Like many healthy people, you probably have some Staphylococcus aureus bacteria — usually simply called staph — on your skin or in your nose or throat. Most of the time, the bacteria cause no problems or relatively minor skin infections. But staph infections can turn deadly if the bacteria burrow deeper into your body, invading your bloodstream, urinary tract, lungs and heart.
In the past, most lethal staph infections occurred in people who were hospitalized or had a chronic illness or weakened immune system. Now, a growing number of otherwise healthy people, many of whom have never been in a hospital, also are developing life-threatening staph infections.
A greater problem is that many staph infections no longer respond to common antibiotics. Though most staph infections can still be successfully treated, it may only be a matter of time before the bacteria become resistant to all currently available medications.
Staph bacteria can cause illness in two ways: through direct infection, which happens in most staph-related skin disorders, and through toxins that the bacteria produce. These toxins are to blame for food poisoning, toxic shock syndrome, and some serious MRSA and CA-MRSA infections. Here's how the bacteria can breach your body's defenses :
- Skin infections. Most skin infections develop when staph bacteria enter your body through a cut or other break in your skin. Having eczema, psoriasis, irritation after shaving, or any condition that makes your skin more fragile and sensitive ups your risk of infection. The invading bacteria may already be present on your skin, or you may come in contact with them in the environment.
- Food poisoning. Staph bacteria thrive in foods that are improperly handled or stored, especially potato, egg, tuna and chicken salads, cream-filled pastries and pies, mayonnaise-based salad dressings, cream sauces, and custards. Staph grows best at room temperature, so refrigerating high-risk foods is key.
- Toxic shock syndrome. In 1980, this often-fatal infection was linked to the use of superabsorbent tampons. The tampons themselves may be a breeding ground for bacteria, or they may irritate your vagina, making it possible for bacteria to enter your bloodstream. But toxic shock can occur for other reasons and can also affect men and children.
- Septic arthritis. Staph bacteria usually spread to a joint from an infection in another part of your body. Having rheumatoid arthritis increases your risk because arthritis drugs suppress your immune system and so increase the likelihood of infection.
- MRSA. This form of staph first emerged in hospitals, and it remains a growing threat in health care facilities worldwide. In 1974, MRSA accounted for only 2 percent of all staph infections. Thirty years later, 60 percent of staph infections were drug resistant. Part of the increase is the result of staph's own survival tactics, including the ability to swap genes with other bacteria. But most of the blame lies with the overuse of antibiotics in humans and animals. Because antibiotics are so widespread in the environment, including in meat and municipal water supplies, germs have many opportunities to become resistant to them. In hospitals and nursing homes, MRSA can spread on the hands of health care workers and on many surfaces, including bedrails, catheters, cart handles — even remote controls.
- CA-MRSA. MRSA was confined to health care settings until the late 1990s, when four previously healthy children in the U.S. Midwest died suddenly of MRSA infections. It's likely that what is now called community-associated MRSA (CA-MRSA) entered the wider world in the nostrils of people who picked up the bacteria in hospitals.
The Centers for Disease Control and Prevention estimates that millions of people now carry CA-MSRA in their noses. Carriers may not be sick, but they can spread the infection and run the risk of becoming ill themselves. The bacteria spread mainly through skin-to-skin contact and through small cuts and abrasions. Overcrowding and poor hygiene also encourage the spread of staph. Once CA-MRSA enters your body, it causes boils and abscesses and, like hospital strains, sometimes sparks massive infections in your bone, blood or lungs. Researchers now think that community strains cause even more severe disease than hospital strains do.
Risk Factor :
Anyone can pick up a staph infection, but MRSA and CA-MRSA target specific populations. Risk factors for hospital-acquired MRSA include :
- A current or recent hospitalization. Despite attempts to eradicate it, MRSA remains widespread in hospitals, where it attacks the most vulnerable — older adults and people with weakened immune systems, burns, surgical wounds or serious underlying health problems such as diabetes.
- Residing in a long term care facility. MRSA is more prevalent in these facilities than it is in hospitals. Most people admitted to a care facility are likely to carry MRSA and have the ability to spread it, even if they're not sick themselves.
- Invasive devices. People who are on dialysis, are catheterized or have feeding tubes are at especially high risk because the bacteria can easily enter the body through these devices.
These are the main risk factors for CA-MRSA :
- Young age. CA-MRSA can be particularly deadly in children, sometimes ravaging their bodies in a matter of hours. The bacteria usually enter through a cut or scrape but can quickly cause a massive systemic infection. Children and young adults are also much more likely to develop necrotizing pneumonia than older people are. Children may be susceptible because their immune systems aren't fully developed, or they don't yet have antibodies to common germs.
- Participating in contact sports. CA-MRSA has crept into both amateur and professional sports teams. The bacteria spread easily through cuts and abrasions and skin-to-skin contact.
- Sharing towels or athletic equipment. Although few outbreaks have been reported in public gyms, CA-MRSA has spread among amateur and professional athletes who share razors, towels, uniforms or equipment.
- Having a weakened immune system. People with weakened immune systems, including those living with HIV/AIDS, are more likely to have severe CA-MRSA infections.
- Living in crowded or unsanitary conditions. Outbreaks of CA-MRSA have occurred in military training camps and in some American and European prisons, killing inmates and infecting guards and other staff.
When to seek medical advice :
Keep an eye on minor skin problems — pimples, insect bites, cuts and scrapes — especially in children. If wounds become infected, see your doctor. Ask to have any skin infection tested for MRSA before starting antibiotic therapy. Drugs that treat ordinary staph aren't effective against MRSA, and their use could lead to serious illness and more-resistant bacteria.
Staph infections can range from minor skin problems to food poisoning, fatal pneumonia, surgical wound infections and endocarditis, a life-threatening inflammation of your heart lining. As a result, signs and symptoms of staph infections vary widely, depending on the location and severity of the infection and on
whether your illness results from direct infection with staph bacteria or from toxins the bacteria produce.
- Skin infections. Staph bacteria cause most skin infections, including boils; cellulitis, a potentially life-threatening infection that leaves skin inflamed and tender; impetigo, a rash common in young children and infants; and scalded skin syndrome, a serious, blistering condition that mainly affects newborns. Though each condition has specific features, most begin with skin redness, swelling, warmth, tenderness and sometimes fever. Some staph infections are localized; others can cover your entire body.
- Food poisoning. Signs and symptoms of staph-related food poisoning usually come on quickly — as soon as one to six hours after eating contaminated food. They include abdominal cramps, nausea, vomiting and diarrhea. The illness often leaves just as suddenly as it came, and most people recover in a day or two, though the effects can be more serious and longer lasting in children and older adults.
- Toxic shock syndrome. This life-threatening condition, which has been linked to the use of certain types of tampons and less often, to skin wounds and surgery, usually develops suddenly, with a high fever, nausea and vomiting, a rash on your palms and soles that resembles sunburn, confusion, muscle aches, seizures and headache.
- Septic arthritis. Unlike rheumatoid arthritis, which may result from an overzealous immune system, or osteoarthritis, which develops after years of wear and tear on joints, septic arthritis is often caused by a staph infection. The bacteria usually target the knees, but other joints can be affected, including your ankle, hip, wrist, elbow and shoulder. You're likely to have swelling and severe pain in the affected joint, along with fever and shaking chills.
- Methicillin-resistant staphylococcus aureus (MRSA). In the 1970s, a particularly dangerous and drug-resistant form of staph infection called MRSA appeared in hospitals. It was one of the first bacteria to outwit common antibiotics. MRSA infections often begin as a superficial skin problem that resembles a pimple or spider bite, but which can quickly turn into a deep, painful abscess that requires surgical draining. Infections in surgical wounds cause pain, redness, swelling and sometimes draining pus.
If the bacteria spread deeper into your body, they can cause fatal infections in your bloodstream, bones, heart lining or lungs. The symptoms vary, depending on which part of your body is affected, but most infections are accompanied by fever, chills and sweats.
- Community-associated methicillin-resistant staphylococcus aureus. (CA-MRSA). Once confined to hospitals, a new kind of MRSA is now increasingly common in the general community. Called CA-MRSA, some community-acquired strains cause skin infections or a deadly pneumonia. Signs and symptoms, which are similar to those of other types of pneumonia, include cough, shortness of breath and chest pain, but the bacteria also cause massive inflammation and destruction of lung tissue.
Most often, doctors diagnose staph infections by checking a tissue sample or nasal secretions for signs of the bacteria. The sample is sent to a lab where it's placed in a dish of nutrients that encourage bacterial growth (culture). But the test can be problematic in suspected cases of MRSA or CA-MRSA. In the time it takes the bacteria to grow — about 48 hours — people who have MRSA infections can become worse or, in the most serious cases, die. Newer tests that can detect staph DNA in a matter of hours are available, but they're more expensive than culture tests and not yet widely used.
Penicillin, the first effective antibiotic against staph, became available in the 1940s. A decade later, half of all staph bacteria were resistant to it. Today, barely 10 percent of staph infections respond to penicillin. This has led to the use of stronger and more toxic antibiotics, such as vancomycin. CA-MRSA may be treated with vancomycin or with other antibiotics that have proved effective against certain strains.
Although vancomycin saves lives, its frequent use makes it more likely that germs will soon grow resistant to it, too. A few cases of vancomycin-resistant MRSA have already been reported. To help reduce that threat, doctors try to limit the use of antibiotics, and vancomycin in particular, to situations where it's truly necessary. Some newer antibiotics are now available as staph infection treatment, but most are prohibitively expensive, and resistance to them has already developed.
|Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.