Necrotizing Fasciitis (flesh eating bacteria )

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Contents

Introduction Necrotizing Fasciitis


Tove Pousette

Medical illustration depicting normal epidermal, dermal and subcutaneous anatomy.Source:Musculoskeletal Illustrations, Frank Corl
Necrotizing fasciitis, also known as flesh-eating disease, is a fatal bacterial infection of the deeper layers of the skin and refers to tissue death. It destroys soft tissue and can harm both the
Tissue decomposition caused by Necrotizing fasciitis, Source: Pediatric supersite infectious diseases in children.
muscles and the skin and can also cause the fatal toxic shock syndrome (TSS) [ and occurs in a broad range of people and can be contracted in various ways.
Medical illustration of advanced necrotizing fasciitis with necrosis of skin, vascular thrombosis and involvement of underlying muscle.Source:Musculoskeletal Illustrations, Frank Corl


Causes Bacteria cause the majority of the cases of Necrotizing Fasciitis but there are rare cases where also certain fungi has caused the same infection. The disease is most commonly caught by bacteria coming into contact with an open wound. The bacteria can enter the body through the smallest opening such as a paper cut but can also occur following a surgical procedure. Sometimes it can also enter through an area where the skin is weakened, but still intact, like a bruise or a blister. The bacteria travels within respiratory droplets and have in some cases has been transmitted between people through who have been in close contact, through body fluids for example, such as through coughing. Necrotizing fasciitis damages the subcutaneous tissues and causes a rapid destruction of fat and fascia and, weakening the immune system and disabling its ability to fight off bacterial infections which can lead to death if not treated. It is a disease that attacks both young and old, healthy and unhealthy people equally. [ Necrotizing fasciitis can be caused by different kind of bacteria and are divided into three types. Type 1 polymicrobial Type 2 or group A streptococcal; Type 3 gas gangrene [2] The most common cause is Group A streptococcus, also called 'GAS' that usually causes strep throat. This group of bacteria multiplies rapidly in the body, progressing quickly throughout the it. Other groups of bacteria that can cause Necrotizing Fasciitis are Staphylococcus aureus, Vicrio vulnificus, Clostridium perfringens and Bacteroudes fragilis.[1] The different bacteria generally functions similarly in their way of attacking the tissue and decreasing the immune response by producing toxins that blocks the bodies defense mechanism. An emerging bacterium that is causing Necrotizing fasciitis has been recorded as on the increase the last couple of years. This bacteria are called Methicillin Resistant Staphylococcus Auerus (MRSA) and is causing a growing concern due to its antibiotic resistance.


Prevention A few ways to decrease the risk of catching Necrotizing fasciitis are to always wash wounds and small openings of the skin with antibiotic substance and cover ones mouth whilst coughing or sneezing and generally avoid contact with people who show symptoms of sore throat.
Symptoms The symptoms appear in different stages, with the earliest usually appearing during the first 24 hours. Necrotizing fasciitis
Early symptoms The symptoms develop quickly throughout the body and can evolve into a critical stage in a short period of time. The first thing that people usually detect is a pain in the area where the wound is located. The pain gradually increases and the tissue becomes swollen and the color of the skin might change. This is followed by flu-like symptoms such as increased body temperature, nausea, faintness and diarrhea. The body also becomes gradually more dehydrated and the person experiences an increased thirst.
Advanced symptoms These symptoms usually appear within a couple of days and include signs of shock, a drop in blood pressure which makes people seem delusional or difficulties breathing.
Critical symptoms When the body has hosted the bacteria for several days it starts to shut down. The body experiences a 'toxic shock' which makes the bodies blood pressure drop dramatically, and can cause unconsciousness and multi-organ failure.[1]
Treatment Patiens who show symptoms of Necrotizing fasciitis are to be taken to the hospital immediately. The mortality rate of people who do not get treated has been measured to be as high as 25 %. [2] The first step to treat this is to perform surgical debridement, removal of the infected tissue in order to prevent further spreading. The patient must also be treated with antibiotics immediately to stop the spreading of the disease. A diagnosis at an early stage is crucial for the patients health and can make a substantial impact but doctors often fail to recognize the disease since the symptoms are very similar to those of flue. There are several ways to diagnose and detect the disease but x-rays and surgical biopsies are rarely conducted in connection to flue-symptoms.


Resistance in MRSA

On of the greatest threats to the continuation of the spread of Necrotizing fasciitis is the emerging prevalence of Methicilin-resistant S. auerous (MRSA). The bacteria was an uncommon cause for the disease but has increased alarmingly recently. The emergence of MRSA has become a growing concern and has evolved into one of the pathogens most difficult to treat in hospitals today. The bacteria was first spotted in 1961 and has since then mutated and developed resistance to almost all β-lactam antibiotics which forces the implementation of more aggressive antibiotic treatment.[5] Estimates show that there are 2.3 million people living in the United States today hosting MRSA bacteria but it the so-called ‘superbug’ is prevalent worldwide [9]. The bacteria are reported to be responsible for about 19.000 deaths each year nationwide. [6]. The bacteria can be spread through skin and body fluids contact as well as indirect contact such as form coins, toys etc. MRSA causes skin and tissue infections and starts at the skin as a small rash that then develop to an open wound.

Increase in MRSA deaths since 1993, Source: AHRQ, Center for Delivery, Organization and Markets, Healthcare Cost and Utilization Project

There are still effective antibiotics to treat MRSA on the market such as rimethoprim-sulfamethoxazole (Bactrim), doxycycline, and clindamycin but recent reports show that a resistance to these antibiotics is currently increasing rapidly. [9] Some physicians argue that there are simply not enough developed and tested drugs available to keep up with the advance of drug-resistant bacteria. The fact that antibiotic resistant MRSA bacteria is causing Necrotizing fasciitis is a grave problem since the disease damages the tissue rapidly and is mainly treated with antibiotics. The MRSA bacteria are also know to cause Pneumonia which magnifies the problem. MRSA that is contracted in a hospital environment is called Hospital-associated Methicillin-Resistant Staphylococcus aureus (HA-MRSA) while MRSA contracted outside the hospital is called Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA). CA-MRSA refers to people who have contracted the disease even though they have not been exposed to risk factors such as hospitalization or surgery. [7] But while the CA-MRSA is spreading throughout communities it is currently making its way to the hospitals as well which aggravates the MRSA problems the hospitals are dealing with. CA-MRSA has shown to be more prevalent amongst frequent drug-users, people with HIV or AIDS and diabetics. [5] Approximately 10 % of the MRSA infections today are CA-MRSA but only 20 % of the patients ends up in the hospital. People infected with CA-MRSA are usually not facing the same risks as people with HA-MRSA if they are diagnosed early and are offered the right treatment. However, if complications do occur they might be more severe since it might cause organ failures, damage to the lungs and kidneys and endocarditis. [8] The main difference between the two strains of MRSA is that the CA-MRSA contains the potent toxin Panton-Valentine leukocidin which targets the white-blood cells, leukocytes, that are used to fight off infections.


Prevention of increased resistance.

In order to decrease the incidence of MRSA and Necrotizing Fasciitis is
Source:Binal Shah wordpress
important to educate hospital personal as well as the general public about the significance of hygiene and disinfection and encourage isolation of infected patients in hospitals. [9] Accurate and early diagnoses need to be conducted in order to inhibit the spread of the disease and raised awareness amongst doctors about what symptoms to pay attention to can help identifying the infections before they intensify. People who have recently been treated with antibiotics face a higher risk if infected by MRSA or Necrotizing Fasciiti and there is a big debate going on currently about how overuse and over-prescription of antibiotics must be taken into account in this issue. Routine prescriptions of antibiotics where people with viral infections are treated with antibiotics contribute to the increasing resistance and the danger it denotes. It is important to ensure that antibiotics are used carefully and when considered necessary. [10]




References

[1], Association of Surgical Technologists (AST), Necrotizing Fasciitis Valentin Rodriguez. Access Journal Archives 2007

[2], Medscapes continually updated clinical references, Emedicine

[3],"Medical illustrations depicting pathophysiologic changes occurring with necrotizing fasciitis" Musculoskeletal Illustrations

[4], The National Necrotizing Fasciitis Foundatio, Fact Sheet


[5], The emergence and evolution of methicillin-resistant Staphylococcus aureus, Science Direct

[6], Medscapes continually updated clinical references, Emedicine

[7] Strategies for Clinical Management of MRSA in the Community, Center for Disease Control and Prevention.

[8] Update on antibiotic-resistant Staph aureus

[9] MRSA (Methicillin-Resistant Staphylococcus aureus) Medicine net.

[10] NCHS Data on Quality of Care and Patient Safety, Center for disease control and prevention.

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