Outbreak of an Infectious or Communicable Disease Essay
Epidemiologic surveillance is used in public and global health. For this Assignment, begin by locating a recent article about an outbreak of an infectious or communicable disease. The article can come from a newspaper or other source but your paper must be supported with at least three scholarly sources of evidence in the literature which may include your text or course readings.Outbreak of an Infectious or Communicable Disease Essay. (no abstract or running head required) Write a 3- to 4-page paper that includes the following: A summary of the article, including the title and author Identify the title of the article with in-text citation and corresponding reference in reference list The relationship among causal agents, susceptible persons, and environmental factors (epidemiological triangle) The role of the nurse in addressing the outbreak Possible health promotion/health protection strategies that could have been implemented by nurses to mitigate the outbreak Prior to submission, refer to the Week 3 Assignment Rubric.
As you will recall from the Module on Health Education, Advocacy and Community Mobilisation, health is defined as a complete state of physical, mental and social well-being and not the mere absence of disease. The term disease refers to a disturbance in the normal functioning of the body and is used interchangeably with ‘illness’. Diseases may be classified as communicable or non-communicable. Communicable diseases are caused by infectious agents that can be transmitted to other people from an infected person, animal or a source in the environment. Communicable diseases constitute the leading cause of health problems in Ethiopia.
Before we describe each communicable disease relevant to Ethiopia in detail in later study sessions, it is important that you first learn about the basic concepts underlying communicable diseases. Understanding these basic concepts will help you a lot, as they form the basis for this Module.
In this first study session, we introduce you to definitions of important terms used in communicable diseases, the types of infectious agents that cause these diseases, the main factors involved in their transmission, and the stages in their natural development.Outbreak of an Infectious or Communicable Disease Essay. This will help you to understand how measures for the prevention and control of communicable diseases are put into place at several levels of the health system, including in homes and at your Health Post – which is the focus of Study Session 2.
When you have studied this session, you should be able to:
1.1 Define and use correctly all of the key terms printed in bold. (SAQs 1.1 and 1.5)
1.2 Identify the main types of infectious agents. (SAQs 1.2 and 1.3)
1.3 Describe the main reservoirs of infectious agents. (SAQ 1.3)
1.4 Describe the chain of transmission of communicable diseases and explain how infectious agents are transmitted by direct and indirect modes. (SAQs 1.3 and 1.5)
1.5 Describe the characteristics of susceptible hosts and the main risk factors for development of communicable diseases. (SAQ 1.4)
1.6 Describe the stages in the natural history of communicable diseases. (SAQ 1.5)
As described in the introduction, the organisms that cause communicable diseases are called infectious agents, and their transmission to new uninfected people is what causes communicable diseases; (note that infectious diseases is an interchangeable term). Familiar examples of communicable diseases are malaria and tuberculosis. Diseases such as heart disease, cancer and diabetes mellitus, which are not caused by infectious agents and are not transmitted between people, are called non–communicable diseases.
This curriculum includes a Module on Non-Communicable Diseases, Emergency Care and Mental Health.
Outpatient refers to someone who comes to a health facility seeking treatment, but does not stay overnight. An inpatient is someone admitted to a health facility, who has at least one overnight stay.
Communicable diseases are the main cause of health problems in Ethiopia. According to the Ethiopian Federal Ministry of Health, communicable diseases accounted for most of the top ten causes of illness and death in 2008/09. As you can see in Table 1.1, most causes of outpatient visits are due to communicable diseases.
|Rank||Diagnosis||Percentage of all outpatient visits|
|1||Malaria (clinical diagnosis without laboratory confirmation)||8.3|
|2||Acute upper respiratory infections||8.1|
|4||Other or unspecified infectious and parasitic diseases||5.0|
|6||Other or unspecified diseases of the respiratory system||4.0|
|7||Malaria (confirmed with species other than Plasmodium falciparum)||3.7|
|8||Diarrhoea with blood (dysentery)||3.7|
|9||Helminthiasis (caused by worms)||3.5|
|10||Diseases of the musculoskeletal system and connective tissue (muscles, bones and joints)||3.0|
|Total % of all causes of outpatient visits||47.2|
A clinical diagnosis is based on the typical signs and symptoms of the disease, without confirmation from diagnostic tests, e.g. in a laboratory.
The naming of infectious agents is discussed in Section 1.2.1.
Table 1.2 shows that most causes of inpatient deaths are due to communicable diseases, including pneumonia, tuberculosis, HIV/AIDS and malaria. These and other communicable diseases will be discussed in detail in later study sessions of this module.
|Rank||Diagnosis||Percentage of all inpatient deaths|
|2||Other or unspecified effects of external causes||7.1|
|4||Human immunodeficiency virus (HIV) disease||5.1|
|6||Other or unspecified diseases of the circulatory system (heart, blood vessels)||3.7|
|7||Hypertension (high blood pressure) and related diseases||3.5|
|8||Malaria (clinical diagnosis without laboratory confirmation)||3.1|
|9||Malaria (confirmed with Plasmodium falciparum)||2.5|
|10||Road traffic injuries||2.3|
|Total % of all causes of inpatient deaths||50.8|
Not all communicable diseases affect a particular group of people, such as a local community, a region, a country or indeed the whole world, in the same way over a period of time. Some communicable diseases persist in a community at a relatively constant level for a very long time and the number of individuals affected remains approximately the same. Outbreak of an Infectious or Communicable Disease Essay. These communicable diseases are known as endemic to that particular group of people; for example, tuberculosis is endemic in the population of Ethiopia and many other African countries.
A case refers to an individual who has a particular disease.
By contrast, the numbers affected by some communicable diseases can undergo a sudden increase over a few days or weeks, or the rise may continue for months or years. When a communicable disease affects a community in this way, it is referred to as an epidemic. Malaria is endemic in some areas of Ethiopia, and it also occurs as epidemics due to an increase in the number of cases suddenly at the beginning or end of the wet season.
The health problems due to communicable diseases can be tackled by the application of relatively easy measures at different levels of the health system. Here, we will use some examples at the individual and community levels, which are relevant to your work as a Health Extension Practitioner.
Some measures can be applied before the occurrence of a communicable disease to protect a community from getting it, and to reduce the number of cases locally in the future. These are called prevention measures. For example, vaccination of children with the measles vaccine is a prevention measure, because the vaccine will protect children from getting measles. Vaccination refers to administration of vaccines to increase resistance of a person against infectious diseases.
Once a communicable disease occurs and is identified in an individual, measures can be applied to reduce the severity of the disease in that person, and to prevent transmission of the infectious agent to other members of the community. These are called control measures. For example, once a child becomes infected with measles, treatment helps reduce the severity of the disease, and possibly prevents the child’s death, but at the same time it decreases the risk of transmission to other children in the community. In this context, treatment of measles is considered a control measure. Outbreak of an Infectious or Communicable Disease Essay.
Next we look at the main ways in which infectious agents are transmitted.
Transmission is a process in which several events happen one after the other in the form of a chain. Hence, this process is known as a chain of transmission (Figure 1.1). Six major factors can be identified: the infectious agent, the reservoir, the route of exit, the mode of transmission, the route of entry and the susceptible host. We will now consider each of these factors in turn.
Tables 1.1 and 1.2 referred to Plasmodium falciparum as an infectious agent causing malaria. This is an example of how infectious agents are named scientifically, using a combination of two words, the ‘genus’ and the ‘species’ names. The genus name is written with its initial letter capitalised, followed by the species name which is not capitalised. In the example above, Plasmodium is the genus name and falciparum refers to one of the species of this genus found in Ethiopia. There are other species in this genus, which also cause malaria, e.g. Plasmodium vivax.
Infectious agents can have varying sizes. Some, such as Plasmodium falciparum and all bacteria and viruses, are tiny and are called micro-organisms, because they can only be seen with the aid of microscopes. Outbreak of an Infectious or Communicable Disease Essay. Others, such as the ascaris worm (Ascaris lumbricoides), can be easily seen with the naked eye. The different types of infectious agents are illustrated in Table 1.3 according to their size, starting with the largest and ending with the smallest, and are then discussed below.
|Type of infectious agent||Number of cells||Visibility||Examples|
|Helminths||many||Visible with the naked eye||Ascaris worm causes ascariasisIts length reaches 15–30 cm||
|Protozoa||1||Visible with a standard microscope||Plasmodium falciparum causes malaria||
|Bacteria||1||Visible only with a special microscope; much smaller in size than protozoa||Vibrio cholerae causes cholera||
|Viruses||0||Visible only with a special microscope; much smaller in size than bacteria||HIV causes AIDS||
Helminths are worms made up of many cells; for example, Ascaris lumbricoides.
Protozoa are micro-organisms made up of one cell; for example, Plasmodium falciparum.
Bacteria are also micro-organisms made up of one cell, but they are much smaller than protozoa and have a different structure; for example Vibrio cholerae, which causes cholera.
Viruses are infectious agents that do not have the structure of a cell. They are more like tiny boxes or particles and are much smaller than bacteria; for example, HIV (the Human Immunodeficiency Virus), which can lead to AIDS.
Though not as common as causes of communicable disease in humans, other types of infectious agents include fungi (e.g. ringworm is caused by a fungus infection), and mites (similar to insects), which cause scabies.
Many infectious agents can survive in different organisms, or on non-living objects, or in the environment. Some can only persist and multiply inside human beings, whereas others can survive in other animals, or for example in soil or water. The place where the infectious agent is normally present before infecting a new human is called a reservoir. Without reservoirs, infectious agents could not survive and hence could not be transmitted to other people. Humans and animals which serve as reservoirs for infectious agents are known as infected hosts. Two examples are people infected with HIV and with the bacteria that cause tuberculosis; these infectious agents persist and multiply in the infected hosts and can be directly transmitted to new hosts. Outbreak of an Infectious or Communicable Disease Essay.