Host resistance and immunity Essay Example | Topics and Well Written Essays - 500 words

Host resistance and immunity - Essay Example A detrimental colonization of the pathogen in the host body results in an infection. Variables that determine the outcome of a host body encounter with a pathogen include the infectivity, pathogenicity, virulence, toxigenicity, resistance, and antigenicity of the pathogens (Qureshi, S. 1999). Pathogenicity of an infection involves a mechanism that leads to the initiation of signs and symptoms of the bacterial or viral infections. An environment that favours the growth of the agent in the host body and its ability to damage the host determines the resultant outcome of the association between disease causing agent and the host body. High pathogenicity levels increases the risk of acquiring an infection. Therefore, once an individual gets exposed to a disease, the pathogenicity of the disease causing agent determines the possibility of the infection. On the other hand, if the bacteria or parasite turns out to be non-pathogenic, the risks of getting infection are low (Qureshi, S. 1999). Virulence refers to the severity of an infection and therefore a highly virulent strain produces severe infections. High virulent strains utilize resources from the host body and leads to tissue damage in host bodies. This increases the possibility of an infection and may lead to death of the host. Virulent strains speed up their growth in order to obtain transmission to new hosts. These strains struggle to gain subsequent transmission before killing the former host. Therefore, once an individual gets exposed to a disease, the virulence of the disease determines the level of damage. To counter an infection, one need to consider immediate treatment before multiplication of a strain that may be detrimental to one or more individuals (Sansonetti, P 2010). Toxigenicity refers to the ability of the agent to produce a toxin, which forms the main disease-causing element in a virus or bacteria. There are two types of toxins produced by disease causing parasites. They