How Long Is Strep Throat Contagious? Symptoms, Treatment & Causes (original) (raw)
What is strep throat?
If strep throat is treated with antibiotics, it is no longer contagious after 24 hours.
Strep throat is one of the causes of a throat or tonsil infection. While virus infections cause the majority of throat infection, strep throat caused Group A Streptococcal bacteria, is important to diagnose because of the potential complications that may occur afterwards.
Strep infection is most common in children between ages 5 and 15, but strep may infect people of all ages.
It is difficult to tell the difference between a sore throat caused by a virus, and one caused by strep.
What are the signs and symptoms of strep throat?
The incubation period for strep throat is 2-5 days after exposure to the bacteria. If you develop a sore throat and a fever, you should consider the possibility that you may have strep throat, especially if another family member or a coworker has been diagnosed with strep.
In addition to a sore throat, patients with strep throat may complain of the following
- headache
- fever
- chills,
- nausea
- abdominal pain
Physical findings, in addition to a red throat and swollen tonsils, may include:
- Streaks of pus on the tonsils or the back of the throat,
- Tiny red spots on the of the mouth (petechiae)
- A red skin rash that starts on the neck and chest and spreads to the rest of the body. The rash may feel rough like sandpaper. When a patient with a strep infection develops this rash, it is called scarlet fever.
If you have a runny nose, constant sneezing, and coughing, it is less likely that you have strep throat.
SLIDESHOW Sore Throat or Strep Throat? How to Tell the Difference See Slideshow
How is strep throat spread?
Strep throat spreads easily through respiratory droplets. The bacteria found in the mouth, throat and nose.
Strep throat is easily spread when an infected person sneezes or coughs. Kissing can also cause person-to-person spread. Strep can also survive on glasses, cups, utensils, toothbrushes, doorknobs, and other objects. If people who do not have strep throat touch these contaminated objects and then touch their mouth or nose, they too can become infected with strep.
Is strep contagious through the air?
Strep bacteria spread through the air via respiratory droplets when an infected person coughs or sneezes, or through direct contact with mucus from the nose or throat of an infected person.
How long is strep contagious?
After antibiotics are started, the patient is no longer infectious after 24-48 hours.
If antibiotics are not taken, strep throat remains contagious for about 2-3 weeks.
Is strep contagious?
Yes, strep throat is contagious. It is caused by Group A Streptococcus bacterium, which spreads through respiratory droplets from the infected person. When an infected person talks, coughs, or sneezes, droplets containing the bacteria can remain suspended in the air and infect others should they inhale the droplets. Strep can also spread by sharing glasses, cups or utensils, or by direct contact with the infected person.
What is the strep throat incubation period?
The incubation period for strep throat is 2 to 5 days after exposure to the bacteria. Following this period, symptoms may develop and include a sore throat, headache, fever, chills, nausea and abdominal pain.
Is there a test to diagnose strep?
Strep throat is diagnosed by a rapid strep test throat swab, done at the bedside with results available within minutes.
It is difficult to tell the difference on physical exam between a sore throat caused by strep and a sore throat caused by a viral infection.
How do I know when I'm cured of the infection?
- Individuals can be cured of strep throat by taking antibiotics.
- A person taking antibiotics is no longer contagious after 24-48 hours.
- Without taking antibiotics, persons with strep throat are infectious for about 2-3 weeks.
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Is strep throat serious? When should I call the doctor?
If you suspect that you have strep throat, you should contact a health care provider. T may be more urgent to seek care if these signs and symptoms are present:
- Have a fever over 102 F or 38.8 C
- Are dehydrated and have an associated headache, abdominal pain, or nausea and vomiting.
- Develop symptoms of drooling, difficulty breathing, and/or swallowing
The major reason to seek medical care for strep throat are the complications that may develop:
- Ear infection
- Peritonsillar abscess
- Invasive streptococcal infection (toxic shock syndrome, necrotizing fasciitis)
- Rheumatic fever
- Autoimmune disorder
- Kidney inflammation (glomerulonephritis)
Early treatment of strep throat may help prevent these and other complications.
Frequently asked questions
- Is strep throat contagious without a fever? Yes, strep throat can be contagious even without a fever. Strep is more likely to spread if the person has symptoms. It is less likely to spread when the person is asymptomatic.
- Can strep throat spread through coughing? Yes, strep throat can spread through coughing. When an infected person coughs, respiratory droplets containing the bacteria become suspended in air and can be breathed in by others.
- When is strep throat no longer contagious? For those taking antibiotics, the infection stops being contagious after 24-48 hours of starting treatment. People with strep who are not treated are contagious for 2-3 weeks.
- Is strep throat contagious during the incubation period? Yes, strep throat is contagious during the incubation period.
- Can you catch strep throat from surfaces? Yes, you can catch strep throat from surfaces such cups, glasses. doorknobs and kitchen counters that may be contaminated with strep bacteria.
- Is strep throat contagious after taking antibiotics? Strep throat is no longer contagious 24-48 hours after starting antibiotics.
- How can you prevent spreading strep throat? You can prevent the spread of strep throat by staying home from work or school and avoiding social contact during the first 1-2 days of treatment with antibiotics. It is important to cover your face when coughing or sneezing. People who have upper respiratory tract infections, like colds or sore throats, should wear masks when in public, to prevent spreading infections to others.
- Are children more contagious with strep throat? Yes, children tend to be more contagious with strep throat.
- Is strep throat contagious after symptoms are gone? Strep is no longer contagious after 24-28 hours after starting antibiotics. It can be contagious in the incubation period, though no symptoms have yet to become apparent.
Medically Reviewed on 1/7/2025
References
Kimberlin DW, Ritu Banerjee R, et al. "Group A Streptococcal Infections". Chapter. Red Book: 2024–2027 Report of the Committee on Infectious Diseases, Committee on Infectious Diseases. American Academy of Pediatrics. 2024.
Sauve L, Forrester AM, et al. Group A streptococcal (GAS) pharyngitis: A practical guide to diagnosis and treatment https://cps.ca/en/documents/position/group-a-streptococcal Updated: 08Feb2024 Accessed: 21Dec2024