When Are You No Longer Contagious with the Flu?
When Are You No Longer Contagious with the Flu?
TL;DR: You’re usually no longer contagious between days 5–7 after flu symptoms start, once you’ve been fever-free for 24 hours (without taking fever-reducing medicine). Children, people with weakened immune systems, and severe cases can remain contagious longer (Carrat et al., AJE; IDSA guideline).
Last updated: September 2025
Employers: See Workplace Policy Tips below.
How Long Is the Flu Contagious? Timeline by Day
The flu contagiousness timeline illustrates how the risk of spreading the flu virus evolves, from early infection through peak infectivity to minimal transmission.
You can spread influenza for about 24 hours before symptoms appear and usually for 4–7 days after onset, with peak infectivity in days 2–3. Australian data show transmission drops after the first several days (AJE review; J Virology 2024; PLoS One; EuroSurveillance).
Flu nurse tip: “The first three days are the riskiest for spread—rest, fluids, and avoid close contact if you can.” — Aitor Aspiazu, Lead Nurse Consultant & Founder
When Can I Go Back to Work After the Flu?
- It’s been at least day 5 since symptoms started, and
- you’ve been fever-free for 24 hours without medication, and
- you’re not coughing constantly or feeling wiped out.
To safely return to work after the flu, ensure it’s been at least five days since symptoms began, you’ve had no fever for 24 hours without medication, and you’re no longer excessively coughing or exhausted.
Still coughing? Mask around others and avoid sharing food or close contact for a couple of days (IDSA; MJA infection control).
Parents: Children can remain contagious longer; check with your GP or nurse if unsure.
Who Is Contagious for Longer With the Flu?
Children can shed virus for more than a week (Johns Hopkins). People with weakened immune systems and severe cases may remain infectious for weeks—get clinical advice on isolation length (IDSA).
Flu nurse tip: “If you care for young kids or live with someone high-risk, give it a little longer before you’re back to normal close contact.” — Aitor Aspiazu, RN & Nurse Immuniser
How Long to Isolate With the Flu? — Hygiene & Surface Survival
The flu virus can survive up to 12 hours on soft surfaces and up to 48 hours on hard surfaces, increasing the risk of indirect transmission through contact.
Influenza viruses can remain viable on hard surfaces for 24–48 hours and on soft, porous materials for roughly 8–12 hours—clean high-touch points and wash hands often (classic survival data).
Also see: When is flu season in Australia? and flu vaccination basics.
FAQs
How long does the flu last?
Most people feel better in 7–10 days, though cough and fatigue can last longer.
How long should I isolate with the flu?
Isolate for at least 5 days after symptoms start and until you’re fever-free for 24 hours without medication. Some people may need longer.
When am I no longer contagious with the flu?
Typically by days 5–7 if you’re fever-free for 24h and clinically improved; longer for children and immunocompromised people (IDSA).
When can I go back to work after having the flu?
After day 5 of symptoms if you’ve been fever-free for 24 hours and feel well enough to work without risking spread.
Can I spread flu before symptoms?
Yes—usually within the 24 hours before symptoms begin (NSW Health).
Employer Flu Policy Guide: When to Send Staff Home
- Send home if: Fever, frequent cough, or early illness (days 1–3).
- Plan absence for: At least 5 days from onset and 24h fever-free; longer for high-risk roles.
- Reduce spread: Hybrid options during peak days, clear “stay home if sick” policy, hand rub, surface cleaning.
- Vaccination access: Run on-site workplace flu vaccinations and offer Flu Vouchers for remote/shift staff.
Effective workplace illness management includes sending home symptomatic employees, planning absences, reducing transmission, and offering flu vaccinations or vouchers.
Stay flu-free:
- For individuals: Get your flu shot early—Australian flu activity often peaks June–September.
- For workplaces: Enquire now about our employee flu vaccinations or set up Pharmacy Vouchers.
Book or enquire about workplace flu vaccinations
Sources: NSW Health; ACT Health; Innate immunity review; Johns Hopkins; Surface survival; plus AJE 2008, IDSA 2019, J Virology 2024, NEJM review, MJA 2006, PLoS One 2015, EuroSurveillance 2023.
- Behind the Syringe
- Flu Insights
Introducing Aitor Aspiazu, your go-to flu expert and a Registered Nurse accredited by AHPRA (NMW0001159845). Boasting over two decades of experience in healthcare, Aitor has navigated everything from Emergency Departments to Corporate Wellness Programs—and yes, he’s even battled the flu himself. As the Founder and Lead Nurse Consultant at Corporate Care, he’s the driving force behind workplace health and well-being. No longer in scrubs, he’s now at the forefront of healthcare innovation, leveraging Artificial Intelligence and automation to revolutionise workplace health and well-being. As the Founder and Lead Nurse Consultant at Corporate Care, he’s the visionary behind cutting-edge flu vaccination programs that keep businesses running smoothly. Off-duty, he’s a proud dad and a Padel addict who represented Australia in the World Padel Championship. Trust Aitor; he’s got your back when it comes to flu prevention and modern healthcare solutions.