Introduction
Pneumonia was a major cause of mortality in the United States during the early years of the 20th century. However, with the development of treatment remedies like antibiotics, the death rate declined significantly (Kang et al, 2012). However, the disease is still present today and affects between three and five million people each year. Reports show that it causes approximately 60,000 deaths every day in the United States. Streptococcal pneumonia is a type of pneumonia caused by bacteria known as Streptococcus pneumonia (Kang et al, 2012). The infection is normally treated using antibiotics. However, if treated improperly, the bacteria can undergo multiplication and spread to other parts of the body (Ranganathan & Sonnappa, 2009). The bacteria affect the lungs and the throat. They may also spread to the brain and bloodstream. Streptococcal pneumonia is not contagious. However, the bacterium that causes the infection is contagious and easily spreads from infected people to healthy people.
History
Streptococcal pneumonia is found in all parts of the world. Carl Friedlander identified the first case of infection in 1882 (Kang et al, 2012). Studies by Friedlander developed the gram stain, which is used to identify bacteria. Further studies by Christian Gram aided in differentiation of Streptococcus pneumoniae and Klebsiella pneumoniae. The studies revealed that the two types of bacteria could cause pneumonia. High rates of mortality caused by S. pneumoniae prompted researchers to develop treatment remedies and vaccines to manage the condition. In 1977, a vaccine against streptococcal pneumonia was developed (Ranganathan & Sonnappa, 2009). The vaccine was used on adults only. Vaccination of children began in 2000 after further refinements of the vaccine. Initially, the bacterium was known as Diplococcus pneumoniae but its name was later changed to Streptococcus pneumoniae (Ranganathan & Sonnappa, 2009)
Genetics
Research has revealed that the high numbers of mortality that result from community-acquired pneumonia are mainly due to peoples’ genetic predispositions (Ranganathan & Sonnappa, 2009). Three responses in the host’s genes that predispose people to the disease include anti-inflammatory responses, antigen recognition, effector mechanisms, and proinflammatory responses. The genome of S. pneumoniae comprises circular DNA that contains more than 2 million base pairs (Kang et al, 2012). Its virulence bases on its ability to repair damages on its DNA structure due to the action of the host’s immune system.
Clinical manifestations
Clinical manifestations of streptococcal pneumonia include high fever, rapid breathing, and chills (Kaplan & Mason, 1998). In addition, the patient might have deep coughs that exude greenish mucus, which is mixed with blood droplets in severe cases. Rapid breathing and coughing causes severe chest pain that intensifies with consequent progression of the infection. Other symptoms that may be observed include vomiting, nausea, anorexia, diarrhea, and weight loss (Kaplan & Mason, 1998). Clinical interviews of patients during treatment include family history, medication history, allergies, and presence of comorbid conditions.
Diagnosis
Diagnosis of streptococcal pneumonia involves observation of physical symptoms and chest x-rays. Diagnosis is sometimes inconclusive because it is difficult to determine pneumonia caused by bacteria, viruses, or fungi. Diagnosis of streptococcal pneumonia involves identification of Streptococcus pneumoniae in the sputum of patients (Evertsen et al, 2010). The infection is confirmed by the presence of neutrophils and gram-positive diplococcic bacteria in the sputum of a patient. The bacterium is confirmed by cultivating it on blood agar and observing alpha-hemolysis. Alpha hemolysis is characterized by greenish coloration around the bacteria colonies on the culture plate (Evertsen et al, 2010). This test has a weakness because there are many streptococcus bacteria that cause a greenish coloration when cultivated on blood agar. To avoid misdiagnosis, the organism is confirmed to be Streptococcus pneumoniae if it exhibits sensitivity to optochin or bile (Evertsen et al, 2010). Atromentin and leucomelone inhibit the action of an enzyme that is essential for biosynthesis of fatty acids in the bacterium. The two substances also aid in identification of the bacterium. Physical examination of patients is used to reveal signs of streptococcal pneumonia such as high heart rate, low levels of oxygen concentration, and high blood pressure (Evertsen et al, 2010). A chest x-ray may be taken in order to reveal the condition of the chest. In case of infection, minimal chest expansion during breathing is observed. A stethoscope may also be used to determine signs of infection that include distorted crackles, percussion, and vocal resonance.
Treatment
Streptococcal pneumonia is treated using antibiotics. However, the bacteria develop resistance due to overuse of antibiotics. The choice of antibiotic to administer depends on factors such as age and the prevailing health condition of the patient (Aneja, 2011). For example, in children, the preferred antibiotic is amoxicillin. It is used if symptoms are mild or moderate. Antibiotics such as fluoroquinolones are discouraged because of their severe side effects, and the ease with which bacteria develop resistance. The infection is usually treated for one to one and half weeks. However, research has revealed that even shorter treatment periods of between 3 and 5 days also eliminate the infection effectively. Streptococcal pneumonia acquired in hospitals is treated differently. Antibiotics administered include cephalosporins, aminoglycosides, Vancomycin, and carbapenems (Aneja, 2011). They are administered intravenously, and in some instances combined to improve effectiveness.
Research has revealed that more than 90% of cases of streptococcal pneumonia acquired in hospitals are eradicated effectively through the initial administration of antibiotics. Hospitalization is necessary when patients show signs of severe dehydration. Cases of severe infection are treated using penicillin G while mild cases are treated using penicillin V (Aneja, 2011). Treatment of the disease has become difficult because of development of bacterial resistance to antibiotics. In cases of bacterial resistance, erythromycin is used for treatment. A vaccine was developed for prevention of the disease. It contains a valent polysaccharide that protects against infection by Streptococcus pneumoniae. The vaccine is however not fully protective because the bacterium has more than 90 different strains (Aneja, 2011).
Management
Management of streptococcal pneumonia involves the use of antibiotics. Vancomycin and imipenem are recommended for patients who show resistance to penicillin (Evertsen et al, 2010). In addition, these drugs are recommended because extended use of celaphalosporin therapy results in high levels of serum concentration. Trovafloxacin is effective against the bacteria if used under in vitro conditions. It is also effective in the treatment of community-acquired pneumonia because its efficacy rate has been shown to be approximately 91%. The U.S. Food and Drug Administration have approved Levofloxacin for management of streptococcal pneumonia (Evertsen et al, 2010). Grepafloxacin acts against proliferation of S. pneumoniae resistant to antibiotics. However, it is not commonly used for treatment of pneumonia because of the nonsusceptibilty of the bacterium to penicillin.
Prevention
Prevention of the disease involves use of vaccines that include Pneumococcal polysaccharide vaccine and Pneumococcal conjugate vaccine (Kaplan & Mason, 1998). The polysaccharide vaccine is the most commonly used. It functions by initiating the production of B-cells which consequently release Immunoglobulin M. The vaccine is only effective when administered to children over 2 years of age because their immune systems are fully developed (Kaplan & Mason, 1998). The vaccine does not stimulate mucosal immunity. Therefore, it does not protect individuals from respiratory tract infections. In addition, it does not promote herd immunity. The conjugated vaccine initiates stronger immune responses because it is a combination of capsular polysaccharides and the CRM 197 toxoid (Kaplan & Mason, 1998).
Conclusion
Streptococcal pneumonia is a type of pneumonia caused by the bacterium Streptococcus pneumoniae. The first case of infection was reported by Carl Friedlander in 1882. High rates of mortality caused by S. pneumoniae prompted researchers to develop treatment remedies to manage the condition. In 1977, a vaccine against streptococcal pneumonia was developed. Clinical manifestations include high fever, rapid breathing, vomiting, headache, and chills. Diagnosis involves identification of Streptococcus pneumoniae in the sputum of patients, which is indicated by the presence of neutrophils and gram-positive diplococcic bacteria. The bacterium is confirmed by cultivating it on blood agar. In addition, it is confirmed to be Streptococcus pneumoniae if it exhibits sensitivity to optochin or bile. Streptococcal pneumonia is treated using antibiotics like cephalosporins, aminoglycosides, Vancomycin, and carbapenems. Choice of antibiotics depends on factors such as age and the health status of the patient. For example, in children, the preferred antibiotic is amoxicillin if symptoms of the disease are mild or moderate. Two vaccines that include Pneumococcal polysaccharide vaccine and Pneumococcal conjugate vaccine are used to protect people from the disease.
References
Aneja, S. (2011). Pneumonia: Management in the Developing World. Pediatric respiratory reviews, 12 (1): 52–9.
Evertsen, J., Baumgardner, D., & Regnery, A. (2010). Diagnosis and Management of Pneumonia and Bronchitis in Outpatient Primary Care Practices. Primary Care Respiratory Journal, 19(3), 237-241.
Kang, C., Baek, J., Kim, S., and Chung, D. 92012). Bacteremic Pneumonia caused by Extensively Drug-Resistant Streptococcus pneumoniae. Journal of Clinical Microbiology, 50(12), 4175-4177.
Kaplan, S., & Mason, E. (1998). Management of Infections due to Antibiotic-Resistant Streptococcus pneumoniae. Clinical Microbiology Reviews, 11(4), 628-644.
Ranganathan, S., & Sonnappa, S. (2009). Pneumonia and other Respiratory Infections. Pediatric clinics of North America, 56 (1): 135–56.