Avian Flu

a v i a n f l u
"T h e I m p e n d i n g P l a g u e"

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Symptoms of Influenza in Humans

Scientific Background
Introduction
The Virus
Strains and Types
Antigenic Shift / Drift
Symptoms of Flu
H5N1
Infection Process
Resevoirs of Infection
Conclusion
Treatment & Prevention
Treatment
Prevention
Reactions & Impacts
Past and Present Reactions
Possible Impacts
History of Influenza

a) Common Symptoms

Symptoms of Influenza in Humans

Fever (above 40 ° C)

Chills (possibly with shivering)

Muscle aches and pains

Sweating

Sore Throat

Nasal Congestion

Dry Cough

Headache

Fatigue

Malaise

b) Signs and Risks

Although the virus is deposited in the respiratory tract, signs and symptoms can be observed and detected throughout the entire body. Contrary to common belief, Influenza is actually pathologically distinct from diseases like the common cold or the stomach flu. Both stated diseases are often confused with the “flu”, which is incorrect. The range of severity of the symptoms of flu is wide and can be mild rhinitis at one end, to even fatal pneumonia at the other.

Some common signs and symptoms of flu are:

Abrupt onset of symptoms

Patients may have the feeling of being completely pin down during the initial hours of rapidly appearing symptoms. This happens within about 2 to 4 days of incubation. Cold symptoms instead appear over a course of a few days.

Fever

Patients usually experience a fever of over 37.8 ° C on the first day. This would usually subside on the second to third day. However, in more serious patients, fever may spike again on the third or fourth day.

Chills / Sweats / Headache

Patients may (or may not) develop chills, headaches and/or sweating before or accompanying the fever.

Sore Throat

Sore throat experiences usually described as a “burning” sensation.

Dry Cough

Happens at the onset of illness.

Substernal soreness, photophobia and ocular problems

When severe substernal pain is detected, it usually point towards the primary involvement of the trachea. Other symptoms also include prolonged fatigue, weakness and general distresses like diarrhoea and nausea.

Malaise

Severe and persistent Malaise.

Myalgia

Possible severe myalgia will occur, usually in the back and the extremities. Related to the severity of the fever.

When symptoms first appear, constitutional symptoms would seem more severe then respiratory symptoms. However, when the former subsides, respiratory symptoms become more evident.

Typical signs and symptoms of flu in adults include an abrupt onset of symptoms within 2 to 4 days of incubation of the virus. These symptoms include fever which surpasses 37.8 ° C that peaks within the first day. This will continue on for about another 4 days. Other symptoms include dry cough, headaches, chills, sweating, sore throat, myalgia, malaise and anorexia. One key differentiating factor of influenza infection from other common respiratory illnesses is that symptoms of malaise would severe and persists for several days. Other symptoms may include muscle fatigue, photophobia and other general distresses like abdominal pains and nausea. As for children, they experience relatively the same type of symptoms except that abdominal distress and myalgia appear more frequently. Their maximum temperature may also be higher, indicating febrile convulsions. Symptoms such as headaches and malaise are usually difficult for children to verbalize and express and may have occurred earlier than they first appeared. Fever and rhinitis are common in children of ages less than 5. In very young infants, rhinitis might be the only respiratory symptom.

In comparison to adults or teenagers, patients in the lower age groups usually tend to experience more of vomiting or diarrhoea. These symptoms nevertheless can be easily detected. However, symptoms such as malaise or myalgia are more difficult to identify in children if present.

c) Flu vs Cold Symptoms

Signs and Symptoms	Flu	Cold
Onset	Sudden	Gradual
Fever	High (over 38° C), usually lasting 3 to 4 days	Rare
Nasal Congestion	Sometimes	Usual
Sneezing	Sometimes	Usual
Dry Cough	Non-productive and can become severe	Hacking
Sore Throat	Sometimes	Common
Headache	Prominent	Rare
Myalgia (aches and pains)	Usual, often severe	Slight
Fatigue and weakness	May last for 2, 3 weeks	Very mild
Extreme exhaustion	Early and prominent	Never occurs
Chest discomfort	Common	Mild

d) Reported Symptoms Of Avian Influenza

Reported symptoms of Avian Influenza in human subjects ranged from typical influenza symptoms as mentioned above, to eye infections (conjunctivitis), severe pneumonia and respiratory diseases such as viral pneumonia, acute respiratory disorder and other possibly fatal complications. The symptoms of Avian Influenza depend on what type of virus caused the infection.