Viral Infection

Viral infections are a major health concern in Australia, affecting thousands of people each year. While most viral infections are mild and self-limiting, some, such as severe flu strains, viral pneumonia, or hepatitis, can lead to serious complications. Vaccination programs, good hygiene, and early diagnosis are essential in controlling the spread of viral diseases.

When to consult a doctor for a viral infection

If symptoms are severe or affecting breathing

See a doctor urgently if you have a very high fever (above 39°C), persistent vomiting, difficulty breathing, severe headache, chest pain, confusion, or extreme weakness, as these may signal complications.

If symptoms last longer than expected or suddenly worsen

Consult a GP if symptoms continue for more than 7–10 days without improvement, worsen after initially getting better, or if you are unsure whether the infection is viral or bacterial and symptoms are not resolving.

If you are at higher risk of complications

Seek medical advice early if the infection occurs in infants, young children, or older adults, or if you have a weakened immune system due to chronic illness, pregnancy, cancer treatment, or other immunocompromising conditions.

This guide does not replace professional care. Consult a doctor to manage your symptoms. In emergencies, call 000. The content is research-backed & medically reviewed by Dr. Ammar AL-ANI, MBChB, CCBST, AMC

Types

Viral infections can affect different parts of the body, and they are classified into several types, including:

Respiratory viruses: Affect the lungs and airways (influenza, COVID-19, RSV, common cold).

Gastrointestinal viruses: Cause stomach and digestive issues (norovirus, rotavirus).

Skin and mucosal viruses: Affect the skin, mouth, or genitals (herpes, HPV, chickenpox).

Bloodborne viruses: Spread through blood and bodily fluids (hepatitis B, hepatitis C, HIV).

Neurological viruses: Affect the brain and nervous system (rabies, viral meningitis, encephalitis).

Mosquito-borne viruses: Spread by insects (dengue fever, Ross River virus).

Causes

Viral infections are caused by viruses, which invade human cells to multiply. Common ways viruses spread include:

Airborne transmission: Coughing, sneezing

Direct contact: Skin-to-skin or mucous membrane contact

Contaminated food or water: Ingesting infected food (norovirus, hepatitis A).

Blood and bodily fluids: Through sexual contact or needle sharing (HIV, hepatitis B).

Insect bites: Mosquitoes, ticks, and fleas (dengue, Ross River virus).

Are viral infections contagious?

Yes, most viral infections are highly contagious, spreading through:

Person-to-person contact (coughing, sneezing, shaking hands).

Contaminated surfaces (touching doorknobs, shared utensils).

Food and water sources (norovirus outbreaks).

Sexual transmission (herpes, HIV).

Insect bites (mosquito-borne viruses).

Some viruses, like influenza and COVID-19, spread rapidly, while others, like hepatitis C, require blood-to-blood contact.

How long can a viral infection last?

The duration of a viral infection depends on the virus and severity:

Common cold: 5 to 10 days

Influenza: 7 to 14 days

Gastroenteritis: 2 to 7 days

COVID-19: 10 to 14 days, but lingering symptoms can persist

Herpes: Recurrent episodes throughout life

Hepatitis: Can be chronic and last for years

How can we prevent viral infections?

We can prevent viral infections through

Vaccination: Flu shots, COVID-19, hepatitis, and HPV vaccines.

Good hygiene: Regular handwashing and wearing face masks.

Avoid close contact: With infected individuals.

Boost immunity: Healthy diet, sleep, and exercise.

Use protection: Safe sex practices to prevent STIs.

If you are experiencing symptoms, speak to a GP first to discuss your health.

Hola Health provides a convenient way for you to consult a doctor online, 24/7 across Australia. Our AHPRA-registered Australian online GP will conduct a comprehensive assessment to provide the best possible care.

Clinical note: An online GP assessment helps provide medical advice for your vital infection symptoms and evaluate if a face-to-face consultation or physical examination is needed. Online GPs can provide prescriptions, referrals or online doctor certificates if clinically indicated. Telehealth is a complementary service; a physical examination (such as checking ears, throat, or lung sounds) may be necessary to differentiate between viral and bacterial infections or to identify complications. Bulk billing is available for eligible patients during Medicare-defined after-hours periods; otherwise, private fees apply. Consultations are secure, encrypted, and Australian-stored (in compliance with the Australian Privacy Principles). Documents such as scripts or medical certificates are provided only if clinically indicated. In case of difficulty breathing, chest pain, persistent high fever, or confusion, call 000 immediately. We recommend sharing your consult summaries with your regular GP to ensure continuity of care.