Quick Answer
Yes, tonsillitis is contagious. The contagious period depends on the cause:
- Viral tonsillitis: Contagious for 7–10 days, until all symptoms clear. Antibiotics won't shorten this.
- Bacterial (strep): No longer contagious after 24–48 hrs on antibiotics, once fever resolves.
- Untreated bacterial: Can remain contagious for up to 10–14 days.
- Glandular fever: Contagious for weeks to months. See a GP.
That sandpaper throat. The fever that crept in overnight. Then the practical question: is it contagious? Can someone with symptoms go to work, send children to school, or are people nearby at risk?
This article answers those questions with guidance from AHPRA-registered GPs. The rules differ depending on whether tonsillitis is viral or bacterial. As of February 2026, the guidance below reflects current Australian clinical practice.
What is Tonsillitis?
Tonsillitis is inflammation of the tonsils: the two oval-shaped lymph tissue pads on either side of the back of the throat. They are the immune system's first checkpoint for inhaled and swallowed pathogens. When they become infected, the result is tonsillitis.
It is one of the most common infections seen by Australian GPs, particularly in children aged 5–15, though adults get it too. According to a review published in American Family Physician,1 the vast majority of tonsillitis cases are viral. Group A Streptococcus (bacterial) accounts for 15–30% in children and 5–15% in adults.
Common symptoms
Sore or scratchy throat, pain when swallowing, red or swollen tonsils (sometimes with white or yellow patches), fever, swollen tender lymph nodes in the neck, headache, fatigue, bad breath, and in children, stomach pain or vomiting. In severe cases, a muffled "hot potato" voice and difficulty opening the mouth can develop. That needs same-day medical attention.
Is Tonsillitis Contagious?
Yes. In most cases, tonsillitis is contagious. The viruses and bacteria responsible spread easily from person to person, particularly in enclosed spaces: classrooms, open-plan offices, shared households, public transport.
How contagious someone is depends on the cause, how far the illness has progressed, and how close contact is with others. One nuance worth knowing: if someone catches the same pathogen, they won't necessarily develop the same symptoms. One person gets full tonsillitis; another just gets a stuffy nose.
Tonsillitis is contagious from before symptoms start. A mild sore throat does not mean someone is safe to be around others.
What is the Incubation Period for Tonsillitis?
The incubation period is the time between exposure to the pathogen and when symptoms appear. During the tail end of this window, someone can already be contagious before they feel unwell.
| Type | Incubation Period | Contagious Before Symptoms? |
|---|---|---|
| Viral tonsillitis | 2–5 days | Yes, up to 2–3 days before symptoms appear |
| Bacterial tonsillitis (strep) | 1–5 days | Yes, approximately 24–48 hrs before symptoms |
| Glandular fever (EBV) | 4–7 weeks | Yes, contagious in saliva for weeks |
Exposure often happens at work or on the school run before anyone realises they are unwell. By the time someone is visibly sick, others in the household have often already been exposed. That is one reason tonsillitis spreads so easily.
How Long is Tonsillitis Contagious For?
This is the question behind most searches. The answer depends on the cause: viral or bacterial.
| Type | Contagious Period | Effect of Antibiotics | Safe to Return? |
|---|---|---|---|
| Viral tonsillitis | 2-3 days before symptoms → until symptoms resolve (~7-10 days) | No effect. Antibiotics don't treat viruses | When fever gone and feeling well |
| Bacterial (strep) on antibiotics | Non-contagious after 24-48 hrs of treatment | Shortens the contagious period sharply | After 24-48 hrs on antibiotics and no fever |
| Bacterial, untreated | Up to 10-14 days | N/A | Avoid others until treated and fever-free |
| Glandular fever (EBV) | Weeks to months in saliva | Antibiotics don't treat EBV | Once fever gone and energy returning. Consult a GP |
As of February 2026: Bacterial tonsillitis plus 24–48 hours on antibiotics plus fever resolved is generally safe for return to work2 or school. Viral tonsillitis means staying home until symptoms clear. When uncertain, speak to a GP.
How to Tell If Tonsillitis Is Viral or Bacterial
This is the most clinically important distinction because treatment differs completely. Symptoms alone cannot confirm the cause, but several patterns help.
| Feature | Suggests Viral | Suggests Bacterial (Strep) |
|---|---|---|
| Cough | Often present | Usually absent. A useful clue |
| Runny nose / congestion | Common | Uncommon |
| Onset | Gradual | Sudden and severe |
| White/yellow patches on tonsils | Sometimes | More common (pus/exudate) |
| Fever | Mild to moderate | Often high (38.5°C+) |
| Hoarse voice | Common | Less typical |
Dr Sarah's Clinical Tip: "The absence of a cough is one of my most useful clinical clues for bacterial (strep) tonsillitis. High fever, white patches on the tonsils, no cough. Group A Strep is top of the list. That said, a GP assessment and sometimes a throat swab are needed to confirm it. Don't try to self-diagnose and self-prescribe."
A throat swab is the only definitive test. Doccy doctors can assess symptoms clinically via telehealth and advise whether a swab or antibiotic prescription is appropriate.
Is Tonsillitis Contagious While on Antibiotics?
For bacterial tonsillitis, transmission risk drops after 24–48 hours of treatment once fever has gone. For viral tonsillitis, antibiotics make no difference to contagiousness.
Bacterial tonsillitis on antibiotics
Antibiotics (penicillin V or amoxicillin in most Australian cases) rapidly reduce the bacterial load in the throat. After 24–48 hours on the correct antibiotic, with fever resolved, someone is generally non-contagious. Most employers and schools accept this as the return-to-work threshold.
Complete the full course. Most people feel better by day 3 and feel tempted to stop there. Stopping early raises the risk of rebound infection and complications.
Dr Sarah's Clinical Tip: "The number one question I get is: 'Can I stop my antibiotics once the pain goes?' No, and I mean it. The bacteria are still present even when you feel better. Stopping the course early is the leading cause of rebound tonsillitis and increases the risk of rheumatic fever, which can cause permanent heart damage. Ten days. Every time."
Viral tonsillitis on antibiotics
Antibiotics are ineffective against viruses. If viral tonsillitis is treated with antibiotics (inappropriate prescribing), contagiousness is unchanged. The contagious period ends when symptoms resolve.
Bacterial tonsillitis: generally non-contagious after 24–48 hrs on antibiotics with fever gone. Viral tonsillitis: contagious until symptoms resolve.
When is it Safe to Return to Work or School?
Current Australian guidance as of 2026:
| Type | When It's Safe to Return | Medical Certificate Needed? |
|---|---|---|
| Viral tonsillitis | When fever has resolved and the person feels well enough | Yes, if absent more than one day |
| Bacterial (on antibiotics) | After 24-48 hrs on antibiotics and fever-free | Yes, if absent more than one day |
| Glandular fever3 | Once fever gone and energy returning. Consult GP | Almost certainly. Extended absence likely |
Under the Fair Work Act 2009, Australian employers can request reasonable medical evidence for personal leave. A medical certificate from an AHPRA-registered doctor satisfies this. Doccy can issue one via telehealth without a clinic visit.
For children returning to school:4 Most Australian schools follow the same rule: fever-free for 24 hours and feeling well. For confirmed strep throat, stay home for at least 24–48 hours after starting antibiotics and until the fever is gone.
How Does Tonsillitis Spread?
Four main routes. Understanding them helps protect others while someone is contagious.
Airborne droplets
Coughing and sneezing release tiny droplets containing the pathogen. Anyone within about one to two metres is at risk. Enclosed, poorly ventilated spaces (classrooms, open-plan offices, public transport) increase transmission.
Direct contact (including kissing)
Saliva-to-saliva contact is one of the most efficient transmission routes. Glandular fever (EBV) is sometimes called the "kissing disease" for this reason. Close physical contact should be avoided while symptomatic.
Shared items
Sharing cutlery, glasses, water bottles, or toothbrushes can transfer pathogens from an infected person's mouth. Separate drinking glasses and avoiding shared food matter more than usual when someone is unwell.
Surface contact
Some viruses and bacteria survive briefly on hard surfaces. Touching a contaminated surface then touching the eyes, nose, or mouth can cause transmission, though this is less common than droplet spread.
Can You Get Tonsillitis if You've Had Your Tonsils Removed?
Someone without tonsils cannot get tonsillitis as such, but the same infection can still occur. Group A Streptococcus can infect the remaining throat tissue, causing strep pharyngitis with very similar symptoms. The pathogens can still spread to others.
A tonsillectomy removes the tonsils, not vulnerability to the pathogens that cause tonsillitis. The main benefit is fewer recurrences, not immunity.
How to Tell If It's Glandular Fever
Glandular fever (infectious mononucleosis, caused by the Epstein-Barr virus) can look nearly identical to severe bacterial tonsillitis. It primarily affects people aged 10–30 and is highly contagious. The virus persists in saliva for weeks to months.
Signs that suggest glandular fever rather than standard tonsillitis:
- Profound fatigue, often the most prominent symptom
- Swollen glands at the back of the neck (not just the front)
- Symptoms lasting more than 10 days
- Swollen spleen or abdominal discomfort
- Skin rash, particularly after taking amoxicillin
- More common in teenagers and young adults than other age groups
Amoxicillin rash warning: Taking amoxicillin when the cause is actually glandular fever causes a widespread red rash in up to 90% of cases. If a rash develops while on antibiotics for a sore throat, stop the antibiotic and see a doctor promptly. It is a diagnostic flag for EBV infection.
Glandular fever is diagnosed via blood test (monospot test or EBV-specific antibodies, plus a full blood count). Antibiotics won't treat it. Rest is the primary treatment. Most people recover over 2–6 weeks.
How to Prevent Spreading Tonsillitis
While contagious, these measures reduce risk for others:
- Stay home, particularly during the first 24–48 hours of bacterial tonsillitis before antibiotics take effect
- Wash hands frequently, especially after coughing, sneezing, or blowing the nose
- Cover coughs and sneezes into the elbow, not the hand
- Do not share cutlery, glasses, water bottles, or toothbrushes
- Avoid kissing until confirmed non-contagious
- Improve ventilation in shared spaces
- Disinfect bathroom taps, door handles, and kitchen benchtops
- Replace the toothbrush once recovered. Bacteria can persist on bristles
What's the Treatment for Tonsillitis?
Viral tonsillitis: symptom management
Viral tonsillitis resolves on its own within 7–10 days. No antiviral treatment exists. Symptom management includes staying well hydrated, using paracetamol or ibuprofen for pain and fever (check dosing carefully; ibuprofen isn't suitable for everyone), rest, and warm honey-lemon drinks, ice blocks, or over-the-counter anaesthetic throat sprays for comfort.
Bacterial tonsillitis: antibiotics
Confirmed or strongly suspected Group A Strep tonsillitis requires antibiotics. Current Australian prescribing guidelines5 recommend:
- Phenoxymethylpenicillin (penicillin V), first-line, 10-day course
- Amoxicillin, alternative first-line
- Cefalexin, for mild penicillin allergy
- Clindamycin or azithromycin, for severe penicillin allergy
Ten days. Full course. Do not stop early because symptoms improve.
Recurrent tonsillitis
If a patient experiences 7 or more episodes in one year, 5 or more per year over two consecutive years, or 3 or more per year over three years, a GP can refer to an ENT specialist to discuss tonsillectomy.
When to See a Doctor
Most tonsillitis cases resolve without drama. See a GP if:
- Sore throat and fever aren't improving after 3–4 days
- Difficulty swallowing liquids
- The mouth won't open fully
- One side of the throat looks more swollen than the other
- A widespread skin rash develops
- Symptoms last more than 10 days
- The infection returns shortly after a treated episode
Go to emergency if: There is difficulty breathing, drooling because swallowing isn't possible, rapidly worsening neck swelling, or neck stiffness. These may indicate quinsy6 (peritonsillar abscess) or epiglottitis. Both are medical emergencies. Call 000 or go to the nearest ED immediately.
Getting a Medical Certificate for Tonsillitis
Tonsillitis keeps people off work for days. Under Australian law, paid personal leave applies, and telehealth means a clinic visit (and spreading infection in a waiting room) is not required to obtain evidence.
Do patients need a sick note for tonsillitis?
Under the Fair Work Act 2009, employers can request reasonable evidence for absences. Tonsillitis qualifies as a valid reason. Most workplaces require a medical certificate for absences longer than one day. Some accept a statutory declaration for very brief absences.
Can patients get a medical certificate for tonsillitis online?
Yes. Doccy's AHPRA-registered doctors assess patients via telehealth and issue a legally valid medical certificate, the same as from any GP clinic, sent directly to the inbox. No waiting room and no travel while contagious.
Can patients get a tonsillitis prescription online?
Yes. If a Doccy doctor determines bacterial tonsillitis requiring antibiotics, they issue an electronic prescription (eScript) sent to a pharmacy of the patient's choice. Someone else can collect the medication while the patient stays home to recover.
Key Takeaways
- Viral tonsillitis stays contagious for 7–10 days. Stay home until symptoms clear. Antibiotics won't help.
- Bacterial tonsillitis: non-contagious after 24–48 hours on antibiotics with fever resolved. Ten-day course; do not stop early.
- Glandular fever stays contagious for weeks to months in saliva. See a GP and allow adequate recovery time.
- Most Australian employers require a medical certificate for absences over one day. Get a medical certificate from Doccy online without leaving home.
Rest when needed. Pushing through tonsillitis at work or school spreads infection before symptoms appear. Protecting others means taking the time the body needs.
Medical disclaimer: This article is for general informational purposes and does not constitute medical advice. Always consult an AHPRA-registered healthcare professional for advice specific to your situation. In a medical emergency, call 000. Last reviewed: February 2026.
Footnotes
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American Academy of Family Physicians — Pharyngitis and tonsillitis (clinical review). https://www.aafp.org/afp/2016/0701/p24.html?utm_source=doccy.com.au ↩
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Fair Work Ombudsman — Paid sick and carer's leave. https://www.fairwork.gov.au/leave/sick-and-carers-leave/paid-sick-and-carers-leave?utm_source=doccy.com.au ↩
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Healthdirect Australia — Glandular fever. https://www.healthdirect.gov.au/glandular-fever?utm_source=doccy.com.au ↩
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NSW Health — Streptococcal infection. https://www.health.nsw.gov.au/Infectious/factsheets/Pages/Streptococcal-infection.aspx?utm_source=doccy.com.au ↩
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South Australian Government (SA Health) — Antimicrobial (antibiotic) treatment guidelines. https://www.sahealth.sa.gov.au/wps/wcm/connect/public+content/sa+health+internet/clinical+resources/clinical+topics/antimicrobials+%28antibiotics%29/treatment+guidelines?utm_source=doccy.com.au ↩
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Healthdirect Australia — Tonsillitis. https://www.healthdirect.gov.au/tonsillitis?utm_source=doccy.com.au ↩
