1. Understanding Zoonosis: The Study of Transmissible Diseases and Infections Sarah Ahmed, MD., PhD., George Tarabelsi, MD., Zara Khan, MD., Shubhankar Joshi, MD., PhD., Francesca Corsini, MD., PhD., Megi Resulaj, MD., PhD. College of Science and Mathematics, University of Massachusetts Boston H5N1 (Avian Influenza) H1N1 Virus (Swine Flu) Rationale References Ebola Future Discussion Special Acknowledgments Zoonosis is a disease or infection that is naturally transmissible from vertebrate animals to humans, and vice-versa. The disease is caused by all types of pathogenic agents, including bacteria, parasites, fungi, and viruses. Humans can get zoonotic diseases by coming into contact with the infected live poultry, rodents, reptiles, amphibians, insects, and other domestic and wild animals. Anyone who has contact with animals can get a zoonotic disease, but people may be more at risk than others. These include people with a weakened immune system, children age 5, the elderly, and pregnant women. About 75% of recently emerging infectious diseases affecting humans are diseases of animal origin, and approximately 60% of all human pathogens are zoonotic. There are four steps of a zoonotic infection: 1. Exposure to the virus Contact between donor and recipient hosts is required for transfer of the virus. This means that there are geographical, ecological, and behavioral factors that allow humans to stay away from, as well as be exposed to, the virus that currently affects a certain animal species. 2. Infection by the virus In order to infect a new host, the virus must be able to efficiently infect the appropriate cells of the new host, and that process can be restricted at many different levels. Hosts often have several responses to viral infections that can kill off the virus before it can reach the cell that it is designated to infect. Therefore, exposure to the virus must be plentiful in order to increase the chance that the virus will infect the cell that it needs to infect. Viruses also often between closely-related hosts because they can more easily infect a cell of a new host that is similar to that a previous host; mutations to the virus's genome is how this ability to cross species is acquired. 3. Spread of the virus to other members of the population Population density plays a large role in the exposure to a virus, as well as the occurrence of epidemics. This is because the virus is able to find many new hosts to infect in a dense population and can use those hosts for reproduction even if the original host has died from infection. 4. Adaptations that the virus acquires in order to infect more effectively. While a certain virus may effectively infect a host and spread throughout a population, its survival is not ensured, especially when considering the current advances in medicine that can prevent infection and kill an existing virus in a host. This is why a virus that is able to "change" frequently (for example, one with a high mutation rate) has an advantage over other viruses. These viruses cannot easily be identified and used for vaccinations because their genome is constantly changing and one vaccination may not be effective for a newer version of the virus. Introduction -4 ways in which one can be infected by zoonotic disease: exposure to the virus, infection by the virus, transmission of the virus to members of the population, and the adaptations the virus makes to infect others more effectively -While we have advanced in understanding the affects of the virus, there are certain aspects that we must continue to explore: the study of when and where the virus forms, what it is that causes the spread of the virus, and how we can limit the virus' natural reservoir, which would in turn, limit the spread of the virus. -The development of a zoonotic disease occurs through the exchange between humans and animals, and as a first defense against the development of these diseases the exchange of bodily fluids between humans and animals must be addressed. Not only to be sure that the exchanges are humane, but also done cleanly in order to deter any more diseases from developing. Conclusion WHAT IS IT? - It is a highly pathogenic avian bird flu virus - Caused outbreaks in parts of Asia and the Middle East over domestic poultry - First detected in China in 1996 from a goose. - There have been about 650 human cases reported from 15 different countries since 2003. - Mortality rate is about 60% of those infected with the virus. SYMPTOMS & COMPLICATIONS OF THOSE INFECTED WITH H5N1: Fever and cough Acute respiratory distress Abdominal pain Diarrhea Pneumonia Respiratory failure Altered mental state Seizures Failure of multiple organs Death TREATMENT AND VACCINATION: - Two antiviral medications previously licensed by the FDA have shown resistance to HPAI H5N1 - It has been recommended to use either oseltamivir (preferred) or zanamivir. ZOONOTIC SPREAD OF AVIAN INFLUENZA: There are three different barriers that a virus must overcome in order to spread from one species to another. 1. Cross-species host-host interaction The species from which the virus originated and the species that received the virus would have to interact first. 2. Virus-host interactions The ability of the virus to infect the nest host species 3. Intraspecies host-host interactions Transferring the virus between infected and non-infected hosts within the species http://www.thejakartapost.com/news/2012/01/10/bird-flu-threat-still-lurking- jakarta0.htm http://rccp.udea.edu.co/index.php/ojs/article/view/742/730 http://www.flu.gov/about_the_flu/h5n1/ http://www.cdc.gov/flu/avianflu/h5n1-virus.htm Link: http://www.flu.gov/about_the_flu/h1n1/ "H1N1 (originally Referred to as Swine Flu)." H1N1 (Swine Flu). U.S. Department of Health & Human Services, n.d. Web. What is it? A respiratory illness found in pigs An Orthomyxovirus that contains: Haemagglutinin – glycoprotein causing red blood cells to clump together and then binding the virus to the red blood cell Neuraminidase – enzymes that assist in transferring the virus particles through the infected cell The virus appeared to be a new strain of H1N1 which resulted to be a triple re-assortment of bird, swine, and human flu How is it spread? Through airborne droplets (coughing or sneezing) of an infected animal Can be transmitted through hand- eye, nose, or mouth contact Prevention and Treatment: No known treatment Preventative care includes flu vaccination and proper personal protective equipment We chose to investigate zoonosis because of the recent attention it has received in the news and media, specifically in cases of Ebola, H5N1, and H1N1. We wish to explore the biological mechanisms which allow these viruses to expand their host range. In addition, some of our examples also illustrate the wide range of consequences these viruses can exhibit, from mild to detrimental. -Do animals show the same symptoms for the disease as humans? -What is the body’s initial response to the diseased cell? Do the cells go undetected? -What are some ways researchers are trying to find a cure for these diseases? We are thankful to Sanofi Genzyme and Dean Andrew Grosovsky for making this possible.