How Long Is Staph Infection Contagious?

Staph infection is contagious, including both methicillin-resistant staph (MRSA) and methicillin-susceptible staph (MSSA). As long as a staph infection is active, it is contagious. Most staph infections can be cured with antibiotics, and infections are no longer contagious about 24 to 48 hours after appropriate antibiotic treatment has started.

Staph infection (Staphylococcus aureus) is an infection caused by a common bacteria found on the skin and inside the nasal cavity. Staph can cause serious infections if it gets into the blood, leading to sepsis or death.

There are two types of staph bacteria that are categorized by how they respond to methicillin, an antibiotic used to treat staph infections:

• Methicillin-resistant staph (MRSA) 
• Methicillin-susceptible staph (MSSA) 

Common types of staph infections include:

• Skin infections (e.g., wound infections, folliculitis, furuncles, impetigo, scalded skin syndrome)
• Soft-tissue infections (e.g., pyomyositis, septic bursitis, septic arthritis)
• Endocarditis (inflammation of the lining of the heart)
• Pneumonia
• Urinary tract infection (UTI)
• Osteomyelitis (inflammation of the bone)
• Food poisoning
• Toxic shock syndrome
• Purpura fulminans
• Infections related to prosthetic devices (e.g., prosthetic joints and heart valves; vascular shunts, grafts, catheters)

Staph infection is contagious, including both methicillin-resistant staph (MRSA) and methicillin-susceptible staph (MSSA).

As long as a staph infection is active, it is contagious. Most staph infections can be cured with antibiotics, and infections are no longer contagious about 24 to 48 hours after appropriate antibiotic treatment has started.

Symptoms of staphylococcal infection depend on the part of the body that is infected. 

Symptoms of staph skin infections, including MRSA, include a bump or infected area on the skin that is:

• Red
• Painful
• Swollen
• Warm to the touch
• Full of pus or another drainage
• Accompanied by a fever

Staph infections are caused by the bacterium Staphylococcus aureus. 

Staph infection can be transmitted by:

• Touching a person who has staph on their skin
• Being near a person who has staph when they cough or sneeze
• Touching a surface such as a table or a doorknob that has the bacteria on it
• If staph bacteria are on your skin and you cut yourself or have another injury with an open wound, you can get a staph infection

Risk factors for developing staph infections include:

• Exposure to patients carrying or infected with staph
• Uncovered and draining wounds, especially in high-contact sports or crowded living
• Sharing personal items, such as towels or razors
• Diabetes
• Intravenous drug abuse
• Trauma 
• Recent stays in a healthcare facility
• Low white blood cells (neutropenia) or neutrophil dysfunction
• Outpatient surgery and procedures, such as dialysis
• Hospital stays or surgery (during and shortly after)
• Foreign bodies, including intravascular catheters and intravenous lines (IVs)
• Nursing homestays

Staph infection is diagnosed with a physical exam and patient history, and tests such as: 

• Blood tests
  • Complete blood count
  • Erythrocyte sedimentation rate 
  • C-reactive protein level 
  • Blood cultures 
  • Peptide nucleic acid fluorescence in situ hybridization (PNA FISH)
  • Multiplex PCR
  • Screening tests for MRSA 
• Imaging tests 
  • Transthoracic echocardiography (TTE)
  • Transesophageal echocardiography (TEE)

Staph infection is treated with antibiotics. The antibiotic used depends on whether the staph infection is methicillin-resistant staph (MRSA) or methicillin-susceptible staph (MSSA). 

Antibiotics used to treat staph infection include: 

• Cefazolin
• Ceftaroline
• Cefuroxime
• Clindamycin
• Dalbavancin
• Daptomycin
• Delafloxacin
• Dicloxacillin
• Doxycycline
• Linezolid
• Minocycline
• Nafcillin
• Oritavancin
• Quinupristin/dalfopristin
• Tedizolid
• Telavancin
• Tigecycline
• Trimethoprim-sulfamethoxazole
• Vancomycin

In some cases, surgery may be needed to treat staph infection:

• Drainage or debridement of abscesses 
• Removal of a prosthesis for infections involving a prosthetic joint