The Most Common Opportunistic Infections - Essay Example

"The Most Common Opportunistic Infections" is a good example of a paper on the immune system.
Although the terms pathogenicity and virulence are commonly used interchangeably, they can be distinguished and adapted to improve the perception of interactions between pathogens and hosts. A microorganism’s genetic capacity to cause disease is referred to as pathogenicity (Al-Fattani & Douglas, 2006). Pathogenicity is an inherent, qualitative attribute of a microorganism, and whether it results in disease or not is a function and aspect of particular host-pathogen interactions. Virulence, on the other hand, is a quantitative and relative attribute that denotes the degree of pathology a microorganism causes. In this sense, virulence is an attribute that expresses what the interaction between a host and pathogen is and is usually associated with the ability of the pathogen to proliferate in the host. Therefore, the two terms are interchangeable basically because virulence is a measure of an organism’s pathogenicity. Opportunistic infections (OIs) are those particularly caused by opportunistic microorganisms that take advantage of certain situations but do not usually result in disease in healthy hosts with healthy immune systems. However, the infections become pathogenic should the body’s immune system get compromised, impaired, or rendered unable to prevent infection. Examples of OIs include candidiasis (of lungs, bronchi, esophagus or trachea), lymphoma, tuberculosis, invasive cervical cancer, and cryptosporidiosis.   

            Persons with healthy immune systems may not exhibit any reaction after exposure to certain bacteria, viruses, and parasites. However, those with compromised immune systems, such as the ones living with HIV/AIDS, are greatly threatened (Chakrabarti, 2005). Since pathogens are typified by specific actions, different species will cause distinct infectious processes. In order for damage to be caused, microorganisms must enter a host and attach themselves to tissues and further survive the protective mechanisms of the host. There, they produce toxins and induce a response from the host that, in essence, is harmful to the host. Any attribute of the organism that contributes to disease or infection is its virulence factor, which includes invasion and adherence factors, and it determines how it invades the host, evades the defenses, and causes disease. For example, adhesion is a virulence factor of Candida albicans. Another factor, morphogenesis, is the transition to a filamentous form from a unicellular yeast. Pathogenicity, on the other hand, is neither absolute nor invariant and can be put in three key categories. While opportunistic pathogens will only be agents of disease among patients predisposed to disease, others rarely cause disease and considered non-pathogens, and primary pathogens are actual agents of disease. Different microorganisms cause different levels of imbalance between host resistance and bacterial pathogenicity, which is the point at which infection begins. In public perception, the microorganisms can be transmitted environmentally from host to host and cause social disruption and panic (Al-Fattani & Douglas, 2006). The Healthcare facilities, therefore, must confront different issues in terms of sets when they deal with events of suspected bioterrorism. Infected or exposed persons form part of the key issues to be addressed, and the prevention of transmission among the patients, visitors, and healthcare staff are among the challenges posed (Chakrabarti, 2005). Pathogenicity and virulence influence public vaccination and need to be enforced.