7th Grade Research 2014

A Great Plague killed nearly half of the people of Europe during in the fourteenth century. A plague is a widespread illness. The plague was also known as "the Black Death" because of the black spots that formed on the skin of diseased people. The devastation of the plague brought great changes to Europe.

The sickness apparently began in Central Asia. In 1347, Italian merchant ships returned from the Black Sea, one of the links along the trade route between Europe and China. The ships were dirty and infested with rats. Fleas living on the blood of infected rats transferred the disease to the seamen.

Many of the sailors were already dying of the plague as the infected ships returned to port, and within days of an infected ship's arrival, the disease spread from the port cities to the surrounding countryside. The plague reached Spain, France, England and Russia within three years. Although it is impossible to calculate exactly how many people died from the plague, evidence suggests that it claimed the lives of as many as 25 million Europeans.

Smallpox is a potentially deadly infectious disease, now eradicated worldwide after successful global immunization programs. Over the centuries before being eliminated, smallpox devastated populations worldwide.

What Causes Smallpox: The Variola Virus Smallpox is caused by the variola virus. There are two forms of this virus. The more dangerous form, variola major, caused smallpox disease that was fatal for about 30% of people infected. A virus called variola minor caused a less deadly form of smallpox, with a fatality rate of about 1%. 

How Smallpox Is Spread Smallpox disease is highly contagious. It spreads from person to person primarily by breathing in the virus, which is transmitted in saliva, during close, face-to-face contact with an infected person.

Fever Headache Muscle pain Backache Chills Loss of appetite Nausea and/or vomiting

High fever Abdominal pain Bleeding from the gums, nose, eyes, and/or stomach Vomit that appears black due to blood content Low blood pressure Liver failure, which may lead to jaundice Kidney failure Confusion Seizure Coma

SymptomsYellow fever symptoms appear within a week after a person is bitten by an infected mosquito. Typically, acute phase symptoms will persist for 3 to 4 days, and then disappear. A small percentage of people progress into the toxic phase. The toxic phase symptoms begin within 24 hours of the end of the acute phase. Recovery from yellow fever provides lifetime immunity from the disease.

Characteristics 1) Start Suddenly 2) Spread Rapidly 3) People of all ages are affected4) Many people become ill5) The attack rate and death rate is high

Yellow fever is an acute viral haemorrhagic disease transmitted by infected mosquitoes. The "yellow" in the name refers to the jaundice that affects some patients. Up to 50% of severely affected persons without treatment will die from yellow fever. There are an estimated 200 000 cases of yellow fever, causing 30 000 deaths, worldwide each year, with 90% occurring in Africa. The virus is endemic in tropical areas of Africa and Latin America, with a combined population of over 900 million people. The number of yellow fever cases has increased over the past two decades due to declining population immunity to infection, deforestation, urbanization, population movements and climate change. There is no specific treatment for yellow fever. Treatment is symptomatic, aimed at reducing the symptoms for the comfort of the patient. Vaccination is the most important preventive measure against yellow fever. The vaccine is safe, affordable and highly effective, and a single dose of yellow fever vaccine is sufficient to confer sustained immunity and life-long protection against yellow fever disease and a booster dose of yellow fever vaccine is not needed. The vaccine provides effective immunity within 30 days for 99% of persons vaccinated.

WHO response WHO is the Secretariat for the International Coordinating Group for Yellow Fever Vaccine Provision (ICG). The ICG maintains an emergency stockpile of yellow fever vaccines to ensure rapid response to outbreaks in high risk countries. The Yellow Fever Initiative is a preventive control strategy of vaccination led by WHO and supported by UNICEF and National Governments, with a particular focus on most high endemic countries in Africa where the disease is most prominent. The Initiative recommends including yellow fever vaccines in routine infant immunizations (starting at age 9 months), implementing mass vaccination campaigns in high-risk areas for people in all age groups aged 9 months and older, and maintaining surveillance and outbreak response capacity. Between 2007 and 2012, 12 countries have completed preventive yellow fever vaccination campaigns: Benin, Burkina Faso, Cameroon, Central African Republic, Côte d’Ivoire, Ghana, Guinea, Liberia, Mali, Senegal, Sierra Leone and Togo. The Yellow Fever Initiative is financially supported by the GAVI Alliance, the European Community Humanitarian Office (ECHO), the Central Emergency Response Fund (CERF), the Ministries of Health, and the country-level partners.

In the autumn of 1348, a central Asian sickness arrived in London and quickly dispatched 60 percent of the city’s population. Within a decade, in what’s believed to be the worst human calamity of all time, something like 25 million Europeans were dead. And when they died, the secrets of their demise disappeared with them. Until now. On Sunday, London scientists who’d studied 25 skeletons discovered in a new rail line announced that those bones held traces of the black death. Most of the ensuing coverage focused on an unrelated theory that the disease wasn’t likely spread by rats’ fleas, as has been taught in every high school in the West, but had perhaps been airborne.

London

Mary Mallon, now known as Typhoid Mary, seemed a healthy woman when a health inspector knocked on her door in 1907, yet she was the cause of several typhoid outbreaks. Since Mary was the first "healthy carrier" of typhoid fever in the United States, she did not understand how someone not sick could spread disease -- so she tried to fight back.