The Irish Potato Famine was caused by a strain of fungus called P. infestans HERB-1. This fungus spread up from Mexico to Mediterranean Europe to Ireland. From 1845-1852 the Irish potato crop was decimated. In 1846 three quarters of the crop was destroyed by this blight. After this especially horrid year seed potatoes where scarce so it took several years for the crop to return to former yields, especially as the fungus P. infestans did not go away until the 1970’s. The potato famine would lead many in Ireland to immigrate to the United States aboard “coffin ships” where TB, life in the slums and the Civil War awaited them.

In the 1840’s and 1850’s Ireland was forced to trade all produce with Great Britain. Because of the poor soil and poor economic conditions many of the Irish where dependent on the potato harvest to support their families. When the potato famine struck many where forced to work in Workhouses to pay off their debts.

The Irish ate potatoes for almost every meal at the time. Loss of this crop led to wide spread malnourishment which caused a number of health concerns, as well as weakened the malnourished immune systems. TB, measles, diarrhea, respiratory conditions, and cholera plagued the Irish as this famine went on. To make matters worse British health officials sent to remedy the solution encouraged the Irish to bake away the rot on the potatoes, or to make them into soups to consume the rancid food. This only led to more disease among the Irish.

Today the HERB-1 strain has gone extinct but has been replaced by the US-1 strain. Farmers in Ireland must spray their crops 12 times a year to prevent growths of P. infestans from destroying crop yields. Research is underway and a new strain of potato has recently been approved by the FDA that has been genetically modified to be resistant to the US-1 strain.

Tuberculosis (TB) is a strain of bacteria that is transmitted from individual to individual through the air. The disease is spread when infected individuals cough, sneeze, talks, or even sings. Spores travel through the air and cause latent infections in individuals who breath in the spores. A latent infection is an infection in which TB is not active, instead is still dormant. Individuals with a latent infection are still treated for TB to prevent the disease from becoming active. If the disease becomes active an individual will experience symptoms such as feelings of sickness or weakness, weight loss, fever, and night sweats. When the lungs become infected symptoms include coughing, chest pain, and the coughing up of blood. When the disease becomes active patients are capable of spreading the disease. The disease is treated by taking multiple drugs for 6 to 12 months. If a patient does not finish their drug regimen then it is possible that the TB inside of them will develop an immunity to the medication.

Historically TB has affected the poor, especially those living in slums, the most. Places where individuals share close proximity or tight living quarters are perfect for spreading the disease. The disease originated in Europe in the 17th century, but grew to epidemic proportions in the 18th and 19th centuries as overcrowded European and colonial cities where perfect for the spread of the disease. Many immigrants coming to the United States in the 1850’s where susceptible to the disease in the day working in sweatshops, and then could spread the disease in their homes as most lived in windowless slums. Many were removed from their homes to live in sanitariums where they would not spread the disease to their families.

Today TB still exists despite the discovery and developments in antibiotics. The HIV/AIDS epidemic as well as malnutrition and poverty give the disease a population to strike. HIV, and malnutrition weaken individuals immune systems and poverty leads to close living spaces. Although it is rare in Western nations TB is still a danger in many 3rd world countries.

When the conquistadors came to conquer the New World they came with a weapon unknown to the Aztecs, smallpox. In their initial invasion the conquistadors were badly beaten by the heavily militaristic Aztecs. After regrouping, months later on their second attack the conquistadors found a civilization devastated by disease. Dead bodies laid in the streets and the Aztecs could mount no defense to the Spanish invasion. An estimated 90% of the population of the Americas succumbed to the disease. After smallpox had brought this devastation to the New World the Spanish, and other European nations were able to conquer and colonize the American Indian Civilizations.

Despite being able to conquer the New World, the Europeans found that they had a very small, and inefficient work force as the American Indians they had enslaved succumbed to European diseases they were not immune to. To find laborers to harvest the natural resources from the colonies the Europeans turned to the West African slave trade. West and North African slaves had already been exposed to European diseases and did not succumb to infection the same way that the American Indians did and were a more economically viable source of labor to power the North Atlantic triangle trade.

Not only was smallpox spread by accident to the natives, it was also used as a means of biological warfare. In North America the British army traded smallpox infected rags with Native American tribes as a way to kill their warriors without having to engage them in combat. This tactic was both effective as it was far reaching as smallpox and other European diseases spread across the American continent decimating Native American populations even before settlers had moved west.