Infection, as defined by Encyclopedia Britannica (2011), is the invasion and multiplication of different pathogenic microorganisms in the body-such as fungi, bacteria and viruses- the body’s reaction to it and the defense mechanisms it activates to counter these pathogens or the toxins they produce. Infections can range from simple to complex ones that can be fatal or debilitating, but because of the continuous researches and studies to protect the human race, antibiotics were discovered.
Antibiotics inhibit the release of toxins of these microorganisms or simply fight against them to eliminate the harmful effects they bring about. Luckily, before one can resort to the use of antibiotics that can also have side effects on the body, there are six components that must be established, and can be interrupted, before an infection can occur. That is what we call the chain of infection. The six components include a pathogen, a reservoir of infection, a portal of exit, a mode of transmission, a portal of entry and finally, a susceptible host.
For an infection to occur, the most important factor would be the pathogen. There are various infective agents being battled every single day. These pathogens continue to grow, multiply and evolve as humans also continue to find a way to avert their emergence and contend against their harmful effects. One of them is Staphylococcus aureus. “Staph”, as it is more commonly known, is one of the most common causes for skin infection. They are Gram- positive bacteria, spherical in shape and occur in grape-like clusters.
These organisms are resistant to high temperatures (as high as 50°C), high salt concentrations and drying (Tolan, 2011). It is a common microorganism and can usually be found in the human axilla, inguinal area or nose. There are a lot of antibiotics that are used to treat staphylococcal infections. They have been found to be most responsive to a group of antibiotics called beta-lactams that include oxacillin, penicillin and amoxicillin (A. D. A. M. Medical Encyclopedia, 2011). However, since bacteria evolve, it has been found out that there is a strain of Staphylococcus aureus that has become resistant to these antibiotics.
This strain is what we call methicillin-resistant Staphylococcus aureus (MRSA). Staphylococcus areus has only been initially resistant to penicillin because it produces ? -lactamase that inhibits the antibacterial function of the said antibiotic (Johnson, 2007). In the early 1960’s, as also reported by Johnson (2007), methicillin, a type of penicillin antibiotic was introduced and was effective against these strains of Staphylococcus areus that were resistant to penicillin. Methicillin was not affected by ? -lactamase.
However, after a short while, the organism also developed a strain that became resistant to the once effective drug, thus the name methicillin-resistant Staphylococcus areus. This strain is also resistant to newer antibiotics but still adapted the same name. There are two types of MRSA- healthcare-associated MRSA and community-associated MRSA. Hospital-acquired MRSA is an infection that is first developed or acquired in healthcare facilities and has been more prevalent than the latter. Individuals that are colonized with MRSA can easily spread the disease with other patients in the hospital.
There are a lot more at-risk persons in healthcare settings which makes it more prevalent, especially if infection control measures are not implemented well. The most people at risk for harbouring the microorganism are those with weakened immune system, those that have prolonged hospital stay or with a history of prolonged hospital stay and/or multiple admissions, those that have undergone recent surgery, or those with foreign objects inserted in their body that makes it so much easier for the pathogen to gain entry.
Not only can it be spread from patient to patient, but to healthcare workers as well, or worse, healthcare workers can be the carriers of the pathogen that can be transferred to patients they come in contact with. It was only until recently (in the 1990’s) that community-acquired MRSA has been discovered and posed a great threat among the public since it can cause severe infections even among healthy individuals. Johnson (2007) wrote that these methicillin-resistant Staphylococcus aureus strains contain a toxin called the Panton-Valentine, also referred to as “PVL”, which increases the microorganism’s ability to cause infections.
Although practically anyone can be susceptible to community-acquired MRSA, certain environmental settings increase the risk of acquisition. These environmental conditions make it easier for the microorganism to be disseminated. It has been found out to be more prevalent in crowded areas such as schools, gyms and athletic teams, correctional facilities, and day care centers, especially with lack of cleanliness and frequent contact with compromised skin (Schoenstadt, 2009).
Outbreaks among these areas and among men engaging in sexual intercourse with the same sex have also been reported. These strains of MRSA have independently evolved and are non-identical with hospital-acquired strains but also respond better to a wider range of antibiotics (Johnson, 2007). They are resistant to beta-lactams but are sensitive to all other antibiotics. But where do these microorganisms usually dwell in the body? The most common reservoir for MRSA is the human nasal area, skin, wound, tracheostomy site, armpit, groin, perineum, perianal area and the rectum.
These are the most ubiquitous sites for colonization, which means no active infection is present though MRSA isolates can still be extracted from these sites. MRSA can also survive in inanimate objects such as stethoscopes and surfaces such as floors and benches for extended periods, especially in hospitals where there are inadequate infection control measures and in communities too, where there is lack of cleanliness. How can it be transmitted? MRSA isolates can be shed or exits the body via droplets from the tubes connected to a person colonized or infected.
It can be from a tracheostomy tube or bladder catheters or just via breathing, coughing or sneezing. One can also extract it from any body fluid from the site of infection (e. g. pus from pimple or severe skin infection). Transmission can easily occur through direct contact with a person colonized or infected. If a person has an active MRSA infection and presents a sore as a symptom, and a person comes in contact with it, an infection can occur when the hands that came in contact with the said sore touches an opening or cut in the skin.
That is how easy transmission can occur, that’s why keeping the skin intact is very essential. Colonization, however, does not need an opening in the skin. One can be colonized through touching of contaminated surfaces or objects, breathing in of droplets expelled from suctioning, normal breathing, coughing or sneezing, or by simply touching the skin of a colonized or infected person (Schoenstadt, 2008). Schoenstadt also cited that up to seven percent of people in hospitals and up to two percent of people in the community are colonized with MRSA, or carriers.
Though they do not present symptoms, they can well spread the pathogen. What happens when the microorganism finds a way inside the body? When the transmission is not interrupted, two things can happen. Either the subject can become colonized or can become infected. What determines colonization and infection is the susceptibility of the individual. Of course everyone is susceptible to be a carrier; however, the emergence of an infection depends on the immune system of the host, or the state in which the pathogen entered the body.
When it enters a break in the skin, or enters through a foreign object inserted (bladder catheter), there is a higher possibility for the development of an infection in a compromised host, than in one with intact barriers. Once an individual is infected, the incubation period takes 1 to 10 days before symptoms can occur. Symptoms include painful, swollen red bumps on the skin that can have pus or other drainage. These symptoms for MRSA skin infections often occur in cuts in the skin or in areas of the body where there is more hair (groin, armpit, and beard, among other areas).
These areas are more commonly the site of infection but MRSA is not limited to the skin. It can also cause more severe infections of the heart (endocarditis), lungs (pneumonia) or bloodstream (bacteremia/septicaemia). Symptoms of these serious infections include chills, chest pain, fever, fatigue, rash, malaise, cough and headache. Once these are experienced, then the infectious disease process has been successfully established in the host. Unfortunately, if none of the components are interrupted before it gets to a susceptible host, the infectious process will be just that- a cycle. The great news is the chain of infection can be broken.
One can do this by exercising proper hand hygiene (constant handwashing), keeping cuts in the skin covered until healed, avoiding direct contact with other people’s wounds and skin openings, keeping environment clean, avoiding sharing of personal equipment such as towels or razors, and being vigilant about other infection control measures especially in the hospital and other healthcare facilities. The infectious disease progress is also largely influenced by certain factors of the environment like general sanitation, temperature, air pollution and water quality (Bonita, Beaglehole, and Kjellstrom, 2006).
It is also imperative that these factors be greatly considered and made part of treatment and prevention plans against MRSA. There should also be immediate consultation with a medical doctor for prompt treatment with antibiotics and drainage of the skin infection once MRSA infection is suspected. Severe MRSA infections of the lungs and bloodstream present high fatality rates (A. D. A. M. , 2011), so instantaneous actions are required. At the end of the day, people still have the power to counter infectious diseases.
These infections are still substantially preventable if everyone practices ways to minimize and gradually eradicate the emergence of these resistant microorganisms, starting at interventions to break its chain of infection. References A. D. A. M. Medical Encyclopedia. (2011). Methicillin-resistant Staphylococcus aureus; Community-acquired MRSA (CA-MRSA);
Hospital-acquired MRSA (HA-MRSA). Retrieved from the U. S. National Library of Medicine Database. Bonita, R. , Beaglehole,R. , and Kjellstrom, T. (2006). Basic Epidemiology, 2nd Edition. [PDF file]. Retrieved from Moodle.Infection. (2011). In Encyclop? dia Britannica.
Retrieved from http://www. britannica. com/EBchecked/topic/287461/infection Johnson, A. (2007). Methicillin-resistant Staphylococcus aureus (MRSA) infection. Retrieved from http://www. netdoctor. co. uk/diseases/facts/mrsa. htm Schoenstadt, A. (2008). MRSA (Methicillin-Resistant Staphylococcus Aureus) Infection. Retrieved from http://bacteria. emedtv. com/mrsa/mrsa-transmission-p2. html Tolan, R. (2011). Medscape. Staphylococcus Aureus Infection. Retrieved from http://emedicine. medscape. com/article/971358-overview.