Communicable Disease Chain and Chain of Infection

Communicable Disease Chain and Chain of Infection

Influenza can also be examined from the communicable disease chain framework. The influenza virus acts as an infectious agent in the chain and is characterized by its invasiveness, virulence, and pathogenicity. The second aspect of the chain of infection, the reservoir, is a human or an animal, depending on the type of the virus (Seasonal influenza, 2019). Once the reservoir is infected, the virus leaves an organism through a portal exit. In the case of influenzas, the respiratory system, specifical secretion like saliva, acts as an exit path for flu. After exiting, the virus is indirectly transmitted through droplets or contact with contaminated vehicles like water and infected surfaces (Seasonal influenza, 2019). When a person indirectly contracts a virus, flu re-enters another organism the same way it exited the previous one. The new host can be more or less susceptible to being infected due to numerous factors like one’s defense mechanisms due to vaccination, as well as artificial and natural immunity. The chain of infection shows that getting sick with the flu virus is a process that can target any individual.

Epidemiologic Triangle

The epidemiologic triangle is a viable concept to investigate and address the process of infection spread, specifically in the case of the influenza virus. The epidemiologic triangle consists of three factors: an agent, or a microbe that causes the disease, a host, or an organism who transmits the disease, and an environment that consists of “external factors that cause or allow disease transmission” (Budd et al., 2017, para. 17). The framework can be applied to influenza to address the specific components that play a role in the epidemiologic process.

Firstly, the influenza virus acts as an agent according to the epidemiological triangle. The so-called “what” of the triangle is a disease-causing viral microbe of flu in the Orthomyxoviridae family that can be of four types: A, B, C, and D (Budd et al., 2017). As a viral agent, influenza infection does not reproduce but infects cells of the contaminated organism to replicate. Secondly, the so-called “host” is an organism that is entered by the agent and suffers from viral infection (Budd et al., 2017). Different hosts can react to the same agent differently, similar to how influenza leads to different symptoms in children and adults. For some types of influenzas, animals can act as hosts, while human-related infections affect only human carriers by provoking specific symptoms. Lastly, the environment includes the favorable conditions that create a fitting climate and a set of factors that lead an agent to be transmitted to a host. The attractive environment for influenza viruses is cold, dry weather in high attitudes and humid and raining conditions that contribute to the disease spread in low latitudes.