Refinar búsqueda
Resultados 1-10 de 40
Antibody response to Raboral VR-G® oral rabies vaccine in captive and free-ranging black-backed jackals (Canis mesomelas)
2022
Koeppel,Katja N. | Geertsma,Peter | Kuhn,Brian F. | van Schalkwyk,Ockert L. | Thompson,Peter N.
Rabies is a zoonotic disease that remains endemic in large parts of southern Africa because of its persistence in wildlife and domestic dog vectors. The black-backed jackals (Canis mesomelas) is primarily the wildlife vector responsible for rabies outbreaks in northern parts of South Africa. Two trials were carried out to investigate antibody responses to the oral rabies vaccine Raboral V-RG® in black-backed jackals under captive and free-ranging conditions. In captive jackals 10/12 (83%; 95% confidence interval [CI]: 52% - 98%), seroconverted after single oral vaccination. Nine captive jackals had protective antibody titres (> 0.5 IU/mL) at 4 weeks (median: 2.1 IU/mL; inter quartile range [IQR]: 0.6-5.7) and 10 jackals had at 12 weeks (median: 3.5 IU/mL; IQR: 1.5-8.3) and three maintained antibody titres for up to 48 weeks (median: 3.4 IU/mL; IQR: 2.0-6.3). Four sites were baited with Raboral V-RG® vaccine for wild jackals, using fishmeal polymer and chicken heads. Baits were distributed by hand or from vehicle at three sites in north-eastern South Africa, with an average baiting density of 4.4 baits/km² and at one site in central South Africa, at 0.12 baits/km². This resulted in protective antibody titres in 3/11 jackals (27%; 95% Cl: 6-61) trapped between 3 and 12 months after baiting in north-eastern South Africa, compared with 4/7 jackals (57%; 95% Cl: 18-90) trapped after 3-18 months in central South Africa. This study shows the potential utility of oral rabies vaccination for the control of wildlife-associated rabies in north-eastern and central South Africa, but extensive studies with wider distribution of bait are needed to assess its potential impact on rabies control in wild jackals.
Mostrar más [+] Menos [-]Predictive risk model of livestock rabies occurrence in Peru
2021
Ricardo Augusto Dias | Francisco Miroslav Ulloa-Stanojlovic
Livestock rabies is endemic in Peru. Hence, its persistence and annual dissemination represent an important economic impact, especially for impoverished farming communities. The disease is mostly transmitted by the hematophagous bat Desmodus rotundus. The present study aimed to adapt an existing predictive model of the occurrence of livestock rabies to Peru, in which the risk of rabies transmission from bats to livestock was estimated using decision-tree models of receptivity and vulnerability. Official rabies surveillance data between 2010 and 2015 were used along with possible risk factors, such as livestock biomass, environmental changes, and geomorphological characteristics. Several scenarios were established to evaluate the prediction of the occurrence of livestock rabies cases by determining more than one cut-off point of the receptivity variables. During the study period, the precision of the model was estimated through the sensitivity (39.46%) and specificity (98.64%) by using confusion matrices. Targeting control efforts, especially in districts with a high estimated risk, could represent the prevention of a significant proportion of livestock rabies cases, which would optimize the human and economic resources of the Peruvian surveillance service. However, the quality of data produced by the surveillance should be improved not only to obtain higher model precision but also to allow the adequate planning of control actions.
Mostrar más [+] Menos [-]Vaccine-induced rabies in a red fox in Poland
2022
Smreczak Marcin | Orłowska Anna | Müller Thomas | Freuling Conrad M. | Kawiak-Sadurska Magdalena | Trębas Paweł
Rabies as a zoonosis threatens public health worldwide. Several thousand people die each year of infections by the rabies virus (RABV). Oral rabies vaccination (ORV) of wildlife was successfully implemented in many European countries and led to rabies being brought under control there. In Poland, ORV was introduced in 1993 using vaccines containing an attenuated strain of the rabies virus. However, attenuated rabies viruses may have residual pathogenicity and cause the disease in target and non-target animals.
Mostrar más [+] Menos [-]Apoptosis in natural rabies virus infection in dogs
2016
Vural Sevil Atalay | Bozkurt Mehmet Fatih | Ozkara Ali | Alcigir Mehmet Eray | Ilhan Fatma Sayin
Introduction: In the present study apoptosis was investigated in the cornu ammonis and cerebellum of 10 dogs naturally infected with rabies virus. Diagnosis of rabies was based on the results of fluorescent antibody staining and experimental inoculation.
Mostrar más [+] Menos [-]Comparison of Adjuvant Efficacy of Different Molecular Weights of Chitosan and Aluminum Hydroxide for Inactivated Rabies Vaccine
2013
Amani A. Saleh
The development of safe, novel adjuvant is necessary to maximize the efficacy of new and/or available vaccines. In this study, three different molecular weights of chitosan (low, medium, high) were evaluated as immunopotentiators/adjuvants of inactivated rabies vaccine in white Norway rats as an experimental model. Two concentrations (1.5% & 3% w/v) of each chitosan type were used in final concentration 5 mg/ml and 10 mg/ml. Results showed that lymphocyte proliferationwere significantly elevated (P < 0.05) in all chitosan vaccinated rats compared to aluminum hydroxide gel vaccinated one. All three type of chitosan produced accelerated and enhanced effects on rabies-neutralizing antibody responses in vaccinated groups. Increases in antibody titers together with lymphocytes proliferation responses revealed that chitosan induced both humoral and cell-mediated immune responses. When compared with aluminum hydroxide vaccineadjuvant, chitosan was superior to aluminum hydroxide. The conclusion of these results suggested that chitosan with different MW had a strong potential to increase both cellular and humoral immune responses and that chitosan may be a promising and efficacious adjuvant candidate suitable for inactivated rabies vaccine.
Mostrar más [+] Menos [-]Preparation of an inactivated penta cell culture vaccine against canine distemper, canine parvo, canine hepatitis "canine adeno-1", canine adeno-2 and rabies viruses for dogs
2005
Naglaa I. Aly | Zeinab T. S. Salama
A penta-dog inactivated cell culture vaccine was prepared to protect dogs againstcanine distemper virus, canine parvovirus, canine adenovirus1, 2 and rabies virus.The potency of this vaccine was compared with that of single inactivated vaccinesprepared against each disease, in different groups of susceptible dogs. It was foundthat the protective dose of penta-dog vaccine (2ml) including the protective amounts of the five viral proteins resulted in full protection of vaccinated dogs against the challenge with virulent strain of the used viruses showing no antagonizing effect between each other with and no adverse postvaccinal reaction. So, the prepared inactivated cell culture penta-dog vaccine is a safe and potent vaccine for dogs which resulted in saving time, cost, and effort stress factors on animals and providing good immune statues.
Mostrar más [+] Menos [-]The effect of Rabies Infection and Vaccination on Pregnancy in Rats as Animal Model
2013
Amani, A. Saleh | A. F. Soliman | A. M. Albehwar | M. B. Shendy
The effect of rabies infection and vaccination on pregnancy was investigated in different groups of pregnant rats as an animal model. Intracerebral and intramuscular experimental infection with CVS rabies virus strain was applied on four pregnant rats groups at the middle (seven days after mating) and late stages of gestation (14 days after mating). Subcutaneous rout vaccination of other three pregnant rat groups five to seven days before; seven and 14 days after mating with the inactivated cell culture local rabies vaccine. Each group of infected rats showed clinical signs of rabies although their fetuses did not show any abnormalities. Virus recovery from the placenta and fetuses from dead and sacrificed animals failed to induce rabies signs in mice inoculated intracerebrally with placenta and fetus suspensions while brains of infected dams; through the routes; revealed positive FA by using fluorescent antibody technique. Vaccinated pregnant rats did not show any abnormalities with normal fetuses and good levels of specific rabies antibodies when estimated by serum neutralization test. These findings indicate that rabies vaccination of pregnant animals is safe and it could be recommended to protect both of dams and their offspring in the first months.
Mostrar más [+] Menos [-]Preparation of inactivated tissue culture rabies vaccine adjuvanted with natural immune stimulants
2005
H. M. Madbouly | A. M. Nour El-Dien | Boseila A. H. Abeer
The challenge virus standard (CVS-11) strain of fixed rabies virus was propagatedin weaning mice brains and in suckling mice brains. It was also propagated on babyhamster kidney cell line (BHK-21) with use of diethylaminoethyl-dextran (DEAEDextran). These passages were titerated in 3-4 weeks old white Swiss mice using mouse inoculation test (MIT). The virus harvest was concentrated using zinc acetate method , inactivated by beta-propiolactone (BPL) and adjuvanted with combination of vitamin E and selenium. The prepared adjuvanted inactivated tissue culture rabies vaccine was subjected to quality control tests as safety, sterility and potency using National Institute of Health (NIH) test against reference vaccine.
Mostrar más [+] Menos [-]Apoptosis in natural rabies virus infection in dogs
2016
Vural, Sevil Atalay | Bozkurt, Mehmet Fatih | Ozkara, Ali | Alcigir, Mehmet Eray | Ilhan, Fatma Sayin
Introduction: In the present study apoptosis was investigated in the cornu ammonis and cerebellum of 10 dogs naturally infected with rabies virus. Diagnosis of rabies was based on the results of fluorescent antibody staining and experimental inoculation.Material and Methods: The paraffin tissue sections were stained with haematoxylin and eosin, avidin-biotin complex peroxidase (ABC-P), and terminal deoxynucleotidyl transferase biotin-dUTP nick end-labelling (TUNEL) methods.Results: Histopathological examination revealed encephalomyelitis of varying severity and the presence of Negri bodies. Dense rabies antigens were determined in the motor neurons with ABC-P method. On the other hand, Bcl-2 protein and Bax protein gave positive reaction in seven and five cases, respectively. TUNEL staining demonstrated very marked apoptotic changes in the nuclei of neurons localised deep in the substantia alba of the cerebellum. Similar changes were also determined in perivascular mononuclear cells and glia cells within the substantia alba. No apoptopic changes were found in the motor neurons of the cornu ammonis.Conclusion: The absence of apoptotic changes in the neurons was considered to be the consequence of the necrotic changes that developed in these neurons.
Mostrar más [+] Menos [-]Determination of the rabies virus variants circulating in Poland in 2021–2023 and their phylogeny with analysis of the strains in the Mazowieckie and Podkarpackie voivodeships
2024
Ciołek Janusz | Orłowska Anna | Smreczak Marcin
Rabies is endemic in Europe and red foxes are the vector and reservoir of the rabies virus (RABV). Based on classification established in the early 1990s, four variants of the rabies virus have been distinguished in Europe. Rabies broke out in January 2021 in the Mazowieckie voivodeship in central north-eastern Poland. The virus spread rapidly, reaching the Świętokrzyskie voivodeship in the central southern part and the Lubelskie voivodeship in the eastern part in the next months. Nine rabies cases were reported in the Podkarpackie voivodeship in south-eastern Poland between 2021 and 2023, mainly in red foxes but also in dogs and wildcat. The aim of the study was the identification of RABV variants in wildlife and domestic animals in Poland between 2021 and 2023.
Mostrar más [+] Menos [-]