Encephalitis and Its Mimics in the Critical Care Unit
Cheston B. Cunha, Burke A. Cunha in Infectious Diseases and Antimicrobial Stewardship in Critical Care Medicine, 2020
The initial presentation of these infections is often unimpressive—typically much less dramatic than that of meningitis, where infection of the brain lining causes severe pain, sensitivity to light and sound, and reflex protective neck stiffness. The meninges and cortical blood vessels have nociceptive receptors, so inflammation is painful; the brain itself has no nociceptors. Fever, often low grade, is common—but less so in the very young, the elderly and the immunocompromised. Neurologic changes are often initially limited to subtle alterations of consciousness or cognition—easily confused with the mild changes typically seen as a non-specific result of systemic infection. Specific etiologic agents may cause more specific symptoms. Enteroviruses and Listeria often cause prominent associated gastrointestinal symptoms. Some arboviruses similarly can present with GI or other non-localizing symptoms.
Hyperkinetic Movement Disorders
Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw in Hankey's Clinical Neurology, 2020
Infectious or postinfectious SSPE.Arbovirus encephalitis.Herpes simplex encephalitis.Human T-lymphotropic virus 1.Whipple's disease.West Nile virus encephalitis.Postinfectious encephalopathy.Progressive multifocal leukoencephalopathy.
The Parasite's Way of Life
Eric S. Loker, Bruce V. Hofkin in Parasitology, 2023
A biological vector is one in which the parasite either develops or reproduces or both. A biological vector itself, unlike a mechanical vector, is infected with a specific parasite. Wuchereria bancrofti and other filarial worms, for instance, undergo essential larval molts within their mosquito vector but do not increase in number. This is an example of what is called cyclodevelopmental transmission. Arboviruses (a non-taxonomic term describing any virus transmitted by arthropods), on the other hand, including dengue virus and yellow fever virus, multiply greatly within mosquitoes but undergo no specific developmental progression. This phenomenon is known as propagative transmission. Finally, parasites that pass through required development and multiplication within their vectors are exhibiting cyclopropagative transmission. Malaria parasites in the genus Plasmodium, utilizing mosquito biological vectors are an example.
West Nile virus and other mosquito-borne viruses present in Eastern Europe
Published in Pathogens and Global Health, 2018
Sebastián Napp, Dusan Petrić, Núria Busquets
Arthropod-borne viruses (arboviruses) are a group of viruses that are transmitted by arthropod vectors and cause disease in humans and animals. Therefore, disease occurrence relies on the presence of the virus, susceptible hosts and competent vectors. Diseases caused by arboviruses have been reported for centuries, but in the recent years, the notification of outbreaks of arboviral diseases has dramatically increased [1]. Human population growth, deforestation, urbanization, movement of people, animals and vectors have contributed to dissemination of arboviruses. The impact of climate change on vector-borne diseases is controversial since it can influence arthropod vectors abundance and virus transmission in different ways. In fact, the effects of the climate are considered species-specific and location-specific [2]. Some arboviruses that had been neglected for a long time, have emerged in the last decades as important health threats, for example Zika virus (ZIKV) in South and Central America [3], Yellow fever virus (YFV) in Brazil [4] and West Nile virus (WNV) lineage 2 in Southern and Eastern Europe [5]. Nowadays arboviruses have a worldwide distribution, being present in all continents except Antarctica. However, each arbovirus will generally have a focal distribution because of its specific requirements in relation to vertebrate hosts, vectors and ecological factors needed to maintain its transmission cycle [1].
Prevalence and identification of arthropod-transmitted viruses in Kassala state, Eastern Sudan
Published in Libyan Journal of Medicine, 2019
Nahla Mohamed, Mamoun Magzoub, Rania El Hadi Mohamed, Fadilah Sfouq Aleanizy, Fulwah Y. Alqahtani, Bakri Y. M. Nour, Mubark M.S. Alkarsany
Dengue, yellow fever, chikungunya, Rift Valley fever, alkhurma haemorrhagic fever, and Sindbis viruses have been reported in more than 34 countries in sub-Saharan Africa and Middle East [10–14]. YFV originated in Africa and spread with the slave trade dating back to at least 1650 [15,16]. Majority of populations infected with arboviruses have mild disease and recover rapidly, except dengue and Rift Valley fever differ in severity; based on several studies in different locations in Sudan such as northern Khartoum and New Halfa Hospital in eastern region [17–19]. The clinical characteristics and symptoms of most of arboviruses are divided into two subgroups: neuroinvasive and non-neuroinvasive. Mostly are asymptomatic and often resolve after 1–2 weeks. The clinical symptoms usually were common include sudden onset of fever, headache, muscle pain, backache, general weakness, red eyes, nausea, and vomiting, lasting 2–4 days usually followed by uneventful recovery. However, the most clinical signs and symptoms of arbovirus infections are non-specific in nature and could be interfere with other parasitic or non-parasitic infections such as malaria or bacterial meningitis. Most of arbovirus infections could be seriously severe, resulting in haemorrhage, high fever, encephalitis, meningitis, or even death [20].
Cytokine release syndrome in COVID-19: a major mechanism of morbidity and mortality
Published in International Reviews of Immunology, 2022
Yifan Que, Chao Hu, Kun Wan, Peng Hu, Runsheng Wang, Jiang Luo, Tianzhi Li, Rongyu Ping, Qinyong Hu, Yu Sun, Xudong Wu, Lei Tu, Yingzhen Du, Christopher Chang, Guogang Xu
Excessive cytokine release can also result from a phenomenon called antibody dependent enhancement (ADE) [40]. This phenomenon was first observed with arboviruses in 1964 and has been observed in multiple viral illnesses including flaviviruses such as Dengue. ADE results from the presence of cross-reactive or low levels of non-neutralizing antibodies to the virus, whereby the antibody-virus interactions facilitate various viral functions including viral entry into the cell or viral replication, as well as the development of an increased inflammatory response. Previous studies have shown that a neutralizing monoclonal antibody against the receptor-binding domain of the S protein of the MERS virus facilitated viral entry [41]. In patients with COVID-19, an increased IgG response and higher levels of total antibodies have also been encountered, and were associated with worse outcomes [42], especially liver injury [43]. Antibodies against S protein were found to promote the accumulation of IMMs in lung [44].
Related Knowledge Centers
- Encephalitis
- Fever
- Tick
- Viral Hemorrhagic Fever
- Virus
- Headache
- Malaise
- Pathogen Transmission
- Disease Vector
- Influenza-Like Illness