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《Research in virology》1991,142(6):483-488
The kinetics of the replication of the Crimean-Congo haemorrhagic fever virus (CCHFV) was studied in intra-anally inoculated adult Hyalomma truncatum and Amblyomma variegatum ticks. The virus was re-isolated by suckling mouse inoculation and revealed by antigen capture with ground ticks and indirect immunofluorescence of haemolymph. The virus was detected in ticks in the first hours post-inoculation (p.i.) and its replication was observed from 36 h p.i. onwards. Virus titre reached a maximum within 3–5 days then decreased slowly to a level of at 2 log LD50/ml for several months until the end of observations.Several specific, non-identified factors seem to favour CCHFV replication in H. truncatum. Long-term virus persistence seems to occur in CCHFV-infected adult ticks. 相似文献
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Crimean-Congo hemorrhagic fever (CCHF) is a severe illness with high fatality. Cases are reported in several countries in
Africa, Europe, the Middle East, and Asia. Phylogenetic analyses based on the virus S (nucleocapsid), M (glycoprotein), and
L (polymerase) genome segments sequences indicate distinct geographic lineages exist but their specific genetic characteristics
require elucidation. In this work we collected all full length S segment sequences and generated a phylogenetic tree based
on the alignment of these 62 samples. We then analyzed the alignment using entries from AAIndex, the Amino Acid Index database,
to identify amino acid mutations that performed significant changes in charge, pka, hydropathy and side chain volume. Finally,
we mapped these changes back to the tree and alignment to identify correlated mutations or sites that characterized a specific
lineage. Based on this analysis we are able to propose a number of sites that appear to be important for virus function and
which would be good candidates for experimental mutational analysis studies. 相似文献
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Bernadette Basuta Mirembe Angella Musewa Daniel Kadobera Esther Kisaakye Doreen Birungi Daniel Eurien Luke Nyakarahuka Stephen Balinandi Alex Tumusiime Jackson Kyondo Sophia Mbula Mulei Jimmy Baluku Benon Kwesiga Steven Ndugwa Kabwama Bao-Ping Zhu Julie R. Harris Julius Julian Lutwama Alex Riolexus Ario 《PLoS neglected tropical diseases》2021,15(3)
IntroductionCrimean-Congo haemorrhagic fever (CCHF) is a tick-borne, zoonotic viral disease that causes haemorrhagic symptoms. Despite having eight confirmed outbreaks between 2013 and 2017, all within Uganda’s ‘cattle corridor’, no targeted tick control programs exist in Uganda to prevent disease. During a seven-month-period from July 2018-January 2019, the Ministry of Health confirmed multiple independent CCHF outbreaks. We investigated to identify risk factors and recommend interventions to prevent future outbreaks.MethodsWe defined a confirmed case as sudden onset of fever (≥37.5°C) with ≥4 of the following signs and symptoms: anorexia, vomiting, diarrhoea, headache, abdominal pain, joint pain, or sudden unexplained bleeding in a resident of the affected districts who tested positive for Crimean-Congo haemorrhagic fever virus (CCHFv) by RT-PCR from 1 July 2018–30 January 2019. We reviewed medical records and performed active case-finding. We conducted a case-control study and compared exposures of case-patients with age-, sex-, and sub-county-matched control-persons (1:4).ResultsWe identified 14 confirmed cases (64% males) with five deaths (case-fatality rate: 36%) from 11 districts in western and central region. Of these, eight (73%) case-patients resided in Uganda’s ‘cattle corridor’. One outbreak involved two case-patients and the remainder involved one. All case-patients had fever and 93% had unexplained bleeding. Case-patients were aged 6–36 years, with persons aged 20–44 years more affected (AR: 7.2/1,000,000) than persons ≤19 years (2.0/1,000,000), p = 0.015. Most (93%) case-patients had contact with livestock ≤2 weeks before symptom onset. Twelve (86%) lived <1 km from grazing fields compared with 27 (48%) controls (ORM-H = 18, 95% CI = 3.2-∞) and 10 (71%) of 14 case-patients found ticks attached to their bodies ≤2 weeks before symptom onset, compared to 15 (27%) of 56 control-persons (ORM-H = 9.3, 95%CI = 1.9–46).ConclusionsCCHF outbreaks occurred sporadically during 2018–2019, both within and outside ‘cattle corridor’ districts of Uganda. Most cases were associated with tick exposure. The Ministry of Health should partner with the Ministry of Agriculture, Animal Industry and Fisheries to develop joint nationwide tick control programs and strategies with shared responsibilities through a One Health approach. 相似文献
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Cellular localization and antigenic characterization of crimean-congo hemorrhagic fever virus glycoproteins
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Bertolotti-Ciarlet A Smith J Strecker K Paragas J Altamura LA McFalls JM Frias-Stäheli N García-Sastre A Schmaljohn CS Doms RW 《Journal of virology》2005,79(10):6152-6161
Crimean-Congo hemorrhagic fever virus (CCHFV), a member of the genus Nairovirus of the family Bunyaviridae, causes severe disease with high rates of mortality in humans. The CCHFV M RNA segment encodes the virus glycoproteins G(N) and G(C). To understand the processing and intracellular localization of the CCHFV glycoproteins as well as their neutralization and protection determinants, we produced and characterized monoclonal antibodies (MAbs) specific for both G(N) and G(C). Using these MAbs, we found that G(N) predominantly colocalized with a Golgi marker when expressed alone or with G(C), while G(C) was transported to the Golgi apparatus only in the presence of G(N). Both proteins remained endo-beta-N-acetylglucosaminidase H sensitive, indicating that the CCHFV glycoproteins are most likely targeted to the cis Golgi apparatus. Golgi targeting information partly resides within the G(N) ectodomain, because a soluble version of G(N) lacking its transmembrane and cytoplasmic domains also localized to the Golgi apparatus. Coexpression of soluble versions of G(N) and G(C) also resulted in localization of soluble G(C) to the Golgi apparatus, indicating that the ectodomains of these proteins are sufficient for the interactions needed for Golgi targeting. Finally, the mucin-like and P35 domains, located at the N terminus of the G(N) precursor protein and removed posttranslationally by endoproteolysis, were required for Golgi targeting of G(N) when it was expressed alone but were dispensable when G(C) was coexpressed. In neutralization assays on SW-13 cells, MAbs to G(C), but not to G(N), prevented CCHFV infection. However, only a subset of G(C) MAbs protected mice in passive-immunization experiments, while some nonneutralizing G(N) MAbs efficiently protected animals from a lethal CCHFV challenge. Thus, neutralization of CCHFV likely depends not only on the properties of the antibody, but on host cell factors as well. In addition, nonneutralizing antibody-dependent mechanisms, such as antibody-dependent cell-mediated cytotoxicity, may be involved in the in vivo protection seen with the MAbs to G(C). 相似文献
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J Martín-Fernández A Igual A Rueda J M Sánchez-Vizcaíno C Alonso-Martí 《Histology and histopathology》1991,6(1):115-121
Twelve miniature pigs were inoculated with an attenuated African swine fever virus to study glomerular involvement in surviving pigs. In acute phase, kidneys were severely affected and displayed a glomerular capillary thrombosis with fibrin deposition in vascular lumen, detected by immunofluorescence. Fibrin-positive deposits were progressively cleared between one to three months after infection in surviving pigs. The histological picture in kidneys of surviving pigs, up to one post-infection year, showed a focal and segmental glomerulonephritis with hyalinosis, and IgM and C3 deposition was detected by immunofluorescence. Its pathogeny as an evolutive stage of acute glomerular injury is pointed out. 相似文献
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Transmission of louping ill virus between infected and uninfected ticks co-feeding on mountain hares 总被引:2,自引:0,他引:2
LINDA D. JONES MICHAEL GAUNT ROSIE S. HAILS KAREN LAURENSON PETER J. HUDSON HUGH REID† PAULINE HENBEST ERNEST A. GOULD 《Medical and veterinary entomology》1997,11(2):172-176
Abstract. Most of the data on oral infection of ticks by louping ill virus have been obtained from experiments in which animals were infected by syringe inoculation with infectious material. Using infected ticks to mimic the natural situation, we have demonstrated that louping ill (LI) virus transmission can occur from infected to uninfected Ixodes acinus feeding in close proximity on mountain hares (Lepus timidus). Under these conditions the hares developed either low or undetectable viraemias. Highest prevalence of LI virus infection was observed in recipient nymphs which had fed to repletion between days 3 and 7 post-attachment of virus-infected adults; following engorgement, 56% of nymphs acquired virus. These results demonstrate the efficient transmission of LI virus between co-feeding ticks on naive mountain hares. However, when ticks were allowed to co-feed on virus-immune hares a significant reduction in the frequency of infection was observed. Neither red deer (Cervus elaphus) nor New Zealand White rabbits supported transmission of LI virus. The significance of virus transmission between cofeeding ticks on LI virus epidemiology is discussed. 相似文献
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Juan F. Vesga Madeleine H. A. Clark Edris Ayazi Andrea Apolloni Toby Leslie W. John Edmunds Raphalle Mtras 《PLoS neglected tropical diseases》2022,16(5)
BackgroundCrimean-Congo haemorrhagic fever virus (CCHFV) is a highly pathogenic virus for which a safe and effective vaccine is not yet available, despite being considered a priority emerging pathogen. Understanding transmission patterns and the use of potential effective vaccines are central elements of the future plan against this infection.MethodsWe developed a series of models of transmission amongst livestock, and spillover infection into humans. We use real-world human and animal data from a CCHFV endemic area in Afghanistan (Herat) to calibrate our models. We assess the value of environmental drivers as proxy indicators of vector activity, and select the best model using deviance information criteria. Finally we assess the impact of vaccination by simulating campaigns targeted to humans or livestock, and to high-risk subpopulations (i.e, farmers).FindingsSaturation deficit is the indicator that better explains tick activity trends in Herat. Recent increments in reported CCHFV cases in this area are more likely explained by increased surveillance capacity instead of changes in the background transmission dynamics. Modelling suggests that clinical cases only represent 31% (95% CrI 28%-33%) of total infections in this area. Vaccination campaigns targeting humans would result in a much larger impact than livestock vaccination (266 vs 31 clinical cases averted respectively) and a more efficient option when assessed in courses per case averted (35 vs 431 respectively). Targeted vaccination of farmers is impactful and more efficient, resulting in 19 courses per case averted (95% CrI 7–62) compared to targeting the general population (35 courses 95% CrI 16–107)ConclusionsCCHFV is endemic in Herat, and transmission cycles are well predicted by environmental drivers like saturation deficit. Vaccinating humans is likely to be more efficient and impactful than animals, and importantly targeted interventions to high risk groups like farmers can offer a more efficient approach to vaccine roll-out. 相似文献
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González LE García JA Núñez C Perrone TM González-Baradat B Gonzatti MI Reyna-Bello A 《Experimental parasitology》2005,111(2):126-129
Trypanosoma vivax is the principal etiological agent of bovine trypanosomosis, a widely disseminated disease in tropical and subtropical regions. Here, we present a simple and reproducible method for the purification of T. vivax from experimentally infected and immunosuppressed sheep, using an isopycnic Percoll gradient, followed by DEAE-cellulose chromatography, with an estimated yield of 11-15%. This method could be used for the purification of T. vivax geographical isolates from various locations and from different natural hosts. 相似文献
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Veerle Msimang Jacqueline Weyer Chantel le Roux Alan Kemp Felicity J. Burt Stefano Tempia Antoinette Grobbelaar Naazneen Moolla Melinda K. Rostal Whitney Bagge Claudia Cordel William B. Karesh Janusz T. Paweska Peter N. Thompson 《PLoS neglected tropical diseases》2021,15(5)
Crimean-Congo haemorrhagic fever (CCHF) is a severe tick-borne viral zoonosis endemic to parts of Africa, Europe, the Middle East and Central Asia. Human cases are reported annually in South Africa, with a 25% case fatality rate since the first case was recognized in 1981. We investigated CCHF virus (CCHFV) seroprevalence and risk factors associated with infection in cattle and humans, and the presence of CCHFV in Hyalomma spp. ticks in central South Africa in 2017–18. CCHFV IgG seroprevalence was 74.2% (95%CI: 64.2–82.1%) in 700 cattle and 3.9% (95%CI: 2.6–5.8%) in 541 farm and wildlife workers. No veterinary personnel (117) or abattoir workers (382) were seropositive. The prevalence of CCHFV RNA was significantly higher in Hyalomma truncatum (1.6%) than in H. rufipes (0.2%) (P = 0.002). Seroprevalence in cattle increased with age and was greater in animals on which ticks were found. Seroprevalence in cattle also showed significant geographic variation. Seroprevalence in humans increased with age and was greater in workers who handled livestock for injection and collection of samples. Our findings support previous evidence of widespread high CCHFV seroprevalence in cattle and show significant occupational exposure amongst farm and wildlife workers. Our seroprevalence estimate suggests that CCHFV infections are five times more frequent than the 215 confirmed CCHF cases diagnosed in South Africa in the last four decades (1981–2019). With many cases undiagnosed, the potential seriousness of CCHF in people, and the lack of an effective vaccine or treatment, there is a need to improve public health awareness, prevention and disease control. 相似文献
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Hyalomma ticks on northward migrating birds in southern Spain: Implications for the risk of entry of Crimean‐Congo haemorrhagic fever virus to Great Britain
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Marion E. England Paul Phipps Jolyon M. Medlock Peter M. Atkinson Barry Atkinson Roger Hewson Paul Gale 《Journal of vector ecology》2016,41(1):128-134
Crimean‐Congo haemorrhagic fever virus (CCHFV) is a zoonotic virus transmitted by Hyalomma ticks, the immature stages of which may be carried by migratory birds. In this study, a total of 12 Hyalomma ticks were recovered from five of 228 migratory birds trapped in Spring, 2012 in southern Spain along the East Atlantic flyway. All collected ticks tested negative for CCHFV. While most birds had zero Hyalomma ticks, two individuals had four and five ticks each and the statistical distribution of Hyalomma tick counts per bird is over‐dispersed compared to the Poisson distribution, demonstrating the need for intensive sampling studies to avoid underestimating the total number of ticks. Rates of tick exchange on migratory birds during their northwards migration will affect the probability that a Hyalomma tick entering Great Britain is positive for CCHFV. Drawing on published data, evidence is presented that the latitude of a European country affects the probability of entry of Hyalomma ticks on wild birds. Further data on Hyalomma infestation rates and tick exchange rates are required along the East Atlantic flyway to further our understanding of the origin of Hyalomma ticks (i.e., Africa or southern Europe) and hence the probability of entry of CCHFV into GB. 相似文献
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Human immunodeficiency virus (HIV) from experimentally infected chimpanzees: isolation and characterization 总被引:2,自引:0,他引:2
B A Castro C M Walker M Tateno C Cheng-Mayer R Heberling J W Eichberg J A Levy 《Journal of medical primatology》1989,18(3-4):337-342
Human immunodeficiency virus-1 (HIV-1) isolates obtained from chimpanzees that had undergone various immunosuppressive treatments were characterized by growth on various primary cells and cell lines as well as by restriction endonuclease analysis. Viruses recovered from animals inoculated with uncloned HIV showed genetic variation from the original inoculum, whereas viruses isolated from an animal infected with a molecular clone of HIV did not. In some cases, virus recovery was possible only after enrichment for CD4+ cells by panning, inoculation with a chimpanzee cytomegalovirus, or a combination of these procedures. These findings indicate a role for viral and host cofactors in the control of virus replication and suggest explanations for the absence of clinical manifestations in HIV-infected chimpanzees. 相似文献
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This research was conducted on ten glass slides selected from the histopathology evaluation chickens. Five slides of control's chickens healthy and five slides of chickens infected experimentally with chicken anemia virus (CAV slide) between one and twenty-one days post infection (PI), they were analyzed in magnifications of 200x and 400x. Histopathology showed severe bone marrow hypoplasia to complete aplasia, fully depletion of the erythrocytic and granulocytic series, both accompanied by space occupying adipocytic replacement. Foci of erythropoietic hyperplasia with intense mielopoietic activity, some hemocytoblast increased of size, with large nucleus. A quantitative analytical technique by Positive Pixel Count Algorithm was applied. It demonstrated that measures area stained of control slides were higher than CAV slides (Average: 61% vs. 25%, respectively). So, the control slides showed strong positivity, due to the presence of bigger quantity of cells of erythrocytic and granulocytic series. The CAV slides of seven days PI had high positivity (average: 94%), it was explained because the chicken anemia virus takes place severe lesions between ten to seventeen days PI, after 21 days PI the cellular regeneration is observed that is evidenced by means of focuses of erythroblastoid cells hyperplasia. This technique demonstrates in a quantitative way the severe decrease of the cellular components of the bone marrow in presence of the infection for CAV, supporting with numeric data the histology image evaluated by the pathologist. Therefore, it can be used as support to the histopathology of field samples to evaluate the presence of lesions taken place by CAV and this way to improve the quality and efficiency of the veterinary pathology services. 相似文献
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Lopes WD Costa AJ Souza FA Rodrigues JD Costa GH Soares VE Silva GS 《Animal reproduction science》2009,111(2-4):312-319
The influence of Toxoplasma gondii on semen variables and sperm morphology of sheep was evaluated in eight reproductive males distributed into three experimental groups: GI, three sheep inoculated with 2.0x10(5) of P strain oocytes; GII, three sheep infected with 1.0x10(6) of RH strain tachyzoites and; GIII two control sheep. Clinical (rectal temperature, cardiac and respiratory frequencies), parasite and serology exams (IIF) were realized. Sperm variables (volume, motility, vigor and concentration) and semen morphology for each sheep were also evaluated. Thus, semen and blood collections were assessed on post-inoculation days (PIDs)-1,3,5,7,11,14 and weekly thereafter up to PID 70. Clinical alterations were observed (hypothermia and anorexia) in infected sheep from groups GI and GII. Parasitic outbreaks were detected in five sheep. All the infected sheep produced antibodies against T. gondii from PID 5 onwards, reaching a peak of 4096 and 8192 for group GI and GII sheep, respectively. Differences (P<0.05) were observed regarding the ejaculate volume between the inoculated groups (oocytes and tachyzoites) and control. Even though experimental toxoplasmic infection resulted in clinical symptomology in the inoculated sheep, the minimal alterations in sperm pathologies could not be directly attributed to T. gondii. 相似文献