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Severe Influenza Pneumonia and Its Mimics in the Critical Care Unit
Published in Cheston B. Cunha, Burke A. Cunha, Infectious Diseases and Antimicrobial Stewardship in Critical Care Medicine, 2020
The season, whether spring or early fall, raises the likelihood of vector-borne infections such as West Nile virus (WNV). The neuroinvasive type of WNV disease displays fever and headache, meningitis, changes in consciousness, and flaccid limb paralysis (poliomyelitis-like syndrome) [38]. Herpes simplex encephalitis, the most frequent sporadic encephalitis, typically presents with acute onset fever, headache, acute confusional states, personality changes, and seizures, with characteristic electroencephalography lesions [38]. Depending on the geographical area, acute febrile encephalopathy can cause arboviruses (Japanese B encephalitis, La Crosse strain of California) or reovirus (Colorado tick fever virus). Cardinal prodromal symptoms of viral encephalitis are nausea, vomiting, fever, headache, and then confusion with disorientation [43]. Enterovirus 71, a brainstem encephalitis, is frequently accompanied by severe cardiorespiratory symptoms after a prodromal stage of fever, photophobia, vomiting, headache, and abdominal pain [44].
Powassan Virus
Published in Sunit K. Singh, Daniel Růžek, Neuroviral Infections, 2013
Laura D. Kramer, Alan P. Dupuis, Norma P. Tavakoli
As stated earlier, the first recorded POWV isolate, although unidentified until after POWV and described in the literature by McLean and Donahue (1959), was isolated from a pool of D. andersoni (Rocky Mountain wood tick) collected along North Cache la Poudre River, Colorado in 1952 (Thomas et al. 1960). D. andersoni larvae and nymphs primarily feed upon small mammals, including mice, chipmunks, and ground squirrels. Adults will feed on larger mammals including wild and domestic ungulates, rabbits, and porcupines (Scott and Brown 2011; Wilkinson 1984; Burgdorfer 1969; Burgdorfer 1975). D. andersoni is the principal vector of Colorado tick fever virus (Emmons 1988). POWV development in this species of tick following feeding on infected rabbits indicated virus multiplication in various tick organs leading to peroral transmission through salivary secretion of infected nymphs and adults, and transstadial transfer of virus, but no transovarial transmission (Chernesky 1969; Artsob 1989).
Comparative aspects of the tick–host relationship: immunobiology, genomics and proteomics
Published in G. F. Wiegertjes, G. Flik, Host-Parasite Interactions, 2004
Francisco J. Alarcon-Chaidez, Stephen K. Wikel
Ixodid ticks also transmit Ehrlichia species, which are Gram-negative intracellular organisms responsible for cases of HGE and also human monocytic ehrlichiosis (HME). Ehrlichia chaffeensis and Ehrlichia ewingii have been identified as the agents of HME, while Anaplasma phagocytophilum is responsible for HGE (Dumler and Bakken, 1998; Telford et al., 1996). Most cases of HME have been shown to occur in areas where the metastriate Amblyomma americanum (Lone Star Tick) predominates although this illness has also been detected within the geographic distribution of the American dog tick, Dermacentor variabilis. These two species of metastriate ticks are also known to transmit spotted fever, a disease caused by obligate intracellular bacteria belonging to the genus Rickettsia, and tularaemia, an illness caused by the Gram-negative coccobacillus Francisella tularensis. In addition to tularaemia, the Rocky Mountain wood tick Dermacentor andersoni transmits Rickettsia rickettsii (spotted fever), and the Colorado tick fever virus.
How relevant are in vitro culture models for study of tick-pathogen interactions?
Published in Pathogens and Global Health, 2021
Cristiano Salata, Sara Moutailler, Houssam Attoui, Erich Zweygarth, Lygia Decker, Lesley Bell-Sakyi
In the first report describing the in vitro growth of an arbovirus in tick organ cultures, the kinetics of replication of Colorado tick fever virus (CTFV) were followed in vector (D. andersoni) developing adult explants [15]. A latent phase of ~10 days preceded detection of active viral replication, the virus persisted in the tissues until 166 days post infection, and the titer in the medium decreased with the senescence of the organ culture. Moreover, using nymphal ticks infected by feeding on viremic animals, CTFV replicated at much higher levels in vitro in developing adult explants than in vivo in live, intact ticks, showing the efficiency of this system for virus propagation.