Poliomyelitis is an infectious Infectious Febrile Infant disease caused by the poliovirus. This virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology is a member of the Picornaviridae Picornaviridae A family of small RNA viruses comprising some important pathogens of humans and animals. Transmission usually occurs mechanically. There are nine genera: aphthovirus; cardiovirus; enterovirus; erbovirus; hepatovirus; kobuvirus; parechovirus; rhinovirus; and teschovirus. Coxsackievirus family. It is a small, single-stranded, positive-sense RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology without a lipid envelope Envelope Bilayer lipid membrane acquired by viral particles during viral morphogenesis. Although the lipids of the viral envelope are host derived, various virus-encoded integral membrane proteins, i.e. Viral envelope proteins are incorporated there. Virology. Transmission occurs through the fecal–oral route and, occasionally, through respiratory aerosols Aerosols Colloids with a gaseous dispersing phase and either liquid (fog) or solid (smoke) dispersed phase; used in fumigation or in inhalation therapy; may contain propellant agents. Coxiella/Q Fever. The majority of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship will be asymptomatic or have a mild, abortive presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor with flu-like symptoms Flu-Like Symptoms Babesia/Babesiosis. Those who develop nonparalytic poliomyelitis will develop signs and symptoms of aseptic meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis. A very minor proportion of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship will progress to paralytic poliomyelitis, with neurologic progression (including asymmetric flaccid paralysis). The diagnosis is determined by the clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor and can be supported by viral culture Viral culture West Nile Virus, PCR PCR Polymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules. Polymerase Chain Reaction (PCR), and serology Serology The study of serum, especially of antigen-antibody reactions in vitro. Yellow Fever Virus. Current antivirals are ineffective, and management is supportive. There are 2 vaccines available, which have almost eradicated this disease worldwide.
Last updated: 12 Apr, 2022
RNA
RNA
A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity.
RNA Types and Structure
virus
Virus
Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range.
Virology
identification
Identification
Defense Mechanisms:
Viruses can be classified in many ways. Most viruses, however, will have a genome formed by either DNA or RNA. RNA genome viruses can be further characterized by either a single- or double-stranded RNA. “Enveloped”
viruses
Viruses
Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells.
Virology are covered by a thin coat of
cell membrane
Cell Membrane
A cell membrane (also known as the plasma membrane or plasmalemma) is a biological membrane that separates the cell contents from the outside environment. A cell membrane is composed of a phospholipid bilayer and proteins that function to protect cellular DNA and mediate the exchange of ions and molecules.
The Cell: Cell Membrane (usually taken from the host cell). If the coat is absent, the
viruses
Viruses
Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells.
Virology are called “naked”
viruses
Viruses
Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells.
Virology.
Viruses
Viruses
Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells.
Virology with single-stranded genomes are “positive-sense”
viruses
Viruses
Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells.
Virology if the
genome
Genome
The complete genetic complement contained in the DNA of a set of chromosomes in a human. The length of the human genome is about 3 billion base pairs.
Basic Terms of Genetics is directly employed as
messenger RNA
Messenger RNA
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
RNA Types and Structure (
mRNA
mRNA
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
RNA Types and Structure), which is translated into
proteins
Proteins
Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein.
Energy Homeostasis. “Negative-sense,” single-stranded
viruses
Viruses
Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells.
Virology employ
RNA
RNA
A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity.
RNA Types and Structure dependent
RNA
RNA
A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity.
RNA Types and Structure polymerase, a viral enzyme, to transcribe their
genome
Genome
The complete genetic complement contained in the DNA of a set of chromosomes in a human. The length of the human genome is about 3 billion base pairs.
Basic Terms of Genetics into
messenger RNA
Messenger RNA
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
RNA Types and Structure.
A 3-dimensional (3D) graphical representation of a tightly packed, icosahedral poliovirus particle
Image: “Poliomyelitis” by CDC. License: Public DomainA transmission electron microscopic (TEM) image depicting numerous, round, poliovirus virions, which measure approximately 30 nm in diameter and exhibit icosahedral symmetry
Image: “A transmission electron microscopic (TEM) image of Poliovirus type-1 virions” by CDC. License: Public DomainPoliomyelitis is caused by 3 serotypes of poliovirus:
Humans are the only known reservoir Reservoir Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (disease vectors) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks. Humans may serve both as disease reservoirs and carriers. Escherichia coli.
This highly contagious virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology is transmitted via:
The pathogenesis of poliovirus:
The
virus
Virus
Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range.
Virology initially enters and infects lymphoid tissues.
Viremia
Viremia
The presence of viruses in the blood.
Erythema Infectiosum occurs, allowing eventual spread to the
nervous system
Nervous system
The nervous system is a small and complex system that consists of an intricate network of neural cells (or neurons) and even more glial cells (for support and insulation). It is divided according to its anatomical components as well as its functional characteristics. The brain and spinal cord are referred to as the central nervous system, and the branches of nerves from these structures are referred to as the peripheral nervous system.
Nervous System: Anatomy, Structure, and Classification. Replication results in tissue damage and symptoms.
The majority of infected individuals are asymptomatic or develop a minor flu-like illness:
Approximately 4% of those infected will develop nonparalytic poliomyelitis. Presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor will be aseptic meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis after a prodrome Prodrome Symptoms that appear 24–48 hours prior to migraine onset. Migraine Headache similar to that of abortive poliomyelitis.
A minority of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with nonparalytic poliomyelitis will progress to the paralytic form Paralytic form Rabies Virus of the disease, characterized by:
A young girl with a deformity Deformity Examination of the Upper Limbs of the right lower extremity as a consequence of paralysis from paralytic poliovirus infection
Image: “Paralytic poliovirus infection” by CDC. License: Public DomainPostpoliomyelitis syndrome manifests as worsening symptoms in poliomyelitis survivors. It can occur decades after the initial infection.
Diagnosis is based on clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor and supported by the diagnostic workup.
Lumbar puncture Lumbar Puncture Febrile Infant:
Specific testing:
There is no effective antiviral Antiviral Antivirals for Hepatitis B therapy for poliomyelitis. Management is supportive.
Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with nonparalytic poliomyelitis make complete recoveries. For those with paralytic poliomyelitis:
There are 2 vaccines used:
A young girl receiving the oral poliovirus vaccine Vaccine Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases. Vaccination
Image: “A child receiving an oral polio vaccine Vaccine Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases. Vaccination” by USAID. License: Public DomainVirus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology | Coxsackievirus Coxsackievirus Coxsackievirus is a member of a family of viruses called Picornaviridae and the genus Enterovirus. Coxsackieviruses are single-stranded, positive-sense RNA viruses, and are divided into coxsackie group A and B viruses. Both groups of viruses cause upper respiratory infections, rashes, aseptic meningitis, or encephalitis. Coxsackievirus | Poliovirus | Echovirus Echovirus Echoviruses are single-stranded positive-sense RNA viruses belonging to the genus Enterovirus. Transmission is most commonly through the fecal-oral route. The majority of patients are asymptomatic. Patients who are symptomatic can exhibit a wide range of illnesses ranging from nonspecific URIs and exanthems to severe and life-threatening illnesses. Echovirus |
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Management | Supportive | Supportive | Supportive |
Prevention | Handwashing | Vaccination Vaccination Vaccination is the administration of a substance to induce the immune system to develop protection against a disease. Unlike passive immunization, which involves the administration of pre-performed antibodies, active immunization constitutes the administration of a vaccine to stimulate the body to produce its own antibodies. Vaccination | Handwashing |