Epidemiology of Influenza


Influenza is an infectious disease that endangers people regardless of their age, health, and location. Centers for Disease Control and Prevention (CDC) state that it is an “acute respiratory disease caused by infection with influenza viruses” (Seasonal influenza, 2019, para. 1). Seasonal flu incidence is between 3% and 11%, while the annual mortality rate is estimated at around 35,000 deaths (Seasonal influenza, 2019). The prevalence is at least 22 million people since the start of the flu season in the United States in 2020. It is estimated that “influenza has resulted in between 9 million – 45 million illnesses, between 140,000 – 810,000 hospitalizations, and between 12,000 – 61,000 deaths annually since 2010” (Seasonal influenza, 2019, para. 10). This paper will describe the communicable disease, social determinants that affect influenza’s development, epidemiologic triangle, the necessity of the community health nurse, as well as local and global implications of flu.

Medical Description

As per the symptoms, influenza can affect a patient on multiple levels, influencing the respiratory system the most. The most prevalent signs of influenza are fever or a feeling of having one, muscle pain, coughing, sore throat, runny nose, lack of energy, and headaches (Seasonal influenza, 2019). Influenza can also cause diarrhea and vomiting, especially among young children. Although the majority of infected people suffer minor health damage from the flu, there are rare occasions of severe and lethal complications among vulnerable populations or maltreatment cases. Some moderately-rates consequences are sinus and ear infections, while the most severe ones are often associated with pneumonia, heart, muscle, brain, and other organ inflammation as a response to the virus (Seasonal influenza, 2019). In addition to the development of new illnesses, the existing chronic issues might be further worsened by influenza’s impact.

Influenza is also a preventable and treatable disease that is actively combated by modern medicine. Every person older than six months is encouraged to be vaccinated annually to avoid getting infected. If one catches flu, they are treated with anti-viral drugs that are different from regular antibiotics since they disrupt the development of the virus instead of destroying it along with other bacteria (Seasonal influenza, 2019). Every healthcare provider must report the total number of Hemophilus influenza, related infant deaths, and novel influenza A virus infections to the CDC.

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.

Given the aforementioned analysis, some specific considerations are developed to prevent the infection’s spread. For instance, concerning the host, vaccinations are widely encouraged and implemented to increase the host’s resistance, immunity, and defense mechanisms that reduce one’s susceptibility to the virus. As a result, many schools and workplaces implement free vaccination to facilitate disease reduction. About the environment, it is evident that the virus thrives in tropical and humid climates, as well as spreads easily through droplets of saliva. Therefore, the communities at risk encourage people to wear face masks, take sick leaves, and vaccinate to avoid being infected and spreading the virus by creating a beneficial environment.

Social Determinants of Health

Social determinants of health are highly influential in viral infections’ spread and containment. Social determinants include “education, race, ethnicity, socioeconomic status, access to healthcare, vaccination, neighborhood-level stressors, and workplace or school policies” and play a vital role in spreading influenza (Cordoba & Aiello, 2016, p. 341). For instance, one’s race and socioeconomic status do not enable a person to have adequate access to healthcare and vaccination, which makes him a more likely target for influenza. This dynamic showcases the importance of acknowledging and addressing the social determinants of health when examining the disease from the epidemiologic perspective.

More specifically, social determinants of health that disrupt people’s ability to seek treatment and vaccination make these individuals the most susceptible to the influenza virus. According to Cordoba and Aiello (2016), institutional barriers to healthcare that stop vulnerable populations from accessing vaccination are the first factors that promote influenza outbreaks. “Existing structures and policies” disfavor people of a certain race, ethnicity, income, and socioeconomic status, creating more risks of virus containment and complications for these groups (Cordoba & Aiello, 2016, p. 341). In addition to being unable to be vaccinated, people with unfavorable socioeconomic status or those from discriminated minority groups are unaware of non-pharmaceutical interventions like isolation and appropriate hand hygiene (Cordoba & Aiello, 2016). Being unable to access prevention techniques of vaccination, non-medical interventions, and treatment options, people with a certain socioeconomic status become easily targeted by the virus.

The second group of social determinants of health that disregard specific populations are neighborhood environments. Since influenza is a highly communicable disease transmitted through saliva droplets, interactions with the environment play a key role in the spread of the disease (Cordoba & Aiello, 2016). Neighborhoods that report lower vaccination rates also suffer from high flu infection statistics due to proximity to unvaccinated individuals and an increased likelihood of being infected (Cordoba & Aiello, 2016). Therefore, as opposed to individual characteristics, environmental and social determinants also play a crucial role in influenza infection rates.

Lastly, the third group of social determinants that target specific groups of people includes workplace and school policies. People who engage in educational or professional activities highly rely on places of work or studying for well-being and income. However, different institutions treat the epidemiological situation of influenza differently. Cordoba and Aiello (2016) reported that schools and offices that provide free vaccination, sick leaves, and closures are at significantly lower risks of virus containment and flu-related mortality. Although these measures require funding, workplaces and schools return their investments in the form of increased well-being of their workers and students. On the contrary, institutions that do not implement prevention strategies put their subordinates at a higher risk of contracting influenza.

Community Health Nurse and Demographic Data

Community health nurse is essential agent of change in healthcare who can significantly influence and contribute to influenza prevention. World Health Organization (WHO, 2017) states that community health nurses are professionals whose primary tasks are to provide patients with treatment, education, maintenance of their health, and opportunities to decrease the occurrences of the disease. Their list of tasks about influenza prevention includes two types of functions: clinical care and complementary competencies (WHO, 2017). According to WHO (2017), clinical care consists of primary and secondary prevention like “health assessment, disease management, case finding, case management, observation and treatment according to delegated responsibility” (p. 14). Complementary competencies describe the needed skillset for nurses to operate effectively within a community setting and include “cultural sensitivity, participatory research, leadership, development of tools for data collection and analysis ” (WHO, 2017, p. 15). By fulfilling all the tasks and utilizing all the competencies described above, community health nurses fulfill an essential role of change agents in disease prevention by case finding, reporting, data collection and analysis, and follow-up.

Demographic data collected by the community health nurses is vital for public health. Demographic data that shows disease emergence and trends not only provides healthcare professionals with the needed information to strategize for future prevention measures but also helps in coping with current public health threats (WHO, 2017). For instance, demographic data can uncover what groups of people are the most vulnerable to influenza, which will help medical staff to target patients with uncovered characteristics to prevent infection intensively.

CDC Against Influenza

Influenza is a global public threat that has been majorly mediated and reduced by the CDC. Intending to increase flu awareness and prevention, the CDC created an Influenza Division International Program that, along with other National Ministries of Health and WHO, collectively responds to the spread of influenza viruses. The Division’s primary goals are creating an evidence-based strategy for control and prevention internationally, educating people worldwide on the associated dangers, and reducing the impact of various types of influenza (“Influenza Division International Program,” 2020). One of the main objectives of the Influenza Division International Program is enhancing the collection and sharing of influenza-related information by assisting other countries in creating and maintaining constant reporting of the virus (“Influenza Division International Program,” 2020). Furthermore, the Division aims to research and identify vulnerable populations to reduce multiple risk factors that endanger people.

Estimating the healthcare and economic impact of flu is another competency of the Influenza Division International Program. Policy-making and lobbying for regulations that will positively impact influenza reduction and prevention is a crucial task of the Influenza Division International Program (2020) that helps to bring pollical attention to the public health problem. Researching the effectiveness of the existing vaccines and developing better ones are among other functions of the Division. Along with multiple partners, Influenza Division International Program forecasts the flu seasons, assists countries worldwide in locating the disease, and researches innovative solutions in a collective effort to reduce the impact of the infection.

Global and Culturally Sensitive Influenza Endemic Measures

Given the high risk of transmutability and specific favorable environments, influenza is a virus that affects countries worldwide. Some areas are affected seasonally due to the emergence of favorable weather conditions. However, there are also regions where the climate creates a constantly attractive environment for influenza, which leads to an endemic situation in certain countries. According to Xue and Zeng (2018), South and East Asia are some of the regions that suffer from the influenza endemic the most. In particular, China, which is a country with drastically different disease prevention, has to address the influenza endemic regularly due to the climate and artificially created cultural practices that cultivate the development of influenza. During an H1N1 influenza pandemic, the country “focused on, responded actively to, and coped with the epidemic scientifically and according to the law through joint prevention and control mechanisms” (Xue & Zeng, 2018, p. 63). A prevention plan included “pre-pandemic preparedness, close contacts management with anti-proliferation control measures, strengthened treatment of severely ill patients, influenza monitoring strategy, and constant optimization of influenza monitoring network” (Xue & Zeng, 2018, p. 65). The strategy constantly facilitates virus containment despite the endemic situation.

There are also specific cultural implications for influenza prevention in Asian countries that contribute to the overall disease minimization. Some region-specific treatments are prescription of traditional Asian medicine to manage influenza symptoms and mixing conventional and Western medication to prevent seasonal flu (Lam, Fowler, & Dawson, 2017). Other culture-specific practices included novelties like “boiling white vinegar to kill air-born germs and diet therapy to enhance health” (Lam et al., 2017, p. 15). It is more culturally accepted in China and other Asian countries to wear face masks as part of the collective culture that aims at containing public health over prioritizing personal comfort.

It is essential to address the issue of influenza on a regional and global level since an emergent pandemic can affect all countries worldwide. Although different countries have varying prevention and treatment methods due to cultural specificities and endemic situations, enhancing those measures to contain the virus continually is vital. When examining influenza, it is critical to consider its medical description and cultural, social, regional, and global implications.


Budd, A., Blanton, L., Grohskopf, L., Campbell, A., Dugan, V., Wentworth, D. E., & Brammer, E. (2017). Manual for the surveillance of vaccine-preventable diseases. Web.

Cordoba, E., & Aiello, A. (2016). Social determinants of influenza illness and outbreaks in the United States. North Carolina Medical Journal, 77(5), 341-345. Web.

Influenza Division International Program. (2020). Web.

Lam, W., Fowler, C., & Dawson, A. (2017). The role of culture in relation to the seasonal influenza prevention practices of Hong Kong Chinese parents with preschool children. International Journal of Health Promotion and Education, 56(1), 3-16. Web.

Seasonal influenza. (2019). Web.

World Health Organization. (2017). Enhancing the role of community health nursing for universal health coverage. Human Resources for Health Observer, 18(1), 1-32. Web.

Xue, L., & Zeng, G. (2018). China’s prevention and control and policy changes to the influenza (H1N1) pandemic. Research Series on The Chinese Dream and China’s Development Path, 43(2), 45-74. Web.

Cite this paper

Select style


NursingBird. (2023, January 6). Epidemiology of Influenza. Retrieved from https://nursingbird.com/epidemiology-of-influenza/


NursingBird. (2023, January 6). Epidemiology of Influenza. https://nursingbird.com/epidemiology-of-influenza/

Work Cited

"Epidemiology of Influenza." NursingBird, 6 Jan. 2023, nursingbird.com/epidemiology-of-influenza/.


NursingBird. (2023) 'Epidemiology of Influenza'. 6 January.


NursingBird. 2023. "Epidemiology of Influenza." January 6, 2023. https://nursingbird.com/epidemiology-of-influenza/.

1. NursingBird. "Epidemiology of Influenza." January 6, 2023. https://nursingbird.com/epidemiology-of-influenza/.


NursingBird. "Epidemiology of Influenza." January 6, 2023. https://nursingbird.com/epidemiology-of-influenza/.