Why Many Microbial Infections Are Described as Opportunistic - Essay Example

? Infectious Disease and Processes Infectious Disease and Processes Opportunistic Infections Generally, the word opportunistic refers to a situation where something/someone takes an immediate unethical advantage of a particular circumstance in order to achieve specific benefits. Jones et al (2000, p. 1026) explain that some micro-organisms are said to be opportunistic since they cannot infect a person under normal circumstances, but are found to take advantage and cause disease when the immune system of the body is impaired. Thus, opportunistic infection is seen to manifest itself only when a person is ill and the body defense mechanisms are affected. At this time, the opportunistic organisms get an opportunity to spread as well as grow fast, hence, causing severe illness. Though such infections can be seen in a healthy person, their growth and spread is highly hindered. In cases of opportunistic infections, a chance is created for nonpathogenic microorganisms to become pathogenic and very harmful (Mitnick et al, 2003, p. 119). These infections mostly manifest themselves in people already infected with viruses like HIV, for instance Tuberculosis (TB). Tuberculosis (TB) as an Opportunistic Infection Viral Example Tuberculosis is an air-borne disease that usually affects the respiratory system (lungs) and is caused by Mycobacterium Tuberculosis bacteria (Currie et al, 2003, p. 2501). It can also affect other body parts like the spine and the kidneys. It is a serious infection that kills a large percentage of people worldwide, especially if not effectively treated. Approximately 2 billion people of the world’s population give positive results to TB tests annually, of which about 3 million end up dying. TB infections had almost become extinct in developed countries before the emergence of HIV epidemic. With the onset of the HIV virus, TB infections were found to be very rampant and severe in people affected with the virus (Jones et al, 2000, p. 1031). This is simply because the HIV virus makes the body’s immune system weak, thus, promoting the growth and spread of the TB bacteria. The close link between HIV and TB was stressed and emphasized during a conference concerned with retroviruses as well as opportunistic infections (CROI) (Mitnick et al, 2003, p. 128). At the conference, a report was release analyzing the recent emergence of TB bacteria which is drug resistant. The World Health Organization (WHO) tried to establish the relationship between this drug-resistant bacteria and the HIV virus. A study was carried out in South Africa where it found out that XDR TB was resistant to a number of drugs meant to treat it, including isoniazid. This was the new case which was discovered however since then beyond 300 new cases have been reported (Tufariello, Chan & Flynn, 2003, p. 578). Nevertheless, it was discovered that people who exhibited such cases positively tested for the HIV virus. The micro-organism that usually causes TB is transmitted from one person to another through air (CDC, 2000, p. 185). These micro-organisms can spread as a result of a cough or sometimes an open sneeze. It is not in all cases that a person can get infected with TB by just a single sneeze or a cough. However, if you are frequently exposed to such sneezes and coughs, the likelihood is very high. This can occur in cases where you live or mostly work with a TB infected individual. Moreover, you can easily get TB in places that are ventilated poorly or crowded (Espinal et al, 2000, p. 275). By so saying, it does not mean that one can get infected through sharing utensils or physically contacting a person who has it. There are mainly two types of infections classified as TB which are differentiated using their different ways of manifestations (Lonnroth et al, 2009, p. 2240). The first one is referred to as latent and this one has no symptoms thus remains in your body in an inactive form. The second one is called active which mostly affects people whose immune system is impaired. In this case, the germs causing disease are very active, grow at a fast rate and spread rapidly throughout the body causing TB related symptoms. The later mostly affects people with the HIV whose CD4 (cells responsible for immunity) count is below (200). Though the active form can infect people without the HIV virus, it rarely happens. Those individuals who have both TB and HIV virus are said to be suffering from AIDs (Espinal et al, 2000, p. 280). Bacterial Examples Gardam et al (2003, p. 148) state that during inhalation, the TB bacteria get trapped in the alveoli where they get into contact with the white blood cells (WBCs). In a healthy person with the very active body defense mechanisms, these white blood cells will work against the bacteria and try to destroy it. On the other hand, when a person’s immune system has been impaired, it means that the RBCs are a very weak and cannot completely destroy all the inhaled bacteria. This suggests that some other bacteria will remain within the WBCs and be carried round the body though blood. When these bacteria find favorable conditions, they will grow and spread very fast, hence, causing severe illness (CDC, 2000, p. 189). If patients do not follow their doctor’s instructions on their medication, a resistant form of TB develops referred to as multi-drug-resistant (MDR). Currie et al (2003, p. 2508) assert that TB can manifest itself differently from one individual to another though its common symptoms include. A persistent cough experienced up to 2 or 3 weeks and the cough is characterized with phlegm or mostly blood. General body weaknesses, as well as fatigue, are also experienced. Other characteristics include pains in the chest, drastic weight loss, appetite loss, abnormal chills or fevers and finally, excessive sweating at night. These symptoms can be used to speculate that one has TB though when one tests positive for HIV she/he should also be tested for TB (Gardam et al, 2003, p. 155). It might be quite difficult to diagnose TB since one may be having it and still test negative or may not be having it but test positive as a result of a related infection. Fortunately, with continued developments in the medical industry, effective diagnosis methods have been put forth. There are several opportunistic infections which take advantage of the body’s poor immune system to manifest them in a more severe manner (Gordin et al, 2000, p. 1445). These infections are not life threatening on normal circumstance but with a weakened body immune system, they become very threatening. For instance, tuberculosis in itself is latent and is easily controlled. However, with the aid of other immunity weakening infections such as HIV, it becomes powerful and resistant that its treatment becomes almost impossible. Wallis et al (2004, p. 257) concur that other opportunistic infections have been linked with diseases such as cancer and diabetes. Patients with such diseases are advised to cooperate with their doctors in order to effectively carry out the treatment process. References CDC, 2000. Notice to Readers: Updated Guidelines for the Use of Rifabutin or Rifampin for the Treatment and Prevention of Tuberculosis among HIV-Infected Patients Taking Protease Inhibitors or Nonnucleoside Reverse Transcriptase Inhibitors, MMWR, 49:185-89. Currie, S. et al, 2003. Tuberculosis Epidemics Driven by HIV: Is Prevention Better than Cure? AIDS, 17(17):2501-2508. Espinal, A. et al, 2000. Infectiousness of Mycobacterium Tuberculosis in HIV-1-infected Patients with Tuberculosis: A Prospective Study. Lancet, 355(9200):275-280. Gardam, A. et al, 2003. Anti-tumour Necrosis Factor Agents and Tuberculosis Risk: Mechanisms of Action and Clinical Management. Lancet Infect Dis, 3:148–55. Gordin, M. et al, 2000. An International, Randomized Trial of Rifampin and Pyrazinamide Versus Isoniazid for Prevention of Tuberculosis in HIV-Infected Persons, JAMA, 283:1445. Jones, L. et al, 2000. HIV-Associated Tuberculosis in the Era of Highly Active Antiretroviral Therapy, Int J Tuberc Lung Dis, 4:1026-31. Lonnroth, K. et al, 2009. Drivers of Tuberculosis Epidemics: The Role of Risk Factors and Social Determinants, Social Science & Medicine, 68(12):2240. Mitnick, C. et al, 2003. Community-based Therapy for Multi-drug-resistant Tuberculosis in Lima, Peru. New England Journal of Medicine, 348(2):119-128. Tufariello, M., Chan, J. & Flynn, L., 2003. Latent Tuberculosis: Mechanisms of Host and Bacillus that Contribute to Persistent Infection, Lancet Infect Dis, 3:578. Wallis, S. et al, 2004. A study of the Safety, Immunology, Virology, and Microbiology of Adjunctive Etanercept in HIV-1-Associated Tuberculosis, AIDS, 18:257. Read More