Infectious Diseases

Infectious diseases are caused by transmittable parasitic agents including bacteria, viruses, fungi, protozoa and a variety of metazoans commonly referred to as helminthes (worms). Infectious diseases kill more people worldwide than any other single cause.

Infectious Diseases

This is a list of predominant parasites that is a concern for each continent of the world. Continents are list alphabetically.

Disease (Causative agent= viral or bacterial)

Antarctica

Parapox virus

Africa

AIDS (Human immunodeficiency virus)

Tuberculosis (Mycobacterium tuberculosis)

Cholera (Vibrio cholerae)

Asia

AIDS (Human immunodeficiency virus)

Tuberculosis (Mycobacterium tuberculosis)

Encephalitis (virus from Flaviviridae family)

Dengue/dengue haemorrhagic fever (dengue virus)

Cholera (Vibrio cholerae)

Australia

AIDS (Human immunodeficiency virus)

Encephalitis (virus from Flaviviridae family)

Dengue/dengue haemorrhagic fever (dengue virus)

Europe

AIDS (Human immunodeficiency virus)

Tuberculosis (Mycobacterium tuberculosis)

North America

AIDS (Human immunodeficiency virus)

Hepatitis C

Diarrhaeal diseases:

Escherichia coli (Escherichia coli O157:H7)

Salmonellosis (Salmonella)

Shigellosis (Shigella)

South America

AIDS (Human immunodeficiency virus)

Tuberculosis (Mycobacterium tuberculosis)

Dengue/dengue haemorrhagic fever (dengue virus)

Cholera (Vibrio cholerae)

Tuberculosis

Bacteria: Mycobacterium tuberculosis

Distribution:

Transmission:

Tuberculosis is a contagious disease. Like the common cold, it spreads through the air. Only people who are sick with TB in their lungs are infectious. When infectious people cough, sneeze, talk or spit, they propel TB germs, known as bacilli, into the air. A person needs only to inhale a small number of these to be infected. Risk of infection dependent upon exposure time, proximity, and host susceptibility.

Pathology:

M. tuberculosis

M. tuberculosis in the lungs




Life cycle:
Damage to the lungs is thought to be due to M. tuberculosis eliciting the inflammatory response.

Affects of Tuberculosis on Other Organs:
Some bacilli disseminate from the lung to other organs in the body via the bloodstream.

TB is a global emergency/threat to national security. Successful control will require new diagnostics, vaccines and treatments for active and latent infections. US elimination strategy must be linked to global TB control efforts, including HIV control.

Parasitic Diseases

Parasitism is the relationship between one partner (the parasite) harms or lives on the expense of the other (the host). Parasites usually live in a very intimate relationship with their host not only depending on the host for nutrient, but also for a habitat. Parasites are a diverse set of eukaryotic pathogens such as protozoa, platyhelminthes (flatworms), nematodes (elongated worms with rigid cuticula), and arthropods (insects, ticks, and mites). Several diseases caused by parasites are found in the tropic (temperature climates), but the correlation is not with temperature it is with levels of sanitation and general public health (usually poor areas).

Parasitic Diseases

This is a list of predominant parasites that is a concern for each continent of the world. Continents are list alphabetically.

Disease (Causative agent= protozoal or helminthic)

Antarctica

Monogenea sp.

Africa

Malaria (Plasmodium falciparum)

Typanosomiasis (Trypanosoma brucei)

Schistosomiasis (Schistosoma haematobium, Schistosoma mansoni, and Schistosoma intercalatum )

Lymphatic filariasis (Wucheria bancrofti)

Onchocerciasis (Onchocerca volvulus)

Leishmaniasis (Leishmania spp.)

Asia

Malaria (Plasmodium falciparum)

Lymphatic filariasis (Brugia malayi)

Schistosomiasis (Schistosoma japonicum)

Leishmaniasis (Leishmania spp.)

Australia

Malaria (Plasmodium falciparum)

Lymphatic filariasis (Wucheria bancrofti)

Leishmaniasis (Leishmania spp.)

Europe

Lymphatic filariasis (Wucheria bancrofti)

Leishmaniasis (Leishmania spp.)

North America

Toxoplasmosis (Toxoplasma gondii)

Diarrhaeal diseases

Giardiasis (Giardia intestinalis)

Cryptosporidosis (Cryptospordium parvum)

Cyclosporiasis (Cyclospora cayetanensis)

South America

Chagas disease (Trypanosoma cruzi)

Malaria (Plasmodium falciparum)

Leishmaniasis (Leishmania spp.)

Schistosomiasis (Schistosoma mansoni)

Lymphatic filariasis (Wucheria bancrofti)

Onchocerciasis (Onchocerca volvulus)

Chagas Disease

Parasite: Trypanosoma cruzi

Distribution:

The disease is endemic in Latin America, most frequently in Argentina, Bolivia, Brazil, Chile, Uruguay, and Venezuela

.

20 million infected
40 million at risk
>50,000 deaths per year

Transmission:

• Reduviid: It is transmitted naturally through the bite of the reduviid bug which defecated during feeding and parasites are eliminated with feces.

T. cruzi host-cell interaction:


Life Cycle:

Chagas Disease:

The parasite enters the cells at the initial site of entry. Transforms into amastigote and duplicates. The cell ruptures and release more parasites. The combination of the parasitized cells plus the inflammatory reaction of the host is responsible for the initial pathology observed.

Acute form:

• 7-10 days incubation period
• Often in children: chagoma, Romaña sign, flu-like symptoms, myocarditis, encephalitis, lymphadenoathy, enlargement of liver and spleen

Chagoma

Enlargement of liver and spleen

Romaña sign

Indeterminate form:

• seropositivity, but no symptoms or physical abnormalities
• normal ECG
• Approximately 70-80% of infected individuals

Chronic form:

• months to decades after first infection
• heart disease: 10-30% of cases sudden death, aneurysm
  
• intestinal form: megaesophague, megacolon
  

Global Warming…Try again Al Gore!

Al Gore and the U.N.’s Intergovernmental Panel on Climate Change won the 2007 Nobel Peace Prize. Al Gore brought global warming to the attention of the American public, but the argument against global warming is not something that is on the news every night. Global warming is the idea that the Earth’s average temperature is rising due to human activities that have increased the amount of greenhouse gases in the atmosphere. As a result, it is expect that glaciers will melt, sea levels will rise, and the amount and pattern of precipitation will change, and this will have a negative affect on mankind. Many Americans did not understand why President George W. Bush questioned the validity of the global warming phenomenon. I would like to bring to people’s attention the argument against global warming.

Almost 20,000 scientists have signed a petition created by the Oregon Institute of Science and Medicine stating that there is not enough scientific evidence that the greenhouse gases emitted from human activity is enough to cause catastrophic heating of the Earth’s atmosphere and result in the Earth having a huge climate change. Temperatures readings in the lower troposphere show no signs of actual temperature change. The estimated warming temperatures taken on land are inaccurate and could be due urban development or human error. On the other hand, who is to say that a little global warming is bad, for example, during the Medieval Warm Period, areas of England were able to grow more crops. Europe had a more bountiful harvest which lead to economic and population growth.

Food for thought: “They can’t even get the weather forecast accurate 10 days out.”- Pastor Jeff Sanders

Natural Catastrophe Fact Sheet

Japan Tsunami Fact Sheet

Assignment 2

The distribution of the word’s water is demonstrated in the image of the pie chart representing the Earth’s water supply. As demonstrated, most of Earth’s water is located in the oceans and seas. Only 3% of Earth’s water is freshwater, and 79% of freshwater is frozen in glaciers and ice caps. Also, illustrated by the pie chart is that there is only about 1% of the Earth’s total water is accessible.

There are four groups of contaminants in drinking water: microbial pathogens, organics, inorganics, and radioactive elements. According the United Nations, one in six people globally lives without consistent access to safe drinking water. Counties such as India, Bangladesh, and many African counties have problems with cholera outbreaks due to unsanitary drinking water.
http://www.youtube.com/watch?v=kfyIebYz3kk


The following image was created by the USDA to map out the global quality of soil. Fertile soil is seen in North America, South America, and in Asia across Europe.

A few examples of countries still using traditional industry include China’s silk trade, Fiji’s sugarcane production, some of France’s perfumes, and India’s leather production. On the other hand, examples of countries with high-tech industries include the United States, England, China, Italy, Australia, Germany, Taiwan, Japan, and South Korea.

Most populated cities in the world:

1. Mumbai, India

2. Shanghai, China
3. Karachi, Pakistan

4. Delhi, India
5. Istanbul, Turkey
6. Sao Paulo, Brazil
7. Moscow, Russia
8. Seoul, South Korea

9. Mexico City, Mexico
10. Jakarta, Indonesia

Most populated cities in the United States:

1. New York City, New York
2. Los Angeles, California
3. Chicago, Illinois
4. Houston, Texas
5. Phoenix, Arizona
6. Philadelphia, Pennsylvania
7. San Antonio, Texas
8. San Diego, California
9. Dallas, Texas
10. San Jose, California

There are tribal groups in the Amazon jungle that have never had contact with modern society.

http://www.youtube.com/watch?v=16fvTonR_gA

The most ethically diverse counties include United States, Kenya, and Liberia. Other counties that are not very ethically diverse include the Dominican Republic, Kiribati, North and South Korea, and the Marshall Islands.

World Population Density Map:

As seen on this map, China and India have the highest population density.

Percentage of population without reasonable access to safe drinking water:

An estimated 5 million people die each year from illnesses related to poor quality drinking water, many of whom are children. That makes me realize how much I take for granted the fact that I can walk in my bathroom and fill up my water bottle without ever worrying about it harming me.