Southern Cross Medical Library

Southern Cross Medical Library

Strep throat is an infection of the throat and tonsils caused by Streptococcal bacteria. Typical symptoms are a sore throat, chills, fever and swollen lymph nodes in the neck.

Strep throat is cured by antibiotic treatment. If left untreated, strep throat can cause serious heart and kidney complications.

Important note:

New Zealanders at high risk of developing rheumatic fever – a serious complication of strep throat – should have any sore throat checked by a doctor. A person is considered to be at high risk of getting rheumatic fever if they or a family or household member has had rheumatic fever before, or they meet two or more of the following criteria:

  • They are Māori or Pacific
  • They are aged 3–35 years
  • They live in crowded living conditions or a lower socioeconomic area of the North Island.

If in doubt, call Healthline on 0800 611 116.


In New Zealand, sore throats are among the top 10 symptoms for which patients go to their doctor.

Sore throats are often associated with a viral infection like colds and flu, and may develop into tonsillitis. A viral sore throat will usually get better by itself and has a low likelihood of complications.

A sore throat caused by bacteria, however, has a higher chance of complication and requires more attention. A sore throat in children that is accompanied by headache, high fever, stomach ache, vomiting, or severe tiredness, with or without a red rash, indicates the need for a visit to a family GP.

Although many types of bacteria can cause throat infections, Streptococcus, or strep, is the most common.

Strep throat is contagious. It is spread by close contact with an infected person, often by inhaling airborne droplets from an infected person's coughs and sneezes. It can also be spread through shared food or drinks.

Family homes and school and university hostels, provide an ideal environment for the transmission of strep throat from one person to another.

Children between the ages of 5 and 15 years have the highest incidence of strep throat.

Signs and symptoms

Symptoms of strep throat develop one to four days after exposure to the bacteria via airborne droplets or by direct contact with an infected person.

The most characteristic symptoms of strep throat are sore throat and painful swallowing. Other symptoms include:

  • Chills and fever
  • Swollen and tender glands (lymph nodes) on the sides of the neck
  • Red and swollen appearance inside the throat
  • Pus-like white or yellow patches or spots may be visible on the back of the throat and on the tonsils
  • Headache, nausea, and vomiting may also be present
  • Earache
  • Body aches and pains.

Some people will develop a red skin rash that feels rough to the touch. The rash usually appears first on the chest and may spread to the neck, stomach, and arms. A strep throat infection accompanied by this distinctive rash is known as scarlet fever. The rash is caused by toxins produced by the Streptococcus bacteria.


Potential complications of untreated strep throat infection include middle ear infection (otitis media), sinus infection (sinusitis), pneumonia, meningitis, kidney disease, and rheumatic fever. Of these, rheumatic fever and kidney disease are of most concern.

Rheumatic fever

Rheumatic fever is a serious but preventable complication of strep throat. Untreated or inadequately treated strep throat may result in bacteria remaining in the tonsils where they can trigger a person’s immune system to mistakenly attack other parts of the body.

This immune response may cause inflammation in the brain, heart, joints and skin. This is rheumatic fever and it usually occurs two to four weeks after a strep throat infection.

The most serious consequence of rheumatic fever is that inflammation affecting the heart can cause scarring of the heart valves, necessitating heart valve replacement surgery. Prompt diagnosis and rapid treatment of strep throat with antibiotics can prevent rheumatic fever.

168 New Zealanders were hospitalised with rheumatic fever in 2019 – the majority were Maori and Pacific children and teenagers (aged 4–19 years).

Visit the Ministry of Health’s rheumatic fever webpage for more information.

Kidney disease

The response of a person’s immune system to a strep throat infection may also cause inflammation of the kidneys.

It usually occurs one to three weeks after a strep throat infection, and typically resolves on its own within several days without causing any long-term kidney damage. Children are at the highest risk of developing this condition following a strep throat infection. Symptoms may include blood in the urine, swollen ankles, and puffy eyes.


Diagnosis of strep throat is important because starting antibiotic treatment within 48 hours lessens the duration of symptoms by one to two days, cuts down the risk of rheumatic fever and kidney disease, and reduces the risk of disease transmission to other people.

During a GP visit, a throat culture might be taken by touching a cotton swab to the throat and tonsils. The swab is then sent to a laboratory where the bacteria can be identified.

Because the throat culture results can take up to 48 hours to come back to the GP, treatment with antibiotics may be started as soon as the throat swab has been done, especially if a person is considered to be at high risk of getting rheumatic fever.


The potential for serious complications means treatment with antibiotics will be started as soon as possible for most people.

Antibiotics, most commonly penicillin in pill form, are used to treat strep throat. In some cases a penicillin injection might be preferred. Alternative antibiotics can be used for people allergic to penicillin.

With antibiotic treatment taken in pill form, the full 10-day course must be completed, even if symptoms resolve after only two to three days, to ensure that the infection does not return and to minimise the risk of developing rheumatic fever and kidney disease.

Treatment for people with strep throat who are at low risk of rheumatic fever may not be treated with antibiotics if their symptoms are mild and they are unlikely to infect others. Instead treatment may be aimed at symptom relief as the infection is likely to get better in a few days on its own.

Symptom relief for sore throat can be gained from a saltwater gargle (half teaspoon of salt to a cup of warm water) and sucking throat lozenges containing ingredients that are cooling, anaesthetic, anti-septic, or anti-inflammatory.Pain relief and reduction of fever can be obtained from use of over-the-counter paracetamol and ibuprofen.


Surgical removal of the tonsils may be recommended for people who have recurrent strep throat. Surgery does carry some risks, including bleeding during and after the operation in some people.

Throat pain and difficulty eating is usual in the first few days after the operation. Full recovery typically takes two to three weeks.


An important part of managing a strep throat infection is to prevent its spread to other people. Simple steps to help prevent the spread of strep throat include:

  • Covering the mouth and nose with a tissue when sneezing or coughing
  • Frequent and thorough washing and drying of hands
  • Avoiding close physical contact, including not kissing and ensuring space between children when they sleep.
  • Not sharing food, liquids, or eating or drinking utensils with an infected person
  • If strep throat is confirmed, staying home for 24 hours after starting antibiotic therapy.

Support and information

Additional information about strep throat and rheumatic fever can be obtained from Healthline, which is a free 24-hour telephone advice service provided by the Ministry of Health. Healthline is staffed by registered nurses who can advise and recommend appropriate care for callers with symptoms.

Free phone: 0800 611 116



Heart Foundation (2019). Group A streptococcal sore throat management guideline: 2019 update (Booklet PDF). Auckland: National Heart Foundation of New Zealand.
Khan, Z.Z. (2018). Group A streptococcal (GAS) infections (Web page). Medscape Drugs and Diseases. New York, NY: WebMD LLC. [Accessed: 13/08/2018]
Ministry of Health (2018). Sore throat (Web Page). Wellington: New Zealand Government Ministry of Health. [Accessed: 13/08/20]
O’Toole, M.T. (Ed.) (2017). Rheumatic Fever. Mosby’s Dictionary of Medicine, Nursing & Health Professions (10th ed.). St Louis, MI: Elsevier.
O’Toole, M.T. (Ed.) (2017). Strep throat. Mosby’s Dictionary of Medicine, Nursing & Health Professions (10th ed.). St Louis, MI: Elsevier.
Ministry of Health (2020). Reducing rheumatic fever (Web Page). Wellington: New Zealand Government Ministry of Health. [Accessed: 13/08/20]

Last reviewed: August 2020


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The purpose of the Southern Cross Medical Library is to provide information of a general nature to help you better understand certain medical conditions. Always seek specific medical advice for treatment appropriate to you. This information is not intended to relate specifically to insurance or healthcare services provided by Southern Cross.