ss-RNA viruses are the cause of seasonal periodic upper respiratory tract infection known as an influenza. There are several subtypes of orthomyxovirus or influenza virus, broadly divided in 3 groups as orthomyxovirus or Influenza virus A, B and C. All three subtype causes influenza like disease in humans. Influenza B virus also affects mammals and birds. Influenza virus C is also observed in pigs. The orthomyxovirus virus once introduced in human system stays in upper respiratory mucosal epithelial cells and multiplies rapidly within the cells. The wide spread insertion of virus in mucosal cells causes severe inflammation of mucosal layers in nose, pharynx, trachea and upper bronchi. The spread of influenza is being observed across the world.
Clinical Manifestation of Orthomyxovirus or Influenza –
The clinical symptoms of orthomyxovirus or Influenza are rarely seen in infants. The symptoms of influenza are most common in toddler and young children. The orthomyxovirus or Influenza virus mostly affects upper respiratory tract infection and rarely in few cases gastrointestinal system. The respiratory tract infection causes rhinitis, pharyngitis, laryngitis and trachea-bronchitis. The orthomyxovirus or Influenza affects gastrointestinal system causing symptoms like nausea, vomiting and diarrhea. Symptoms are observed after 3 to 4 days from the time of exposure to virus. The orthomyxovirus or Influenza causes optimum symptoms for 1 to 3 days from the initial beginning of the symptom. If the symptoms continue for prolonged period of time, then orthomyxovirus or Influenza virus may spread further down into lungs. In few cases there may be superimpose bacterial infection caused by staphylococci, streptococci or pneumococci.
Transmission of Orthomyxovirus or Influenza:
The orthomyxovirus or influenza is transmitted from infected individual to healthy individual. Most common meeting place is day care for toddler and school for younger children. The influenza virus transmission is also observed during travelling in enclosed space like airplane and train. The orthomyxovirus or influenza viruses are in large numbers embedded in mucosa or nasal secretion of infected individual. The spread of such mucosa over the furniture and surrounding objects transmits the orthomyxovirus viruses and influenza disease when healthy individual touches the infected surface. The school epidemic of influenza lasts for 3 to 4 months and often repeated every year. The orthomyxovirus viruses or influenza are also transmitted from infected individual through air droplets or contact by touch. Infected air droplets are spread in surrounding atmosphere during sneezing and coughing.
Common Symptoms of Orthomyxovirus or Influenza Includes –
- Fever- 100 to 103
- Body ache
- Joint pain
Symptoms of Rhinitis Caused Due to Orthomyxovirus or Influenza Virus
Symptoms of Laryngitis Caused Due to Orthomyxovirus or Influenza Virus
- Cough with expectoration,
- Chest pain with coughing
Recent study published by Silvennoinen et al suggests 77% children were suffering with cough and 78% had rhinitis. High fever was a prominent sign.
Diagnosis of Orthomyxovirus or Influenza Virus:
- Complete Blood Count- The blood test often comes as a normal result. The white blood cell count is increased in bacterial infection but in viral infection it may remain normal or slightly lower in number.
- Detection of Virus- Blood sample and tissue sample from nasopharynx is examine for detection of viruses.
- Antibody Titer- Significant rise of antibody in serum of patient is suffering with viral infection.
- Viral Antigen of Epithelial Cells- The mucosal sample from nose and throat often shows viral antigen on the surface mucosal cells of sample taken from nasopharynx. The viral antigen is detected by immunostaining tests or enzyme immunoassays (ELISA).
Treatment of Orthomyxovirus or Influenza Virus:
- Tylenol and NSAIDs- Tylenol and NSAIDs like motrin and naproxen are prescribed for fever, body ache and joint pain caused due to orthomyxovirus or Influenza virus. These medicines are anti-inflammatory and helps to reduce the mucosal inflammation and gives symptomatic relief from symptoms of influenza. Tylenol, motrin and naproxen are available over the counter.
- Nasal Decongestant or Nasal Drop- Inflammation of nasal mucosa causes continuous secretion of mucosa and blockage of nose. The discomfort is relieved by using long acting nasal drop. Nasal drops are useful if used prior to going to sleep. Alternatively, phenylephrine tablet can be used. Phenylephrine pills and nasal drops are sold over the counter. One should consult primary care physician or specialist prior to using these nasal drops since the medication can cause several side effects.
- Cough Suppressant- Most cough suppressant contains dextromethorphan. The prolonged use of cough suppressant can cause several side effects. Consult physician prior to taking these medications for treating Influenza.
- Antiviral Medication- Antiviral medications are prescribed by physician. If symptoms of orthomyxovirus or Influenza virus are continued after 7 days and getting worse one should consult physician. In most cases physician will opt to prescribed antiviral medication if influenza is getting worst and symptoms are continued for over 7 to 10 days. Most common antiviral medication used are amantadine and rimantadine.
Prevention of Orthomyxovirus or Influenza Virus:
Most of the adults and children develop immunity by producing antibodies during past attack of influenza. These antibodies help to defend against recurrence of influenza virus infection. Such improved defense mechanism is also known as improved immunity.
The influenza infection is also prevented by taking antiviral vaccine prior to the influenza season. The inactivated virus helps to build antibodies in the body, which defends against influenza viral infection. Vaccination against influenza viral infection is widely use across the world. The vaccine consists of inactivated or live attenuated H1N1 and H3N2 human influenza type A viruses. The vaccine often does not work against wild influenza virus. In few cases children and adult are prophylactically treated by antiviral medications like rimantadine and amantadineto prevent influenza. The study published by Darvishian et al suggests influenza vaccine does help to reduce the occurrence of influenza symptoms in elderly patients.
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Influenza C virus infection in military recruits–symptoms and clinical manifestation.
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