Causes And Potential Consequences Of An Influenza Epidemic Biology Essay

Published: Last Edited:

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.

This report investigates the risks of Influenza as an Epidemic/Pandemic within the Cooinda Region by analysis of factors attributing to the spread of influenza within the community. This report will discuss past influenza pandemics and how these effected the growing population; biological factors eg: differences between bacteria and viruses; environmental factors, how these aide in the spread of the virus. Through research and analysis, we have examined control methods for the influenza virus and health service controls that will reduce further infection prior to, and during, an epidemic/pandemic.

Influenza Pandemics in the past

In the last century there were 3 major influenza pandemics - Spanish flu, Asian flu and Hong Kong Flu.

Spanish Influenza 1918-1919

This occurred in 3 waves and killed an estimated 50 million people worldwide, approximately 10,000 were Australian. It's estimated that 25% of the world's population was infected and there was an unusually high death rate in people aged 15-35. It came on suddenly, rapidly progressed to respiratory failure and in some cases death occurred, most people died from bacterial disease after influenza infection and this is known as secondary bacterial infection.

War and troop movement are thought to have assisted the global spread and severity. It reached Australia in 1919 and that's partly due to maritime quarantine that the government had implemented. Health Services in all countries were greatly stretched during this period.

During this time the understanding of the influenza virus was limited, most scientists and physicians believed that influenza was caused by Pfeiffer's bacillus bacteria and not a virus. They knew that influenza spread through contact with an infected person when they sneezed or coughed, however they couldn't locate the cause of influenza.

Researchers around the world tried to find a vaccine but none were effective in treating influenza, antibiotics weren't available.

Management of influenza:

covering nose/mouth when sneezing and coughing

wearing face masks

banning spitting in public

Asian influenza 1957-1958

This outbreak was mild in comparison to the previous pandemic, resulting in milder symptoms and less deaths although infection rate was high. It occurred in 2 waves, the first was mainly school children and the second were elderly. It is estimated that about 2 million people, mainly elderly and infants died worldwide. Studies have shown that a genetic re-assortment of a bird virus was responsible for this pandemic.

Hong Kong influenza 1968-1970

This pandemic was also mild in comparison to the 1918-19 pandemic. It mainly affected the elderly and resulted in approximately one million deaths worldwide. Studies show that a genetic re-assortment of a virus was also responsible for this pandemic.

Biological Causes


The influenza virus 'is roughly round, but it can also be elongated or irregularly shaped' (National Institute of Allergy and Infectious Diseases (NIAID), 2008). Influenza's most prominent feature is a layer of spikes coming out from its exterior. It is characterised by two protein spikes (NIAID, 2008) which are:

'Hemaglutinin (HA), which allows the virus to "stick" to a cell and initiate infection' (NIAID, 2008).

'Neuraminidase (NA), which enables newly formed viruses to exit the host cell' (NIAID, 2008).

Virus Strains

The three main influenza virus strains are classified as A, B & C. Classifications are 'based upon their protein composition' (NIAID, 2008) and can be described as follows:

Type A

Causes human pandemics

Can be fatal

Found in a variety of animals including ducks, chickens, pigs, whales and humans

Type B

Widely circulates in humans

Responsible for small outbreaks

Type C

Rarely causes infection

Never been connected to a pandemic

Found in humans, pigs and dogs (Influenza & Better Health)

New strains of the virus emerge at regular intervals and are named according to their geographic origin (Harris.P et al 2nd Edition, 2010).

Genetic Changes

Antigenic drift occurs in 'type A and B influenza as the virus makes copies of itself' (NIAID, 2008). The human immune system cannot recognize new strains of virus after drifting has occurred. Therefore a new flu vaccine must be produced each year to fight that year's strains (NIAID, 2008).

Antigenic shift occurs in type A influenza, characterised by infrequent and sudden changes. When two different flu strains attack the same cell and exchange genetic material this creates a new influenza A subtype. Humans have no immunity to each new subtype, which places the global community at risk of influenza pandemics/epidemics each Flu season (NIAID, 2008).

Bactria -v- Virus

Bacterium is a tiny single cell organism, responsible for causing a range of infections, and is broadly classified into four groups: Bacilli, Cocci, Spirochaetes and Vibrios. Access routes for bacteria include cuts, contaminated food or water, close contact with an infected person's faeces and the droplets expelled through coughing, sneezing or vomiting. This stimulates the immune response, the body produces antibodies to attach and destroy the invading bacteria. (Better Health)

Viruses are small microorganism that can only reproduce inside a hosts living cell. The four main types of viruses are: Icosahedra, Helical, Enveloped and Complex. Some of the most serious communicable diseases known to medical science are viral in origin including Influenza. (Better Health)

Environmental Factors

Environmental factors and ecological changes can be responsible for influenza outbreaks including:

Agricultural or Economic Developments

Climate Change

Temperature and relative humidity

Human demographic changes/movement of people

Physical contact between humans and possible pathogens. (McMichael, 2004)

Ecological Disruptions

Ecological factors and changes are the major identified factors in disease emergence. The WHO (2008, pg3) identified that cities of developing countries provide prolific breeding grounds for environmental and health hazards and poverty increases susceptibility to respiratory illnesses. This correlates with the following factors:

Unplanned and unsustainable urban planning


Unsafe water

Deforestation (McMichael, 2004)

Researchers have documented evidence that waterbirds like ducks are major hosts of the influenza virus. The disease is spread by infected birds through their nasal secretions, saliva and droppings (Rothstein, 2005, p446). This impacts the Cooinda region as it has immense foliage and may be in bird's migratory path.

Climate Change

Global climate change is affecting biological systems everywhere. Rising temperatures worldwide are affecting weather patterns and causing events such as heatwaves, drought, bushfires, floods and tsunami (McMichael, 2004). The possible link between the risk of disease and climate change has been widely reported and suggests there is a growing concern about the impact of global warmings on health (McMichael, 2006). The Cooinda Region is an area susceptible to drought, bushfires and flood, appropriate action plans can minimise the potential spread of disease.

Modes of Transmission

The Influenza virus can pass from human to human through infected respiratory discharge. The disease is mainly spread through hands from an infected person. Hands can pick up a virus through touching contaminated items or surfaces. Influenza virus is most likely to spread indoors due to reduced or weak ventilation, humidity and UV radiation all of which affect the distribution of influenza via airborne particles. (Collignon, 2006).

We live in a microbial world that will continue to generate infectious disease, through many different measures. Therefore we need to anticipate, understand better and be prepared (McMichael, 2004).

Health Service Controls

The Cooinda community contains people from a diverse range of backgrounds and communal ties. It is reasonable to assume that, throughout their day to day duties, Health Care Workers (HCW) can expect to have contact with clients at risk of, or infected with the Influenza Virus.

At Risk Groups

The Cooinda community covers a broad spectrum of intra communal, cultural and ancestral people that may be of specific or increased risk of contracting Influenza. Specifically, The National Health and Medical Research Council (2010) identified at risk groups in the population;

Individuals over 65 years old.

Aboriginal and Torres Strait Islanders over 50 years and above, or aged 15 - 49 with other risk factors

Individuals with

Chronic lung diseases (ie Cystic Fibrosis), heart conditions, and illnesses requiring regular follow up or hospitalisation in the preceding year

Immune Deficiency

Nursing Home residents, staff and carers

Children ages 6 months to 10 years on long term aspirin therapy

Women who are planning on, or are, pregnant in their second/third trimester.


WHO has released recommendations outlining 21 Influenza specific infection control measures (see appendix B) (WHO, 2009). Of paramount importance were adherences to administrative controls designed to prevent contamination and infection, education of staff and abiding by Standard Precautions.

The Department of Health and Ageing (DHA) define Standard Precautions as 'work practices required for the basic level of infection control' (DHA, 2010). Standard precautions are a HCW's primary defence in minimising infection transmission. Standard Precautions fully controlled by HCW's are adherence to hand hygiene; the use of personal protective equipment; using the aseptic technique and appropriate disposal of infectious waste. Health care facilities also assist to maintain Standard Precautions by ensuring adequate environmental controls and support services are provided (WHO, 2009).

5.3 Education

To reiterate WHO's recommendations, it is imperative that all HCW within the Cooinda community are prioritised for influenza immunizations, assessed and re-educated in areas with an identified knowledge deficit. Clinical workshops aimed at refreshing staff on basic skills and updating precautionary measures may be helpful (WHO, 2009)

HCW's should also be encouraged to identify and educate at risk clients of the benefits of immunisation and basic cough etiquette in a manner that is culturally sensitive and personally appropriate. (WHO, 2009).

Conclusion and Recommendations

This report details extensive investigations into the risk of an influenza epidemic/pandemic occurring within the Cooinda region. It is evident that there are many biological and environmental factors attributing to the spread of an influenza epidemic/pandemic within the region. Utilising the resources available within the restricted time frame, and with the health of the Cooinda community and its health care staff of utmost importance, our team has compiled the most pertinent recommendations for the prevention and control of influenza virus with the resources available.:

Immunisations: At risk groups should be vaccinated with the seasonal influenza vaccines. As new strains of influenza emerge development of new vaccines needs to occur.

Antibiotics: Compile influenza screening blood tests and cultures on those potentially infected to determine what antibiotics should be provided for people who have developed bacterial infections.

Isolation: restrict access to infected people to control the pandemic

PPE: Use of gloves, masks, gowns, goggles to prevent transmission of the influenza virus.

Hygiene: Practise good hand sanitisation and waste disposal of infected products.

Environmental & Community Issues: Raising awareness of issue specific to the Cooinda Community, such as poverty reduction strategies and development plans.


Australian Government, Department of Health and Ageing.Pandemic influenza, History of pandemics. Retrieved from on 13 March 2010

Better Health Channel. (2008). Infections - Bacterial and Viral. Retrieved from on 19 March 2010.

Better Health Channel. (2010). Flu (Influenza). Retrieved from on 19 March 2010.

Collignon,P.J. ,& Carnie,J.A. (2006). Infection Control and Pandemic Influenza. The Medical Journal of Australia: MJA. Vol 185 (10), S54-S57. Retrieved from on 18 March 2010.

Harris, P., Nagy, S., & Vardaxis, N. (2010) Mosby's dictionary of Medicine, Nursing & Health Professions, 2nd Australian and New Zealand Edition.

Department of Health and Ageing, Victoria (2010). Blue book - Guidelines for the control of infectious diseases. Retrieved from on 17 March, 2010

McMichael, A.J. (2004). Environmental and social influences on emerging infectious disease: past, present and future. The Royal Society Phil. Trans. R. Soc. Lond. B vol 359 (p.1049 - 1057) retrieved from on 18 March 2010.

McMichael, A.J., Woodruff, R.E., &Kilbourne Hales, S. (2006). Climate Change and Human Health: Present and Future Risks. The Lancet: Lancet Vol. 367: p.859-69. Retrieved from on 18 March 2010.

Morse, S. S., (2004). Factors and Determinants in Diseases Emergence. Rev. sci. tech. Off. int. Epiz., 2004, 23 (2), 443-451 retrieved from on 18 March 2010

National Health and Medical Research Council (2010). More on 'at risk' groups retrieved from on 27 March, 2010

National Institute of Allergy and Infectious Diseases (2008), Flu (Influenza) The Flu types - Seasonal, pandemic, Avian (Bird), Swine, (NIAID) retrieved from on 29 March 2010

Rothstein, J. J. (2005). Environmental Factors Affecting the spread of Bird Flu. Foundation for Environmental Security & Sustainability: FESS Issue Brief. Retrieved from on 18 March 2010.

United States Department of Health and Human Services. The Great Pandemic, The United States in 1918-1919. Retrieved From on 15 March 2010

World Health Organization (2008), First Inter-Ministerial Conference on Health and Environment in Africa: Economic and Development Dimensions of Environmental Risk Factors to Human Health. Libreville, Gabon: WHO retrieved from on 24 March 2010.

World Health Organisation (2009). Infection prevention and control during health care for confirmed, probable, or suspected cases of pandemic (H1N1) 2009 virus infection and influenza-like illnesses. Retrieved from on 16 March, 2010

World Health Organisation (2009). Core programs for infection prevention and control programs. Retrieved from on16 March, 2010



Agricultural Origin - The art or science of cultivating the ground, including the harvesting of crops, and the rearing and management of live stock; tillage; husbandry; farming.

Antibodies - An immunoglobulin (lg) produced by lymphocytes in response to bacteria, viruses or other antigenic substances.

Antibiotics - An antimicrobial agent, derived from cultures of a microorganism or produced semi-synthetically, used to treat infections.

Antigenic drift - The tendency of a virus (especially influenza) or other microorganism to alter its genetic makeup, periodically producing a mutant antigen requiring new antibodies and vaccines to combat its effects Influenza - A highly contagious infection of the respiratory tract caused by RNA myxo-virus and transmitted by airborne droplet infection. It occurs in isolated cases, epidemics and pandemics. Symptoms include sore throat, cough, fever, muscular pains and weakness.

Antigenic shift - A sudden, major change in the antigenicity of a virus, seen especially in influenza viruses, resulting from the recombination of the genomes of two virus strains.

Bacilli - Multiple numbers of any rod-shaped bacteria

Bacterium - The small unicellular microorganisms of the class Schizomycetes. The genera vary morphologically, being Cocci, Bacilli, Spirochaetes or Vibrios.

Climate - a composite of the prevailing weather conditions that characterise any particular geographic region including air pressure, temperature, precipitation, sunshine and humidity. Because these factors affect health, they must be considered in the diagnosis and treatment of certain illnesses, especially those affecting respiration.

Cocci - A Spherical bacterial cell.

Complex - A combination of signs and symptoms of disease that forms a syndrome or a group of items, such as chemical molecules, that are related in structure or function, as are the iron and protein portions of haemoglobin or the cobalt and protein portions of vitamin B12

Communicable - Contagious, transmissible by direct or indirect means, as a communicable disease.

Contaminated - A condition of being soiled, stained, touched or otherwise exposed to harmful agents, making an object potentially unsafe for use as intended or without barrier techniques.

Contamination - The presence of extraneous, especially infectious, material that renders a substance or preparation impure or harmful.

Deficit - A lack or impairment in mental or physical functioning.

Deforestation - is the clearance of naturally occurring forests by logging and burning

Disease - A specific illness or disorder characterised by a recognisable set of signs and symptoms, attributable to heredity, infection, diet, or environment.

Diverse - of a different kind, form, character

Ecological - The study of the interaction between organisms and their environment.

Enveloped - A virus having an outer lipoprotein bilayer acquired by budding through the host cell membrane.

Environmental Health - the total various aspects of substances, forces and conditions in and about a community that affect the health and wellbeing of a population.

Epidemic - A disease that spreads rapidly through a demographic segment of the human population, such as everyone in a given geographic area, a military base or similar population unit, or everyone of a certain age or sex, such as the children or women of a region.

Etiquette - the code of ethical behaviour regarding professional practice or action among the members of a profession in their dealings with each other: medical etiquette.

Hazards - Source of risk or danger.

Helical - A virus in which the protein capsid appears in a coiled pattern.

Hemagglutinin - A type of antibody that agglutinates red blood cells.

Icosahedra - A polyhedron having 20 faces.

Immune - 1: not susceptible or responsive especially: having a high degree of resistance to a disease <immune to diphtheria>, 2: having or producing antibodies or lymphocytes capable of reacting with a specific antigen

Immunisation - A process by which resistance to an infectious disease is induced or augmented.

Infection - A disease caused by the invasion of the body by pathogenic microorganisms.

Infection - A disease caused by the invasion of the body by pathogenic microorganisms.

Migration - Migration refers to directed, regular, or systematic movement of a group of objects, organisms, people or animals, to go from one place to another at each seasons (animals).

Pandemic - A disease occurring throughout the population of a country, a people or the world.

Pollution - the introduction of harmful substances or products into the environment.

Poverty - 1. A lack of material wealth needed to maintain existence - 2. A loss of emotional capacity to feel love or sympathy.

Precautions - An action taken in advance to protect against possible danger, failure, or injury; a safeguard.

Sanitation - arrangements to protect public health, especially drainage and disposal of sewage.

Spirochaetes - Any bacterium of the genus Spirochaeta that is motile and spiral-shaped with flexible filaments. Kinds of spirochaetes include the organisms responsible for leptospirosis, relapsing fever, syphilis and yaws.

Urbanization - the process by which large numbers of people become permanently concentrated in relatively small areas, forming cities.

Ventilation - To provide with fresh air.

Vibrios - any bacterium that is curved and motile, such as those belonging to the genus Vibrio. Cholera and several other epidemic forms of gastroenteritis are caused by members of this genus.

Appendix B

21 Key elements for infection prevention in health‐care settings as per WHO (2010).

1. Health‐care facility managerial activities

Develop procedures to ensure proper implementation of administrative controls, environmental controls, and use of PPE. Policies that address adequate staffing and supplies, training of staff, education of patients and visitors, and a strategy for risk communication are particularly needed.

2. Basic infection control recommendations for all health‐care facilities

Standard and Droplet Precautions should be used when caring for a patient with an acute, febrile, respiratory illness.

3. Respiratory hygiene/cough etiquette

All persons should cover their mouth and nose with a disposable tissue when coughing or sneezing, discard the tissue in a receptacle and perform hand hygiene. Additionally, whenever available, patients should wear a medical mask in waiting areas and when they are being transported within the facility.

4. Triage early recognition and reporting of pandemic (H1N1) infection

Consider pandemic (H1N1) 2009 virus infection in patients with acute, febrile, respiratory illness in places where community‐level spread is occurring. Patients may present with other respiratory infections that are co‐circulating in the community (e.g. parainfluenza virus, non‐H1N1 2009 influenza viruses, etc.). Implement IPC, including application of a medical mask and hand hygiene, for any person presenting with a respiratory illness.

5. Infection control considerations in outpatient settings.

Apply strategies to limit unnecessary office visits by ill patients, such as diverting patients to designated pandemic influenza triage and evaluation sites, and using pre‐health‐care facility triage to determine patients who need on‐site medical evaluation. Implement signage at entry points advising persons who are ill to use respiratory hygiene/cough etiquette (see 3) and to inform reception personnel so that steps may be taken to protect other patients. Health services targeting healthy populations, such as women who are pregnant, children attending immunization services or well‐child visits, and patients with non-infectious disease health problems or injury should implement measures to separate persons with an ILI from patients who are healthy. Women who are pregnant have been identified as a group at particular risk for severe disease when infected by pandemic (H1N1) 2009 virus. Therefore, the protection of pregnant women from exposure to persons with an ILI is a priority that requires special attention. Health services that care for patients at high risk for complications of influenza (e.g. oncology clinics, hemodialysis centers) and whose treatment cannot be reasonably delayed should implement strategies to avoid exposing vulnerable patients (e.g. have patients who are ill call before coming for an appointment, scheduling them at different times in the day, and ensuring immediate implementation of IPC measures upon entering the facility.)

6. Placement of hospitalized patients with a presumptive diagnosis of pandemic (H1N1) 2009

Place patients with the same presumptive diagnosis in wards, keeping at least 1 metre distance separation between beds. Implement rooming‐in policies to keep mothers and babies together. All persons entering the isolation area should adhere to Standard and Droplet Precautions. If it becomes necessary to place patients with presumptive or diagnosed influenza in the same room with asymptomatic patients, emphasis should be placed on maximizing their physical separation; i.e., at least 1 metre distance and greater, if possible.

7. Additional measures for inpatient health‐care services to reduce pandemic (H1N1) 2009 virus transmission associated with health care

Limit the number of HCWs/family members/visitors in contact with a patient ill with the pandemic (H1N1) 2009 virus. To the extent possible, assign HCWs to the same group of patients both for continuity of care and to reduce opportunities for inadvertent infection control breaches that could result in unprotected exposure. Family members/visitors should be limited to those essential for patient support and should use the same infection control precautions as HCWs who are providing routine care. (Family members/visitors should be restricted from an environment, when aerosolgenerating procedures associated with an increase in the risk of infection transmission are being performed.)

8. Specimen transport/handling within health‐care facilities

Follow applicable transport regulations and requirements and use Standard precautions for specimen transport to the laboratory. Health‐care facility laboratories should follow good biosafety practices.

9. Pre‐hospital care (e.g. transportation to hospital)

When transporting patients to hospital, infection control precautions are similar to those practiced during hospital care for all involved in the care of patients suspected of being infected with the pandemic (H1N1) 2009 virus.

10. Occupational health

Monitor HCWs in contact with patients who are ill with pandemic (H1N1) 2009 virus infection. HCWs with symptoms should stay at home. Workers at high risk for severe disease and complications of pandemic (H1N1) 2009 infection should follow recommended IPC measures carefully. Breaches in IPC measures may not always be prevented and alternatives, such as reassignment of workers at high risk for severe disease and complications of pandemic (H1N1) 2009 to other duties, should be considered. Antiviral chemoprophylaxis for pandemic (H1N1) 2009 virus may give rise to antiviral resistance and is generally not recommended. For people who have been exposed to an infected person and are at a higher risk of developing severe or complicated illness, an alternative option is to closely monitor them for symptoms and promptly administer antiviral treatment, if symptoms develop. If, to comply with local policies, antiviral chemoprophylaxis is applied, users should be mindful that it is not a substitute for proper infection control.

11. H1N1 vaccination

WHO has advised that all countries should immunize their HCWs as a first priority to protect the essential health‐care infrastructure.

12. Prioritization of PPE when supplies are limited

PPE supplies (e.g., gloves, medical masks, respirators, gowns) may be limited as demand for resources increases during a pandemic. Administrative measures should be employed to set priorities for the use of limited resources, including controlling unnecessary use of PPE in low‐risk circumstances. While PPE for the care of patients with pandemic (H1N1) 2009 should be pursued, risks for transmission of other pathogens (e.g., bloodborne pathogens, airborne pathogens) must also be considered.

13. Waste disposal

Standard Precautions should be used when handling and disposing of sharps and

contaminated items.

14. Dishes/eating utensils

Wash dishes/eating utensils using routine procedures with water and detergent. Wear non‐sterile disposable or utility gloves when handling soiled dishes and eating utensils.

15. Linen and laundry

Wash linen and laundry with routine procedures, water and usual detergent; avoid

shaking linen/laundry during handling before washing. Wear non‐sterile disposable or utility gloves when handling soiled linen and laundry.

16. Environmental cleaning

Ensure that appropriate and regular cleaning is performed with water and usual detergent on soiled and/or frequently touched surfaces (e.g. door handles).

17. Patient care equipment

Ensure cleaning and disinfection of reusable equipment between patients.

18. Patient discharge

If a patient with pandemic (H1N1) 2009 illness is still considered to be infectious upon hospital discharge (i.e. discharged within the period of infection control precautions [see IV.2], instruct family members on appropriate infection control precautions in the home.

19. Health‐care facility engineering controls

Health‐care facility spaces should be well ventilated. Aerosol‐generating procedures should be performed in environments that are adequately ventilated through mechanical or natural means.

20. Mortuary care

Mortuary staff and the burial team should apply Standard Precautions, i.e. perform proper hand hygiene and use appropriate PPE according to the risk of exposure to body fluids (e.g. gown, gloves, and facial protection, if there is a risk of splashes from bodily fluids/secretions onto staff member's body and face).

21. Health care in the community

Limit contact with the person with influenza‐like symptoms, as much as possible. If close contact is unavoidable, use the best available protection against respiratory droplets and perform hand hygiene.