All cases had a clinical presentation of encephalitis and were confirmed serologically. Clinically most cases presented with fever, meningitis syndrome with altered mental status. Tremors were common (56% of cases). There were three deaths. [ncbi.nlm.nih.gov]

The results of the present nonrandomized, unblinded, interventional pilot study of the use of IFN-α2b therapy for St. [doi.org]

Infections may be limited to an influenza-like illness or present as an aseptic meningitis or encephalitis. Clinical manifestations of the encephalitic presentation may include seizures, lethargy, myoclonus, focal neurologic signs, coma, and death. [ebi.ac.uk]

• Fever

  /immunology West Nile Fever/transmission West Nile Fever/veterinary* West Nile Fever/virology West Nile virus/genetics* West Nile virus/immunology West Nile virus/physiology Substance Viral Nonstructural Proteins Grant support AI065359 /NH/NIH HHS/United [ncbi.nlm.nih.gov]

  Ross River Fever (RRF) is a mosquito-borne infectious disease caused by infectio... Rift Valley Fever (RVF) is a virus (genus: Phlebovirus, family: Bunyaviridae) th... [valentbiosciences.com]

  The mild form of the disease results in fever and headaches. Serious cases of the illness include symptoms such as high fever, neck stiffness and persisting headaches. [mosquitonix.com]

  People with mild illness often have only a headache and fever. [cdc.gov]

• High Fever

  Louis Encephalitis will have no symptoms or signs and never feel sick Mild Symptoms: Most of those who do have symptoms or signs will have a fever and headaches Severe Symptoms: Few of those infected have the severe symptoms such as high fever, severe [smcmvcd.org]

  The mild form of the disease results in fever and headaches. Serious cases of the illness include symptoms such as high fever, neck stiffness and persisting headaches. [mosquitonix.com]

  Severe Symptoms: Headache High fever Neck stiffness Stupor Disorientation Coma Tremors Additional Resources: California Department of Public Health: St Louis Encephalitis Centers for Disease Control and Prevention: St Louis Encephalitis [shastamosquito.org]

  Louis encephalitis infections produce mild symptoms that include fever and headache. In more severe cases, high fever, neck stiffness, disorientation, tremors, coma, and convulsions can occur. [valentbiosciences.com]

• Chills

  Symptomatology on admission included fever, chills, severe headache, abdominal pain, myalgia, arthralgia and jaundice. SLE virus was isolated from her blood drawn on the 8th day of illness and subsequent seroconversion was documented. [ncbi.nlm.nih.gov]

  Disease onset is characterized by generalized malaise, fever, chills, headache, drowsiness, nausea, and sore throat or cough followed in 1 to 4 days by meningeal and neurologic signs. [mayocliniclabs.com]

  Clinical Features The incubation period varies from 3 to 6 days, following which there is an abrupt onset of chills, fever, and headache. [virology-online.com]

  Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. [lecturio.com]

• Rigor

  Common symptoms were fever, rigors, diarrhea, headache, and confusion. One patient died 3 days after hospitalization. [ncbi.nlm.nih.gov]

  %/protein/Gluc Treatment 69/m Kidney 7/28/2015 9/2/2015 Survived 27/14%/50/86 INF+IVIG 67/m Kidney 12/13/2013 7/24/2015 Died 102/36%/108/54 None 57/m Kidney/heart 10/6/2012 7/2/2105 Survived 84/16%/114/58 INF+IVIG Most common symptoms: fever (3/3), rigors [atcmeetingabstracts.com]

  Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. [lecturio.com]

  Epidemiology United States statistics Determining the true incidence of encephalitis is impossible, because reporting policies are neither standardized nor rigorously enforced. [emedicine.medscape.com]

• Nausea

  Initial symptoms of those who become ill include fever, headache, nausea, vomiting, and tiredness from 5 to 15 days after being infected. [placermosquito.org]

  […] by a virus of the Flaviviridae family transmitted by an infected mosquito, and characterized by the onset of flulike symptoms such as fever, malaise, headache, cough, and sore throat that can progress to meningitis or encephalitis with symptoms like nausea [orpha.net]

  Initial symptoms of those who become ill include fever, headache, nausea, vomiting, and tiredness. Severe neuroinvasive disease (often involving encephalitis, an inflammation of the brain) occurs more commonly in older adults. [cdc.gov]

  Depending on the symptoms, options may be: Pain medicines—for headaches Anti-nausea medicines Fluids—by mouth or IV Breathing support Prevention To reduce the risk of St. [winchesterhospital.org]

• Vomiting

  Initial symptoms of those who become ill include fever, headache, nausea, vomiting, and tiredness from 5 to 15 days after being infected. [placermosquito.org]

  […] virus of the Flaviviridae family transmitted by an infected mosquito, and characterized by the onset of flulike symptoms such as fever, malaise, headache, cough, and sore throat that can progress to meningitis or encephalitis with symptoms like nausea, vomiting [orpha.net]

  Initial symptoms of those who become ill include fever, headache, nausea, vomiting, and tiredness. Severe neuroinvasive disease (often involving encephalitis, an inflammation of the brain) occurs more commonly in older adults. [cdc.gov]

  Louis encephalitis-infected mosquito do not become ill, but those who do will experience symptoms such as fever, headache, nausea, vomiting and fatigue. [latimes.com]

• Hypertension

  Hypertension and vascular disease may predispose to neuroinvasive disease, but this epidemiologic study has not ruled out the confounding effects of age. [ncbi.nlm.nih.gov]

  During the evolution he added: mental confusion, photophobia, inability to recognize parents or medical staff, obey simple commands, and arterial hypertension. 6 days after he spontaneously improved. IgM for St. [scienceopen.com]

  Male sex is a risk factor Most SLEV infection outbreaks occur in people of low socioeconomic status, which is probably due to less access to heath care and poor environmental control of mosquitoes Comorbidity with atherosclerosis, heart disease, and hypertension [emedicine.com]

• Photophobia

  Photophobia, cranial nerve palsies, and even coma may occur. [orpha.net]

  Photophobia is seldom present. The neurologic examination findings are usually normal. Five percent of patients with SLEV infection present with deep coma, and 25% develop cranial nerve palsies. Fewer exhibit ataxia. [emedicine.medscape.com]

  During the evolution he added: mental confusion, photophobia, inability to recognize parents or medical staff, obey simple commands, and arterial hypertension. 6 days after he spontaneously improved. IgM for St. [scienceopen.com]

• Diplopia

  Additional signs noted at, or after, admission to the hospital were nystagmus, diplopia, ophthalmoplegia, respiratory insufficiency, tremor, ataxia, peripheral weakness, confusion, or decreased level of consciousness. [doi.org]

• Dysuria

  Illness is classified into 3 syndromes: Constitutional symptoms, fever, headache, myalgia, cough, sore throat, dysuria, urinary urgency Aseptic meningitis Fatal encephalitis Symptoms: Asymptomatic in the vast majority (>99%) Malaise, fever, headache, [visualdx.com]

  Pharyngitis Urinary: Dysuria Dysuria Painful urination. It is often associated with infections of the lower urinary tract. [lecturio.com]

  […] encephalitis include the following: Encephalitis caused by varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), measles virus, or mumps virus: Rash, lymphadenopathy, hepatosplenomegaly, and parotid enlargement St Louis encephalitis: Dysuria [emedicine.medscape.com]

• Headache

  headaches, coma, tremors, convulsions, paralysis, and possible death Is St. [smcmvcd.org]

  Fever Headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. [lecturio.com]

  People with mild illness often have only a headache and fever. [cdc.gov]

  The mild form of the disease results in fever and headaches. Serious cases of the illness include symptoms such as high fever, neck stiffness and persisting headaches. [mosquitonix.com]

• Confusion

  tremors, clumsiness, and ataxia Confusion, delirium or somnolence with weakness, seizures Occasionally, tremulousness with cerebellar and cranial nerve deficits Neurologic and psychologic sequelae are not uncommon Hematuria Incubation period is 4-21 [visualdx.com]

  SLEV infections can be unrecognized or confused with other ones caused by an arbovirus, such as dengue. [ncbi.nlm.nih.gov]

  Flaviviridae family transmitted by an infected mosquito, and characterized by the onset of flulike symptoms such as fever, malaise, headache, cough, and sore throat that can progress to meningitis or encephalitis with symptoms like nausea, vomiting, confusion [orpha.net]

• Dizziness

  Symptoms of onset illness include fever, headache, dizziness, nausea and malaise. Most commonly, severe cases of SLEV occur in elderly people. Cases of children with SLEV are generally milder than cases in elderly. [alabamapublichealth.gov]

  Onset of illness is usually abrupt, with fever, headache, dizziness, nausea, and malaise. Signs and symptoms intensify over a period of several days to a week. [cdc.gov]

• Irritability

  […] infected mosquito, and characterized by the onset of flulike symptoms such as fever, malaise, headache, cough, and sore throat that can progress to meningitis or encephalitis with symptoms like nausea, vomiting, confusion, stiff neck, disorientation, irritability [orpha.net]

  Other symptoms include fever, nausea, stiff neck/back, light sensitivity, confusion, drowsiness, irritability, and motor skill impairment. Wild bird populations are central to the transmission cycle. [amcdsjc.org]

  Do not apply insect repellent to a child’s hands, eyes, mouth, cuts, or irritated skin. Adults: Spray insect repellent onto your hands and then apply to a child’s face. Tips for Everyone Always follow the product label instructions. [cdc.gov]

  Symptoms of irritability, sleeplessness, depression, memory loss, and headaches can last up to 3 years. Infections with arboviruses, including SLE, can occur at any age. [mayocliniclabs.com]

• Neck Stiffness

  Clonus and neck stiffness were detected at physical exam. Cerebrospinal fluid revealed mononuclear leukocytosis; bilateral ischemic compromise was observed in thalamus by magnetic resonance. [ncbi.nlm.nih.gov]

  More severe disease is marked by fever, headache, neck stiffness, stupor, disorientation, coma, tremors, occasional convulsions (especially in infants) and spastic (but rarely flaccid) paralysis. [cdc.gov]

  Serious cases of the illness include symptoms such as high fever, neck stiffness and persisting headaches. As the disease progresses, infected people may develop tremors, convulsions, stupor, disorientation and spastic paralysis. [mosquitonix.com]

  Severe Symptoms: Headache High fever Neck stiffness Stupor Disorientation Coma Tremors Additional Resources: California Department of Public Health: St Louis Encephalitis Centers for Disease Control and Prevention: St Louis Encephalitis [shastamosquito.org]

  In more severe cases, high fever, neck stiffness, disorientation, tremors, coma, and convulsions can occur. [valentbiosciences.com]

Technical Appendix: Additional description of diagnostic workup and methods used in study of fatal human case of St. Louis encephalitis virus infection. [ncbi.nlm.nih.gov]

• Periodic Lateralized Epileptiform Discharges

  Electroencephalograms were obtained for 9 patients and results on all were abnormal, showing status epilepticus (1 patient) ( Figure 1 ), bilateral periodic lateralized epileptiform discharges (1 patient), and background diffuse slowing (7 patients). [jamanetwork.com]

• Hyponatremia

  Of this group, 13 patients appeared to have hyponatremia due to inappropriate secretion of antidiuretic hormone; the remaining patients were probably hyponatremic from salt depletion. [annals.org]

  The medical literature also contains reports of syndrome of inappropriate antidiuretic hormone secretion (SIADH) and hyponatremia in patients with St. [emedicine.com]

  […] from SIADH,[12] and therefore, its related complications including cerebral edema and central pontine myelinolysis (from overly rapid correction of hyponatremia.). [ncbi.nlm.nih.gov]

• Hypocapnia

  In two of the conscious patients cerebral blood flow was normal despite normal arterial oxygen tension and systemic hypocapnia; inflammatory cerebral vasodilatation may have accounted for the findings. [annals.org]

Treatment significantly reduced the levels of viral RNA in the serum, brain, and spleen [ 8 ]. [doi.org]

There is currently no therapeutic treatment for SLE. Current methods consist primarily of symptom treatment and supportive care. Many SLE epidemics have been documented in North America. In 1990, there were 223 cases in Florida. [floridahealth.gov]

Treatment of St. Louis Encephalitis Virus Infection Care is based on symptoms, as there is no cure or specific treatment for SLE disease. For severe cases of illness, supportive treatment includes hospitalization, IV fluids and respiratory support. [vdci.net]

The EEG proved valuable in diagnosis and prognosis. Results of brain scans were normal. Virus in CSF or urine was not demonstrated, nor was viral antigen in CSF or urine sediments. [archinte.jamanetwork.com]

MRI T2: the degree of signal hyperintensity within the substantia nigra may be varied in terms of symmetry and laterality 5 Treatment and prognosis Only supportive treatment is available, with mortality ranging from 5-15% 3. [radiopaedia.org]

Sections Continuing Education Activity Introduction Etiology Epidemiology Pathophysiology History and Physical Evaluation Treatment / Management Differential Diagnosis Prognosis Complications Deterrence and Patient Education Enhancing Healthcare Team [pubmed.ncbi.nlm.nih.gov]

Prognosis The mortality rate of St. Louis encephalitis is 2-30%. This figure is higher in older patients. [7] Of persons who survive St. [emedicine.com]

Louis encephalitis virus (SLEV) as the etiologic agent. [ncbi.nlm.nih.gov]

Etiology Limited data evidence marked inflammatory and gliotic changes within the substantia nigra and cerebellum that are also present, to a lesser extent, diffusely throughout the brain 6. [radiopaedia.org]

Etiology and Pathophysiology St. Louis encephalitis is caused by an enveloped, single-stranded, positive-sense ribonucleic acid (RNA) virus of the Flaviviridae subgroup. St. [emedicine.com]

Louis Encephalitis Tree Number: B04.820.230.475.330 B04.820.250.350.300.330 Definition English: A species of FLAVIVIRUS, one of the Japanese encephalitis virus group (ENCEPHALITIS VIRUSES, JAPANESE), which is the etiologic agent of ST. [decs.bvs.br]

Louis/epidemiology* Encephalitis, St. Louis/history Encephalitis, St. Louis/transmission Encephalitis, St. [ncbi.nlm.nih.gov]

[…] the field of epidemiologic research. [aje.oxfordjournals.org]

Etiology and Pathophysiology St. Louis encephalitis is caused by an enveloped, single-stranded, positive-sense ribonucleic acid (RNA) virus of the Flaviviridae subgroup. St. [emedicine.com]

Abstract Studies of pathophysiology in epidemic St. Louis encephalitis were undertaken during the 1966 Dallas epidemic. Eighteen of 52 patients were hyponatremic during their acute illness. [annals.org]

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test Since 1933, outbreaks of St. [mayocliniclabs.com]

According to the Centers for Disease Control and Prevention (CDC), most people infected will not become ill. Initial symptoms of those who become ill include fever, headache, nausea, vomiting, and tiredness from 5 to 15 days after being infected. [placermosquito.org]

Few mosquitoes actually carry the virus, but it is important to take prevention measures when spending time outside. St. Louis encephalitis is preventable. Visit our Mosquito Bite Prevention page to learn how to prevent mosquito bites. [dhs.wisconsin.gov]

Prevention The best way to prevent SLEV disease is to avoid mosquito bites. Please see our mosquito prevention page for more information. For more information about St. Louis encephalitis virus, visit the CDC SLEV webpage. [in.gov]

Severe illnesses are treated by supportive therapy which may include hospitalization, respiratory support, intravenous (IV) fluids, and prevention of other infections. How can St. Louis encephalitis be prevented? Prevent mosquito bites. [vdh.virginia.gov]

Hills, Arboviral Diseases Branch, Centers for Disease Control and Prevention, Fort Collins, CO, E-mails: [email protected], [email protected], [email protected], and [email protected]. [ajtmh.org]