By Amirah Halwani, AA Pharmacist.

What causes influenza?

According to the World Health Organization (WHO), influenza affects approximately 5% to 10% of adults and 20% to 30% of children every year across the globe. Influenza is a highly contagious respiratory tract infection caused by influenza viruses of the Orthomyxoviridae family and can be divided into three strains: influenza A, B and C. In Malaysia, influenza A is more commonly detected than influenza B. The diseases caused by these viruses are often collectively referred to simply as “flu.”

How do you get infected?

The virus has the potential to spread easily when someone is in proximity withthe virus through droplets trapped in the air (from coughing and sneezing) or through touching an infected surface.

The virus penetrates the respiratory epithelial cells in the trachea and bronchi, undergoing replication which results in the destruction of the host cell. Virus is shed in respiratory secretions for 5 to 10 days. An infected adult may transmit the virus from day one before symptoms appear until day five after getting sick, whilst infected children may be contagious for up to seven days upon contracting the virus.

What are the symptoms?

It is common to mistake common cold for the flu due to overlapping symptoms, yet they are different diseases caused by different group of viruses. Generally, flu has more serious symptoms and they tend to last longer.

Symptom Flu Cold
Fever Usually present, high (102°F to 104°F or 39°C to 40°C); lasts 3 to 4 days Rare
Headache Usually (can be severe) Rare
Aches and pains Usually and often severe Sometimes; slight
Fatigue and weakness Usually; can last 14 to 21 days or longer Sometimes; mild
Extreme exhaustion Usually Uncommon
Stuffy nose Common Common
Sneezing Sometimes Common
Sore throat Common Common
Chest discomfort, cough Usually; can be severe Sometimes; mild to moderate, hacking cough
Complications Can lead to pneumonia or respiratory failure; can worsen a current chronic condition; can be life-threatening Can lead to sinus congestion or earache

Have you heard of Flu Shots?

Influenza vaccination (also known as flu shots or flu jabs) is widely acknowledged by WHO as one of the most effective ways to prevent the influenza-associated morbidity and mortality. It provides protection for adults and children from suffering at the hand of multiple influenza strains, helping to reduce the spread of the disease and the risk of complications.

Influenza vaccination given as single dose is recommended for everyone 6 months of age or older in Malaysia. It is especially recommended for children with chronic decompensated respiratory or cardiac disorders, e.g. cyanotic heart disease, chronic lung disease and HIV infection. It is given intramuscularly as inactivated vaccine which provide protective efficacy 70% up to 90%. There is a 50% to 70% chance of risk reduction in people at high risk of contracting the influenza virus who get vaccinated on a yearly basis for continuing protection. Every year separate recommendations about strains to be included in the vaccine are made following influenza season as the nature of influenza viruses keep mutating.

In temperate countries like the United Kingdom and United States, vaccination is routinely offered to those in high risk groups but in Malaysia, due to lack of awareness of the dangers of influenza, not many people get themselves vaccinated. Influenza vaccination rates at Malaysia are very low although the vaccines have been available for decades.

Non-pharmacological Advices

Person infected with the virus are advisable to get plenty of rest, drink lots of fluids and practice cough etiquette to reduce the spread of disease to others. They are recommended to always wash their hands correctly with soap and water after cough, sneeze or blow their nose or may use hand sanitiser and wear masks too if need to be in close proximity to other people.

Reference:

  1. Taubenberger, J. K., & Morens, D. M. (2008). The Pathology of Influenza Virus Infections. Annual Review of Pathology3, 499–522. http://doi.org/10.1146/annurev.pathmechdis.3.121806.154316
  2. Sam JI (2015). The Burden of Influenza in Malaysia. Med J Malaysia. 70(3):127-130.
  3. Centers for Disease Control and Prevention [CDC], (2018). Key facts about Seasonal Influenza (flu) Vaccine. https://www.cdc.gov/flu/protect/keyfacts.htm [Accessed February 28, 2018].
  4. Medi Resource Inc. (2018). Flu and Cold. www.medbroadcast.com/healthfeature/gethealthfeature/Flu-and-Cold [Accessed February 28, 2018].
  5. Paediatric Protocol for Malaysian Hospitals 3rd Edition, 2012.
  6. New Straits Times. Meera Murugesan (2nd December 2015) Common Cold or Influenza?
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