Geographic distribution of Cholera
Cholera was originally endemic to the Indian subcontinent, with the Ganges River likely serving as a contamination reservoir. It spread by trade routes (land and sea) to Russia, then to Western Europe, and from Europe to North America. It is now no longer considered an issue in Europe and North America, due to filtering and chlorination of the water supply.
Throughout history, devastating outbreaks of cholera have
resulted in millions of cases and hundreds of thousands of
deaths. Altogether seven cholera pandemics
have been re-corded. The latest one, which is still ongoing, started in Indonesia in 1961, reached the African continent in the 1970s and South America in 1991. By 1994, over 1 million cases and nearly 10 000 deaths had been reported on the American continent.
Cholera outbreaks can occur sporadically in any part of the world where water supplies, sanitation, food safety and hygiene practices are inadequate. Overcrowded communities with poor sanitation and unsafe drinking-water supplies are most frequently affected.
- Geographic distribution of choléra
- extract of Wikipedia
In 2004, cases of cholera caused by Vibrio cholerae were reported from all regions of the world. A total of 56 countries officially reported to WHO 101 383 cases and 2345 deaths.
The overall number of notified cases declined by 9% compared with the previous year. However, the number of deaths increased by 24%, from 1894 in 2003 to 2345 in 2004. The overall case-fatality rate (CFR) increased to 2.3% and remained high among vulnerable groups in high-risk areas, with rates of up to 41%.
Africa reported a total of 95 560 cases, accounting for 94% of the global total of officially notified cholera cases. This was fewer than in 2003 (108 067). However, the number of deaths notified and the number of countries reporting to WHO from this continent both increased.
The small number of cases reported from the Americas remained stable, whereas the number of cases notified
from Asia increased by 66%, reaching 5764 cases.
Europe and Oceania notified only imported cases.
Compared with 2003, an additional 11 countries reported cholera cases to WHO, of which 6 recorded only imported cases. Furthermore,the overall number of imported cases increased 3-fold compared with the previous year.
Globally, the actual figures of cholera cases are
estimated to be much higher owing to underreporting
and other limitations of surveillance systems, such as inconsistency in the case definition used and lack of standard vocabulary.
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