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1.
J Environ Public Health ; 2021: 8881191, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34594384

RESUMO

Introduction: Rift Valley fever (RVF) is a mosquito-borne viral zoonosis. The Uganda Ministry of Health received alerts of suspected viral haemorrhagic fever in humans from Kiruhura, Buikwe, Kiboga, and Mityana districts. Laboratory results from Uganda Virus Research Institute indicated that human cases were positive for Rift Valley fever virus (RVFV) by polymerase chain reaction. We investigated to determine the scope of outbreaks, identify exposure factors, and recommend evidence-based control and prevention measures. Methods: A suspected case was defined as a person with acute fever onset, negative malaria test result, and at least two of the following symptoms: headache, muscle or joint pain, bleeding, and any gastroenteritis symptom (nausea, vomiting, abdominal pain, diarrhoea) in a resident of Kiruhura, Buikwe, Mityana, and Kiboga districts from 1st October 2017 to 30th January 2018. A confirmed case was defined as a suspected case with laboratory confirmation by either detection of RVF nucleic acid by reverse-transcriptase polymerase chain reaction (RT-PCR) or demonstration of serum IgM or IgG antibodies by ELISA. Community case finding was conducted in all affected districts. In-depth interviews were conducted with human cases that were infected with RVF who included herdsmen and slaughterers/meat handlers to identify exposure factors for RVF infection. A total of 24 human and 362 animal blood samples were tested. Animal blood samples were purposively collected from farms that had reported stormy abortions in livestock and unexplained death of animals after a short illness (107 cattle, 83 goats, and 43 sheep). Convenient sampling for the wildlife (10 zebras, 1 topi, and 1 impala) was conducted to investigate infection in animals from Kiruhura, Buikwe, Mityana, and Kiboga districts. Human blood was tested for anti-RVFV IgM and IgG and animal blood for anti-RVFV IgG. Environmental assessments were conducted during the outbreaks in all the affected districts. Results: Sporadic RVF outbreaks occurred from mid-October 2017 to mid-January 2018 affecting humans, domestic animals, and wildlife. Human cases were reported from Kiruhura, Buikwe, Kiboga, and Mityana districts. Of the 24 human blood samples tested, anti-RVFV IgG was detected in 7 (29%) human samples; 1 human sample had detectable IgM only, and 6 had both IgM and IgG. Three of the seven confirmed human cases died among humans. Results from testing animal blood samples obtained from Kiruhura district indicated that 44% (64/146) cattle, 46% (35/76) goats, and 45% (9/20) sheep tested positive for RVF. Among wildlife, (1/10) zebras, (1/1) topi, and (1/1) impala tested positive for RVFV by serological tests. One blood sample from sheep in Kiboga district tested RVFV positive. All the human cases were exposed through contact or consumption of meat from infected animals. Conclusion: RVF outbreaks occurred in humans and animals in Kiruhura, Buikwe, Mityana, and Kiboga districts. Human cases were potentially infected through contact with infected animals and their products.


Assuntos
Surtos de Doenças , Febre do Vale de Rift , Animais , Surtos de Doenças/veterinária , Humanos , Febre do Vale de Rift/epidemiologia , Vírus da Febre do Vale do Rift/isolamento & purificação , Uganda/epidemiologia
2.
Nat Commun ; 12(1): 5593, 2021 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-34552082

RESUMO

The persistence mechanisms of Rift Valley fever (RVF), a zoonotic arboviral haemorrhagic fever, at both local and broader geographical scales have yet to be fully understood and rigorously quantified. We developed a mathematical metapopulation model describing RVF virus transmission in livestock across the four islands of the Comoros archipelago, accounting for island-specific environments and inter-island animal movements. By fitting our model in a Bayesian framework to 2004-2015 surveillance data, we estimated the importance of environmental drivers and animal movements on disease persistence, and tested the impact of different control scenarios on reducing disease burden throughout the archipelago. Here we report that (i) the archipelago network was able to sustain viral transmission in the absence of explicit disease introduction events after early 2007, (ii) repeated outbreaks during 2004-2020 may have gone under-detected by local surveillance, and (iii) co-ordinated within-island control measures are more effective than between-island animal movement restrictions.


Assuntos
Modelos Teóricos , Febre do Vale de Rift/prevenção & controle , Febre do Vale de Rift/transmissão , Vírus da Febre do Vale do Rift/fisiologia , Animais , Comores/epidemiologia , Gado/virologia , Febre do Vale de Rift/epidemiologia , Estudos Soroepidemiológicos , Zoonoses/epidemiologia , Zoonoses/prevenção & controle , Zoonoses/transmissão
3.
BMC Vet Res ; 17(1): 280, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34419043

RESUMO

BACKGROUND: Fourteen-years after the last Rift Valley fever (RVF) virus (RVFV) outbreak, Somalia still suffers from preventable transboundary diseases. The tradition of unheated milk consumption and handling of aborted materials poses a public health risk for zoonotic diseases. Limited data are available on RVF and Brucella spp. in Somali people and their animals. Hence, this study has evaluated the occurrence of RVFV and Brucella spp. antibodies in cattle, goats and sheep sera from Afgoye and Jowhar districts of Somalia. METHODS: Serum samples from 609 ruminants (201 cattle, 203 goats and 205 sheep), were serologically screened for RVF by a commercial cELISA, and Brucella species by modified Rose Bengal Plate Test (mRBPT) and a commercial iELISA. RESULTS: Two out of 609 (0.3 %; 95 %CI: 0.04-1.2 %) ruminants were RVF seropositive, both were female cattle from both districts. Anti-Brucella spp. antibodies were detected in 64/609 (10.5 %; 95 %CI: 8.2-13.2 %) ruminants by mRBPT, which were 39/201 (19.4 %) cattle, 16/203 (7.9 %) goats and 9/205 (4.4 %) sheep. Cattle were 5.2 and 2.8 times more likely to be Brucella-seropositive than sheep (p = 0.000003) and goats (p = 0.001), respectively. When mRBPT-positive samples were tested by iELISA, 29/64 (45.3 %; 95 %CI: 32.8-58.3 %) ruminant sera were positive for Brucella spp. Only 23/39 (58.9 %) cattle sera and 6/16 (37.5 %) goat sera were positive to Brucella spp. by iELISA. CONCLUSIONS: The present study showed the serological evidence of RVF and brucellosis in ruminants from Afgoye and Jowhar districts of Somalia. Considering the negligence of the zoonotic diseases at the human-animal interface in Somali communities, a One Health approach is needed to protect public health.


Assuntos
Brucella/isolamento & purificação , Brucelose/veterinária , Febre do Vale de Rift/epidemiologia , Vírus da Febre do Vale do Rift/isolamento & purificação , Animais , Brucelose/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Feminino , Doenças das Cabras/epidemiologia , Doenças das Cabras/microbiologia , Cabras , Estudos Soroepidemiológicos , Ovinos , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/microbiologia , Somália/epidemiologia , Zoonoses/epidemiologia
4.
Glob Health Action ; 14(1): 1957554, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34415237

RESUMO

BACKGROUND: Rift Valley Fever virus (RVFV) is a zoonotic arbovirus of public health impact infecting livestock, wildlife, and humans mainly in Africa and other parts of the world. Despite its public health importance, mechanisms of RVFV maintenance during interepidemic periods (IEPS) remain unclear. OBJECTIVE: We aimed to examine comparatively exposure to RVFV between humans and goats and RVFV infection between humans, goats and mosquitoes. METHODS: A cross sectional study was performed in the Lower Moshi area of the Kilimanjaro region from March to June 2020. RVFV exposure was determined by detecting IgG/IgM to RVFV using a competitive enzyme linked immunosorbent assay whereas infection was determined by real time quantitative polymerase chain reaction (RT-qPCR) assay. RESULTS: Results show that the male gender was related to RVFV seropositivity (χ2 = 5.351; p=0.030). Being 50 years and above was related to seropositivity (χ2 =14.430; p=0.006) whereas bed net use, larger numbers of persons living in the same house (>7 persons) and RVFV seropositivity in goats were related to higher seropositivity to RVFV among humans χ2 =6.003; p=0.021, χ2 =23.213; p < 0.001 and χ2 =27.053; p < 0.001), respectively. By the use of RT-qPCR, goats exhibited the highest RVFV infection rate of 4.1%, followed by humans (2.6%), Ae. aegypti (2.3%), and Cx. pipiens complex(1.5%). Likewise, a higher proportion of goats (23.3%) were RVFV seropositive as compared with humans (13.2%). CONCLUSION: Our findings suggest the Lower Moshi area as a potential hotspot for Rift Valley Fever (RVF), posing the danger of being a source of RVFV spread to other areas. Goats had the highest infection rate, suggesting goats as important hosts for virus maintenance during IEPs. We recommend the implementation of strategies that will warrant active RVF surveillance through the identification of RVF hotspots for targeted control of the disease.


Assuntos
Epidemias , Febre do Vale de Rift , Vírus da Febre do Vale do Rift , Animais , Anticorpos Antivirais , Estudos Transversais , Humanos , Masculino , Febre do Vale de Rift/epidemiologia , Estudos Soroepidemiológicos , Tanzânia/epidemiologia
5.
PLoS One ; 16(5): e0251263, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34010292

RESUMO

Rift Valley fever virus (RVFV), an arbovirus belonging to the Phlebovirus genus of the Phenuiviridae family, causes the zoonotic and mosquito-borne RVF. The virus, which primarily affects livestock (ruminants and camels) and humans, is at the origin of recent major outbreaks across the African continent (Mauritania, Libya, Sudan), and in the South-Western Indian Ocean (SWIO) islands (Mayotte). In order to be better prepared for upcoming outbreaks, to predict its introduction in RVFV unscathed countries, and to run efficient surveillance programmes, the priority is harmonising and improving the diagnostic capacity of endemic countries and/or countries considered to be at risk of RVF. A serological inter-laboratory proficiency test (PT) was implemented to assess the capacity of veterinary laboratories to detect antibodies against RVFV. A total of 18 laboratories in 13 countries in the Middle East, North Africa, South Africa, and the Indian Ocean participated in the initiative. Two commercial kits and two in-house serological assays for the detection of RVFV specific IgG antibodies were tested. Sixteen of the 18 participating laboratories (88.9%) used commercial kits, the analytical performance of test sensitivity and specificity based on the seroneutralisation test considered as the reference was 100%. The results obtained by the laboratories which used the in-house assay were correct in only one of the two criteria (either sensitivity or specificity). In conclusion, most of the laboratories performed well in detecting RVFV specific IgG antibodies and can therefore be considered to be prepared. Three laboratories in three countries need to improve their detection capacities. Our study demonstrates the importance of conducting regular proficiency tests to evaluate the level of preparedness of countries and of building a network of competent laboratories in terms of laboratory diagnosis to better face future emerging diseases in emergency conditions.


Assuntos
Febre do Vale de Rift/diagnóstico , África/epidemiologia , Animais , Anticorpos Antivirais/sangue , Doenças Endêmicas/veterinária , Ensaio de Imunoadsorção Enzimática/normas , Ensaio de Imunoadsorção Enzimática/estatística & dados numéricos , Ensaio de Imunoadsorção Enzimática/veterinária , Humanos , Imunoglobulina G/sangue , Oceano Índico/epidemiologia , Laboratórios/normas , Oriente Médio/epidemiologia , Garantia da Qualidade dos Cuidados de Saúde , Reprodutibilidade dos Testes , Febre do Vale de Rift/epidemiologia , Febre do Vale de Rift/imunologia , Vírus da Febre do Vale do Rift/imunologia , Fatores de Risco , Testes Sorológicos/normas , Testes Sorológicos/estatística & dados numéricos , Testes Sorológicos/veterinária
6.
BMC Vet Res ; 17(1): 157, 2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33849526

RESUMO

BACKGROUND: Prior to the first recorded outbreak of Rift Valley fever (RVF) in Uganda, in March 2016, earlier studies done until the 1970's indicated the presence of the RVF virus (RVFV) in the country, without any recorded outbreaks in either man or animals. While severe outbreaks of RVF occurred in the neighboring countries, none were reported in Uganda despite forecasts that placed some parts of Uganda at similar risk. The Ministry of Agriculture, Animal Industry and Fisheries (MAAIF) undertook studies to determine the RVF sero-prevalence in risk prone areas. Three datasets from cattle sheep and goats were obtained; one from retrospective samples collected in 2010-2011 from the northern region; the second from the western region in 2013 while the third was from a cross-sectional survey done in 2016 in the south-western region. Laboratory analysis involved the use of the Enzyme Linked Immunosorbent Assays (ELISA). Data were subjected to descriptive statistical analyses, including non-parametric chi-square tests for comparisons between districts and species in the regions. RESULTS: During the Yellow Fever outbreak investigation of 2010-2011 in the northern region, a total sero-prevalence of 6.7% was obtained for anti RVFV reacting antibodies (IgG and IgM) among the domestic ruminant population. The 2013 sero-survey in the western region showed a prevalence of 18.6% in cattle and 2.3% in small ruminants. The 2016 sero-survey in the districts of Kabale, Kanungu, Kasese, Kisoro and Rubirizi, in the south-western region, had the respective district RVF sero-prevalence of 16.0, 2.1, 0.8, 15.1and 2.7% among the domestic ruminants combined for this region; bovines exhibited the highest cumulative sero-prevalence of 15.2%, compared to 5.3 and 4.0% respectively for sheep and goats per species for the region. CONCLUSIONS: The absence of apparent outbreaks in Uganda, despite neighboring enzootic areas, having minimal restrictions to the exchange of livestock and their products across borders, suggest an unexpected RVF activity in the study areas that needs to be unraveled. Therefore, more in-depth studies are planned to mitigate the risk of an overt RVF outbreak in humans and animals as has occurred in neighboring countries.


Assuntos
Doenças dos Animais/epidemiologia , Febre do Vale de Rift/epidemiologia , Vírus da Febre do Vale do Rift/imunologia , Doenças dos Animais/virologia , Animais , Bovinos , Ensaio de Imunoadsorção Enzimática/veterinária , Cabras , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Prevalência , Vírus da Febre do Vale do Rift/isolamento & purificação , Estudos Soroepidemiológicos , Ovinos , Uganda/epidemiologia
7.
Trop Anim Health Prod ; 53(2): 195, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33666802

RESUMO

This study reports the monitoring of several emerging viral pathogens in Mauritania, which was carried out by the analysis of bovine and camel samples taken at the slaughterhouse of Nouakchott. Blood and serum were collected by random sampling from 159 camels and 118 cattle in March 2013 at the large animals abattoir in Nouakchott. Serological tests for Rift Valley Fever (RVF), Peste des Petits Ruminants (PPR), West Nile disease (WND), epizootic haemorrhagic disease (EHD) and African horse sickness (AHS) were carried out using commercial ELISA kits. The samples, which resulted positives for PPR, WND and AHS, were tested with the confirmatory virus neutralization test (VNT). According to ELISA results, serological prevalence of RVF was 45% (95% CI 52.3-37.7) in camels and 16% (95% CI 22.6-9.4) in cattle. The difference between the observed prevalences in camels and in cattle was significant (p value ≤ 0.01). PPR was absent in camels and had 12% prevalence (95% CI, 17.86-6.14) in cattle. Furthermore, camels showed 92% (95% CI, 96.1-87.9) prevalence of WNV, 73% (95% CI, 82.3-63.64) of EHD and 3% (95% CI, 5.6-0.4) of AHS. This data are of relevance since provided useful feedbacks on the circulation of the pathogens in field. Moreover, this survey provided new information on the susceptibility of camels to several emerging pathogens and on the possible use of this species as sentinel animal.


Assuntos
Matadouros , Camelus/virologia , Doenças dos Bovinos/epidemiologia , Viroses/veterinária , Doença Equina Africana/epidemiologia , Doença Equina Africana/virologia , Animais , Anticorpos Antivirais/análise , Anticorpos Antivirais/imunologia , Bovinos , Doenças dos Bovinos/virologia , Ensaio de Imunoadsorção Enzimática/veterinária , Vírus da Doença Hemorrágica Epizoótica/imunologia , Vírus da Doença Hemorrágica Epizoótica/isolamento & purificação , Mauritânia/epidemiologia , Vírus da Peste dos Pequenos Ruminantes/imunologia , Vírus da Peste dos Pequenos Ruminantes/isolamento & purificação , Febre do Vale de Rift/epidemiologia , Febre do Vale de Rift/virologia , Estudos Soroepidemiológicos , Viroses/epidemiologia , Viroses/virologia , Febre do Nilo Ocidental/epidemiologia , Febre do Nilo Ocidental/veterinária , Febre do Nilo Ocidental/virologia
8.
PLoS Negl Trop Dis ; 15(3): e0009202, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33684126

RESUMO

Rift Valley fever (RVF) is a vector-borne viral disease of major animal and public health importance. In 2018-19, it caused an epidemic in both livestock and human populations of the island of Mayotte. Using Bayesian modelling approaches, we assessed the spatio-temporal pattern of RVF virus (RVFV) infection in livestock and human populations across the island, and factors shaping it. First, we assessed if (i) livestock movements, (ii) spatial proximity from communes with infected animals, and (iii) livestock density were associated with the temporal sequence of RVFV introduction into Mayotte communes' livestock populations. Second, we assessed whether the rate of human infection was associated with (a) spatial proximity from and (b) livestock density of communes with infected animals. Our analyses showed that the temporal sequence of RVFV introduction into communes' livestock populations was associated with livestock movements and spatial proximity from communes with infected animals, with livestock movements being associated with the best model fit. Moreover, the pattern of human cases was associated with their spatial proximity from communes with infected animals, with the risk of human infection sharply increasing if livestock in the same or close communes were infected. This study highlights the importance of understanding livestock movement networks in informing the design of risk-based RVF surveillance programs.


Assuntos
Gado , Febre do Vale de Rift/epidemiologia , Animais , Comores/epidemiologia , Epidemias/veterinária , Humanos , Modelos Biológicos , Fatores de Risco , Zoonoses
9.
PLoS Negl Trop Dis ; 15(3): e0009275, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33770095

RESUMO

Camels are increasingly becoming the livestock of choice for pastoralists reeling from effects of climate change in semi-arid and arid parts of Kenya. As the population of camels rises, better understanding of their role in the epidemiology of zoonotic diseases in Kenya is a public health priority. Rift Valley fever (RVF), brucellosis and Q fever are three of the top priority diseases in the country but the involvement of camels in the transmission dynamics of these diseases is poorly understood. We analyzed 120 camel serum samples from northern Kenya to establish seropositivity rates of the three pathogens and to characterize the infecting Brucella species using molecular assays. We found seropositivity of 24.2% (95% confidence interval [CI]: 16.5-31.8%) for Brucella, 20.8% (95% CI: 13.6-28.1%) and 14.2% (95% CI: 7.9-20.4%) for Coxiella burnetii and Rift valley fever virus respectively. We found 27.5% (95% CI: 19.5-35.5%) of the animals were seropositive for at least one pathogen and 13.3% (95% CI: 7.2-19.4%) were seropositive for at least two pathogens. B. melitensis was the only Brucella spp. detected. The high sero-positivity rates are indicative of the endemicity of these pathogens among camel populations and the possible role the species has in the epidemiology of zoonotic diseases. Considering the strong association between human infection and contact with livestock for most zoonotic infections in Kenya, there is immediate need to conduct further research to determine the role of camels in transmission of these zoonoses to other livestock species and humans. This information will be useful for designing more effective surveillance systems and intervention measures.


Assuntos
Anticorpos Antibacterianos/sangue , Anticorpos Antivirais/sangue , Brucelose/epidemiologia , Camelus/microbiologia , Febre Q/epidemiologia , Febre do Vale de Rift/epidemiologia , Animais , Brucella/imunologia , Brucelose/transmissão , Coxiella burnetii/imunologia , Feminino , Humanos , Quênia/epidemiologia , Gado/microbiologia , Masculino , Febre Q/transmissão , Febre do Vale de Rift/transmissão , Vírus da Febre do Vale do Rift/imunologia , Estudos Soroepidemiológicos
10.
Comp Immunol Microbiol Infect Dis ; 75: 101620, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33609990

RESUMO

Rift Valley fever (RVF) is a disease caused by RVF virus (RVFV) which can cause infections in a range of wild and domestic ruminants as well as in humans and characterized by an increased incidence of abortion in ruminants. This study aims to survey the seroprevalence and risk factors of this zoonose among aborted sheep in Kurdistan province, the west of Iran. 182 blood samples were collected from aborted sheep during the past one month under age groups <1, ≥1-3, >3-5 year in four seasons in two groups of border and non-border cities of Kurdistan province. The presence of RVFV-specific Antibodies was investigated by using competitive ELISA. Indirect immunofluorescence assay (IIFA) was used to confirm positive samples, after separation of serum, as well as blood samples were analyzed for description of hematological parameters. Of a total sheep sampled 1.65 % (n = 3) were positive for RVFV antibodies in both test. The results of IIFA were correlated with the ELISA results. All of the positive samples showed leucopenia and had significant relation with seroprevalence of RVF (P < 0.05). The seroprevalence of RVF in the border cities were significantly higher than other group (P < 0.05) Age of sheep and season had no significant effect on prevalence of RVF (P > 0.05). Results obtained in this study indicated the presence of low-level RVFV circulation among the sheep of Kurdistan Province in Iran, so it is necessary to carry out further studies in other areas of Iran. Doing an epidemiologically study aimed at isolating RVFV in the ruminants of Kurdistan province is recommended. The risk factor of bordering with Iran's western neighbor (Iraq) requires seriously control of the exchange of animals and the relevant products between the two countries.


Assuntos
Doenças das Cabras , Febre do Vale de Rift , Doenças dos Ovinos , Animais , Anticorpos Antivirais , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Cabras , Irã (Geográfico)/epidemiologia , Gravidez , Febre do Vale de Rift/epidemiologia , Fatores de Risco , Estudos Soroepidemiológicos , Ovinos , Doenças dos Ovinos/epidemiologia
11.
Onderstepoort J Vet Res ; 88(1): e1-e5, 2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33567844

RESUMO

In this study, the serological surveillance of Rift Valley Fever virus (RVFV) in southern Egypt was carried out for 460 serum samples collected from domestic animals (unvaccinated), including cattle, sheep, goat, camel and donkey reared in three different provinces (Qena, Luxor and Aswan). Enzyme linked immunosorbent assay (ELISA) was used to detect RVFV antibodies. The results showed that 97 out of 460 animals were positive by using blocking ELISA. The percentage of RVFV infection in cattle, sheep, goat, camel and donkey was 5.55%, 65.21%, 14.44%, 20.65% and 0%, respectively. Geographical distribution and breeding system were taken into consideration for RVFV infection in these animals. The most prevalent type of infection was identified in intensive breeding farms systems (27.63%), and then in individual breeding systems (11.68%). Qena had a higher infection rate of RVFV (23.55%), in comparison to Aswan and Luxor (20.65% and 14.14%, respectively). Marked seroprevalence recorded in this study indicates a high incidence of infection in sheep (65.21%) and camel (20.65%); this necessitates the application of more effective strategies to control these types of infections in Egypt. This study provides a concise picture about the RVFV disease in southern Egypt. We need more similar studies targeted to clarify the reliable epidemiological status of RVFV disease in southern Egypt and other localities.


Assuntos
Doenças dos Bovinos , Doenças das Cabras , Febre do Vale de Rift , Vírus da Febre do Vale do Rift , Animais , Animais Domésticos , Anticorpos Antivirais , Bovinos , Doenças dos Bovinos/epidemiologia , Egito/epidemiologia , Ensaio de Imunoadsorção Enzimática/veterinária , Doenças das Cabras/epidemiologia , Febre do Vale de Rift/epidemiologia , Estudos Soroepidemiológicos , Ovinos
12.
J Virol ; 95(9)2021 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-33597209

RESUMO

The potential for emerging mosquito-borne viruses to cause fetal infection in pregnant women was overlooked until the Zika fever outbreak several years ago. Rift Valley fever virus (RVFV) is an emerging arbovirus with a long history of fetal infection and death in pregnant livestock. The effect of RVFV infection on pregnant women is not well understood. This Gem examines the effects that this important emerging pathogen has during pregnancy, its potential impact on pregnant women, and the current research efforts designed to understand and mitigate adverse effects of RVFV infection during pregnancy.


Assuntos
Surtos de Doenças , Complicações Infecciosas na Gravidez , Febre do Vale de Rift , Vírus da Febre do Vale do Rift/patogenicidade , Animais , Animais Domésticos/virologia , Feminino , Humanos , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/virologia , Febre do Vale de Rift/epidemiologia , Febre do Vale de Rift/virologia , Zoonoses Virais/epidemiologia
13.
Sci Rep ; 11(1): 1477, 2021 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-33446733

RESUMO

Rift Valley fever virus (RVFV) is a mosquito-borne bunyavirus that is pathogenic to ruminants and humans. The virus is endemic to Africa and the Arabian Peninsula where outbreaks are characterized by abortion storms and mortality of newborns, particularly in sheep herds. Vector competence experiments in laboratory settings have suggested that over 50 mosquito species are capable of transmitting RVFV. Transmission of mosquito-borne viruses in the field is however influenced by numerous factors, including population densities, blood feeding behavior, extrinsic incubation period, longevity of vectors, and viremia levels in vertebrate hosts. Animal models to study these important aspects of RVFV transmission are currently lacking. In the present work, RVFV was transmitted to European (Texel-swifter cross-breed) lambs by laboratory-reared Aedes aegypti mosquitoes that were infected either by membrane feeding on a virus-spiked blood meal or by feeding on lambs that developed viremia after intravenous inoculation of RVFV. Feeding of mosquitoes on viremic lambs resulted in strikingly higher infection rates as compared to membrane feeding. Subsequent transmission of RVFV from lamb to lamb by infected mosquitoes was highly efficient in both models. The animal models described here can be used to study mosquito-mediated transmission of RVFV among the major natural target species and to evaluate the efficacy of vaccines against mosquito-mediated RVFV infection.


Assuntos
Febre do Vale de Rift/epidemiologia , Febre do Vale de Rift/transmissão , Vírus da Febre do Vale do Rift/metabolismo , Aedes/virologia , Animais , Surtos de Doenças , Vetores de Doenças , Modelos Animais , Mosquitos Vetores/virologia , Vírus da Febre do Vale do Rift/patogenicidade , Carneiro Doméstico/virologia
14.
PLoS Negl Trop Dis ; 15(1): e0008100, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33493173

RESUMO

Information on zoonotic diseases in humans and livestock are limited in pastoral/agro-pastoral communities in Ethiopia. A multi-stage cross sectional cluster design study was implemented with the aim to establish the seroprevalence of zoonotic diseases including brucellosis, Q-fever and Rift Valley fever (RVF) in humans and livestock in Adadle Woreda of the Somali Region, Ethiopia. Blood samples were collected from humans and livestock and tested by relevant serological tests. For brucellosis, Rose Bengal test (RBT) and indirect ELISA was used for screening and confirmatory diagnosis respectively. Indirect and competitive ELISA were also used for Q-fever and RVF respectively. The individual seropositivity of Q-fever in livestock was 9.6% (95% CI 5.9-15.1) in cattle, 55.7% (95% CI 46.0-65.0) in camels, 48.8% (95% CI 42.5-55.0) in goats, and 28.9% (95% CI 25.0-33.2) in sheep. In humans, seropositivity of Q-fever was 27.0% (95% CI 20.4-34.0), with prevalence in males of 28.9% vs 24.2% in females (OR = 1.3; 95% CI 0.6-2.5). Camel seropositivity of Q-fever was significantly associated with age (OR = 8.1; 95% CI 2.8-23.7). The individual apparent seroprevalence of RVF was 13.2% (95% CI 8.7-18.8) in humans, 17.9% (95% CI 11.0-27.8) in cattle, 42.6% (95% CI 34.8-50.7) in camels, 6.3% (95% CI 3.3-11.6) in goats and 7.4% (95% CI 4.7-11.5) in sheep. Camels had the highest seropositivity of both Q-fever and RVF. Only a weak correlation was observed between human and livestock seropositivity for both Q-fever and RVF. Only cattle and camels were seropositive for brucellosis by iELISA. The individual seroprevalence of brucellosis was 2.8(0.9-6.4) in humans, 1.5% (95% CI 0.2-5.2) in cattle and 0.6% (95% CI 0.0-3.2) in camels. This study showed the importance of zoonoses in Somali Region and is the first published study to describe RVF exposure in humans and livestock in the country. Even though human exposure to RVF virus was reported, public health sector of Somali Region has not given attention to such zoonoses. Collaboration between public and animal health sectors for further investigation on these zoonoses using the One Health concept is indispensable.


Assuntos
Brucelose/epidemiologia , Gado , Febre Q/epidemiologia , Febre do Vale de Rift/epidemiologia , Adolescente , Adulto , Animais , Brucella , Bovinos , Estudos Transversais , Ensaio de Imunoadsorção Enzimática/veterinária , Etiópia/epidemiologia , Feminino , Doenças das Cabras/epidemiologia , Cabras , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Estudos Soroepidemiológicos , Ovinos , Doenças dos Ovinos/epidemiologia , Somália/epidemiologia , Inquéritos e Questionários , Adulto Jovem , Zoonoses/epidemiologia
15.
Trop Anim Health Prod ; 53(1): 92, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33415465

RESUMO

West Nile fever (WNF) and Rift Valley fever (RVF) are emerging and re-emerging zoonotic diseases of veterinary and public health importance in Africa. Despite the existence of potential vectors and a wide range of hosts, the transmission of these diseases in domestic animals has not been well documented in the South Omo area of Ethiopia. This study aimed to estimate the sero-prevalence of IgG antibodies produced against West Nile virus (WNV) and Rift Valley fever virus (RVFV) infections among cattle in the South Omo area. Between May and June 2019, blood samples were collected from 397 cattle and screened for IgG antibodies against WNV and RVFV infections using enzyme-linked immunosorbent assay (ELISA). The overall sero-prevalence of IgG antibody to WNV infection was 4.8% (95% CI: 2.67-6.88%), while it was 5.0% to RVFV infection (95% CI: 2.87-7.18). Compared to 1-3 years old cattle, those in the age group ≥ 7 years had significantly higher odds of being positive for WNV (AOR = 6.82; 95% CI: 1.72-26.99) and RVFV (AOR = 4.38; 95% CI: 1.08-17.88) infections. The occurrence of WNV and RVFV infections in cattle population in the present study area indicates the risk of transmission to humans. Strengthening the surveillance system and conducting further studies to identify active cases in domestic and wild animals as well as in humans is crucial to reduce the risk of possible outbreaks.


Assuntos
Doenças dos Bovinos/epidemiologia , Febre do Vale de Rift/epidemiologia , Vírus da Febre do Vale do Rift/fisiologia , Febre do Nilo Ocidental/veterinária , Vírus do Nilo Ocidental/fisiologia , Criação de Animais Domésticos , Animais , Bovinos , Doenças dos Bovinos/virologia , Etiópia/epidemiologia , Prevalência , Febre do Vale de Rift/virologia , Estudos Soroepidemiológicos , Febre do Nilo Ocidental/epidemiologia , Febre do Nilo Ocidental/virologia
16.
Emerg Infect Dis ; 27(2): 653-655, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33496248

RESUMO

The epidemiology of Rift Valley fever virus (RVFV) and Crimean-Congo hemorrhagic fever virus (CCHFV) in Jordan is unknown. Our investigation showed 3% of 989 tested dairy cattle, sheep, and goats were RVFV seropositive and 14% were CCHFV seropositive. Ongoing surveillance is needed to assess risk to humans and protect public health.


Assuntos
Vírus da Febre Hemorrágica da Crimeia-Congo , Febre Hemorrágica da Crimeia/epidemiologia , Febre do Vale de Rift/epidemiologia , Vírus da Febre do Vale do Rift , Animais , Anticorpos Antivirais , Bovinos , Vírus da Febre Hemorrágica da Crimeia-Congo/imunologia , Febre Hemorrágica da Crimeia/veterinária , Jordânia/epidemiologia , Vírus da Febre do Vale do Rift/imunologia , Ruminantes , Ovinos , Zoonoses
17.
Transbound Emerg Dis ; 68(3): 1229-1239, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32767820

RESUMO

Numerous infectious diseases impacting livestock impose an important economic burden and in some cases also represent a threat to humans and are classified as zoonoses. Some zoonotic diseases are transmitted by vectors and, due to complex environmental and socio-economic factors, the distribution of many of these pathogens is changing, with increasing numbers being found in previously unaffected countries. Here, we developed a multiplex assay, based on a suspension microarray, able to detect specific antibodies to five important pathogens of livestock (three of them zoonotic) that are currently emerging in new geographical locations: Rift Valley fever virus (RVFV), Crimean-Congo haemorrhagic fever virus (CCHFV), Schmallenberg virus (SBV), Bluetongue virus (BTV) and the bacteria complex Mycobacterium tuberculosis. Using the Luminex platform, polystyrene microspheres were coated with recombinant proteins from each of the five pathogens. The mix of microspheres was used for the simultaneous detection of antibodies against the five corresponding diseases affecting ruminants. The following panel of sera was included in the study: 50 sera from sheep experimentally infected with RVFV, 74 sera from calves and lambs vaccinated with SBV, 26 sera from cattle vaccinated with Mycobacterium bovis, 30 field sera from different species of ruminants infected with CCHFV and 88 calf sera infected with BTV. Finally, to determine its diagnostic specificity 220 field sera from Spanish farms free of the five diseases were assessed. All the sera were classified using commercial ELISAs specific for each disease, used in this study as the reference technique. The results showed the multiplex assay exhibited good performance characteristics with values of sensitivity ranging from 93% to 100% and of specificity ranging from 96% to 99% depending on the pathogen. This new tool allows the simultaneous detection of antibodies against five important pathogens, reducing the volume of sample needed and the time of analysis where these pathogens are usually tested individually.


Assuntos
Anticorpos Antibacterianos/sangue , Anticorpos Antivirais/sangue , Mycobacterium tuberculosis/imunologia , Infecções por Vírus de RNA/veterinária , Vírus de RNA/imunologia , Ruminantes/imunologia , Testes Sorológicos/veterinária , Tuberculose/veterinária , Animais , Vírus Bluetongue/imunologia , Bovinos , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/epidemiologia , Ensaio de Imunoadsorção Enzimática/veterinária , Vírus da Febre Hemorrágica da Crimeia-Congo/imunologia , Infecções por Vírus de RNA/diagnóstico , Infecções por Vírus de RNA/epidemiologia , Febre do Vale de Rift/diagnóstico , Febre do Vale de Rift/epidemiologia , Vírus da Febre do Vale do Rift/imunologia , Ruminantes/virologia , Ovinos/imunologia , Doenças dos Ovinos/diagnóstico , Doenças dos Ovinos/epidemiologia , Tuberculose/diagnóstico , Tuberculose/epidemiologia , Zoonoses
18.
Transbound Emerg Dis ; 68(2): 445-457, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32568445

RESUMO

Rift Valley fever (RVF) is a mosquito-borne zoonotic disease. Since its first outbreak in 1930, RVF epidemics have caused huge economic losses and public health impacts in Africa. In 2000, RVF became a disease of global concern as it spread to the Arabian Peninsula. In our study, a Geographic Information System-based risk assessment for the occurrence of Rift Valley fever in China was established by means of ecological niche modelling. Based on occurrence records (RVF records from FAO EMPRES-i, vector records from literatures and GBIF) and high-resolution environmental layers, the prediction maps of RVF occurrence probability and distribution of five potential RVF vectors in China were modelled using Maxent. An internal validation was adopted for model verification, and high AUC values were obtained (0.918 for RVF and 0.837-0.992 for vectors). By overlaying the RVF prediction map with the combined RVF vector prediction map using Fuzzy overlay tool ('AND' operator) of ArcMap 10.2, we got the first risk map of possible RVF vector transmission. This map was further overlaid with the latest livestock distribution map ('AND' operator) to generate the second risk map of possible RVF threat to domestic livestock. The south-west border provinces in China, Yunnan, Guangxi and Tibet were predicted to have a high possibility of RVF occurrence. Conditions conducive to the local amplification of RVF also exist in these areas. Temperature seasonality, mean temperature of dry season and precipitation of the driest month were considered as key environmental variables for RVF, and common environmental conditions were found conductive for vectors. It is suggested to establish proper surveillance systems in south-west border areas to minimize the possibility of RVF invasion. Our findings can serve as a valuable reference for prevention measures to be implemented.


Assuntos
Febre do Vale de Rift/epidemiologia , Animais , China/epidemiologia , Culicidae , Surtos de Doenças/prevenção & controle , Vetores de Doenças , Ecossistema , Epidemias , Humanos , Mosquitos Vetores , Vírus da Febre do Vale do Rift , Medição de Risco , Estações do Ano , Tibet
19.
J Virol Methods ; 287: 114003, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33164863

RESUMO

The last major Rift Valley fever outbreak in South Africa was between 2008 and 2011. Viruses isolated between 2008 and 2010 were phylogenetically assigned to Lineage C, Lineage K and the novel lineage H. The 2011 outbreaks occurred primarily in the Eastern, Western and Northern Cape provinces, with no sequence data or phylogenetic relationship published. Samples from these outbreaks were submitted to the Faculty of Veterinary Sciences, University of Pretoria, for immunohistochemical confirmation of Rift Valley fever phlebovirus presence. These samples were formalin-fixed and paraffin-embedded (FFPE) and stored at the Pathology section for several years. This study describes a modified extraction method used to obtain RNA from the FFPE samples, as well as the primer combinations used to phylogenetically classify them as belonging to the novel lineage H.


Assuntos
Febre do Vale de Rift , Vírus da Febre do Vale do Rift , Animais , Surtos de Doenças , Formaldeído , Inclusão em Parafina , Filogenia , Estudos Retrospectivos , Febre do Vale de Rift/epidemiologia , Vírus da Febre do Vale do Rift/genética , África do Sul/epidemiologia
20.
Viruses ; 12(12)2020 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-33339456

RESUMO

Outbreaks of Rift Valley fever (RVF) occurred in Namibia in 2010 and 2011. Complete genome characterization was obtained from virus isolates collected during disease outbreaks in southern Namibia in 2010 and from wildlife in Etosha National Park in 2011, close to the area where RVF outbreaks occurred in domestic livestock. The virus strains were sequenced using Sanger sequencing (Namibia_2010) or next generation sequencing (Namibia_2011). A sequence-independent, single-primer amplification (SISPA) protocol was used in combination with the Illumina Next 500 sequencer. Phylogenetic analysis of the sequences of the small (S), medium (M), and large (L) genome segments of RVF virus (RVFV) provided evidence that two distinct RVFV strains circulated in the country. The strain collected in Namibia in 2010 is genetically similar to RVFV strains circulating in South Africa in 2009 and 2010, confirming that the outbreaks reported in the southern part of Namibia in 2010 were caused by possible dissemination of the infection from South Africa. Isolates collected in 2011 were close to RVFV isolates from 2010 collected in humans in Sudan and which belong to the large lineage containing RVFV strains that caused an outbreak in 2006-2008 in eastern Africa. This investigation showed that the RVFV strains circulating in Namibia in 2010 and 2011 were from two different introductions and that RVFV has the ability to move across regions. This supports the need for risk-based surveillance and monitoring.


Assuntos
Variação Genética , Febre do Vale de Rift/epidemiologia , Febre do Vale de Rift/virologia , Vírus da Febre do Vale do Rift/genética , Animais , Surtos de Doenças , Genoma Viral , Genômica/métodos , História do Século XXI , Itália/epidemiologia , Gado , Namíbia , Filogenia , Febre do Vale de Rift/história
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