What Causes Flu and How Does the Flu Virus Spread

Flu isn’t just a respiratory problem or a high fever. It’s a contagious illness caused by a group of viruses affecting the health of a healthy person and those with weakened immune systems. Currently, there’s a continuous rise in flu cases, despite the DOH’s report of no influenza outbreak in the Philippines. Whether you are one of those who are experiencing symptoms of the flu, it’s best to be knowledgeable of what causes flu and how it spreads. In this guide, we’ll cover everything from the types of flu, and how the flu virus affects the health of people. Let’s begin! 

What Causes Flu: Understanding Influenza Viruses

The culprit behind influenza is the influenza virus. Flu occurs due to a group of constantly evolving viruses that infect your respiratory system. According to the World Health Organization (WHO) these viruses can cause seasonal epidemics.

Here are the types of influenza viruses:

Influenza A Virus

Influenza A is the most common and typically the most severe type of flu virus affecting humans. What makes influenza type A particularly challenging is its ability to mutate quickly, creating new strains that your immune system hasn’t encountered before. This type causes most seasonal flu outbreaks and has been responsible for major flu pandemics throughout history. 

It can be classified by two proteins on their surface: hemagglutinin (H) and neuraminidase (N). You might have heard of H1N1 or H3N2—these are different subtypes of influenza A virus.

Influenza B Virus

Another type of flu are the Influenza B viruses. It is known to only infect humans and tend to be less severe than influenza A. Although, influenza B can still cause significant illness. 

Furthermore, this type of virus can mutate slower than influenza A and doesn’t cause pandemics. However, they’re still a major contributor to seasonal flu, especially among young children and can circulate alongside influenza A during flu season.

Influenza C Virus

Meanwhile, influenza c viruses isn’t a contagious virus that can trigger an epidemic. Commonly, patients affected by this condition can experience mild respiratory illness that doesn’t lead to severe flu. In short, it can affect humans, but doesn’t pose a significant threat to public health.

Influenza D Virus

The last type of flu is the influenza D virus, which is the only type that doesn’t infect humans. This type of flu is one of the main concerns of livestock owners, specifically cattle owners. However, it is important to understand that animals can’t transmit the influenza d virus to humans.

While influenza d virus isn’t transmissible to humans, drinking unpasteurized milk from an infected cattle can pose a high risk. At the same time, consuming beef from an infected cattle can also be dangerous.

How Does the Flu Spread: What Causes Flu?

Understanding how the flu spreads is crucial for prevention. The influenza virus is incredibly efficient at jumping from person to person, which is why during the flu season, several cases of flu are confirmed. 

Learn how flu spreads through the following transmission methods:

Respiratory Droplets

The most common way flu spreads is through respiratory droplets. When an infected person coughs, sneezes, or even talks, they release tiny droplets containing the flu virus into the air. These droplets can travel up to six feet and land in the mouths or noses of people nearby. 

It is mostly a concern, especially in places with little to no ventilation. People gathering in such a place can easily inhale these respiratory droplets and get infected. 

Indirect Contact or Surface Contact

Another form of transmission is indirect touching of items that may have been harboring the flu virus. Flu viruses can survive on surfaces for up to 48 hours. This means that touching contaminated items like doorknobs, smartphones, shared utensils, and even money can possibly lead to getting the flu.

However, take note that just touching contaminated materials doesn’t automatically get you sick. What causes flu in this form of transmission is when you touch your eyes, nose, or mouth, allowing the virus to enter your respiratory tract. Thus, showing why hand hygiene is so crucial during flu season.

Close Contact Situations

When it comes to transmission of the flu virus, another possible method involves being in close contact with infected people. Take note that people can spread the flu even before they have their symptoms. So, being in close proximity with a person exposed to the virus raises the possibility of you getting infected.

Filipino families often live in multi-generational households, which means when one person gets sick, the virus can quickly spread to young children, parents, and elderly relatives. Schools, offices, markets, and public transportation also create perfect conditions for viral infections to spread.

How Flu Viruses Work in Your Body?

After it enters the body, the virus acts fast and attaches itself to cells in your respiratory tract, specifically in your nose, throat, and lungs. Once it attaches, it hijacks the cells to create new virus particles. Afterward, your immune system fights back against the invasion, which manifests as your flu symptoms.

The fever, body aches, and fatigue you experience aren’t directly caused by the virus destroying your cells. Instead, they’re the result of your immune system releasing chemicals to fight the infection. It’s like your body declaring war on the invader, and unfortunately, you feel caught in the crossfire.

Influenza Virus: Contagious Period

As mentioned, people can be contagious and a carrier of the virus without them knowing. Infected individuals become contagious before they even have their flu symptoms. Incubation period is within 1 to 4 days, this includes the day of exposure until before the symptoms appear. 

Contagious period:

• You are most contagious around 3 to 4 days of being sick (with symptoms showing)
• You are still contagious after 10 days of onset symptoms

Take note that there are cases where an infected person can be asymptomatic. However, they can still spread the virus to other people.

Who’s at a Higher Risk of Getting Infected?

Anyone can develop symptoms of flu, but there are groups of people who are at a higher risk of getting infected. The most vulnerable individuals are those with a weak immune system.

Here are the vulnerable age groups that can face complications and other severe illnesses due to flu.

• Young children: Children under five years old, particularly those younger than two, are at significantly higher risk for serious flu complications. Their immune systems are still developing, making them more susceptible to severe illness.
• Older adults: Adults aged 65 and older face increased vulnerability due to age-related changes in their immune systems. Even healthy adults should take extra precautions during seasonal flu outbreaks. Many Filipino seniors also have underlying health conditions that compound their risk.
• People with weakened immune systems: Individuals with compromised immune systems have a much harder time fighting off influenza infection. (e.g., pregnant women, individuals with chronic conditions, etc.).

Why Immediate Flu Treatment Matters?

Many Filipinos tend to “tough it out” when they get sick, hoping their sore throat, runny nose, muscle aches, and other similar symptoms will pass on their own. However, symptoms of influenza can prolong without proper management.

Here’s why prompt treatment and management are crucial.

1. It Can Prevent Complications

In severe cases, flu causes respiratory failure or worsen chronic medical conditions. At the same time, it can lead to serious complications including pneumonia, bronchitis, sinus infections, and ear infections. It’s best to receive early treatment with antiviral medications to reduce the severity and duration of illness.

2. It Can Stop the Spread of Virus in Filipino Communities

Getting immediate treatment is an advantage not only for yourself, but also for those people around you. When you take proper precautions as you manage your symptoms, you’re preventing the further spread of the virus in your community. 

Practical Prevention Strategies for Filipino Families

Personal Hygiene Practices

One of the most effective ways to prevent getting infected is by practicing proper hygiene. This includes washing your hands with soap for at least 20 seconds as well as using alcohol for further sanitation. It’s best to apply these precautions after coughing, sneezing, or being in public spaces.

Environmental Measures

Another preventive strategy involves the disinfection of your environment. Sanitizing every corner of your home helps to protect you and your family from being exposed to the virus. Practice regular cleaning of your area, and try to improve ventilation in your home to not harbor the virus that can trigger developing an infectious disease.

Social Practices During Flu Season

Furthermore, isolating at home is another effective way to avoid spreading respiratory illness to others. If you’re suffering from flu symptoms, this social practice can help keep your loved ones safe from the virus.

Boosting Your Immune System with Influenza Vaccines

Aside from the natural way of boosting your immune system, you can also benefit more by getting a flu shot. Influenza vaccines, commonly known as flu shots, remain our best defense against seasonal flu. While flu vaccines don’t guarantee you won’t get sick, they significantly reduce your risk of infection and, if you do get sick, typically result in milder illness.

Read this related article to discover more about the natural home remedies for flu.

When to Seek Doctor Consultation

Knowing when to move from home care to professional medical attention is crucial. While many cases of seasonal influenza can be managed at home, certain situations require a doctor’s expertise.

You should consult a doctor if you experience the following:

• difficulty breathing
• persistent chest pain
• sudden dizziness
• confusion
• severe vomiting

Also, you must seek medical care if flu symptoms improve but then return with fever and worse cough. 

Note: For young children, additional warning signs include fast breathing, bluish skin color, not drinking enough fluids, or extreme irritability.

Booking Immediate Doctor Consultation for Flu

If you think you have the flu or just a common cold, consulting a doctor is the ideal choice to determine your current condition. Today, you have telemedicine or online consultation options for easy and instant access to medical care. 

Here are different options to use the online consultation option of NowServing, one of the leading telemedicine platforms in the Philippines.

• Download the NowServing app to your device for seamless communication with a licensed doctor in the Philippines.
• You can also use their online consultation page via the NowServing website.
• For a more specific option, you can try to look for the “Cold & Flu” page to book a doctor that manages this health condition. When booking your doctor, simply choose the online consultation option.

Discover when to only use online consultation for flu with this guide.

Frequently Asked Questions (FAQs) About What Causes Flu

How long does the flu virus survive outside the body?

The flu virus can survive on hard surfaces for up to 48 hours, on soft surfaces like fabric for about 12 hours, and in the air for several hours in the form of respiratory droplets. Furthermore, this survival time varies based on temperature and humidity. Influenza virus tends to survive longer in cold, dry conditions, which is partly why flu season coincides with cooler months.

Does the flu virus thrive in cold, increasing the spread of flu?

As mentioned, the flu virus can survive more in cold, dry conditions. That’s why you can notice more cases of flu in the Philippines during the rainy season. There are reports of an increase in flu cases in different cities, especially in Manila. So, practicing precautions are encouraged.

Can you get the flu from going out with wet hair or being in air-conditioned rooms?

No, there’s no correlation to getting flu and the 2 mentioned conditions. You should remember that influenza is solely caused by influenza viruses. Also, influenza A, B, and C are the only types of flu virus that can affect humans.

Can I get flu from animals?

Animals cannot directly transmit the fly virus to humans. Influenza D virus is a type of flu virus that only affects livestock animals like cattle. Still, you can’t get infected by the influenza D virus, unless you drink unpasteurized milk from an infected animal. Take note that this case of possible transmission is very rare.

How soon after exposure does influenza symptoms appear?

The incubation period for flu is typically one to four days, with an average of two days. This means you can be infected today and not show symptoms until a couple days later. Remember, you can be contagious during this pre-symptomatic period, which is why flu spreads so efficiently through communities.

How long does it take to recover from the flu virus?

In most cases, you can recover from a flu within 7 days. However, you can still be contagious around the 10th day of being sick from flu. So, it’s best to rest a few more days to avoid spreading the virus. At the same time, it allows your body to rebuild its immune system and be healthier. 

Can healthy people get seriously ill from the flu?

While healthy people generally recover from the flu without major complications, severe illness can occur in anyone. Though the risk is lower, previously healthy individuals have experienced serious complications from influenza infection. This is why prevention and appropriate medical care matter for everyone, not just those in high-risk groups.

Conclusion

Understanding what causes flu and how it spreads empowers you to protect yourself and your loved ones more effectively. By recognizing the role of influenza viruses and understanding transmission methods, you’re better equipped to navigate flu season safely in the Philippines.

Remember, prevention is a simple, yet effective first line of defense against the threat of flu. If you’ve been infected, and need immediate doctor consultation, book an online consultation with a flu doctor on NowServing!