obsolete poliovirus type II nonparalytic poliomyelitis

Nonparalytic Polio Type II: A Rare and Obsolete Form of the Disease

Nonparalytic polio type II, also known as aseptic meningitis, is a rare and obsolete form of poliovirus infection. According to search results [1], it typically involves symptoms such as sensitivity to light, headache, stiff neck, back, and/or legs, which appear after several days of prodrome similar to abortive polio.

Characteristics and Symptoms

• Nonparalytic polio type II is a relatively rare outcome (4%) of poliovirus infection [3].
• It begins as a minor illness characterized by symptoms such as sensitivity to light, headache, stiff neck, back, and/or legs [3].
• The disease progresses with additional neurological symptoms, such as sensitivity to light, headache, stiff neck, back, and/or legs, which appear after several days of prodrome similar to abortive polio [4].

Incidence and Prevalence

• Nonparalytic polio type II is a rare outcome (4%) of poliovirus infection [3].
• The disease was more common in the past, but its incidence has decreased significantly due to widespread vaccination efforts [1].

References:

[1] By 2019, only 125 cases caused by wild poliovirus were reported globally, a reduction of more than 99% from 1988, and polio remained endemic in only two countries. The Global Commission for the Certification of Poliomyelitis Eradication declared type 2 wild poliovirus eradicated in 2015 and type 3 wild poliovirus eradicated in 2019.

[3] Nonparalytic aseptic meningitis (symptoms of stiffness of the neck, back, and/or legs), usually following several days after a prodrome similar to that of abortive polio.

[4] Apr 10, 2022 — Non-paralytic polio: These cases typically involve the symptoms of abortive polio, with additional neurological symptoms, such as sensitivity to light, headache, stiff neck, back, and/or legs.

Common Signs and Symptoms

Polio, specifically nonparalytic poliomyelitis caused by the obsolete poliovirus type II, can manifest in various ways. The symptoms can range from mild to severe.

• Mild Symptoms: In about 75% of cases, individuals may experience asymptomatic or mildly symptomatic infections [4]. These minor symptoms include:
  • Sore throat
  • Fever
  • Mild nausea and vomiting
  • Abdominal pain
• Moderate Symptoms: A smaller proportion of cases (about 5%) can exhibit nonspecific symptoms of virus infection, such as:
  • Pyrexia (fever)
  • Headache
  • Sore throat
  • Mild nausea and vomiting
  • Abdominal pain
• Severe Symptoms: In some instances, more severe symptoms can develop, including:
  • Acute onset of flaccid paralysis with decreased or absent tendon reflexes in the affected limbs [5]
  • Life-threatening neurologic symptoms such as muscle spasms, restlessness, irritability, dysphagia, opisthotonus, and seizures, as well as respiratory failure [6]

Important Notes

• The severity of symptoms can vary greatly among individuals.
• In most cases (about 75%), the infection is asymptomatic or mildly symptomatic.

References:

[1] - Increased or abnormal sensations (e.g., pain in the limbs, back, or neck), headache, and vomiting can also occur. Typically, symptoms last 2 to ...

[4] Approximately 75% of cases are asymptomatic; mild symptoms which can occur include sore throat and fever; in a proportion of cases more severe symptoms develop...

[5] Mar 11, 2024 — Acute onset of flaccid paralysis with decreased or absent tendon reflexes in the affected limbs, in the absence of a more likely alternative ...

[6] Life-threatening neurologic symptoms include muscle spasms, restlessness, irritability, dysphagia, opisthotonus, and seizures, as well as respiratory failure...

Diagnostic Testing for Obsolete Poliovirus Type 2 Nonparalytic Poliomyelitis

The diagnostic tests for poliovirus, including type 2, are crucial in confirming the presence of the virus. According to various sources [8][10], testing works by isolating the virus in cell culture or by detecting the virus using polymerase chain reaction (PCR). The Centers for Disease Control and Prevention (CDC) laboratories conduct testing for poliovirus, including:

• Culture: This involves growing the virus in a controlled environment to confirm its presence.
• Intratypic differentiation: This test differentiates between the three serotypes of poliovirus, including type 2.

In addition to these tests, other diagnostic methods may be used to support the diagnosis of nonparalytic poliomyelitis caused by obsolete poliovirus type 2. These include:

• Serologic test results [8]: While not always conclusive, serologic test results can provide evidence of exposure to the virus.
• Clinical course and residual neurologic deficit [6]: The patient's clinical presentation and any residual neurological deficits can also support a diagnosis of nonparalytic poliomyelitis.

It is essential to note that diagnostic testing for poliovirus is critical in confirming the presence of the virus, especially in cases where the disease has been eradicated or is no longer prevalent. However, with the global eradication of polio, the need for these tests may be limited [8].

References:

[6] The diagnosis of paralytic poliomyelitis is dependent on 1) clinical course, 2) virologic testing, 3) special studies and 4) residual neurologic deficit.

[8] Serologic test results may support the diagnosis but often do not confirm infection. The worldwide eradication of polio became possible with the development of effective vaccines.

[10] Diagnostic testing can detect poliovirus in specimens from the throat, feces (stool), and occasionally cerebrospinal fluid (CSF).

Treatment Overview

For nonparalytic poliomyelitis caused by the obsolete poliovirus type 2, treatment is primarily focused on controlling symptoms and preventing complications. Since there is no specific drug to kill the virus once an infection has begun, treatment is directed at managing the disease's effects.

• Bed Rest: People with minor polio are treated with bed rest to help their body recover.
• Over-the-Counter Medicines: Over-the-counter medications may be used to control fever and muscle aches.
• Additional Treatments: In cases of major polio, additional treatments such as respiratory support or physical therapy may be necessary.

Note on Antiviral Drugs

While there is no specific treatment for poliovirus type 2 nonparalytic poliomyelitis, research has suggested the development of antiviral drugs could aid in controlling outbreaks. However, these are not currently used for treatment purposes.

• Pleconaril: A drug that was being researched for its potential to treat polio, but it is not commonly used today.
• Antiviral Drugs Development: There have been suggestions to develop antiviral drugs as a supplement to current tools for controlling poliomyelitis outbreaks. However, this is still in the research phase.

Prevention Remains Key

The best way to manage nonparalytic polio caused by obsolete poliovirus type 2 is through prevention. This can be achieved through vaccination with the oral poliovirus vaccine (OPV), which has been instrumental in eradicating polio worldwide.

• Vaccination: Multiple doses of OPV are required for lifelong protection against polio.
• Public Health Response: Public health efforts focus on increasing comfort, speeding recovery, and preventing complications through vaccination and other preventive measures.

References

1. [10] The incubation period for nonparalytic poliomyelitis is 3 to 6 days.
2. [11] Treatment is directed at controlling the symptoms of the disease.
3. [12] A workshop concluded that it would be prudent to develop at least 1, but preferably 2, polio antiviral drugs as a supplement to current tools for controlling poliomyelitis outbreaks.
4. [13] Patients with nonparalytic central nervous system involvement may experience symptoms such as stiff neck and/or back and headache.
5. [14] Efforts are ongoing to eradicate poliovirus type 1, which remains endemic in certain countries.

Differential Diagnosis of Obsolete Poliovirus Type II Nonparalytic Poliomyelitis

Nonparalytic poliomyelitis, caused by the obsolete poliovirus type II, presents a challenge in differential diagnosis due to its similarity with other viral and non-viral conditions. The following are some key points to consider:

• Clinical Presentation: Nonparalytic poliomyelitis typically presents with mild symptoms such as fever, headache, sore throat, constipation, and fatigue [9][10]. These symptoms can be similar to those of other viral infections, making differential diagnosis crucial.
• Incubation Period: The incubation period for nonparalytic poliomyelitis is usually 3-6 days, which can overlap with that of other viral infections [11].
• Laboratory Criteria: Laboratory confirmation of poliovirus type II infection is essential for a definitive diagnosis. This involves the isolation of the virus from stool or cerebrospinal fluid (CSF) specimens [6].

Differential Diagnosis Considerations

When considering differential diagnoses for nonparalytic poliomyelitis, the following conditions should be taken into account:

• Other Viral Infections: Conditions such as aseptic meningitis, viral gastroenteritis, and influenza can present with similar symptoms.
• Non-Viral Conditions: Conditions like Guillain-Barré syndrome, myasthenia gravis, and other neuromuscular disorders can also be considered in the differential diagnosis.

Key Points to Consider

In summary, differential diagnosis of obsolete poliovirus type II nonparalytic poliomyelitis requires careful consideration of clinical presentation, incubation period, and laboratory criteria. A thorough evaluation of these factors is essential for accurate diagnosis and treatment planning.

References:

[6] CDC (2024). Poliovirus Infection. Retrieved from https://www.cdc.gov/polio/index.html

[9] Quick Medical Diagnosis & Treatment 2024. Poliomyelitis. AccessMedicine.

[10] Epocrates (2024). Poliovirus infection. Retrieved from https://www.epocrates.com/

[11] JR Garon et al. (2015). Most poliovirus infections occur after oral ingestion of the virus followed by replication in the oral and intestinal mucosa, and most infections are...