SeminarInfluenza
Section snippets
Virology
Influenza viruses are enveloped particles with two surface glycoproteins—haemagglutinin and neuraminidase. Influenza viruses belong to the family Orthomyxoviridae, which includes four genera: influenzavirus A, influenzavirus B, influenzavirus C, and thogotovirus.3 Influenza A and B viruses contain eight single-stranded, negative-sense RNA segments that encode at least ten polypeptides, of which eight are structural viral proteins, and two are found in infected cells.
Influenza A viruses are
Epidemiology
Influenza viruses are unique in their ability to cause both recurrent annual epidemics and more serious pandemics that spread rapidly and may affect all or most age-groups. The size of epidemics and pandemics, and their relative impact, reflects the interplay beween the extent of antigenic variation of the virus, the amount of protective immunity in populations, and the relative virulence of the viruses. Although the epidemiology of influenza has been studied extensively since the virus was
Clinical illness and complications
Influenza in adults and adolescents typically presents with an abrupt onset of fever and chills, accompanied by headache and sore throat, myalgias, malaise, anorexia, and a dry cough. Fever (38–40°C) peaks within 24 h of onset and lasts 1–5 days. Physical signs include the appearance of being unwell, hot and moist skin, flushed face, injected eyes, hyperaemic mucous membranes, and a clear nasal discharge. Although several of the symptoms of influenza are common to all age-groups, a review of
Laboratory diagnosis
A definitive diagnosis of influenza requires laboratory confirmation. There are several new diagnostic tests for influenza available or soon to be available. Diagnostic tests for influenza fall into four broad categories: virus isolation, detection of viral proteins, detection of viral nucleic acid, and serological diagnosis. The best clinical sample to use with the first three diagnostic methods is a combination of nasopharyngeal and throat swabs. The importance of appropriate collection and
Control and prevention
The two approaches available for the control and prevention of influenza are the use of vaccines and the use of antiviral agents.
References (47)
- et al.
A virus obtained from influenza patients
Lancet
(1933) - et al.
Outbreak of A2/Hong Kong/68 influenza at an international medical conference
Lancet
(1969) - et al.
Clinical features and rapid viral diagnosis of human disease associated with avian influenza A H5N1 virus
Lancet
(1998) - et al.
PCR on cerebrospinal fluid to show influenza-associated acute encephalopathy or encephalitis
Lancet
(1998) - et al.
Safe administration of influenza vaccine to patients with egg allergy
J Pediatr
(1998) - et al.
Pneumonia and influenza deaths during epidemics: implications for prevention
Arch Intern Med
(1982) - et al.
The impact of influenza epidemics on mortality: introducing a severity index
Am J Public Health
(1997) - Virus taxonomy. Seventh Report of the International Committee on Taxonomy of viruses. New York: Academic Press (in...
- et al.
Evolution and ecology of influenza A viruses
Microbiol Rev
(1992) - et al.
An outbreak of influenza aboard a commercial airliner
Am J Epidemiol
(1979)
Human influenza
Influenza A infections in young children
N EnglJ Med
Serious respiratory tract illness as a result of Asian influenza and influenza B infections in children
J Pediatr
Gastric ‘flu’ influenza B causing abdominal symptoms in children
Lancet
Influenzavirus A2 infections presenting with febrile convulsions and gastrointestinal symptoms in young children
Clin Pediatr
Type A2 influenza viral infections in children
Am J Dis Child
Diagnosis of influenza
MedJ Aust
Age and Asian influenza, 1957
BMJ
Comparison of influenza B/Hong Kong virus infections among infants, children, and young adults
J Infect Dis
Influenza A virus infection imitating bacterial sepsis in early infancy
Pediatr Infect Dis J
Outbreak of influenza A2 (Hong Kong strain) in a children's home
South Med J
Studies in influenza in the pandemic of 1957–1958, I: an epidemiologic, clinical and serologic investigation of an intrahospital epidemic, with a note on vaccination efficacy
J Clin Invest
Respiratory syncytial virus and influenza A infections in the hospitalized elderly
J Infect Dis
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