| Monday, November 07, 2005
| `THE PATHS OF INFECTION
|Amid ancient armies, in sailing ships and on jet planes, epidemics have alwasy shadowed humans. Are we ready for the next big one?
** Ancient World -
500 B.C. to 300 B.C. : The plague of Athens, perhaps typhus, ends the Golden Age of Greece.
300 B.C. to 100 B.C. : Roman troops returning from the Middle East birng a plague that killed 4 million to 7 million in Europe.
** Age of Exploration -
1345 : The Black Death arises in Central Asia before spreading to Europe.
1350 : By 1350 the Black Death has killed 20 million to 30 million Europeans, a third of the total population.
1495 : European contact withe New World populations.
1520 : Smallpox, brought by the Conquistadores, kills nearly half of the Aztec population.
1590 : First documented flu pandemix sweeps into Europe.
1660 : TB causes 1 in every deaths in London.
1720 : Smallpox epidemic in Boston leads to early innoculation in the New World.
** Age of Industrialization -
1790 to 1800 : Yellow fever 10 percent of Philadelphia's population.
1830 to 1840 : Cholera kills 500,000 people in New York City.
1910 to 1920 : Flu epidemic kills 20 million to 40 million people worldwide.
1960 : 30,000 in Ethiopia killed by yellow fever.
** Age of Technology -
1980 : Smallpox eradicated.
1981 : First reported AIDS case.
HISTORY'S BIG KILLERS
1.75 Million Deaths (2003)
Cause: Airborne Mycobacterium tuberculosis, first indentified in 1882, has infected humans since ancient times.
Treatment: Can be cured with a combiantion of antibiotics. A vaccine can be given to children in affected areas.
Outlook: AIDS and multi-drug-resistant strains have triggered a resugence.
1.3 Million Deaths a year
Cause: A one celled parasitec called plasmodium that is transmitted by female Anopheles mosquitoes.
Treatment: Conventional drugs are becoming less effective. New treatments based on artemisinin are in short supply.
Outlook: About 40 percent of the world's population is at risk.
No Current Fatalities
Cause: The Variola virus, thought to have evolved from an animal poxvirus in central Africa thousands of years ago.
Treatment: None available, but there is an effective vaccine.
Outlook: Last natural case occured in Somalia 1977.
500,000 Deaths (2003)
Cause: One of the most contagious desease known, it's an acute respiratory illness caused by a virus in the paramyxovirus family.
182 Deaths (2003)
Cause: The Yersinia Pestis bacterium infects fleas and rodents, which brings disease into human homes.
Treatment: Antibiotics, such as streptomycin and tetramycine.
Outlook: Endemic to many countries, particularly in Africa and Asia, incidence has increased recelty.
1,894 Deaths (2003)
Cause: The Virbio Cholerae bactirium causes acute intestinal infection and is spread through water and food.
Treament: Most causes can be cured with oral rehydration salts. Three oral vaccines are available.
Outlook: Nearly every developing country faces an outbreak or the threat of one.
250,000 Deaths a Year.
Cause: A virus that attacts the upper respiratory tract. It's easily transmitted through the air when an infected person coughs or sneezes.
Treatment: Vaccines available but the virus' genetic makeup is constanly changng.
Outlook: Millions infected every year. The elderly and chronically ill are most at risk.
** YELLOW FEVER
650 -3,250 Deaths (2004)
Cause: Carried by the Aedes and Haemogogus mosquitoes, which mainly pass the virus from monkeys to humans.
Treatment: No specific treament. Vaccine confers immunity within a week.
Outlook: Once nearly eliminated, epdidemics occur intermittenly in Africa and South America.
126 Deaths (2004)
Cause: The highly infectious poliovirus invades the nervous system and destroys the nerve cells that activate muscles.
Treatment: There's no cure, but vaccines have been around since the 1950's.
Outlook: A qualified success story. Polio is now found only in parts of Africa and South Asia.
3.1 Million Deaths (2004)
Cause: The human immunodeficiency virus (HIV) slowly attacks and destoys the immune system, leaving the victim vulnearble to infections that can lead to death.
Treatment: No cure or effective vaccine. Antiretroviral drugs can help, and their cost has fallen sharply.
Outlook: HIV infection rates are on the rise and AIDS is now the no. 4 cause of death worldwide.
New diseases continue to threaten the human population. Since 2003, a steain of avian-flu called H5N1 has infected more thatn 110 people in Southeast Asia and killed at least 60. In 2002, a corona virus likely jumped from a palm civet to a human in southern China -- the first known infected of SARS. Before it was contained in 2003. SARS infected 8,098 people worldwide and killed 774. In the western hemisphere, another avian virus., West Nile, root in 1999.To date, it has infected more than 16,000 people in the U.S. alone and killed more than 800.
(Source: TIME/Global Health/GlaxoSmithKline)
|posted by infraternam meam @ 11:59 PM