive results due to detection of DNA from Coxiella-like endosymbionts, we sequenced a fragment of the IS1111 element for three positive samples. The sequences confirmed that the DNA belongs to bacteria of the genus Coxiella, but the data do not allow confident assignment to C. burnetii at the species level. These positive ticks originated from eight neighboring households, suggesting a potential localized focus that requires further assessment in livestock and humans to determine the epidemiological significance. This research enhances the understanding of Vietnam's tick fauna and associated pathogens of medical and veterinary importance.

Borrelia miyamotoi and Neoehrlichia mikurensis are recently discovered tick-borne pathogens. The aim of this study was to ascertain the extent of transmission among high-risk groups and healthy controls. The study design is retrospective cohort study. Blood from a total of 1180 individuals, collected between 2002-2021: (i) 180 tick-exposed individuals, (ii) 400 immunocompromised individuals and (iii) 600 blood donors was included. Infection was examined by a protein array (B. miyamotoi) and PCR. Neoehrlichia mikurensis DNA was detected in only one individual with Lyme neuroborreliosis (LNB) with symptoms compatible with both infections. Borrelia miyamotoi seroprevalence (being either IgM or IgG positive) among tick-exposed individuals (8.3 %, 95%CI 5.1-13.3) was significantly higher compared to healthy blood donors (1.5 %, 95 % CI 0.8-2.8) and immunocompromised individuals (3.3 %, 95 %CI 1.9-5.5), p < 0.0001. Altogether, 37 of 1180 individuals (3.1 %, 95 %CI 2.2-4.3) were found to be B. miyamotoi seropositive. Neoehrlichiosis and Borrelia miyamotoi disease should be considered in patients with febrile illness and relevant exposure and in non-characteristic presentations of Lyme borreliosis in Denmark.

Bats from three provinces in Vietnam (Lai Chau, Son La, and Dong Thap) were examined for the presence of pathogenic Leptospira or specific antibodies using polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and microscopic agglutination test (MAT). Tissue specimens from 298 bats belonging to 11 species were analyzed using a real-time PCR assay specific for leptospires of pathogenic species. Leptospiral DNA was identified in 40 bats from following species: Rousettus amplexicaudatus (5/9; 55.5 %), Rousettus leschenaultii (17/42; 40.4 %), Myotis hasseltii (8/25; 32 %), Taphozous longimanus (3/12; 25 %), and Eonycteris spelaea (7/32; 21.9 %). Based on secY phylogeny, sequences from M. hasseltii bore a strong resemblance to L. borgpetersenii. Sequences from other species revealed unique lineages: one of them resembled Leptospira sp., previously identified in Rousettus madagascariensis (Madagascar) and Rousettus aegyptiacus (South Africa); the second lineage showed close relation to L. kirshneri; and the third held an intermediary position between L. noguchii and L. interrogans. Through ELISA, anti-Leptospira antibodies were found in 83 of 306 bats, with the highest seroprevalence observed in R. leschenaultii (44/48; 91.6 %), R. amplexicaudatus (6/8; 75 %), and E. spelaea (19/25; 76 %). 66 of these ELISA-positive samples were tested using MAT; 41 of them were confirmed in MAT as positive. The predominant serogroups in our study were Tarassovi and Mini.

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.

The impact of the emerging tick-borne pathogen Borrelia miyamotoi is not fully understood. We utilised a protein array to investigate B. miyamotoi seroreactivity in various human populations in the Netherlands and Sweden. The IgM/IgG seroprevalence in Dutch healthy (2·5%, 95%CI 1·5-4·1) and population controls (2·0%, 95%CI 0·9-4·4) was lower (p = 0·01 and p = 0·01) compared to the tick-bite cohort (6·1%, 95%CI 3·9-9·5). In accordance, the Swedish healthy controls (1·0%, 95%CI 0·1-6·9) revealed a lower (p = 0·005 and p < 0·001) IgM/IgG seroprevalence compared to the tick-bite (8·9%, 95%CI 5·7-13·7) and fever after tick-bite cohort (16·5%, 95%CI 10·6-24·8). Altogether, 15 of 2175 individuals had serologic evidence of early B. miyamotoi infection. The risk of infection with B. miyamotoi was 0·7% (95%CI 0·3-1·4) in tick-bitten individuals, and of disease 7·3% (95%CI 2·6-12·8) in those with a febrile illness after tick-bite. Our findings provide insights into the risk of infection and disease with this pathogen in Europe.

In 2021, a patient died from Marburg virus (MARV) disease in Guinea and it was the first confirmed case in West Africa. The origin of the outbreak has not been identified. It was revealed that the patient didn't travel anywhere before the illness. Prior to outbreak, MARV had been found in bats in the neighboring Sierra Leone, but never in Guinea. Therefore, the origin of infection is unclear: was it an autochthonous case with spillover from a local population of bats or an imported case with spillover from fruit bats foraging/migrating from Sierra Leone? In this paper, we studied Rousettus aegyptiacus in Guinea as the possible source of MARV infection caused the patient death in 2021 in Guinea. We caught bats in 32 sites of Guéckédou prefecture, including seven caves and 25 locations of the flight path. A total of 501 fruit bats (Pteropodidae) were captured, including 66 R. aegyptiacus. The PCR screening showed three positive MARV R. aegyptiacus, roosting in two caves discovered in Guéckédou prefecture. After Sanger sequencing and phylogenetic analyses it was shown that found MARV belongs to the Angola-like lineage but it is not identical to the isolate obtained during the outbreak of 2021.

The Zika virus (ZIKV) is a widespread mosquito-borne pathogen. Phylogenetically, two lineages of ZIKV are distinguished: African and Asian–American. The latter became the cause of the 2015–2016 pandemic, with severe consequences for newborns. In West African countries, the African lineage was found, but there is evidence of the emergence of the Asian–American lineage in Cape Verde and Angola. This highlights the need to not only monitor ZIKV but also sequence the isolates. In this article, we present a case report of Zika fever in a pregnant woman from Guinea identified in 2018. Viral RNA was detected through qRT-PCR in a serum sample. In addition, the seroconversion of anti-Zika IgM and IgG antibodies was detected in repeated blood samples. Subsequently, the virus was isolated from the C6/36 cell line. The detected ZIKV belonged to the African lineage, the Nigerian sublineage. The strains with the closest sequences were isolated from mosquitoes in Senegal in 2011 and 2015. In addition, we conducted the serological screening of 116 blood samples collected from patients presenting to the hospital of Faranah with fevers during the period 2018–2021. As a result, it was found that IgM-positive patients were identified each year and that the seroprevalence varied between 5.6% and 17.1%.

A new filovirus named Měnglà virus was found in bats in southern China in 2015. This species has been assigned to the new genus Dianlovirus and has only been detected in China. In this article, we report the detection of filoviruses in bats captured in Vietnam. We studied 248 bats of 15 species caught in the provinces of Lai Chau and Son La in northern Vietnam and in the province of Dong Thap in the southern part of the country. Filovirus RNA was found in four Rousettus leschenaultii and one Rousettus amplexicaudatus from Lai Chau Province. Phylogenetic analysis of the polymerase gene fragment showed that three positive samples belong to Dianlovirus, and two samples form a separate clade closer to Orthomarburgvirus. An enzyme-linked immunosorbent assay showed that 9% of Rousettus, 13% of Eonycteris, and 10% of Cynopterus bats had antibodies to the glycoprotein of marburgviruses.

Relevance. The Sverdlovsk region is a highly endemic territory for infections transmitted by ixodic ticks. The possibilities of laboratory diagnostics of tick–borne infections in the routine practice of a clinician in the region today are limited mainly by testing blood serum for antibodies to the tick-borne encephalitis virus (TBE virus) and Lyme disease (LD) pathogens – Borrelia burgdorferi sensu lato complex, therefore, among tick-borne infections in the region currently mainly TBE and LD are registered. In case of negative results for antibodies to the pathogens of the above infections, the diagnosis may remain unknown. Aims. To study the etiological structure of infections transmitted by ixodic ticks in the Sverdlovsk region at the present stage, as well as to characterize the epidemiological and clinical features of the course of tick-borne infections detected in conditions of a combination of natural foci. Materials and methods. The study included 227 patients undergoing inpatient or outpatient treatment during the epidemic season of tick activity in 2021 (June-August) at LLS MO "New Hospital" (Urban Center of Natural Focal Infections). The case histories (epidemiological, clinical and laboratory indicators) were studied from each patient, as well as the material (blood) was examined prospectively and retrospectively using molecular biological (PCR) and serological (ELISA, planar protein biochip) methods. Results and discussion. During the study, six diseases were identified among the examined patients: TBE, LD (erythematous and nonerythematous forms), Borrelia miyamotoi disease (BMD), human granulocytic anaplasmosis (HGA), human monocytic ehrlichiosis (HME), as well as "Viral fever transmitted by arthropods" (VFTA). Among the examined patients, the proportion of patients with monoinfection was 49,5%, with mixed infection – 50,5%. Additional studies conducted by us using specific PCR for the presence DNA rickettsia and the causative agent of Q-fever in the blood of patients gave negative results. The general epidemiological characteristics for the above identified infections were the vector-borne mechanism, the prevalence of diseases in groups of middle-aged and elderly people, the largest number of cases of infection with pathogens of any tick-borne infection occurred in Yekaterinburg and its surroundings, for all infections, the duration of tick bite in most cases did not exceed one day; there were differences by sex, incubation period. Clinical symptoms were similar, except for the erythematous form of LD (the presence of erythema migrans at the byte site of tick), because the vast majority of patients had a general infectious syndrome; general laboratory indicators varied. Confirmation of the diagnosis was based on the results of the complex application of molecular biological and serological research methods. Conclusions. The modern etiological structure of infections transmitted by ixodic ticks in the Sverdlovsk region is represented not only by TBE and LD, but also by new disease to our country, such as BMD, HGA, HME, while a high proportion of mixed infections in various combinations has been revealed.

This paper describes the protein array as a novel serological test for the diagnosis ofBorrelia miyamotoidisease (BMD), by reporting the methodology, the development of a diagnostic algorithm, and its extensive validation. With rising numbers of ticks and tick bites, tick-borne diseases, such as BMD, urgently deserve further societal and medical attention.B. miyamotoiis prevalent inIxodesticks across the northern hemisphere.

Особенности аносмии при COVID-19 и аллергическом рините. Влияние масок на выраженность симптомовФедеральное бюджетное учреждение науки «Центральный научно-исследовательский институт эпидемиологии» Федеральной службы по надзору в сфере

In 2021, a patient died from Marburg virus (MARV) disease in Guinea, which was the first confirmed case in West Africa. The source of the outbreak has not been identified. It was revealed only that the patient had not traveled anywhere before the illness. Prior to this outbreak, MARV had been found in bats in the neighboring Sierra Leone. In Guinea, this virus has never been found before. Therefore, the question of the source of infection arose: was it an autochthonous case with spillover from a local population of bats or an imported case with spillover from fruit bats foraging/migrating from Sierra Leone? In this paper, we aimed to conduct a study of Rousettus aegyptiacus in Guinea and determine the source of the most likely infection of a patient who died from Marburg virus disease in 2021 in Guinea. We caught bats at 32 sites in Guéckédou prefecture, including seven caves and 25 locations on the flight path. A total of 501 fruit bats (Pteropodidae) were captured, including 66 R. aegyptiacus . The subsequent screening showed three PCR-positive MARV bats. We have found and described two caves in Guéckédou prefecture where MARV-positive R. aegyptiacus roost. Sequencing has shown that at least two different MARV genetic variants circulate in R. aegyptiacus in Guinea: an Angola-like strain and MARV strains of major marburgvirus lineages.

Purpose: Borrelia (BOR), Rickettsia (RICK) and Hantaviruses (HANT) can make significant contribution in morbidity of vector-borne and emerging infectious disease. Hereby we aimed to investigate the indirect evidences of presence of these pathogens in the rural areas of North Vietnam by studying the possibility of contact with vectors and reservoirs hosts and the seroprevalence in adult healthy population Methods & Materials: 220 and 121 healthy residents of communes Ma Ly Pho (Phong Thổ District, Lai Chau province) and Tà Xùa (Bắc Yên District, Son La province) in North Vietnam were interviewed and serosurveyed. 61% and 58% of studied populations respectively were female, average age was 40.4±14.5 and 38,9±14.8 years. The prevalence of IgM/IgG to RICK and HANT were studied using Rickettsia Conorii ELISA IgG/IgM kit (Vircell, Spain) and NovaLisa Hantavirus IgG/IgM kit (NovaTec, Germany). IgM/IgG to BOR were detected using the microarray containing 13 and 14 antigens of Borrelia miyamotoi (Bm) and Borrelia burgdorferi sensu lato (Bbsl) respectively (CRIE, Russia). Results: 98% and 65% of respondents in communes Ma Ly Pho and Tà Xùa respectively had rural occupations. 95% and 90% confirmed the presence of rodents near home. 38% and 37% caught, killed or cooked rodents and bats. 8% and 3% noticed tick-bites in the past.IgM to RICK, HANT, Bbsl and Bm were detected in 23, 12, 25 and 2 out of 220 and in 4, 0, 21 and 2 out of 121 samples of healthy residents in communes Ma Ly Pho and Tà Xùa respectively. IgG to indicate pathogens were detected in 5, 5, 53 and 4 out of 220 and in 3, 4, 27 and 2 out of 121 samples. Conclusion: We showed the high possibility of contact with vector and host animals and high seroprevalence of RICK, HANT and BOR among the rural population in North Vietnam. Future investigations of acute febrile patients and vector and host animals are needed to find out the exact causative agents and to estimate the incidence of these diseases.

Acute febrile illnesses occur frequently in Guinea. Acute fever itself is not a unique, hallmark indication (pathognomonic sign) of any one illness or disease. In the infectious disease context, fever's underlying cause can be a wide range of viral or bacterial pathogens, including the Ebola virus. In this study, molecular and serological methods were used to analyze samples from patients hospitalized with acute febrile illness in various regions of Guinea. This analysis was undertaken with the goal of accomplishing differential diagnosis (determination of causative pathogen) in such cases. As a result, a number of pathogens, both viral and bacterial, were identified in Guinea as causative agents behind acute febrile illness. In approximately 60% of the studied samples, however, a definitive determination could not be made.

Aim. Estimation of the prevalence of Ixodes tick-borne borreliosis (ITBB) without erythema migrans in the Krasnoyarsk Territory in comparison with the prevalence of ITBB with erythema, that is Lyme disease (LD). Detection of cases of «new» infection caused by Borrelia miyamotoi (ITBB-BM) among patients with suspected tick-borne infection, primarily among patients with ITBB without erythema (ITBB-W/O-E). Materials and methods. We analyzed the database of Rospotrebnadzor containing individualized information about cases of ITBB officially registered in the Krasnoyarsk Territory in 2011 — 2016. Blood samples from 18 patients with suspected of tick-borne infection hospitalized in the Krasnoyarsk Emergency Hospital in 2017 were collected and studied. ITBB-BM was diagnosed if B. miyamotoi DNA was found in patient’s blood and/or the antibodies to specific antigens of B. miyamotoi were detected. Results. With an average annual incidence rate of ITBB of about 10 cases per 100,000 population, the proportion of ITBB-W/O-E among all ITBB in the Krasnoyarsk Territory is about 45%. Epidemiological characteristics of ITBB-W/O-E and LD are similar, but these diseases are very different clinically. All cases of ITBBW/O-E and some cases of tick-borne infections of unknown etiology, subjected to our enhanced laboratory diagnostics, were caused by B. miyamotoi. Conclusion. ITBB-W/O-E is a widespread disease in the Krasnoyarsk Territory, caused mainly by B. miyamotoi. The results of the study significantly expand the known geographic area of the ITBB-BM.

Purpose: CCF is an arboviral disease characterized by fever, severe intoxication and hemorrhagic syndrome with high mortality. CCFV is spread in many countries of Europe, Africa and Asia, including the South of the Russian Federation and Guinea. Here we aimed to develop and evaluate the recombinant protein-based microarray for detection of IgM/IgG to CCFV antigens. Methods & Materials: The microarray includes recombinant proteins NP, it's antigenic fragment NPsh, 3 glycoprotein G1 antigenic fragments and one of protein L. The microarray development was conducted using sera collected in the endemic region of Russia from 20 patients (40 samples in total), in which CCFV RNA was determined using the «AmpliSensCCFV-FL» kit (CRIE, Russia), and 100 samples of healthy controls. IgM/IgG levels were measured using ELISA kit (Bioservice, Russia) and developed microarray. The seroprevalence of CCFV infection in humans in Guinea, was determined in serum samples from Guinean healthy population (200 in total). Results: According to data obtained while testing of healthy controls samples, the presence of IgG/IgM to one of G1 or L fragment leads to negative result of analysis, to two of G1 fragments – to equivocal result and to NP and/or one G1 and L fragments together – to positive result. Thus the specificity of microarray was determined to be 98%. When specified interpretation criteria and only serums obtained on day 4-7 of the disease are used, the clinical diagnosis could be confirmed by the combination of IgG and IgM detection in 17/20 cases (16/20 for ELISA), and for paired serum samples - in 20/20 cases (both methods). The advantage of microarray is determination of IgM/IgG separately but in one well due to usage of Cy3/Cy5-labeled specific antibodies. From 200 Guinean samples IgM to CCFV antigens were found in 2 sera (1%), IgG – in 14 sera (7%). This data consistent with data obtained for neighbor countries. Conclusion: We showed that developed microarray is highly sensitive and specific diagnostic mean. The results shown that approximately 8% of the study population in Guinea, have a history of CCFV infection. As far the study is the first case of determination of prevalence of CCFV in humans in Guinea.

Purpose: During Borrelia miyamotoi disease (BMD) patients produce antibodies to glycerophosphodiester-phosphodiesterase (GlpQ) and to highly antigenic surface variable major proteins (Vmps). Individual B.miyamotoi spirochetes expresses presumably one VMP, but in vivo “switching” between Vmps may occur, as observed in animal models of B. miyamotoi. Methods & Materials: We here studied IgM and IgG antibody responses by producing a plane protein microarray containing GlpQ and four Vmps: variable small protein (Vsp) 1, variable large protein (Vlp) 15/16 (Delta subfamily), Vlp5 (Gamma subfamily), Vlp18 (Alpha subfamily). This selection of Vmps represents all subfamilies of B.miyamotoi Vmps and these specific VMPs were selected based on expression in B.miyamotoi strains HT31 or LB-2001. In addition our microarray contains 14 antigenic variants of 8 B.burgdorferi sensu lato proteins. We tested 219 sera from 50 PCR-confirmed Russian BMD patients. Samples were drawn between hospital admission and one year after disease. In addition, we tested 70 sera from 70 healthy blood donors. Results: Antibodies to GlpQ were detected in 46/50 BMD cases and 50/50 BMD patients produced antibodies to at least one Vmp: IgM and/or IgG antibodies to Vlp15/16, Vsp1, Vlp5 and Vlp18 were detected in 34, 22, 13, and 11 patients, respectively. Interestingly, antibodies to two different Vmps were detected in blood of 13 patients, antibodies to 3 or 4 Vmps – in blood of 4 and 3 patients, respectively. IgM antibodies peaked approximately 13 days after onset disease and decreased one year after; IgG antibodies reached a plateau at day 40 that remained year after. Conclusion: Serial measurement of anti-GlpQ and anti-Vmp antibodies provided the possibility to diagnose BMD with 99% specificity and 92% sensitivity. Since about 40% of patients responded to two of more Vmps, this suggests antigen switching and immune evasion in BMD. This study was supported by the grant of Russian Scientific Foundation (project 15-15-00072).