Avian Influenza : Causes, Symptoms and precautions

 

What is Avian Influenza?

My dear friends, 

Avian influenza, also known as bird flu, is a type of influenza A virus that affects birds but can also be transmitted to humans. Here are some key facts about avian influenza--

Types of Avian Influenza

1. Low-pathogenic (LPAI)

 These viruses cause mild or no symptoms in birds but can still be transmitted to humans.

2. High-pathogenic (HPAI)

 These viruses cause severe disease in birds and can also be transmitted to humans, resulting in more severe symptoms.

Transmission to Humans

1. Direct contact

People can become infected through direct contact with infected birds, such as through handling live birds or touching contaminated surfaces.

2. Indirect contact

People can also become infected through indirect contact, such as through contaminated surfaces or air.

3. Airborne transmission

In rare cases, people can become infected through airborne transmission, such as when an infected bird coughs or sneezes, releasing the virus into the air.

Symptoms of Avian Influenza

Avian influenza, also known as bird flu, can cause a range of symptoms in birds and occasionally in humans. Here are the common symptoms of avian influenza in birds--

Birds

1* Sudden death with no apparent cause

2* Discoloration of skin or feathers

3* Difficulty standing or walking

4* Lameness or paralysis of limbs

5* Loss of appetite

6* Diarrhea or vomiting

7* Lack of energy or lethargy

8* High respiratory rate or labored breathing

9* Swollen joints or limbs

10* Soft or brittle bones

In severe cases, the bird may exhibit--

* Discoloration of wattles or combs (turkeys, chickens, guinea fowl, pheasants, waterfowl)

1* Conjunctivitis or eyelid swelling

2* Sneezing or gasping

3* In some birds, a greenish coloration of the stool

4* Abdominal symptoms such as distended gut or swollen abdomen

5* Death

Humans

In rare cases, avian influenza viruses can infect humans, primarily poultry workers, veterinarians, or people who work directly with birds. Humans usually contract the virus from the droppings, discharge, or feathers of an infected bird. Humans usually develop symptoms within 48 hours of exposure to an infected bird.

Here are the common symptoms of avian influenza in humans--

1* Fever (may reach 104°F (40°C))

2* Respiratory symptoms such as:

3 + Cough (similar to a common cold, but can be productive, producing mucus and respiratory secretions)

 4+ Shortness of breath (dyspnea) or difficulty breathing (if the infection progresses)

5* Muscle aches

6* Headache

7* Tiredness or lack of energy

8* Weakness

9* Diarrhea or abdominal pain

Pneumonia and lung collapse can occur in people severely infected with avian influenza. Some cases of pneumonia can be fatal in severely immunocompromised or elderly individuals.

The influenza viruses responsible for causing infection in humans can evolve through antigenic drift, so it is essential for travelers and individuals working closely with birds to receive advice about the risk of outbreaks associated with their specific trip to an affected area and discuss any preventive measures available in their area. Regular human influenza vaccination may be no protection against avian H5N1 but an H5N1 subunit vaccine has also produced some immune response as studies have shown. However they are still not sufficient with a good protective effectiveness even with two doses when first administered.

If an illness is suspected to be bird flu, immediate isolation (separation from contact humans) is necessary in countries with well-established animal laboratory and diagnostic capabilities that must be consulted to further specify the causative viruses such as avian paramyxo viruses or coronavirus especially if it has coevolved to a reassorted strain with H6 strains.

Risk Groups

1. Bird handlers

 People who work with birds, such as farmers, veterinarians, and poultry workers, are at higher risk.

2. Travelers

People who travel to areas where avian influenza outbreaks are occurring may be at higher risk.

3. Pregnant women and young children

 These individuals may be more susceptible to severe symptoms.

Prevention and Control Measures

1. Wash hands frequently

Regular hand washing with soap and water can help prevent transmission.

2. Use personal protective equipment (PPE)

 Wear masks, gloves, and gowns when handling birds or contaminated surfaces.

3. Avoid close contact

 Avoid close proximity to infected birds or people who are infected.

4. Get vaccinated

For people in high-risk groups, vaccination can provide some protection against avian influenza.

Outbreaks and Pandemics

1. 1817

The first reported avian influenza outbreak occurred in 1817 in Italy.

2. 1918

 A pandemic occurred in 1918, causing an estimated 50 million deaths worldwide.

3. 2003-2004

An H7N7 outbreak in the Netherlands caused a significant number of human cases.

4. 2005-2009

 An H5N1 outbreak in Asia caused several human cases and deaths.

Global Response

1. WHO

The World Health Organization (WHO) plays a crucial role in monitoring and responding to avian influenza outbreaks.

2. National authorities

Governments and public health agencies collaborate to implement preventive measures and respond to outbreaks.

3. International partnerships

 Collaborations between countries and international organizations help to share information and coordinate responses to outbreaks.

Remember, while the risk of avian influenza transmission to humans is low, it is essential to prioritize preventive measures and take actions to reduce the risk of transmission.