The  viral respiratory disease, known as influenza or the flu has widely terrorised the humanity from a long time. The main cause for this are the influenza viruses which are responsible for causing this fatal respiratory illness. Most particularly in susceptible groups like old people, children and immunocompromised people , this disease effects millions of people causing considerably mortality and morbidity rates. The history, signs, kinds, diagnosis, prophylaxis and effects of influenza on social life will all be discussed  in this article.

The history of this disease can be traced to dating as far back as 412 B.C in Greece.However, the recent outbreak of it in 1918 known as the Spanish flu resulted in the deaths of millions of people all over the world.

Orthomyxoviridae family of viruses, influenza virus is the main reason for this disease. It is mainly of four types Influenza A,B,C and D. AMong them , most of the seasonal flus are caused by Influenza A and B.while influenza C is not much deadly and is known to cause mild respiratory symptoms. However, the last of the family Influenza D does not effects humans and is mainly found in cattles.

Usually the symptoms of influenza are usually same as common cold but are usually severe in comparison to them.These are:

• Fever and chills
• Cough
• Sore throat
• Runny nose
• Muscles or body aches
• Fatigue
• Headaches
• Loss of apetite
• Shortness of Breath
• Chest congestion
• Nausea,vomiting and diarrohea

Influenza can also lead to other respiratory diseases like bronchitis,pneumonia and sinusitis in sever cases of influenza.It can also be proved to fatal in some cases.

Influenza is usually transmitted through the droplets from one person to another when he coughs sneezes or talk loudly and is highly contagious. The other way this virus is transmitted is through contact with such surface where influenza droplets are present and then touching the eyes, mouth or nose.

It is very difficult to control the transmission of influenza as it can be spread even without showing any symptom in the patient. Usually young children, elderly persons, pregnant women and immunocompromised persons are contagious for a long time but the healthy adults can be responsible for transmission one day before the symptoms arrive and upto 5-7 days.

A medical examination by a health care worker is usually necessary for the diagnosis of Influenza.Clinical symptoms helps in the diagnosis of influenza whic includes:Fever,Cough and Body pain and for the verification of which is provided by laboratory testing like Rapid Influenza Diagnostic Tests(RIDT) or polymerase chain reactions which is a molecular test. Samples are taken from nose and throat and tests are performed on them to identify the presence of influenza virus.

It is crucial to note that these tests are not reliable as they can come positive or negative or sometime maybe false positive. In order for the physician to diagnose influenza, clinical judgement and whole presentation of symptoms is necessary.

A lot of antiviral medications are available for the treatment of influenza and the use of these medications in the early stages of influenza can help reduce the disease in high risk people. Two anti-viral classes used for the treatment of influenza are:

1. Neuraminidase inhibitors: Oseltamivir, zanamivir and peramivir are the examples of this class. These medicines work by blocking the action of neuraminidase enzymes which helps the virus in release from infected cells thus inhibiting its release and slowing down the spread of the virus.
2. Baloxavir marbovil:It is taken as a single dose and is approved treeatment for influenza virus in patients ages 12 or above.It works by blocking the replication of virus.It blocks the endonuclease enzymes involved in replication.

It is important to note that these medications work during the early onset of symptoms probably within 48 hours and are taken under the supervision of a physician.

In addition,supportive measures like rest,hydration are also recommended and also medications to reduce symptoms like paracetamol and ibuprofen can also be used.

As it is a well known saying, prevention is better than cure. One of the most effective ways to prevent influenza is by vaccination. For individuals who are at high risk of influenza which includes children, elderly people and immunocompromised person , flu vaccine is usually recommended for people aged 6 months or above. It is typically administered annually.

There are usually 2 different influenza vaccines Quadrivalent and Trivalent. Quadrivalent vaccines is usually protects against 4 influenza strains(2 influenza A and 2 Influenza B strains) while Trivalent usually protects from 3 influenza strains(2 Influenza A and 1 Influenza B). In addition to the injections, flu vaccines can also be administered by nasal spray but are not recommended for pregnant women and immunocompromised population.

Vaccination helps reduce the severity of illness and does not usually guarantees protection as it is not effective against all the strains of influenza.

Apart from vaccination other preventive measures for Influenza virus are as follows:

• 

  Washing hands frequently with soap for 20 seconds especially after coughing sneezing. If soap is not available alcoholic hand sanitizer can do the job.

• Whenever sneezing and coughing, use elbow or tissue to cover the mouth in order to prevent the droplets from spreading which can result in spread of influenza virus.
• Stay home if you are infected with influenza and also stay away from people who are infected with influenza
• Frequently touched surfaces such as door knob, mobile phones and switches must be properly cleaned and disinfected to prevent the spread of virus
• Staying physically active, getting enough sleep and maintaining a balanced diet can help to strengthen the immune system which in turn helps reducing the risk of getting sick.

Avoid flu with healthy diet:

Immune system is impaired by eating processed foods such as sugary snacks, high sodium foods, thus make you more exposed to the influenza virus attacks.

Consuming high fats food i-e transfat and saturated fats can impair the immune system and causes inflammation in the body. So, it is actually healthier to limit the intake of such foods and choosing healthier fats including: nuts, seeds, fatty fishes.

Caffeine:

Drinking alot of coffee which is rich in caffeine can disrupt the sleep patterns thus in turn weakens the immune system. Prioritise getting enough sleep by limiting the intake of caffeine especially in the evening.

High alcohol consumption is one of the major reason for compromising of immune system thus impairs body’s ability to provide protection against different diseases.

It is actually not enough to maintain balanced diet and not getting vaccination as a result it is not the substitute for other measures of prevention.

Influenza significantly affects public health around the world by creating sporadic pandemic and seasonal epidemics with high morbidity and mortality rates.According to WHO, every year influenza epidemic affects the 3 to 5 million people worldwide and is responsible for the deaths of between 290000 and 650000 people worldwide.

Influenza has negative impacts on both health and economy aswell. The expenses associated with influenza illness are very high which includes hospitalization and medication.

In addition to the ongoing pendemic of Covid 19, the influenza outbreak can have serious side effects leading increase in demand of hospitalization, health care workers and economic disruptions.

The factors such as strain of th virus ,effectiveness of the vaccine and the public health measures can impact on the severity of the influenza virus.

A multi-faceted approach including vaccinations,anti-viral medications and public health measures is requied for the control of influenza.The most effective strategy in prevention of influenza is vaccination.Anti-viral medications can also be used to treat influenza and as a preventive measures.

Public health measures plays a crucial role in prevention and control of the disease . These measures includes surveillance, public health measures and outbreak investigations. Surveillance helps in composition of vaccines for upcoming season by identifying circulating strains of virus. Outbreak investigations helps controlling outbreak in high crowd area like school and public places. Public health awareness helps in raising the awareness among public for vaccines and other preventive measures.

Influenza is a very dangerous disease which affects both health and economy. It continues to be difficult to manage even after knowing the virus. However, it can be prevented through vaccinations and different anti viral medications, However challenges such as adherence to medication public measures and pendemic preparedness while vaccines accessibility, effectiveness remain areas of concerns.

Influenza remains a global public health challenge that requires for its control and prevention. As we face constant threat of influenza every year, it is important to prioritise prevention strategies and promotes evidence based interventions to reduce the burden of this disease.