Determination of Antiviral Activity
Adorjan Aszalos in Modern Analysis of Antibiotics, 2020
A generalized statement can be made regarding essentially all the group A and B arboviruses, and that is that they will induce a fatal encephalitis in a variety of laboratory animals, but especially the mouse when injected intracerebrally. Younger mice are usually more susceptible than the adult animal. Peripheral exposure, including intranasal instillation, will often also produce a CNS-associated illness. With several of the viruses (such as yellow fever virus), some adaptation to the animal is required before reproducible infections occur. This adaptation is accomplished by successive passage of the virus through the brain of the animal [277]. Examples of chemotherapy experiments with these viruses include reports by Odelola [278] using West Nile virus in mice, Stephen et al. [256] using Chikungunya virus infections in monkeys and yellow fever virus and Venezuelan equine encephalitis virus infections of mice, Bauer and Sadler [279] with Semliki Forest, dengue, and less known arboviruses in mice, Mizuma et al. [280] using Japanese encephalitis in mice, Kramer et al. [281] using St. Louis encephalitis in mice, and Gresikova et al. [282] with tick-borne encephalitis in mice.
Arthropod-borne virus encephalitis
Avindra Nath, Joseph R. Berger in Clinical Neurovirology, 2020
Although Japanese encephalitis is undoubtedly the most widespread destructive arbovirus encephalitis, afflicting tens of thousands of people annually in Asia, this section will start with Venezuelan equine encephalitis which can also afflict tens of thousands of people as well as horses in South and Central America and Mexico. Outbreaks of Venezuelan equine encephalitis are typically separated by several years or decades. A very large number of people are afflicted by the Central European, or milder, form of tick-borne encephalitis, and an unknown number in the former Soviet Union by the severe Far Eastern form of Russian spring–summer tick-borne encephalitis. Other arboviral encephalitides discussed in this section are Murray Valley encephalitis of Australia and Rift Valley fever, which, in the past two decades, has become a broader geographic threat than simply east Africa.
Encephalitis: what it is and what it does
Ava Easton in Life After Encephalitis, 2016
Some forms of encephalitis are preventable. For example tick-borne encephalitis and Japanese encephalitis are vaccine-preventable. Travellers, in particular those from many Western countries, have access to vaccinations via their health services or travel clinics, if they are travelling to areas where these types of encephalitis may be endemic, particularly rural areas. Despite this an increasing number of people are travelling to what they consider ‘harmless’ locations such as Austria, Sweden and Switzerland for walking holidays without considering vaccination against tick-borne encephalitis (www.encephalitis.info/files/8813/8694/8907/Putting_Tick-borne_Diseases_on_the_Map.pdf, accessed 9 July 2015). Vaccination programmes can dramatically drive down incidence in endemic countries. However, in resource-poor countries where, for example, Japanese encephalitis is prevalent, delivering vaccination programmes to indigenous populations can prove challenging (Michael and Solomon, 2012). In addition many environmental prevention measures can be taken such as using sprays to deter vectors (ticks and mosquitoes), using mosquito nets and full clothing protection, and in other instances such as rabies encephalitis, avoiding engagement with animals such as dogs and bats.
Low prevalence of tick-borne encephalitis virus antibodies in Norwegian blood donors
Published in Infectious Diseases, 2021
Åshild Marvik, Yngvar Tveten, Anne-Berit Pedersen, Karin Stiasny, Åshild Kristine Andreassen, Nils Grude
Tick-borne encephalitis (TBE) is one of the most important tick-borne diseases in Europe and Asia [1–4]. The causative agent, tick-borne encephalitis virus (TBEV), is neurotropic and consists of three subtypes described according to their main distribution area: European (TBEV-Eu), Far-Eastern (TBEV-FE) and Siberian subtype (TBEV-Sib) [5]. Three other subtypes of TBEV, TBEV Baikalian (TBEV 886-84), TBEV 178-179 and TBEV Himalayan have also been suggested [6–9]. TBE is a zoonotic disease and transmission to humans is mainly due to tick bites and only a minor extent due to the alimentary route through infected dairy products [1,4,10]. Ticks and small rodents constitute the reservoirs for TBEV. Ixodes ricinus is the principal vector for TBEV-Eu and occurs in large parts of Europe. Ixodes persulcatus, the vector for the Far-Eastern and Siberian subtypes, occurs in Eastern Europe, Siberia and far east including Japan [2]. Thus, in Europe, human disease caused by TBEV-Eu predominates [2,3,11].
Rapid travel to a Zika vaccine: are we heading towards success or more questions?
Published in Expert Opinion on Biological Therapy, 2018
Carl Britto, Christina Dold, Arturo Reyes-Sandoval, Christine S. Rollier
Serological approaches also serve to inform another aspect of vaccine development namely correlates of protection. A correlate of protection is important though not mandatory for initial WHO pre-qualification and recommendation by the strategic advisory group of experts (SAGE) committee for immunization. A correlate of protection will also help with licensure of future vaccine candidates based on non-inferior immunogenicity. The correlates of protection may be in the form of neutralizing antibodies as are seen with yellow fever and Japanese encephalitis vaccines. Total binding antibody responses and neutralizing antibodies are correlates for the tick-borne encephalitis vaccine [30]. It is thus important to delineate a correlate of protection for ZIKV infection in order to ensure a strong future for ZIKV vaccine development and deployment. Neutralizing antibodies generated in humans, as well as non-human primates and subsequently administered to ZIKV infected mice models demonstrated protection, and while the requirement for protection in non-human primate is estimated to be log 2.0–2.1 [46–48], but it remains to be determined what the protective titers are in humans exposed to ZIKV and whether there in waning of neutralizing antibody titers over time.
Role of environmental factors in multiple sclerosis
Published in Expert Review of Neurotherapeutics, 2021
Amin Zarghami, Ying Li, Suzi B. Claflin, Ingrid van der Mei, Bruce V. Taylor
Interestingly, there is some evidence to suggest that some vaccinations may be protective against MS onset. A 2019 case-control study (12,262 MS cases/79,185 controls) demonstrated that HBV vaccination was associated with a reduced MS onset risk (OR:0.84; 95%CI: 0.72–0.97) [220]. Similarly, a 2011 meta-analysis (n = 3 studies on diphtheria vaccination; n = 8 studies on tetanus vaccination) suggested that the diphtheria and tetanus vaccines may be associated with decreased risk of MS onset (Table 1) [218]. A 2006 meta-analysis (n = 9) found that getting a tetanus vaccination in the 5 years before the first MS symptom was protective against MS onset and dose-responsive [221]. Finally, a 2019 case-control study (12,262 MS cases) found that tick-borne encephalitis (TBE) vaccination in the 5 years before diagnosis was associated with a decreased risk of MS onset (OR:0.90; 95%CI:0.84–0.96) [220].
Related Knowledge Centers
- Central Nervous System
- Encephalitis
- Meningitis
- Meningoencephalitis
- Myelitis
- Sequela
- Virus
- Zoonosis
- Infection
- Tick-Borne Encephalitis Virus