How Do You Get E. Coli – And How to Prevent It
What Is Subacute Bacterial Endocarditis?
Subacute bacterial endocarditis is a type of infective endocarditis. It's an infection that occurs when germs such as bacteria enter the bloodstream and attack the lining of the heart valves. This causes growths, called vegetations, on the heart valves.
Vegetations can cause holes in the valves and cause the infection to spread outside of the heart and blood vessels. Endocarditis is fatal without treatment.
Infective endocarditis can be either acute or subacute. Acute infective endocarditis can develop suddenly and become life-threatening within days. Subacute infective endocarditis develops slowly over a period of several weeks to several months.
Your heart valves are not supplied directly with blood. Your immune system fights infection with white blood cells that are in your bloodstream. These cells can't reach your heart valves. That makes it difficult to fight the infection, either with your immune system or with antibiotics that travel through the bloodstream.
Subacute bacterial endocarditis is often caused by a particular group of streptococci bacteria that usually live in your mouth and throat. Normally, your immune system destroys any harmful bacteria that enter your bloodstream. Under certain circumstances, these bacteria can cause endocarditis.
Symptoms of subacute bacterial endocarditis typically develop slowly and may be different for each person.
Some common symptoms of endocarditis may include:
Less common symptoms of endocarditis can include:
People who have the following issues are more at risk for developing bacterial endocarditis:
Your doctor will listen to your symptoms, review your medical history, and do a physical exam. You may also need additional testing which may include the following.
Blood cultures. Blood samples are drawn over 24 hours and tested to see if specific bacteria are present in your blood. This will help identify the type of bacteria and help your doctor determine the best antibiotic to treat it.
Echocardiogram. This test uses sound waves to help your doctor visualize your heart. It will show any abnormalities such as growths, abscesses, or damage to your heart. This may be done with a tube inserted through your mouth so that the pictures can be taken from right behind the heart.
Serological tests. These blood tests check for evidence of infection by seeing if your immune system is showing increased activity. This may be needed if the blood cultures don't show any signs of bacteria.
Antibiotics. Subacute bacterial endocarditis is treated with high doses of intravenous (IV) antibiotics. You will probably have to spend a week or so in the hospital to make sure that your antibiotics are working. After that, you may be able to continue IV antibiotics at home or in your doctor's office. You'll probably need to take antibiotics for several weeks to completely clear up the infection.
Surgery. You may need heart valve surgery to treat endocarditis that won't respond to antibiotics alone. Your heart valve may have to be replaced if it was damaged by the endocarditis.
Subacute bacterial endocarditis can cause complications as a result of the vegetations breaking off and traveling to other parts of your body. Some of these include:
You can help prevent subacute bacterial endocarditis by taking the following steps.
Take good care of your teeth and gums. Brush and floss your teeth daily and get regular dental care. Subacute bacterial endocarditis is usually caused by bacteria that live in your mouth and throat. Poor dental hygiene may allow the bacteria to get into your bloodstream.
Understand the symptoms of endocarditis. Call your doctor immediately if you develop any of the symptoms of subacute bacterial endocarditis. This could be a fever that won't go away, unexplained tiredness, skin infections, or cuts or sores that won't heal.
Don't use intravenous drugs. IV drug use is a big risk factor for developing endocarditis. Dirty needles can carry bacteria directly into your bloodstream.
Dental Health And Endocarditis Prevention
Endocarditis is a rare, life-threatening inflammation of the lining of the heart muscle and its valves. It is caused by a bacterial infection. Although it can occur in anyone, it is much more common in people with certain heart conditions and in those who've had it before. If your risk is high, you can take steps to lower it.
In 2007, the American Heart Association Endocarditis Committee -- together with other experts -- issued guidelines to help prevent endocarditis. These replaced guidelines issued in 1997. After reviewing published studies, the committee found that only a small number of cases of infective endocarditis might be prevented by antibiotics for dental procedures. In patients with heart conditions associated with the highest risk of serious complications from endocarditis, it says that antibiotic treatment before dental procedures involving manipulation of the gums seems reasonable.
In very rare cases, bacteria in the mouth may trigger endocarditis in people at higher risk. Here's what happens: Bacteria found in tooth plaque may multiply and cause gingivitis (gum disease). If not treated, this may become advanced. The gums become inflamed (red and swollen) and often bleed during tooth brushing, flossing, or certain dental procedures involving manipulation of the gums. When gums bleed, the bacteria can enter the bloodstream and can infect other parts of the body. In the case of endocarditis, this affects the inner lining of the heart and the surfaces of its valves. The bacteria stick to these surfaces and create growths or pockets of bacteria.
Because this is so rare, the new guidelines suggest antibiotics prior to dental procedures only for patients who are at highest risk for serious complications from endocarditis. In fact, in most cases, the risk of problems from antibiotics exceeds the benefits from preventive antibiotics. These attract blood products that may lead to clots.
To prevent endocarditis, patients with certain heart conditions receive a single dose of an antibiotic. You receive it about one hour prior to certain dental treatments.
The American Heart Association and American Dental Association now suggest that you receive antibiotics prior to dental treatment only if you have:
The new guidelines suggest preventive treatment for all patients with cardiac conditions listed above, but not for all dental procedures.
The guidelines suggest treatment only:
The guidelines do not recommend antibiotics for these dental procedures or events:
Possible symptoms of endocarditis include:
Keep in mind that receiving antibiotics greatly lowers the risk of endocarditis. However, it is not a guarantee. Also keep in mind that most cases of procedure-related endocarditis occur within two weeks of the procedure. So if you have any of these symptoms beyond this time, it is not very likely that you have endocarditis. It is always wise to check with your doctor or dentist if you have any concerns.
U.S. Study Links Extractions, Surgeries To Endocarditis
A notable link was found between invasive dental procedures, especially extractions and surgeries, and subsequent infective endocarditis in high-risk patients, according to a large U.S. Study published on August 17 in the Journal of the American College of Cardiology.
Additionally, there is a noteworthy correlation between antibiotic prophylaxis (AP) and a reduced risk of infective endocarditis (IE) following invasive dental procedures (IDPs). The landmark study included nearly 8 million people.
"These data support recommendations that patients at high risk for IE receive AP before IDPs," wrote the authors, led by Dr. Peter Lockhart of the Carolinas Medical Center-Atrium Health in Charlotte, NC.
The findings support guidelines from the American Heart Association (AHA) and the European Society of Cardiology (ESC), which recommend the use of prophylactic antibiotics for high-risk patients.
However, the current study comes in direct opposition to a study published in JAMA Network Open in January that showed no significant relationship between invasive dental procedures and subsequent prosthetic joint infections, which are rare but serious complications of endocarditis. That study included nearly 8,500 patients admitted to hospitals in England.
Analyzing infection risk
To investigate the potential association between invasive dental procedures and infective endocarditis and the effectiveness of prophylaxis antibiotics in reducing the occurrence of infection, the authors performed a case-crossover analysis and cohort study that included nearly 8 million patients in the U.S. The data were extracted from the Commercial/Medicare Supplemental prescription and dental databases as well as the IBM MarketScan databases.
Of those patients included in the study, 3,774 (475 cases per million) were hospitalized with infective endocarditis. Of those hospitalized, 1,292 (34%) were at high infective endocarditis risk, 831 (22%) were at moderate risk, and 1,651 (nearly 44%) were at low or unknown risk for the heart infection.
Furthermore, the overall adjusted infective endocarditis incidence within 30 days of a dental procedure was 468 per million procedures in patients at high risk. It was 24 per 1 million procedures in those at moderate risk, and four per 1 million procedures in those at low or unknown risk.
A subanalysis of procedures showed that the odds of infective endocarditis were dramatically higher following extractions (odds ratio [OR]: 9.22; 95% confidence interval [CI]: 5.54-15.88; p = < 0.0001) and other oral surgical procedures (OR: 20.18; 95% CI: 11.22-36.74; p = < 0.0001), according to the study.
Preventive antibiotics were prescribed to cover 33%, 10%, and 3% of invasive dental procedures in those at high, moderate, and low/unknown infective endocarditis risk, respectively. In high-risk patients, prophylactic antibiotics given for invasive dental procedures were linked with a significant reduction in infective endocarditis risk (OR: 0.38; 95% CI: 0.22-0.62; p = 0.002). This was in comparison to those who were not prescribed antibiotic prophylaxis, the authors wrote.
Notably, this reduction was most prominent following extractions (OR: 0.13; 95% CI: 0.03-0.34; p < 0.0001) and other oral surgical procedures (OR: 0.09; 95% CI: 0.01-0.35; p = 0.002). But preventive antibiotics offered no remarkable benefit following other invasive dental procedures or in patients at moderate, low, or unknown risk of developing infective endocarditis, they wrote.
The study had several limitations, including the use of the MarketScan databases. Though the dataset encompasses a large sample of U.S. Employer-provided health insurance enrollees, the study only included those with medical, dental, and prescription benefits. Therefore, it is unlikely to be representative of the entire population in the U.S., the authors wrote.
A matter of contention
For multiple reasons, including antibiotic resistance, prescribing antibiotics before invasive dental procedures to prevent infective endocarditis has been a major talking point in dentistry.
To explain the 30% to 40% of infective endocarditis cases caused by oral streptococci, a causal link with invasive dental procedures has been postulated. To prevent this condition, the AHA and other professional organizations have issued guidelines on antibiotic prophylaxis to prevent infective endocarditis in patients undergoing invasive dental procedures for decades.
Despite this practice becoming the standard of care for the prevention of infective endocarditis in many countries, a clinical trial of antibiotic prophylaxis effectiveness in decreasing infective endocarditis risk has never been conducted. Also, clinicians continue to question if regular daily activities such as toothbrushing are more likely than invasive dental procedures to cause IE.
Since the study showed a correlation between invasive dental procedures and infective endocarditis, more research is necessary to explore the risk of oral bacterial infective endocarditis posed by routine daily activities, including toothbrushing and chewing, specifically in those with poor oral hygiene, the authors wrote.
"(Nevertheless,) these data support the American Heart Association, and other, recommendations that those at high IE risk should receive AP before IDP," Lockhart et al wrote.
Disclosure: A research grant from the Delta Dental of Michigan Research Committee and Renaissance Health Service Corporation funded the study. However, the funding source had no role in the design and conduct of the study.
Authors Lockhart, Martin Thornhill, PhD, and Dr. Patrick O'Gara received support from the Delta Dental Research and Data Institute for this work. Additionally, Lockhart is a member of the writing committee reviewing the current AHA guidelines on antibiotic prophylaxis to prevent infective endocarditis. Lockhart and Dr. Larry Baddour were members of the AHA Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease and were involved in producing the 2007 and 2021 AHA guidelines on the prevention of infective endocarditis. Baddour received consulting fees from Boston Scientific, Botanix Pharmaceuticals, and Roivant Sciences. O'Gara has received support in the last three years from Medtronic, Edwards Scientific, and the National Heart, Lung, and Blood Institute that was unconnected to this study.
Though unconnected to this study, Mark Dayer, PhD, received support during the last three years from Biotronik. Bernard Prendergast has received unrestricted research and educational grants and lecture fees from Edwards Lifesciences, lecture fees from Abbott and Anteris, and consultancy fees from and serves on the scientific advisory board for Anteris and Microport. Prendergast also was a member of the ESC's Task Force on the Prevention, Diagnosis, and Treatment of Infective Endocarditis, which produced its infective endocarditis guidelines.
Comments
Post a Comment