Unit 3 Research Project

3. Epidemiologists often draw causal webs to illustrate the interrelationships among biological, social, and environmental variables that contribute to disease outbreak. Based on what you have learned so far, what variables should be included in a causal web for cholera?

1. Understanding epidemiologic concepts of the chain of transmission of organisms from host to victim, describe how EH could have been infected.

NiV transmission includes many types of forms to transfer from agent to hosts. Infected bats shed the virus via their excretions and secretions such as their urine, excreta, semen, and saliva, despite them being symptomless carriers. While Nipah virus is extremely contagious among hosts such as pigs, goats, and humans, it is primarily best spread through coughing. The leading source of transmission in humans, however, is through direct contact with infected pigs. This explains why pig farmers were much likely to be infected when exposed to ill livestock in 1999. In fact, “ninety percent of the infected people in the 1998-1999 outbreaks were pig farmers or had contact with pigs” (World Health, p.5). How can we prove the emergence of bat-related infections? While several bat species were losing their natural habitats, it made sense that the

The speed with which the disease was spread in a largely rural and, by modern standards, not densely populated, society; the short interval between infection and death;

Diamond addresses many things about how interacting or being near different animals can cause different diseases that typically spreads to humans. Germs can be passed on from animals to humans when then can be passed on to other humans. All humans have different types of effects to these germs. Diamond says, “In an epidemic those people with genes for resistance to that particular microbe are more likely to survive than are people lacking such genes” (Diamond 201). Some people can be more immune to some diseases due to being more genetically resistant to the particular disease, but, there are others who are not immune to the diseases which can lead to death quickly. Those that are not immune to the disease can be wiped out causing them to die and not be able to create their own family. This can affect the way on how the individual differs in the way the germs effect them. Diamond says, “The rapid spread of microbes, and the rapid course of symptoms, mean that everybody in a local human population is quickly infected and soon thereafter is either dead or else recovered and immune” (Diamond 203). Generally, humans with weak immune systems usually die off without having a family and then, there are others that are immune to diseases. But if one person is exposed to the disease, many others are then exposed to it because of it spreading to others rapidly.

Infections can be spread through many things, these include; food borne infection, person to person, water borne infection, airborne infection, insect borne infection and fomites.

The epidemilogic triangle describes the relationships and interactions among the infectious agent, the host, and

In a developing society where a variety people come together, different customs and practices, as well as diseases, are exchanged. One example of an outbreak of a disease is the

Most diseases begin with what is called "the virgin field"—a scenario in which humans have no natural or man-made immunity to the disease. To see the progress of a disease in a particular community, start by predicting how many sick days will be reported when you run the Kold disease through a medium-sized population, and record your prediction in the data table. In this first run-through, we'll assume that the population does not move around the field; they interact with their neighbors, but do not travel long distances.

century trade routes, this was the underlying causing factor in the spread of disease. The

The spread of infection requires three elements. The first is; A source of infecting microorganisms: This could be an exogenous infection which arises from microorganisms external to the individual and do not exist as normal flora. They usually have a preferred portal of entry like the gastrointestinal for Salmonella. Another source is endogenous infections which can occur when part of the client’s flora becomes altered and an overgrowth results e.g. Yeasts infection. Second requirement is means of transmission for the microorganism, which also explains the three primary modes of pathogen transmission. For example, vertical transmission is when a pathogen is

Preston (1995) argues, “[a] hot virus from the rainforest lives within a twenty-four hour plane flight from every city on earth” (p. 16). In addition, only one host is needed to spread the hot virus into a massive outbreak in any part of the world, and such an outbreak could plunge the global population into oblivion. To further explain, Preston (1995) draws the conclusion that the airline routes that tie earth’s cities together are a “web,” and once a hot virus enters the “web,” it can be delivered to far corners of the earth in one day (p. 16). Simple and flawed decisions by humans can make this frightening idea a

A communicable disease chain is the mechanism by which an infective agent or pathogen is transmitted. The chain requires an infective agent, a source of infection, a mode of transmission and a host. An example of an infective agent could be bacteria, a virus, fungus, protozoan or helminth. The source of infective agents can be transmission from host to host, an infected human or animal, insects, soil or livestock. The mode of transmission is how the infective agent is carried from host to host. Transmission can be by air, ingestion or physical contact. To complete a life cycle or to replicate, the infective agent requires a host.

This model helps us to understand how the agent, host and environment coexist with each other in a state of equilibrium or balance and then represents the spread of disease or injury when there is a shift to that equilibrium or balance

“The rodents spread the plague from China to Europe and it hit Britain in 1348.”(Bates, Claire) So if the world is so populated more people will be homeless, and the disease could spread easier wiping out millions. The black death was also spread by people getting bites from infected rats, the disease travels through the body into the lungs, and when the person coughs or sneezes, the disease is transmitted into the air and can infect people who breath in that same air. So if the world becomes too over populated and there aren’t enough houses people will be living on the streets where disease could spread easier and faster just like the black death. “Indirect contact infections spread when an infected person sneezes or coughs, sending infectious droplets into the air.”(DIRECT…) So if everyone if coughing and sneezing then anyone who breathes in that contaminated air could get the disease. “Last year, it called dengue the “most rapidly spreading mosquito-borne viral disease” in the world—faster than West Nile virus or malaria.”(The deadly…) If this disease was to break out when the world is overpopulated a disease could take out almost half the entire human race.There are hundreds of diseases that can be spread by animals, some examples are all types of Influenza, Bubonic Plague, zoonotic diseases, HIV/AIDS, Ebola, and Polio. One disease is the Zika virus, it is spread by mosquito bites who bite women and when if the infected women gets pregnant the Zika virus transfers the virus to the child, once the child is born the child could be born with a fatal brain defect. When the world becomes more populated more people could get bit with more mosquitos and get the Zika virus and a whole new generation of kids could be born with a brain