What is an invasive staph infection?

Invasive staphylococcus aureus (staph) infections happen when bacteria get inside your body.

Staph bacteria are often found on your skin or in your nose. Even healthy people can have staph bacteria on their skin. They usually don't cause any problems.

However, if bacteria get deep into your body, it can be very serious. The bacteria can infect your:

• blood stream (septicaemia, sepsis and toxic shock syndrome)
• bones and joints (osteomyelitis and septic arthritis)
• heart (infective endocarditis)
• lungs (pneumonia)

Invasive staph infections are less common than staph skin infections.

Who is at risk of a staph infection?

Some people have a higher chance of getting a serious staph infection. This includes. people who:

• have been in hospital
• have medical devices going into their bodies, like a catheter
• inject drugs
• have contact with someone who has a staph infection

What are the symptoms of invasive staph infections?

The symptoms of staph infections vary, depending on the type of infection you have.

Some of the more serious symptoms to be aware of are:

• difficulty breathing
• headache
• fatigue (tiredness)
• pain and swelling in your joint
• chest pain
• feel very unwell

Other signs of an invasive staph infection are:

• a fever (temperature of 38°C or over) or are shivering
• cough
• red, warm tender skin at the site of the pain
• difficulty moving a joint
• confusion or disorientation
• a skin rash that looks like sunburn
• blood spots in your eyes or bleeding underneath your fingernails or toenails

Your symptoms may come on gradually over several weeks or more quickly.

Children with sepsis can get very sick very quickly. Signs of sepsis in a child are:

• a rash that doesn't fade when you press it
• fast breathing or shortness of breath
• fast heartbeat
• sleepy or confused
• cold, clammy skin — bluish lips and fingers
• unexplained pain

Find out more about the symptoms of osteomyelitis.

What causes invasive staph infections?

A staph infection happens when staphylococcus bacteria get inside your body and multiply (grow in number).

• Infective endocarditis happens when staph bacteria infect your heart. It's more common in people who have problems with their heart valves, but it can happen to anyone. Endocarditis can be life-threatening.
• Osteomyelitis is an infection in your bone. It can affect any bone. However, it's more common in the knee, hip and ankle.
• Pneumonia can be caused by a staph infection in your lungs.
• Sepsis is when your body damages its own tissues and organs due to an infection. This is a medical emergency.
• Septic arthritis is an infection in a joint, such as your knee, shoulder or hip joint. It's more common in young children.
• Toxic shock syndrome is very rare. It happens when staph bacteria get into your bloodstream and release poisons. This can lead to organ and tissue damage.

When should I see my doctor?

Signs that you have an invasive staph infection depend on which part of your body is infected.

How are invasive staph infections diagnosed?

Your doctor will ask about your symptoms and examine you.

Tests that can help with the diagnosis are:

• blood tests
• wound cultures — to test which bacteria is causing your infection
• biopsy — your doctor might take a small piece of infected tissue for testing
• ultrasound — real-time pictures of the inside of your body
• CT scan — a 3D image of a part of your body
• bone scans

How are invasive staph infections treated?

Treatment of your staph infection will depend on how bad your infection is and where it is in your body.

Medicines for staph infections

Serious bacterial infections are treated with antibiotics. These medicines either kill the bacteria or stop them multiplying. This helps your body's immune system fight the bacteria.

Serious staph infections may need to be treated with intravenous antibiotics in hospital. Your doctor's choice of antibiotic will depend on the bacteria causing your infection.

Antibiotic resistance is a growing problem, so antibiotics must always be used as prescribed. Resistance happens when bacteria adapt to protect themselves from an antibiotic.

What are the complications of invasive staph infections?

There are several possible complications of invasive staph infections, such as:

• post-sepsis syndrome
• methicillin-resistant staphylococcus aureus (MRSA)
• death in severe cases

Post-sepsis syndrome

This syndrome affects up to 1 in 2 people who survive sepsis. Symptoms include:

• sleep disturbances, including insomnia
• nightmares, hallucinations, flashbacks and panic attacks
• muscle and joint pains
• extreme tiredness
• trouble concentrating
• loss of self-confidence

Symptoms of post-sepsis syndrome usually last between 6 and 18 months.

Methicillin-resistant staphylococcus aureus (MRSA)

Infections caused by methicillin-resistant staphylococcus aureus (MRSA) are more difficult to treat. This is because the bacteria are resistant to some commonly used antibiotics. An antibiotic won't work if the bacteria is resistant to it.

There are still some antibiotics that can be used to treat an infection caused by MRSA.

Antibiotic resistance is caused by overuse of antibiotics. Doctors are now more cautious about prescribing antibiotics.

You should only use antibiotics when you really need them. This can help to lower the chance of staph bacteria becoming resistant.

Can invasive staph infections be prevented?

You can lower your chance of getting a staph infection through good personal hygiene.

You should wash your hands:

• after going to the bathroom
• after blowing your nose
• before handling and eating food
• after handling animals, including domestic pets
• before and after touching or cleaning an infected part of your body

Always wash your hands well with soap and running water. Then dry them with a clean towel or disposable paper towel.

Do not share personal items, such as:

• clothes
• nail scissors and tweezers
• razors
• toothbrushes
• towels
• wash cloths

Resources and support

The Health Translations website has information on sepsis and the signs of sepsis in babies and children. These are available in English and other languages.

Learn about hand hygiene in languages other than English.

You can find out more about antibiotic resistance on the Australian Government Antimicrobial Resistance webpage.

The Health Translations website has information on MRSA in the community, in English and other languages.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.