Biology

Necrotizing fasciitis also known as flesh-eating bacteria is a rare but serious disease where bacteria destroy tissues underlying the skin. The disease is known to spread very fast causing death and damage of the tissues. The death of the tissues is known as necrosis or gangrene, explaining why the disease may also be known as synergistic gangrene. This condition takes place infrequently, but it can affect any region of the body. However the arms and the legs are commonly affected by the disease. In case the disease affects the genitals, it is referred to as Fournier gangrene (Medina, Gonzalez-Rivas, Blanco, Tejido and Leiva, 2009). Studies have revealed that about one person out of four who contract this die from it. The fast spreading strands of bacteria have resulted in the death of patients in days. Most of the people who suffer from this condition are usually in good health before they contract it. The moment a person contacts the bacteria, it starts working on destroying the soft tissue and the fascia, the casing of tissue that covers the muscle immediately. This disease is as a result of any opportunity that bacteria can get to enter into a persons body (Davis, 1996). The term flesh-eating bacteria is actually a misnomer. This is due to the fact that the bacteria do not actually eat the soft tissue and the fascia. They destroy or damage them by discharging enzymes and toxins that can spread very fast throughout the body. Different types of bacteria release different types of enzymes and toxins. For instance streptococci and staphylococci release hyaluronidase. This enzyme damages hyaluronic acid that is basically part of connective tissue (Kotrappa, Bansal and Amin, 1996).

Back ground
The first discovery of necrotizing fasciitis was made in the year 1783, in France. Despite the fact that the discovery was made in the 18th century, it was not until between the 1840s and 1870s that the disease was fully described. In the year 1920, twenty cases were isolated in China by Meleney where hemolytic streptococcus was the causative agent. The term necrotizing fasciitis was first coined by Dr. B. Wilson in 1952 (Kotrappa, Bansal and Amin, 1996). However, Dr. B. Wilson did not identify any specific bacteria that he could link to the condition. It is possible that the disease had been affecting and killing people for many centuries before it was identified and described between the 18th and 19th century. Since the name that was given to the disease by Dr. B. Wilson, there have been many other terms and names given to it. Some of the other names include flesh-eating bacterial necrotizing cellulitis suppurative fasciitis and Fourniers gangrene among others (Medina, Gonzalez-Rivas, Blanco, Tejido and Leiva, 2009 36). All through the 19th and 20th centuries, doctors realized that the disease took place at irregular intervals. It was particularly limited to military health facilities, often during the time of war. Nevertheless, there have been some cases of outbreak in other populations. After the Second World War, necrotizing fasciitis appeared to be on the decrease, reemerging again throughout the world in the 1980s (Davis, 1996).  

Causes of necrotizing fasciitis
Most of the cases have been as a result of group A beta-hemolytic streptococci (Streptococcus pyogenes) (Roemmele and Batdorff, 2000). However, researchers have now come to an agreement that different types and species of bacteria either in isolation or in groups (polymicrobial) can lead to this condition. There are two types of the condition type I describing a polymicrobial contagion, is caused by anaerobic species. The organisms work in conjunction with facultative anaerobic bacteria like streptococcal, enterococci, as well as Gram-negative rods. Type II describing a monomicrobial contagion, is the one that is referred to as streptococcal gangrene, and it is as a result of streptococci, with other organisms either present or absent. Despite the fact that type I is more frequent than type II, it is not as dangerous as the latter. Most of the serious cases and deaths are as a result of type II contagion. There are cases where the disease can be caused by marine vibros, that is, Gram-negative organisms. This only takes place where the victim is bitten by a fish or a shellfish (Henrickson, Wong, Allen, Ford, and Epstein, 2001). In very rare occasions, myotic species, that is, fungus can cause the disease. This mostly happened with patients who have very weak immune systems. One example of such an infection is Mucormycosis (Lee, Carrick and Scott et al, 2007).  

Group A Streptococci
Group A Streptococci is bacteria common in the throat and on the skin. Some people may have this group of bacteria in these regions for some time without showing any signs of sickness. Most infections caused by Group A Streptococci are mild diseases like strep throat.  It is on very rare cases that these bacteria can lead to serious or life-threatening conditions. Such occasions occur when Group A Streptococci moves to areas of the body where they are not commonly found like the blood, the muscle or the lungs (Roemmele and Batdorff, 2000). Persistent Group A Streptococci infections takes place where the immune system of the victim cannot fight the bacteria and keep them out of the body. This can happen in case the victim has cuts or other breaks in the skin that through which the bacteria can access the tissues. It can also take place when the defense of the body against infections is weakened due to chronic conditions or diseases that lower the immunity of the body. These are not the only factors since some strong strains of Group A Streptococci can cause more serious infections than others. Diabetes mellitus and immunosuppression are other conditions that may predispose people to the condition.

When the condition is as a result of lightening Group A Streptococci, a person can move from being in a perfect health to the door of death within days (George, 2004).

Mode of infection
The condition can take place as a complication of different surgical processes. It can also happen as a result of other medical conditions such as cardiac catheterization diagnostic laparoscopy and veinsclerotherapy among others. The condition can also come up following a skin biopsy. Another loophole for the bacteria is a needle puncture mostly for drug users who injects themselves (Schwartz and Kapila, 2010). Others include insect bites, frostbites, fractures, and any other injury to the skin or bone. Bacteria that lead to the disease can also be transmitted from one individual to the other through intimate contact like kissing, or coming into contact with an infected area of the skin. In almost all cases, it is a skin injury that precedes necrotizing fasciitis. Once the bacteria enter the body through a break, sore or cut, they move from the subcutaneous tissue via the superficial and the fascial planes. It is presumed that their movement is made possible by the release of enzymes and toxins. As the bacteria continue to grow beneath the surface of the skin, they generate toxins that destroy the tissues. It is argued by medical experts that almost any skin break has the potential of becoming infected by the bacteria that are responsible for the disease (Lee, Carrick and Scott et al, 2007).  

History and symptoms
People who are at greater risk of acquiring the disease after coming into contact with the bacteria are those who have a break on the skin of a weakened immune system. The contagion starts locally at a region of trauma. The infection can be serious, mild or even non-apparent.  Once a person contracts the infection, he or she starts with constitutional signs of fever and chills. It is after two to three days that erythema is apparent. During this point, there is development of supralesional vesiculation. From the infected region, Serosanguineous liquid can drain. There are very many different symptoms that are evident in people suffering from necrotizing fasciitis (Tilden, 2007). Crepitation shows that there is gas generated by aerobic and anaerobic organisms. In younger patients there is evident of edema and induration that is followed in a day or two by erythema. People suffering from this condition may suffer serious pain that may look like severe considering the physical appearance of the skin. As the infection progresses, the tissues begin to swell, mostly within hours. The area of infection can be discolored (Kotrappa, Bansal and Amin, 1996).  

In the initial phases of the infection, indications of inflammation may not be evident especially if the bacteria have penetrated deep into the tissue. In cases where the bacteria are not deep into the tissue, inflammations like reddening and swelling, or hot skin become evident very fast. The color of the skin may change to purple, progressing to dusky, dark color. There may be formation of blisters that are followed by the destruction of subcutaneous tissues. The dead tissues can become visible. There can be development of black parches that are full of pus. The skin can also break opening to form wounds (Medina, Gonzalez-Rivas, Blanco, Tejido and Leiva, 2009).  

Most of the times, people suffering from this condition are very ill. The combination of signs and complications can result to organ failure. This is due to the release of a super antigen by a particular strain of Streptococci. This results to clones of T4 lymphocytes that make cytokines active causing the generation of oxygen free radicals and nitrous oxides. In the cases where the disease is not treated, the mortality rate has been revealed to be as high as 73 (Roemmele and Batdorff, 2000). This is because devoid of surgery and medical treatment like administering of antibiotics, the contagion is likely to spread very fast throughout the body ultimately causing death (George, 2004).

Effects of the bacteria    
In normal conditions, the skin is held tightly by proteins. These proteins constitute a connective tissue that maintain the dermis, epidermis and muscle in a tight connection. The moment the bacteria penetrate the skin, they lead to detrimental effects by eating the protein that form the connective tissue. Once the infection is not treated, the bacteria continue to eat and destroy the skin and the underlying tissue until it affects the muscle. On reaching this point, there is no way of saving the patient unless the infected region is eliminated through a surgical procedure to avoid further spreading of the bacteria. Apart from causing the tissue to die, the bacteria also causes other body organs to undergo systematic shock. This is what results to multi-organ failure or low blood pressure. Basically speaking, the disease can cause the failure of all organs of the body (Schwartz and Kapila, 2010).

Diagnosis
The infection is diagnosed depending with the rate that the symptoms appear and the rate at which the infection is spreading. The physical appearance of the skin is one of the possibilities of the infection. This may appear in conjunction with pain, fever and chills. The doctor can test the infected tissue for the possibility of necrotizing fasciitis. This is done by swab-streaking the affected region and then viewing the organisms under a microscope. Some of the tests that are used to look at the damage to the organs or the level at which the infection has spread include x ray, magnetic resonance imaging (MRI), or computed tomography scans (CT scans) (Schwartz and Kapila, 2010). These are very significant procedures in the diagnosis of necrotizing fasciitis. Necrosis can be revealed during respiratory surgical operation. This is the procedure that is referred to as exploratory surgery. During this procedure samples are collected on any event of bacterial infection. The most important and the best diagnosis of the infection is visual, that is, identification of the symptoms.  X ray, magnetic resonance imaging (MRI), and computed tomography scans (CT scans) are used to reveal the underlying skin (Tilden, 2007). These procedures are utilized in showing the fatherly patterns in the tissue that result from buildup of gas in dying tissues. CT scans displays gas collected in the soft tissue from persistence Group A Streptococci (Lee, Carrick and Scott et al, 2007).  

Treatment of necrotizing fasciitis
The infection is treatable and once treated it is unlikely to recur. This is because once the bacteria are completely eliminated from the body, they move out completely. The initial treatment of the bacteria starts once they start entering the body through broken section of the skin. This is automatic through the defense mechanism of the body. Nevertheless, this is not possible with more dangerous and uncommon strains of organisms. The macrophages cannot be able to fight such bacteria and this is what results to the need of antibiotics. The condition requires fast, aggressive treatment that includes antibiotics and surgical debridement. Some of the antibiotics that are common in the treatment of necrotizing fasciitis are penicillin, an aminoglycoside or third-generation cephalosporin. The choice of antibiotics is usually based on the type of the bacteria. However, many of the physicians have the belief that a combination of antibiotics is necessary for protecting the patient from methicillin-resistant Staphylococcus aureus (MRSA) (George, 2004). There are other medications such as analgesics that are used to relieve pain in the process of surgical debridement. The choice of the type of surgeon who carries out the surgery depends on the infected area. In this process the dead tissues are removed to hinder spreading. During the period of treatment, the patient requires hospitalization and immediate use of intravenous antibiotics (Schwartz and Kapila, 2010).

Over the treatment period, the place that is operated on is left open for sometime for later reinspection. This is aimed at ensuring that there is no further damage is being caused to the remaining tissue. The surgical site is only closed after the physicians carrying out the operation are sure the infection has been completely eliminated. The wound is mostly closed through skin grafting. This marks the beginning of the healing process. The healing process may involve a long period of physical rehabilitation. The patient also requires a long period of psychological, emotional and spiritual healing.  Once the patient has undergone the operation, he or she is closely monitored to check for further infection, shock or any other complication that may arise. Another procedure that can be employed in case it is available is hyperbaric oxygen therapy (Lee, Carrick and Scott et al, 2007).

Risk factors and complications
Very few people who come into contact with Group A Streptococci, will contract Group A Streptococci infection. Most of the people with the bacteria may develop throat or skin infection without any signs of necrotizing fasciitis. Despite the fact that even people with good health can acquire invasive Group A Streptococci infection, only those with chronic ailments are at higher risks (Kotrappa, Bansal and Amin, 1996).

Conclusion and recommendations
Necrotizing fasciitis is an uncommon disease, but can affect any person despite of the geographical location. Before and since its identification and description, a lot of people have suffered from it, with some dying. Spreading of this disease, like many others can be lowered by maintaining good hygiene. Proper washing of hands, particularly after sneezing or coughing and before food preparation and eating is vital to control the spreading of the disease. When one is suffering from sore throat, it is important to see a doctor immediately to find out the cause. Wounds should always be kept clean and continually monitored for signs of infection (PM Medical Health News, 2009). Any reddening, swelling, pain at the part where the wound is should be investigated by a doctor. Any person with signs of infection on a wound, particularly if it is accompanied by fever should seek medical attention. There are cases where antibiotic therapy is necessary for people exposed to patients of necrotizing fasciitis. This decision should be reached under a doctors directive. More research is necessary to clear all misunderstood and unclear issues concerning the disease. For example, researches have not revealed the reasons why the usually mild Group A Streptococcus infection at times gets to be more severe risk. Researchers are not sure the reason why this group might lead to mild infections to some people and life-threatening infections to others (PM Medical Health News, 2009).