obsolete influenza virus encephalitis

Influenza Virus Encephalitis: A Rare but Severe Complication

Influenza virus encephalitis, also known as postinfluenzal encephalopathy, is a rare and severe complication of influenza infection. It is characterized by inflammation of the brain, which can lead to symptoms such as headache, high fever, vomiting, convulsions, and consciousness disorders.

Types of Influenza Virus Encephalitis

There are several types of influenza virus encephalitis, including:

• Acute necrotizing encephalopathy: This is the most severe form of influenza-associated encephalopathy, with reported mortality rates of 30%–40%.
• Postinfluenzal encephalitis syndrome: This is a rare and extremely serious condition that occurs 2 to 3 weeks after recovery from influenza. It is characterized by inflammatory changes in the cerebrospinal fluid (CSF) and has a good prognosis.
• Encephalopathy: This is an important complication associated with influenza, most frequently observed in young children.

Symptoms of Influenza Virus Encephalitis

The symptoms of influenza virus encephal

Influenza Virus Encephalopathy: A Rare but Serious Complication

Influenza virus encephalopathy is a rare manifestation of influenza infection in adults, which can present with confusion and focal neurological symptoms. The onset of this condition typically occurs within a few days of the onset of influenza signs and symptoms.

Common Signs and Symptoms:

• Altered mental status (confusion)
• Focal neurologic signs (e.g., seizures, hemiplegia, aphasia)
• Fever
• Headache
• Seizures

These symptoms can range from mild to severe and may be accompanied by other flu-like symptoms such as fever, sore throat, cough, and malaise.

Important Considerations:

• Early diagnosis is crucial for effective treatment.
• Influenza encephalitis requires emergency treatment in a hospital setting, including tests to find the cause of the condition.
• The pandemic of the 2009 H1N1 Influenza A virus increased the incidence of influenza-associated encephalitis and encephalopathy (IAE).

References:

• [2] The onset of influenza-associated encephalopathy (IAE) typically occurs within a few days of the onset of influenza signs and symptoms, and the outcomes range from mild to severe.
• [5] Encephalitis can cause drowsiness, confusion, seizures, fever, and headache. It requires emergency treatment in hospital, including tests to find the cause.
• [12] Influenza virus associated encephalopathy is an acute non-inflammatory encephalopathy that presents with seizures and coma on the day, or the day after, influenza symptoms start.

Note: The references provided are based on the search results and may not be a comprehensive list of all relevant studies or sources.

Diagnostic Tests for Obsolete Influenza Virus Encephalitis

The diagnostic tests for obsolete influenza virus encephalitis have evolved over time, with various methods being used to identify the specific virus responsible for this condition. According to search result [3], pathologic examination and testing of brain tissue is considered the "gold standard" diagnostic test for this syndrome. However, due to potential morbidity associated with an invasive neurosurgical procedure, this method is rarely done premortem.

In the past, serological tests were used to diagnose encephalitis caused by influenza virus in convalescence [15]. These tests involved detecting antibodies against the virus in a patient's blood or cerebrospinal fluid (CSF). However, with advancements in technology, more sensitive and specific diagnostic methods have been developed.

Nucleic Acid Amplification Tests

Search result [13] mentions that nucleic acid amplification tests (NAATs), such as polymerase chain reaction (PCR), should be performed on CSF specimens to identify certain etiologic agents in patients with encephalitis. This method involves detecting the genetic material of the virus, making it a more sensitive and specific diagnostic tool.

Rapid Influenza Diagnostic Tests

Search result [14] discusses rapid influenza diagnostic tests (RIDTs), which are immunoassays that can identify the presence of influenza A and B viral nucleoprotein antigens in respiratory specimens. While these tests are useful for detecting current infections, they may not be as effective for diagnosing obsolete influenza virus encephalitis.

Other Diagnostic Methods

Search result [11] mentions that nasopharyngeal and endotracheal aspirate specimens were positive for pandemic 2009 H1N1 influenza by PCR. However, this information is more relevant to current diagnostic practices rather than obsolete influenza virus encephalitis.

In conclusion, while various diagnostic tests have been used to identify the specific virus responsible for obsolete influenza virus encephalitis, pathologic examination and testing of brain tissue remains the most accurate method. However, due to its invasive nature, this method is rarely used premortem. Nucleic acid amplification tests, such as PCR, may also be useful in diagnosing this condition.

References:

[3] Search result 3

Treatment Options for Obsolete Influenza Virus Encephalitis

In the past, treatment options for influenza virus encephalitis were limited and often ineffective. However, with advancements in medical research, several antiviral medications have been developed to combat this condition.

• Acyclovir: This medication was previously used to treat viral encephalitis caused by herpes simplex virus (HSV), varicella-zoster virus (VZV), and cytomegalovirus (CMV) [8][10]. Although it is not specifically designed for influenza virus encephalitis, acyclovir may have some efficacy in treating this condition.
• Ganciclovir: This antiviral medication has been used to treat CMV infections, including those affecting the central nervous system [8].
• Oseltamivir and Zanamivir: These medications are typically used to treat influenza virus infections, but they may also have some efficacy in treating encephalitis caused by this virus [6][7].

It's essential to note that these treatment options may not be effective for all cases of influenza virus encephalitis. The clinical course and outcome can vary significantly depending on the individual case.

References:

• [8] - Viral encephalitis, treatable causes · HSV: acyclovir 10mg/kg IV q8h x 14-21d.
• [6] - Recommended antiviral medications include oseltamivir and zanamivir, on the basis of recent viral surveillance and resistance data indicating ...
• [7] - Oseltamivir, peramivir, and zanamivir work by inhibiting influenza virus neuraminidase, a glycoprotein spike that protrudes from the virus ...
• [10] - Before acyclovir (and the drug used to treat it previously, vidarabine), 70% of pa- tients died of infection.12 Even using acyclovir, which is the current ...

The differential diagnosis for obsolete influenza virus encephalitis involves considering various conditions that may present with similar symptoms. According to the available information, some of these conditions include:

• Reye syndrome [2]
• Acute encephal