The Staph bacteria is a robust one. It can easily live freely in the environment or can find refuge in the skin or the upper respiratory tract of a person or an animal. It is also a normal inhabitant in the lower reproductive tract of women. In fact, an estimated 20-30% of the human population carry Staphylococcus Aureus in the long term. It is one of the leading causes of skin and soft tissue infections. It is also a foodborne illness.
What is Staphylococcus Aureus?
Staphylococcus aureus, also called “golden staph,” is a bacterium that can grow without the need for oxygen.
Staphylococcus was identified in 1880 by Sir Alexander Ogston in Aberdeen, Scotland who found it in pus from a surgical abscess in a knee joint. The bacterium is a part of normal human flora and does not cause infection. For most people, the bacteria live in their noses and on their skin.
When the bacterium lives inside the human body without causing an infection, it is called colonization. In fact, about 20% of the population is always colonized with Staphylococcus Aureus, and about 60% of people are colonized off and on. Staph infections can turn deadly only if the bacteria invade other parts of the body and enter into the joints, lungs, heart, bones, and bloodstream.
How Does Someone Become Ill with Staphylococcus Aureus?
Staphylococcus Aureus can spread if a food handler contaminates the food with unclean hands and/or if the food is also not properly refrigerated. The equipment and surfaces where food is prepared can also get contaminated by the bacteria. These bacteria spread rapidly at room temperature and produce a toxin that can spread illness. This is why leaving food out for longer than two hours (or 1 hour in warm outdoor temperatures) can cause illness.
The infection can also spread if a person comes in contact with an infected wound, has skin to skin contact with an infected person, or comes in contact with objects that have been used by infected person – such as towels, clothing, sheets etc.
Pets (mainly cats and dogs) also carry these bacteria. It is likely that a person can become infected with this bacterium if they come in contact with an infected animal. Some believe health-care workers’ dogs could be considered a significant source of antibiotic-resistant S. aureus, especially in times of outbreak.
What are the Symptoms of a Staphylococcus Aureus Infection?
Staphylococcus Aureus can cause a variety of symptoms ranging from skin infections to food poisoning. Here is a list of symptoms Staphylococcus Aureus can cause:
- Food Poisoning: When a Staphylococcus Aureus infection leads to food poisoning, it can cause symptoms, such as vomiting, diarrhea, abdominal cramps, etc. The incubation period is very quick, about 1-6 hours.
- Abscesses: These are small pockets of infection that form at the site of an injury. The area around the abscess might feel warm and is usually red, painful and swollen.
- Cellulitis: It is an infection that affects the underlying layers of the skin. It most often occurs in legs and arms even though other parts of the body might get affected too. A scrape or cut in the skin might allow bacteria to enter through the skin. Symptoms include redness, swelling, or sometimes pain at the site of the infection.
- Folliculitis: It is the least serious symptom. It infects a hair follicle and causes a tiny, slightly painful abrasion.
- In animals and humans that are immunodeficient or immunocompromised, this bacterium can lead to some life-threatening conditions.
Is Staphylococcus Aureus contagious?
Yes. All types of Staphylococcus Aureus infections are quite contagious. An infected person can easily spread the bacteria to others through sneezing, coughing, or touching foods when sick.
What is the Diagnosis and Treatment of Staphylococcus Aureus Infections?
Staphylococcus skin infections are usually diagnosed on the basis of their appearance. Other infections, like food poisoning infections for example, require samples of blood, stool, or other infected fluids. These samples are then sent to a laboratory to grow (or culture) the bacteria. These tests will help in confirming the diagnosis and find out which antibiotics will work the best for the culture.
The treatment of Staphylococcus Aureus generally includes cephalosporins, nafcillin, and related antibiotic drugs such as sulfa drugs or vancomycin. Many Staphylococcus Aureus infections are becoming antibiotic resistant. By 1950, penicillin-resistant Staphylococcus Aureus isolates increased to 40% and the numbers increased to 80% by 1960. Antibiotic resistance strains are increasingly being treated by vancomycin.
Do Staphylococcus Aureus Infections Have Long-Term Complications?
Although most Staphylococcus Aureus infections are not serious, Staphylococcus Aureus can sometimes lead to complications. These can include:
- Toxic Shock Syndrome: Toxic Shock syndrome is a rare, life threatening condition that can be a side effect of some bacterial infections, especially Staph infections. Its symptoms include: high grade fever, confusion, seizures, headaches, etc.
- Bacteremia or blood poisoning: It is a common cause of death in people that have severe skin rashes. Symptoms can include a persistent high fever.
- Pneumonia: Pneumonia causes severe lung inflammation. It can cause high fever, shortness of breath and coughing. Pneumonia can be life threatening – especially in children, elderly and those who have compromised immune system.
- Endocarditis: It can damage the heart valves and lead to heart failure.
- Osteomyelitis: Osteomyelitis can cause chills, fever, and bone pain. The skin and soft tissues can become red and swollen and accumulate in nearby joints too.
- Mastitis: It can also develop as a result of Staphylococcus Aureus. It develops within 1-4 weeks of delivery and can cause cellulitis and abscesses. The bacteria can release in large numbers in the mother’s milk and can then infect the nursing infant. This is important to note because the similar infection can occur in dairy cows. This is why drinking raw milk may be another method of transmission of the infection.
Can Someone Prevent Staphylococcus Aureus Infection?
Staph preventive measures are based on good hygiene. Wash your hands with with antibacterial soaps or hand wash. People who have Staphylococcus Aureus infections should avoid handling food and touching other people.
For food handlers, refrigerating and storing foods at 41 degrees Fahrenheit or below will help greatly reduce the growth process. Foods should be chilled to this temperature within about 4 hours to be safest.
Staphylococcus Aureus and Antibiotic Resistance?
Staphylococcus Aureus is naturally susceptible to almost all antibiotics that have ever been developed. Resistance is mostly acquired by horizontal gene transfer, even though chromosomal mutation and antibiotic selection can play an important role too.
But many strains have developed antibiotic resistance. When the carriers take antibiotics, the antibiotics is successful in killing the strains that are non-resistant, but they will leave behind resistant strains, which can then multiply.
Methicillin Resistant Staphylococcus Aureus (MRSA) are the most common forms of antibiotic resistant Staphylococcus Aureus right now. Strains of bacteria that are resistant to antibiotics related to penicillin (called beta lactam antibiotics) are called MRSA. They are quite common in health care facilities but, in recent years, are spreading to the general community.
Each year around 500,000 patients in hospitals contract a Staphylococcus Aureus infection. Around 50,000 people die each year in the United States due to Staphylococcus infection.
Is there a Vaccine?
Not yet. Despite much research and development, there is no vaccine that is approved for Staphylococcus Aureus at this time.