Related Experiment Video
Updated: May 18, 2026
07:23
Detection of Infectious Virus from Field-collected Mosquitoes by Vero Cell Culture Assay
Published on: June 9, 2011
Powassan virus encephalitis, Minnesota, USA.
Justin Birge1, Steven Sonnesyn
1Abbott Northwestern Hospital, Minneapolis, Minnesota, USA. birgejustin@gmail.com
Emerging Infectious Diseases
|September 29, 2012
Summary
Powassan virus (POWV) causes rare tick-borne encephalitis in North America. Increased cases in Minnesota and Wisconsin, including a fatal encephalitis case, highlight the need for suspecting POWV in tick-exposed patients.
Area of Science:
- * Neuroscience
- * Infectious Diseases
- * Public Health
Background:
- * Powassan virus (POWV) is a rare tick-borne flavivirus responsible for encephalitis in North America.
- * Historically, confirmed POWV cases were concentrated in the northeastern United States.
- * Recent years have seen an increase in confirmed POWV cases in Minnesota and Wisconsin.
Observation:
- * A fatal case of POWV encephalitis occurred in Minnesota.
- * The patient had a history of tick exposure.
- * Clinical presentation was consistent with viral encephalitis.
Findings:
- * Laboratory confirmation of Powassan virus as the causative agent of encephalitis.
- * The case represents a severe outcome of POWV infection.
- * Geographic distribution of POWV appears to be expanding or increasing in the upper Midwest.
Implications:
- * Clinicians should consider POWV in the differential diagnosis of viral encephalitis, especially in tick-endemic areas.
- * Public health awareness regarding tick-borne illnesses and preventative measures is crucial.
- * Further surveillance and research are needed to understand the epidemiology and clinical spectrum of POWV in the United States.
Related Concept Videos
01:25Arboviral Encephalitis
Arboviral encephalitis refers to brain inflammation caused by arthropod-borne viruses, particularly those transmitted through mosquito vectors. Among these, West Nile virus (WNV), a member of the Flaviviridae family, is a significant public health concern. WNV is an enveloped, positive-sense, single-stranded RNA virus. Human infection typically begins when an infected mosquito introduces the virus into the dermis during feeding. The primary transmission cycle involves birds as amplifying hosts...
01:18Viral Meningitis
Viral meningitis is the most common form of meningitis and is often referred to as aseptic meningitis to indicate the absence of bacterial involvement. It is generally milder than bacterial meningitis, with symptoms including fever, headache, stiff neck, drowsiness, nausea, photophobia, and vomiting. Rarely, more severe manifestations or death may occur. Common causative agents include enteroviruses, particularly coxsackie A and B viruses and echoviruses, all members of the Enterovirus genus...
01:26Encephalitis ll: Pathophysiology
Encephalitis is inflammation of the brain parenchyma caused by direct viral invasion or immune-mediated mechanisms triggered by infections or tumors. Both processes lead to neuronal injury, disrupted neurotransmission, and diverse neurological symptoms, often with overlapping clinical and pathological features.Autoimmune EncephalitisIn autoimmune encephalitis, antibodies target neuronal antigens on cell surfaces, synapses, or within neurons. A key example is anti-NMDAR encephalitis, which can...
01:19Encephalitis l: Introduction
Encephalitis is inflammation of the brain parenchyma, most often due to infections or autoimmune processes. It presents with neuropsychiatric features such as fever, altered mental status, behavioral changes, cognitive dysfunction, seizures, focal deficits, and sometimes autonomic instability. In some cases, the meninges are also involved, resulting in meningoencephalitis.Infectious CausesInfectious encephalitis is most commonly viral but can also result from bacterial, fungal, or parasitic...
01:26Bacterial Meningitis II: Pathophysiology
Bacterial meningitis typically begins when pathogens such as Neisseria meningitidis and Streptococcus pneumoniae colonize the nasopharynx and invade the bloodstream. This process is facilitated by bacterial virulence factors, such as polysaccharide capsules, which resist phagocytosis and complement-mediated killing. Less commonly, bacteria reach the central nervous system via contiguous spread from infections like otitis media or sinusitis, through congenital or acquired dural defects, or...
01:22Bacterial Meningitis I: Introduction
Bacterial meningitis is a severe, life-threatening inflammation of the meninges, particularly the pia mater and arachnoid mater, affecting the subarachnoid space, ventricles, and cerebrospinal fluid (CSF). If untreated, it can lead to significant neurological complications or death.Causative AgentsCommon pathogens vary with age and immune status. In adults, major organisms include Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. Streptococcus agalactiae (group B...