Strep And Staph: What Are The Differences?

Strep and staph are types of bacteria that can cause infections in the body. They come from the same bacteria family and have similar basic structures but look very different at the microscopic level. The two bacteria tend to affect different body areas, but both can become deadly if left untreated.

Strep, or streptococcus, is most commonly found in the respiratory system, including the throat. The bacteria is the cause of the infection known as "strep throat." Several million people in the United States will experience a strep infection each year, with most cases being mild and resolving on their own or after a course of antibiotics. Only 11,000 to 13,000 strep throat cases are classified as severe.¹

While strep bacteria most commonly causes throat infections, it can also cause: 

• Urinary tract infections

• Skin infections

• Blood infections

• Pneumonia 

• Cellulitis 

• Impetigo

• Scarlet fever

• Toxic shock syndrome 

• Meningitis in newborns 

Staph, or staphylococcus, shares a similar round structure with strep, but staph develops in grape-like clusters. Staph is commonly found on the skin, where it can cause infections in cuts, scrapes, or surgical incisions. These infections are relatively common and may go away on their own or with antibiotics.

In some cases, staph bacteria can spread into other areas of the body, such as the joints, heart, lungs, bones, and bloodstream, where it can cause serious health problems. In 2017, around 119,000 people had bloodstream staph infections, with nearly 20,000 of those cases being fatal.²

The two bacterial infections share a lot in common, including their general structure, some of their symptoms, and their risk of complications. It's important to know what signs to watch for and when you should see a doctor for treatment of a bacterial infection.

Symptoms

Because strep and staph are bacterial infections in the body, they share a few symptoms commonly associated with infection, including pain and fever. Because the two bacteria are often found in different areas, they can have contrasting initial symptoms. 

What are the symptoms of strep throat infections?

There are different strains of streptococcus bacteria, so the symptoms of a strep infection will vary and depend on the location of the infection. Most commonly, strep bacteria are found in the respiratory system, especially in the throat. 

An infection here can cause symptoms such as:

• Pain when trying to swallow, including when you eat or drink

• Swollen lymph nodes in your neck 

• Inflamed tonsils or white spots on the back of your throat

In rare cases, other bacterial infections, such as a staph infection, may also cause a sore throat. Strep bacteria can also cause infections in other areas of the body, such as the lower digestive tract or the vagina, where it can be passed onto a baby during delivery.

Your symptoms will vary depending on where your infection develops, so it’s important to seek medical advice for any new or unusual symptoms you may be experiencing. 

What are the symptoms of a staph infection?

Staph infections are most common on the skin. The bacteria can enter the skin through a cut, scrape, or incision and cause symptoms such as: 

• Redness, swelling, or pain on the skin

• Pus or weeping sores 

• Skin that feels hot or tender to the touch

Staph infections in the skin are usually mild and easily treated. However, staph can infect other areas of the body and create more severe complications. Staph can infect areas such as the bones, joints, heart, lungs, and the bloodstream.

Infections in these areas may result in symptoms such as vomiting, diarrhea, and a high fever. You may also experience tenderness in the affected area, shortness of breath, or excess fluid in the extremities in the case of endocarditis (inflammation of the heart due to a staph infection). 

Causes

While strep and staph bacteria entering the body can cause infections, the transmission of the bacteria types varies.

What causes strep throat?

Strep, or streptococcus bacteria, is commonly transmitted through respiratory droplets. Droplets from your respiratory tract can leave your mouth when you cough, sneeze or talk, and this can pass the bacteria on to others. Someone can contract a strep infection if they: 

• Breathe in infected droplets

• Touch infected droplets, then touch their nose or mouth 

• Share a drinking glass, straw, or silverware with an infected person

In rare cases, it's also possible to contract streptococcus bacteria from food, resulting in food poisoning and flu-like symptoms. 

What causes staph infections?

Staph bacteria travels via skin-to-skin contact. The bacteria is prevalently found on the skin and, in most cases, won't cause any issues. It only becomes problematic when it can enter the skin through a cut, scrape, or incision. Once inside the skin, it can colonize and start an infection. 

If the infection stays within the skin, it is usually easily treated with antibiotics or may go away on its own. If staph infection travels to the bloodstream, lungs, heart, or joints, it can cause more severe complications and medical emergencies. 

It is also possible to contract staph infections by eating contaminated food, causing stomach pains, vomiting, and diarrhea. 

Prevention

As with all bacterial infections, good personal hygiene is key to prevention. You can help prevent bacterial infections by: 

• Covering your mouth when you sneeze or cough

• Washing your hands thoroughly with soap and warm water for at least 20 seconds

• Staying home from work or school when you feel unwell

• Avoid sharing personal items such as drinking glasses, towels, or utensils

You should also cover cuts and scrapes to prevent the transmission of staph bacteria into the wound and always dispose of used bandages appropriately. Avoid sharing towels, too, as staph can be transferred via the fabric. 

It's also possible to contract strep and staph through mishandled food products. If you feel unwell or show any signs of infection, you shouldn't handle or prepare food for others. In all cases, washing your hands thoroughly before handling food is essential to prevent the spreading of bacteria to others. 

Complications

Both strep throat and staph bacteria can cause infections that range from mild to severe. In rare cases, the conditions can cause complications that can become life-threatening. 

If left untreated, a strep throat infection can result in: 

• Kidney inflammation

• Rheumatic fever

• Sinus infections

• Ear infections

An untreated staph infection can also travel deeper into the body and cause severe medical conditions. Staph infections can: 

• Create infections in the joints, bones, and heart 

• Cause pneumonia 

• Travel to the bloodstream and cause sepsis

Staph infections that enter the bloodstream are very serious. They can cause sepsis, your body's reaction to a severe infection that can cause organ failure, tissue damage, and even death. The symptoms of sepsis include fever and low blood pressure.³

The link between strep, staph, and toxic shock syndrome (TSS)

Both staph and strep infections can travel deeper into the body and release toxins, causing a condition known as toxic shock syndrome (TSS). TSS is a life-threatening infection that can cause: 

• High fever

• Low blood pressure 

• Diarrhea

• Vomiting

• Disorientation

• A rash or sunburn on the body

• Multiorgan failure

If you are experiencing any symptoms associated with TSS, you should seek medical attention immediately. 

Is strep throat worse than a staph infection?

Strep throat and staph infections both range from very mild to life-threatening illnesses. In most cases, both conditions are mild enough to go away on their own or after taking antibiotics. However, strep and staph infections can cause serious medical conditions if left untreated. In the most severe cases, they can cause toxic shock syndrome. 

TSS is the body's reaction to serious infections. The condition can cause organ failure, tissue damage, and death. The mortality rate of toxic shock syndrome caused by streptococcus bacteria can exceed 50%.⁴

TSS caused by other bacteria (such as staphylococcus) has a mortality rate of less than 3%. In this case, a streptococcal infection is more dangerous than a staphylococcal infection.

Diagnosis

Your doctor can diagnose a strep or staph infection by confirming the presence of the infection-causing bacteria. They may do this by taking samples of the infected area or testing your blood and urine. 

To diagnose strep throat, your doctor may gently swipe at the back of your throat with a cotton bud to collect a sample. With that sample, they may run one of two tests: 

• Rapid strep test

• Throat culture

These tests will let your doctor know if the streptococcus bacteria is present. 

In the case of a staph infection, the type of testing used to diagnose the condition will largely depend on the location of the infection. For minor staph infections on the skin, a doctor may diagnose it after a visual examination and asking about your symptoms.

For staph infections affecting other areas of the body, your doctor may need a culture, stool sample, nasal swab, or blood test to make a definitive diagnosis.

Treatment of strep and staph

Doctors routinely treat strep and staph infections with antibiotics. Most cases require taking a short course of antibiotics. More severe infections, such as those that have traveled to the heart, may require antibiotic treatment lasting up to six weeks.

You should stay home from work or school until you've been on antibiotics for at least 12 hours and your fever is gone to avoid spreading the bacteria to others. This advice is essential in cases of strep throat, which can quickly pass through respiratory droplets. 

In some cases, strep and staph bacteria can become resistant to antibiotic treatments. One common resistant bacteria strain is called methicillin-resistant staphylococcus aureus (MRSA).

The infections can spread through skin-to-skin contact, resulting in widespread community outbreaks, and have become a serious concern for doctors because they are so challenging to treat. Vancomycin, a powerful antibiotic given through an IV, is the preferred treatment for MRSA. 

If you are given antibiotics for a strep or staph infection, it's crucial that you take the medication as prescribed and finish the entire course of treatment, even if you are feeling better. Doing so can help prevent antibiotic resistance in the future. 

When should you see a doctor?

Most cases of strep and staph infections are mild enough to go away by themselves or through antibiotic treatments. You can try at-home remedies such as getting plenty of rest, drinking lots of fluids, and keeping infection sites clean. However, you should make an appointment with your doctor right away if: 

• Symptoms don't go away within a few days

• Symptoms start to get worse

• You develop a fever of more than 101 degrees

• You start to feel nauseated or begin vomiting

• You have blisters, swelling, or tenderness at the infection site

These are signs that your infection may worsen, and you should seek medical attention immediately. Allowing the infection to go untreated could lead to life-threatening conditions such as sepsis and toxic shock syndrome. 

The lowdown

Streptococcus (strep) and staphylococcus (staph) bacteria are two common causes of infections in the body. The bacteria strep infections are most commonly found in the throat, resulting in strep throat.

Strep is usually passed via respiratory droplets from sneezing, coughing, or speaking, whereas staph bacteria are commonly found on the skin and pass through skin-to-skin contact. Staph bacteria can cause infection when entering the skin through a cut or scrape. 

The symptoms of a strep or staph infection will vary depending on the location of the infection. Most commonly, strep bacteria causes an infection in the throat, where it may cause pain when swallowing, a fever, or swollen lymph nodes in the neck. Staph infections most commonly affect the skin and can cause redness, swelling, and tenderness.

In most cases, a course of antibiotics can treat bacterial infections and ease symptoms. If left untreated, strep and staph infections can travel deeper into the body and cause life-threatening conditions.

Symptoms of serious infections include fever, chills, vomiting, and disorientation. In the most severe cases, these infections can result in toxic shock syndrome, the body's response to toxins released by the bacteria. TSS can cause organ failure, tissue damage, and death.

A doctor can diagnose a strep or staph infection by using a culture, blood, or urine test, depending on the site of infection. Based on the results, they'll prescribe the appropriate course of antibiotics, and you should start to feel better within 24 to 48 hours. If your symptoms don't go away or worsen, you should contact your doctor again to ensure the infection hasn't spread to other areas of the body.

If you are experiencing any signs of strep or staph infection, talk to your doctor about treatment options to avoid more serious medical conditions. 

Frequently asked questions

Are staph and strep the same family?

No. They are both gram-positive bacteria but belong to different family classifications. However, they share many similarities. The two bacteria are spherical, but staph grows in clusters like grapes, while strep grows in long chains. Both bacteria are gram-positive, meaning they give a positive result on a Gram stain test used for diagnosing bacterial infections.⁵

What is the best test to differentiate between staphylococcus and streptococcus?

Your doctor can diagnose a strep or staph infection through a swab of the infected site or, depending on the site of the infection, via blood or urine testing. It may take one or up to three tests to conclusively differentiate the bacteria. Doctors may use the following tests: - Catalase test - Coagulase test - Antibiotic susceptibility test

What are other causes of sore throats?

Viral infections can also cause a sore throat, often accompanied by a cough, runny nose, and raspy voice. In the case of a viral infection, your doctor will not prescribe antibiotics but instead offer other treatment options to help your body fight the virus.