Do you cough, sneeze, and people with a fever around you? Every year a seasonal winter epidemic repeats. Please find out how the flu is spread, its symptoms, and how to treat it to give it the slip. This viral infection affects the respiratory system and is quickly spread.
There are three flu viruses (A, B, and C) that belong to the Orthomyxoviridae family. A and B viruses belong to the genus Influenza Virus and C to the genus Influenza C . Viruses B and C mainly affect man. Virus A has been isolated in ducks, humans, pigs, horses, and marine mammals, being the most aggressive of the three genera and responsible for pandemics due to its high mutational capacity.
The virus that produces the flu tends to change continuously, either by mutations or genetic rearrangement; thus, it avoids the host’s immunity. Virus A has changed several times over the past 100 years.
Implementing adequate hygiene measures and getting vaccinated if you are part of the groups considered at risk or vulnerable are vital guidelines to avoid falling ill, especially in winter periods. With the coronavirus pandemic’s coexistence, this year becomes even more critical to prevent complications, especially in older people, and over saturate health care systems.
Causes of the flu
The causes of the flu can be due to direct contact with a sick person or contaminated material, to the transmission of the virus through respiratory drops released by coughing or sneezing, or by air.
The influenza virus initially binds to and destroys the cells of the upper respiratory mucosa (mucus-secreting cells, hair cells, and epithelial cells), thus eliminating the first defense system of the respiratory system, and can subsequently reach the lower respiratory tract causing severe desquamation of the bronchial or alveolar epithelium.
How the flu spreads
Influenza viruses can enter the body through the respiratory tract’s mucous membranes (nasal cavity, larynx, trachea, bronchi), oral mucosa, or conjunctiva.
The spread of the influenza virus occurs during the period in which it can be transmitted, which begins one day before the onset of symptoms and ends 5-7 days later when the symptoms have resolved. In the case of children, they can transmit it after seven days of illness.
Not all people who come into contact with the virus will become infected, although they can serve as a vector, as transmitters of the infection. In this way, the flu spreads very quickly, being very difficult to control its spread with the classic public health measures, such as isolating the sick, since when a case is detected, the spread has already begun.
Flu symptoms and complications
An adult infected with the influenza virus presents a clinical picture characterized by flu symptoms: cough, fever, headache, sore throat, and nasal mucus.
The disease usually progresses smoothly towards a cure, with full recovery occurring between three and seven days after the disease’s onset; in some cases, the cough and general malaise can last for another week or two.
Complications of the flu
In general, the flu does not require medical assistance; however, if any of the following symptoms occur, a medical consultation is essential: persistent high fever, difficulty breathing, chest pain, bluish skin, dizziness, confusion, arterial hypotension.
The flu can be complicated by producing primary viral pneumonia or bacterial super infection pneumonia:
- The primary viral pneumonia is rare in seasonal flu, although it is most common in a pandemic. It appears rapidly between three and five days after the disease’s onset, generally in patients with obstructive pulmonary diseases, heart disease, morbid obesity, or pregnant women.
- Secondary bacterial pneumonia occurs when flu symptoms begin to improve, appearing in the elderly during seasonal flu, especially those with chronic diseases. Its cause is an infection by bacteria such as pneumococcus, staphylococcus, or others.
