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Virology Journal Oct 2023The live-attenuated Rift Valley Fever Smithburn (SB) vaccine is one of the oldest products widely used in ruminants for control of RVF infections. Vaccinations with RVF...
BACKGROUND
The live-attenuated Rift Valley Fever Smithburn (SB) vaccine is one of the oldest products widely used in ruminants for control of RVF infections. Vaccinations with RVF Smithburn result in residual pathogenic effect and is limited for use in non-pregnant animals. Commercially available RVFV inactivated vaccines are considered safer options to control the disease. These products are prepared from virulent RVFV isolates and present occupational safety concerns. This research study evaluates the ability of an inactivated SB vaccine strain to elicit neutralising antibody response in sheep.
METHODS
The RVF Smithburn vaccine was inactivated with binary ethylenimine at 37 °C. Inactivated RVFV cultures were adjuvanted with Montande™ Gel-01 and aluminium hydroxide (Al (OH)) gel for immunogenicity and safety determination in sheep. The commercial RVF inactivated vaccine and a placebo were included as positive and negative control groups, respectively.
RESULTS
Inactivated RVFV vaccine formulations were safe with all animals showing no clinical signs of RVFV infection and temperature reactions following prime-boost injections. The aluminium hydroxide formulated vaccine induced an immune response as early as 14 days post primary vaccination with neutralising antibody titre of 1:20 and a peak antibody titre of 1:83 was reached on day 56. A similar trend was observed in the animal group vaccinated with the commercial inactivated RVF vaccine obtaining the highest antibody titre of 1:128 on day 56. The neutralizing antibody levels remained within a threshold for the duration of the study. Merino sheep vaccinated with Montanide™ Gel-01-Smithburn were characterised with overall lower immune response when compared to aluminium hydroxide vaccine emulsions.
CONCLUSIONS
These finding suggests that the inactivated RVF Smithburn vaccine strain adjuvanted with aluminium-hydroxide can be used an alternative to the products prepared from virulent RVFV isolates for protection of ruminants against the disease. The vaccine can further be evaluated for safety in pregnant ewes.
Topics: Animals; Female; Aluminum Hydroxide; Antibodies, Neutralizing; Antibodies, Viral; Rift Valley Fever; Rift Valley fever virus; Ruminants; Sheep; Sheep Diseases; Vaccines, Attenuated; Vaccines, Inactivated; Viral Vaccines
PubMed: 37789354
DOI: 10.1186/s12985-023-02180-2 -
Viruses Dec 2023In recent years, numerous viruses have been identified from ticks, and some have been linked to clinical cases of emerging tick-borne diseases. Chinese northeast...
In recent years, numerous viruses have been identified from ticks, and some have been linked to clinical cases of emerging tick-borne diseases. Chinese northeast frontier is tick infested. However, there is a notable lack of systematic monitoring efforts to assess the viral composition in the area, leaving the ecological landscape of viruses carried by ticks not clear enough. Between April and June 2017, 7101 ticks were collected to perform virus surveillance on the China-North Korea border, specifically in Tonghua, Baishan, and Yanbian. A total of 2127 were identified. Further investigation revealed the diversity of tick-borne viruses by transcriptome sequencing of . All ticks tested negative for tick-borne encephalitis virus. Transcriptome sequencing expanded 121 genomic sequence data of 12 different virus species from . Notably, a new segmented flavivirus, named Baishan Forest Tick Virus, were identified, closely related to Alongshan virus and Harz mountain virus. Therefore, this new virus may pose a potential threat to humans. Furthermore, the study revealed the existence of seven emerging tick-borne viruses dating back to 2017. These previously identified viruses included Mudanjiang phlebovirus, Onega tick phlebovirus, Sara tick phlebovirus, Yichun mivirus, and three unnamed viruses (one belonging to the family and the other two belonging to the family). The existence of these emerging tick-borne viruses in tick samples collected in 2017 suggests that their history may extend further than previously recognized. This study provides invaluable insights into the virome of Ixodes persulcatus in the China-North Korea border region, enhancing our ongoing efforts to manage the risks associated with tick-borne viruses.
Topics: Humans; Animals; Ixodes; Democratic People's Republic of Korea; Virome; China; RNA; Thogotovirus
PubMed: 38257762
DOI: 10.3390/v16010062 -
Viruses Oct 2023Mosquitoes in the genera and are vectors of Rift Valley fever virus (RVFV), which emerges in periodic epidemics in Africa and Saudi Arabia. Factors that influence the...
Mosquitoes in the genera and are vectors of Rift Valley fever virus (RVFV), which emerges in periodic epidemics in Africa and Saudi Arabia. Factors that influence the transmission dynamics of RVFV are not well characterized. To address this, we interrogated mosquito host-signaling responses through analysis of differentially expressed genes (DEGs) in two mosquito species with marked differences in RVFV vector competence: (, low competence) and (, high competence). Mosquito-host transcripts related to three different signaling pathways were investigated. Selected genes from the Wingless (Wg, WNT-beta-catenin) pathway, which is a conserved regulator of cell proliferation and differentiation, were assessed. One of these, (), differentially regulates progression/inhibition of the WNT and JNK (c-Jun N-terminal Kinase) pathways. A negative regulator of the JNK-signaling pathway, puckered, was also assessed. Lastly, Janus kinase/signal transducers and activators of transcription (JAK-STAT) are important for innate immunity; in this context, we tested domeless levels. Here, individual and were exposed to RVFV MP-12 via oral bloodmeals and held for 14 days. Robust decreases in DEGs in both and were observed. In particular, expression, but not , was correlated to the presence/absence of viral RNA at 14 days post-challenge (dpc). Moreover, there was an inverse relationship between the viral copy number and expression. silencing resulted in increased viral copy numbers compared to controls at 3 dpc, consistent with a role for in antiviral immunity. Analysis of cis-regulatory regions for the genes of interest revealed clues to upstream regulation of these pathways.
Topics: Animals; Rift Valley fever virus; Aedes; Rift Valley Fever; Mosquito Vectors; Culex
PubMed: 38005818
DOI: 10.3390/v15112140 -
The Journal of Veterinary Medical... Feb 2024Severe fever with thrombocytopenia syndrome (SFTS) is a potentially fatal tick-borne zoonotic disease, endemic to Asian regions, including western Japan. Cats appear to...
Severe fever with thrombocytopenia syndrome (SFTS) is a potentially fatal tick-borne zoonotic disease, endemic to Asian regions, including western Japan. Cats appear to suffer a particularly severe form of the disease; however, feline SFTS is not clinically well characterized. Accordingly, in this study, we investigated the associations of, demographic, hematological and biochemical, immunological, and virological parameters with clinical outcome (fatal cases vs. survivors) in SFTSV-positive cats. Viral genomic analysis was also performed. Viral load in blood, total bilirubin, creatine phosphokinase, serum amyloid A, interleukin-6, tumor necrotic factor-α, and virus-specific IgM and IgG differed significantly between survivors and fatal cases, and thus may have utility as prognosticators. Furthermore, survivor profiling revealed high-level of viremia with multiple parameters (white blood cells, platelet, total bilirubin, glucose, and serum amyloid A) beyond the reference range in the 7-day acute phase, and signs of clinical recovery in the post-acute phase (parameters returning to, or tending toward, the reference range). However, SFTSV was still detectable from some survived cats even 14 days after onset of disease, indicating the risk of infection posed by close-contact exposure may persist through the post-acute phase. This study provides useful information for prognostic assessments of acute feline SFTS, and may contribute to early treatment plans for cats with SFTS. Our findings also alert pet owners and animal health professionals to the need for prolonged vigilance against animal-to-human transmission when handling cats that have been diagnosed with SFTS.
Topics: Animals; Humans; Cats; Severe Fever with Thrombocytopenia Syndrome; Prognosis; Phlebovirus; Bunyaviridae Infections; Serum Amyloid A Protein; Tick-Borne Diseases; Bilirubin; Cat Diseases
PubMed: 38171741
DOI: 10.1292/jvms.22-0427 -
Methods in Molecular Biology (Clifton,... 2024Rift Valley fever virus (RVFV) is an important mosquito-borne virus that can cause severe disease manifestations in humans including ocular damage, vision loss,...
Rift Valley fever virus (RVFV) is an important mosquito-borne virus that can cause severe disease manifestations in humans including ocular damage, vision loss, late-onset encephalitis, and hemorrhagic fever. In ruminants, RVFV can cause high mortality rates in young animals and high rates of abortion in pregnant animals resulting in an enormous negative impact on the economy of affected regions. To date, no licensed vaccines in humans or anti-RVFV therapeutics for animal or human use are available. The development of reverse genetics has facilitated the generation of recombinant infectious viruses that serve as powerful tools for investigating the molecular biology and pathogenesis of RVFV. Infectious recombinant RVFV can be rescued entirely from cDNAs containing predetermined mutations in their genomes to investigate virus-host interactions and mechanisms of pathogenesis and generate live-attenuated vaccines. In this chapter, we will describe the experimental procedures for the implementation of RVFV reverse genetics.
Topics: Animals; Humans; Rift Valley fever virus; Rift Valley Fever; Reverse Genetics; Vaccines, Attenuated; Mutation
PubMed: 38064029
DOI: 10.1007/978-1-0716-3533-9_7 -
PLoS Neglected Tropical Diseases Oct 2023Brucella spp. and Rift Valley fever virus (RVFV) are classified as priority zoonotic agents in Kenya, based on their public health and socioeconomic impact on the...
Brucella spp. and Rift Valley fever virus (RVFV) are classified as priority zoonotic agents in Kenya, based on their public health and socioeconomic impact on the country. Data on the pathogen-specific and co-exposure levels is scarce due to limited active surveillance. This study investigated seroprevalence and co-exposure of Brucella spp. and RVFV and associated risk factors among slaughterhouse workers in Isiolo County, northern Kenya. A cross-sectional serosurvey was done in all 19 slaughterhouses in Isiolo County, enrolling 378 participants into the study. The overall seroprevalences for Brucella spp. and RVFV were 40.2% (95% CI: 35.2-45.4) and 18.3% (95% CI: 14.5-22.5), respectively while 10.3% (95% CI 7.4%-13.8%) of individuals were positive for antibodies against both Brucella spp. and RVFV. Virus neutralisation tests (VNT) confirmed anti-RVFV antibodies in 85% of ELISA-positive samples. Our seroprevalence results were comparable to community-level seroprevalences previously reported in the area. Since most of the study participants were not from livestock-keeping households, our findings attribute most of the detected infections to occupational exposure. The high exposure levels indicate slaughterhouse workers are the most at-risk population and there is need for infection, prevention, and control programs among this high-risk group. This is the first VNT confirmation of virus-neutralising antibodies among slaughterhouse workers in Isiolo County and corroborates reports of the area being a high-risk RVFV area as occasioned by previously reported outbreaks. This necessitates sensitization campaigns to enhance awareness of the risks involved and appropriate mitigation measures.
Topics: Animals; Humans; Rift Valley fever virus; Rift Valley Fever; Abattoirs; Brucella; Seroepidemiologic Studies; Kenya; Cross-Sectional Studies; Antibodies, Viral
PubMed: 37797043
DOI: 10.1371/journal.pntd.0011677 -
Frontiers in Cellular and Infection... 2023The Hedi virus (HEDV) and Wuxiang virus (WUXV) are newly discovered Bunyaviruses transmitted by sandflies. The geographical distribution of isolation of these two...
INTRODUCTION
The Hedi virus (HEDV) and Wuxiang virus (WUXV) are newly discovered Bunyaviruses transmitted by sandflies. The geographical distribution of isolation of these two viruses continues to expand and it has been reported that WUXV causes neurological symptoms and even death in suckling mice. However, little is known about the prevalence of the two viruses in mammalian infections.
METHODS
In order to understand the infection status of HEDV and WUXV in humans and animals from regions where the viruses have been isolated, this study used Western blotting to detect the positive rates of HEDV and WUXV IgG antibodies in serum samples from febrile patients, dogs, and chickens in the forementioned regions.
RESULTS
The results showed that of the 29 human serum samples, 17.24% (5/29) tested positive for HEDV, while 68.96% (20/29) were positive for WUXV. In the 31 dog serum samples, 87.10% (27/31) were positive for HEDV and 70.97% (22/31) were positive for WUXV, while in the 36 chicken serum samples, 47.22% (17/36) were positive for HEDV, and 52.78% (19/36) were positive for WUXV.
DISCUSSION
These findings suggest there are widespread infections of HEDV and WUXV in mammals (dogs, chickens) and humans from the regions where these viruses have been isolated. Moreover, the positive rate of HEDV infections was higher in local animals compared to that measured in human specimens. This is the first seroepidemiological study of these two sandfly-transmitted viruses. The findings of the study have practical implications for vector-borne viral infections and related zoonotic infections in China, as well as providing an important reference for studies on the relationship between sandfly-transmitted viruses and zoonotic infections outside of China.
Topics: Humans; Animals; Dogs; Mice; Psychodidae; Sandfly fever Naples virus; Chickens; Phlebotomus; Zoonoses; Mammals; Antibodies, Viral; China
PubMed: 38235489
DOI: 10.3389/fcimb.2023.1291937 -
Veterinary Medicine and Science Sep 2023Rift Valley fever (RVF) is a severe zoonotic mosquito-borne disease that represents an important threat to human and animal health, with major public health and... (Meta-Analysis)
Meta-Analysis
Rift Valley fever (RVF) is a severe zoonotic mosquito-borne disease that represents an important threat to human and animal health, with major public health and socioeconomic impacts. This disease is endemic throughout many African countries and the Arabian Peninsula. This systematic review with meta-analysis was conducted to determine the RVF prevalence in humans, mosquitoes and other animal species in Africa. The review also provides contemporary data on RVF case fatality rate (CFR) in humans. In this systematic review with meta-analysis, a comprehensive literature search was conducted on the PubMed, Embase, Web of Science and Global Index Medicus databases from January 2000 to June 2022 to identify relevant studies. Pooled CFR and prevalence estimates were calculated using the random-effects model. Subgroup analysis and sensitivity analysis were performed, and the I -statistic was used to investigate a potential source of heterogeneity. A total of 205 articles were included in the final analysis. The overall RVF CFR in humans was found to be 27.5% [95% CI = 8.0-52.5]. The overall pooled prevalence was 7.8% [95% CI = 6.2-9.6] in humans and 9.3% [95% CI = 8.1-10.6] in animals, respectively. The RVF prevalence in individual mosquitoes ranged from 0.0% to 25%. Subgroup analysis showed substantial heterogeneity with respect to geographical regions and human categories. The study shows that there is a correspondingly similar prevalence of RVF in human and animals; however, human CFR is much higher than the observed prevalence. The lack of a surveillance programme and the fact that this virus has subclinical circulation in animals and humans could explain these observations. The implementation of a One Health approach for RVF surveillance and control would be of great interest for human and animal health.
Topics: Animals; Humans; Africa; Culicidae; Disease Outbreaks; Rift Valley Fever; Rift Valley fever virus
PubMed: 37548116
DOI: 10.1002/vms3.1238 -
Microorganisms Sep 2023Emerging viruses pose an important global public health challenge, and early action is needed to control their spread. The family contains a great number of arboviruses...
Emerging viruses pose an important global public health challenge, and early action is needed to control their spread. The family contains a great number of arboviruses which are potentially pathogenic for humans. For example, phleboviruses affect a large range of hosts, including humans and animals. Some infections usually have an asymptomatic course, but others lead to severe complications, such as Toscana virus, which is able to cause meningitis and encephalitis. Unfortunately, to date, no vaccines or antiviral treatments have been found. In the present study, we evaluated the effect of melittin-related peptides, namely the frog-derived RV-23 and AR-23, on sandfly fever Naples virus infection in vitro. Both peptides exhibited a strong antiviral activity by targeting the viral particles and blocking the virus-cell interaction. Their action was directed to an early phase of SFNV infection, in particular at viral adsorption on host cells, by interfering with the binding of common glycosaminoglycan receptors. Given the better antimicrobial behavior of AR-23 and RV-23 compared to melittin in terms of selectivity, our studies expand our understanding of the potential of these peptides as antimicrobials and stimulate further investigations in the direction of novel antiviral strategies against phlebovirus infection.
PubMed: 37894104
DOI: 10.3390/microorganisms11102446 -
Preventive Veterinary Medicine Dec 2023To assess pastoralists' and agropastoralists' knowledge on Rift Valley fever (RVF), participatory epidemiological studies were conducted with 215 livestock keepers and...
To assess pastoralists' and agropastoralists' knowledge on Rift Valley fever (RVF), participatory epidemiological studies were conducted with 215 livestock keepers and 27 key informants in Napak, Butebo, Isingiro and Lyantonde districts, Uganda, between January and February 2022. Livestock keepers in all four districts had knowledge of RVF and even had local names or descriptions for it. Pastoralists and agropastoralists possessed valuable knowledge of RVF clinical descriptions and epidemiological risk factors such as the presence of infected mosquitoes, living in flood-prone areas, and excessive rainfall. RVF was ranked among the top ten most important cattle diseases. Pastoralists called RVF Lonyang, symbolizing a disease associated with jaundice, high fever, abortions in pregnant cows, and sudden death in calves. Key informants identified infected domestic animals, the presence of infected mosquitoes, livestock movement and trade, and infected wild animals as risk pathways for the introduction of RVF into an area. Drinking raw blood and milk was perceived as the most likely pathway for human exposure to RVF virus; while the highest consequence was high treatment costs. The results indicate that pastoralists provided key epidemiological information that could be essential for designing an effective national RVF surveillance and early warning system.
Topics: Pregnancy; Female; Animals; Cattle; Humans; Rift Valley Fever; Uganda; Rift Valley fever virus; Animals, Domestic; Risk Factors; Livestock; Culicidae
PubMed: 37984160
DOI: 10.1016/j.prevetmed.2023.106071