Types of Diseases
Defining the word disease is actually more difficult than it would seem, due to the wide range of medical phenomena that it covers. The World Health Organization defines health as a state of "complete physical, mental or social well-being, not merely the absence of disease or infirmity". Health is easy to define but what constitutes a disease has changed over time. Therefore, it is best to discuss diseases by dividing them up into various sectors such as the following:
- Emergent Diseases
- Communicable Diseases
- Sexually Transmitted Diseases
- Infectious Diseases
- Blood and Immune System Diseases
Emergent diseases, the majority if which are new, recently introduced or non-indigenous to a location and include the Hantavirus, occur for many reasons. Many are introduced by travel or immigration while others are introduced by microbial adaptation or hybridization, changes in environment or ecosystems as well as changes in human demographics and behavior. The Centers for Disease control defines emergent diseases as "diseases of infectious origin whose incidence in humans has increased in the past two decades or threatens to increase in the near future.
Communicable are diseases, which are easily spread through contact. One of the most common is the retrovirus. This virus causes a diarrhoeal disease. Many studies have shown that children in the preschool setting are at a significantly greater risk for diarrhoeal disease. Outbreaks of rotavirus at a day care program or preschool sometimes require that the school be closed and even that children be hospitalized. More common diseases younger children contract are upper respiratory infections (URI). The average preschool child has six to ten URI's a year. Most typical is the rhinovirus though there are thousands that can cause an URI.
Upper repertory infections and diarrhoeal diseases are spread through the air. Though both are a cause for concern for children with weakened immune systems, with the correct treatment, such as antibiotics, and increase in fluid intake, these diseases are usually no more than a nuisance. The problem is there are many diseases out there that are cause for more concern. Outbreaks of bacterial meningitis for example, have been reported on the increase in recent years. Bacteria meningitis can cause an infection of the fluids of the spinal cord and the brain. This more serious disease is not transmitted through casual contact but by direct contact.
Many children, especially those that have been sheltered and have no siblings, are apt to contract infections more than those that have had some exposure in their first months of preschool. In fact, overall children in preschool are twice as likely to contract a disease as those who are not. With about 13 million children under the age of six in some sort of day care or preschool, that leads to a lot of illness. About two-thirds of children this age are in a preschool setting when their parents are in work.
The child's illness does not only affect the child but also the child's parents, who may have to take time off work to care for the child, and even friends and family who can contract the illness that the child brings home. In fact, a study in the American Journal of Epidemiology found that 3 and 4 years olds drive the flu epidemics. These children are infected and show flu symptoms a month earlier than adult.
Children are more susceptible to disease because of two facts. The first factor is that most of us have built an immunity that helps to prevent many germs from causing disease in us. Children have not been exposed to many of these germs and therefore are more susceptible. Some children are better off than others are because they have older siblings who bring home illnesses and they become immune earlier.
Children are also in close proximity with each other more in a day care than in a home setting. While at home there may be siblings and friends, there probably are not as many children as in day care. When all the children live eat and breathe in the same area all the time, such as at home, then they are less likely to pick up germs for which they have no immunity. A preschool brings together children that live, breath, and eat in many different areas, increasing the likelihood of exposure to outside germs.
There are other reasons for the spread of germs in a preschool. Preschoolers who have older siblings may be exposed through them. A parent may send a child off to preschool that is carrying the germ because of the incubation period that some diseases have. Influenza for example has an incubation period of one to three days that is the virus can be spread for three days before any systems occur.
Another problem is that many of these children are not vaccinated against a host of diseases. While the flu shot is strongly suggested to people with weakened immune systems, older people, and babies, the preschool age children, are not included. This is because it is thought that children with regularly functioning immune systems will fight the disease off. The problem with this is that it was found that children under the age of five have the greatest number of deaths from flu in the population. Because this figure incorporates infants, toddlers, and preschoolers, there is not way to know how many of these deaths are in the preschool age but is still something of a concern.
One of the major reasons that germs are spread in the preschool setting is that children do not understand the significance of germs and how they are spread. Children at this age do not realize that sneezing and not covering their mouths, not washing their hands, or not eating after other children expose them to greater risks of catching a virus or infection. The concept of the germ to them is beyond their comprehension. Though they understand that germs transmit diseases they cannot grasp something they cannot see. Preschool children seem to link a germ with a bug or something else that is less than appealing. Because older siblings and adults use the term bug, many preschoolers associate a picture of a bug to the germ. They may not understand how it can be transmitted or how to stop it from being transmitted.
Children are also for the first time being immersed in socialization. They are just being taught how to social and act properly amongst other peers. Because of this, there are many more opportunities for the children to transmit germs back and forth. They are more apt than older children to, for example, drink out of the same container, eat something that has fallen on the floor, sneeze onto a ball and then pass it to a friend, and many other common things that children are taught not to do.
However, this looks dismal for the parent sending the children into this infectious environment, the learning experience for the children, far outweigh the problems with spreading disease. Besides, there are a few things that preschools can do in order to cut down on infections. First, the obvious, if a child is exhibiting symptoms of a malady; the child should be kept at home and not sent to preschool to continue to spread the illness. Another idea is that preschoolers get all the vaccines that are necessary for children who are entering elementary school. Parents should also consult their doctors about having the child vaccinated for flu and chicken pox.
The CDC widely publicizes the threat of diseases that exist in other parts of the world, but have relatively low mortality rates. The outbreak of the SARS virus in the Far East and Canada in 2003 is an example of a disease that the CDC characterizes as a threat to the public health of the United States, with the news media emphasizing the danger. This virus produces severe acute respiratory symptoms that are similar to the flu, but the majority of people that are infected with the virus recover. The mortality rate is very low and due to complications from other diseases that that the person infected with SARS may have. Only 149 cases were detected in the United States with none of the victims dying from the disease. Despite the relatively low impact on public health of SARS, it was portrayed by the CDC and the media as an imminent danger to Americans that could result in the death of large numbers of individuals. The publicity surrounding the SARS virus that was largely orchestrated by the CDC prompted Congress to make a supplementary appropriation to the CDC's Emerging Infectious Disease program that included SARS research and containment. These events further establish a connection between the claims of the CDC regarding the risk of a disease and the agency's funding level.
The most recent claim of the CDC regarding a potential disease threat is the avian flu. This disease is spread to humans as a result of contact with poultry that is infected by the virus. There is no evidence that the disease can be spread from human to human. In addition, the actual rate of deaths among individuals that have contracted the disease from exposure to infected poultry is far lower than the rate of death indicated by the CDC in its news and media releases. The CDC global health program focuses on the avian flu, with the program requesting an increase in funding in the current budget. In addition, the CDC is requesting an increase in funding as part of its immunization program to develop a vaccine for the avian flu although there is no clear indication that the flu will result in a pandemic.