Introduction
Legionnaires’ disease is also referred to as legion fever or legionellosis. Legionnaires’ disease is a severe respiratory contagion that comes as a result of bacterial infection. The condition became famous in 1976 after it attacked a group of people attending an American Legion convention. Scientists eventually learned that the bacteria responsible for Legionnaires’ disease could thrive in stagnant water. The scientific name for Legionnaires’ disease is Legionella pneumophila. Cunha (2011) posits, “Legionella is gram-negative” (p. 78). Besides, legionella can either be coccoid-shaped or rod-shaped. A majority of the legionella species are “motile and have one to three polar or lateral flagella” (Cunha, 2011, p. 81). Scientists allege that Legionella pneumophila is visible in gram-stained medical samples. Failure to detect gram-negative rods in a specimen obtained from a patient suffering from pneumonia is a diagnostic feature of Legionnaires’ disease. The presence of other gram-negative bacilli on typical agars should not redirect a person from the identification of Legionnaires’ disease. This paper will discuss the causative agents, methods of reproduction, and environmental conditions that favor the growth of the bacteria that cause Legionnaires’ disease. Besides, the paper will discuss the epidemiology of the disease as well as its incubation. The paper will end by discussing the signs and symptoms, clinical diagnosis, and treatment of the disease.
Causative Agents
According to scientists, the primary causative agent of Legionnaires’ disease is legionella pneumophila. Legionella pneumophila is a kind of bacteria that infects the respiratory system (Cunha, 2011). Other causative agents include legionella longbeachae, legionella micdadei, legionella feeleii, and legionella anisa. These causative agents result in Pontiac fever. Pontiac fever is a less severe infection.
Method of Reproduction and Environmental Conditions
Legionella pneumonia relates well with other microorganisms. It underlines the reason the bacteria reproduce well in the biofilm. Cunha (2011) maintains, “Legionella pneumonia live in symbiosis with amoeba and ciliated protozoa” (p. 94). Legionella pneumonia replicates and thrives as an intercellular parasite in these microorganisms. Fields, Benson, and Besser (2006) allege that legionella pneumonia does well in warm, humid regions. One can easily find the bacteria in central air conditioning systems located in hotels, office buildings, and hospitals. Additionally, the bacteria can survive in cooling towers, water heating systems, nebulizers, whirlpool spas, showers, and evaporative coolers among other areas. The temperatures that exceed 1040F support the reproduction of bacteria.
Epidemiology
Persons suffering from medical conditions that compromise their immune system are likely to contract Legionnaires’ disease. For instance, a person that is taking immunosuppressive drugs is at a high risk of contracting the disease. Additionally, heavy smokers, the elderly, and persons with chronic lung infections are likely to suffer from Legionnaires’ disease. Legionnaires’ disease is not contagious (Fields et al., 2006). The disease cannot be transmitted through contact. The medical professional claims that Legionnaires’ disease is transmitted through aspiration or inhalation of aerosolized or tainted water. A person suffers from Legionnaires’ disease only once.
Fields et al. (2006) argue that Legionnaires’ disease is commonly found in fountains, hospitals, cruise ships, and hotels with complicated portable cooling and water systems. A good example of the Legionnaires’ disease epidemic was the outbreak that occurred in 1976. About 4,000 affiliates of the American Legion assembled in Philadelphia for an annual meeting. Three days after the convention, the attendants started to exhibit feverish sickness. The medical practitioners realized that there was a correlation between the illness and the Legionnaires’ meeting, thus the term Legionnaires’ disease.
Incubation, Signs, and Tissues Affected
Medical practitioners maintain that Legionnaires’ disease has an incubation period of between two to ten days. The disease affects lung tissues resulting in scars. One of the signs of Legionnaires’ disease is muscle aches. Other symptoms include headache, fatigue, diarrhea, general illness, and abdominal pain (Fields et al., 2006). The initial symptoms occur two to ten days after infection. A person that is suffering from acute Legionnaires’ disease may exhibit a dry cough, chills, high fever, and chest pain. Some people may also suffer from hallucinations, memory lapses, and confusion.
Clinical Diagnosis
Kumpers et al. (2008) argue, “The most useful diagnostic tests detect the bacteria in coughed-up mucus, find Legionella antigens in urine samples, or allow comparison of Legionella antibody levels in two blood samples taken 3 to 6 weeks apart” (p. 385). The urine test is fast, efficient, and dependable. Nevertheless, the test does not detect all the strains of legionella pneumophilla. Thus, medical practitioners are supposed to combine the urine test with other diagnostic procedures. Other diagnostic procedures include a blood test, chest X-ray, ACT scan, and analysis of lung tissue among others.
Treatment
Health professionals use antibiotics to cure Legionnaires’ disease. Some antibiotics that treat the disease include ketolides, macrolides, quinolones, and tetracyclines. Legionella pneumophilla replicates in the cell. As a result, medical practitioners use antibiotics that have exceptional intracellular diffusion (Kumpers et al., 2008). The most preferred treatment procedures include macrolides and quinolones that treat the respiratory tract.
Conclusion
Legionnaires’ disease is a respiratory illness that comes as a result of bacterial infection. The primary causative agent of Legionnaires’ disease is legionella pneumophila. The bacteria thrive in warm, moist regions like in the evaporative coolers and showers. Individuals suffering from Legionnaires” disease may complain of a headache or fatigue. The disease can be diagnosed by testing urine antigens. Doctors use antibiotics to cure Legionnaires’ disease.
References
Cunha, B. (2011). Legionnaires’ disease: Clinical differentiation from typical and other atypical pneumonias. Infectious Disease Clinics of North America, 24(1), 73-105.
Fields, B., Benson, R., & Besser, R. (2006). Legionella and Legionnaires’ disease: 25 years of investigation. Clinical Microbiology Reviews, 15(3), 506-526.
Kumpers, P., Tiede, A., Kirschner, P., Girke, J., Ganser, A., & Peest, D. (2008). Legionnaires’ disease in immunocompromised patients: A case report of legionella longbeachae pneumonia and review of the literature. Journal of Medical Microbiology, 57(3), 384-387.