Cholera is an infectious disease characterised by watery diarrhoea which can, within a few hours, lead to severe dehydration. If the disease is not treated, it is fatal in over 50% of cases.
The agent responsible is Vibrio cholerae, a short, curved rod-shaped bacterium which, once it has passed the gastric barrier, is capable of producing a powerful toxin that is the cause of the disease symptoms.
The infection occurs following the ingestion of food (vegetables, fruit, shellfish) or following the intake of water contaminated with the faeces or vomit of infected people.
Symptoms and complications
The disease manifests, after a brief incubation period of 2-3 days with intense and frequent diarrhoea, which becomes increasingly liquid and colourless, with a typical "rice water" appearance and with a huge loss of liquids and mineral salts. There is often vomiting which exacerbates the state of dehydration. The patient is hypotensive, with a high heart rate and reduced or even absent diuresis. If action is not promptly taken with adequate hydration and a replenishing of the minerals lost, the clinical situation can lead to death.
Impact on the population
The shortage or lack of drinking water, contaminated water and inadequate sanitary conditions in some areas, often combined with a general state of poverty and degradation, are the main causes of the spread of cholera. The areas typically at risk are urban suburbs or refugee camps, where the total lack of infrastructure makes the sanitary conditions completely inadequate, and where the absence of an efficient sewage system favours the contamination of the water. These conditions make developing countries the places most at risk of the spread of cholera. In 2005, coinciding with a rise in vulnerable populations, an increase in the spread of the disease was recorded. In 2006, the number of cases increased significantly, totalling 236,896 infections in 52 different countries. However, the number is certainly underestimated, as it is estimated that only 10% of actual cases are reported to the WHO. In the 2006-2008 period, cholera outbreaks and epidemics were recorded in sub-Saharan Africa and in southern and eastern Asia. In the years 2007 and 2008, WHO reported the presence of cholera epidemics in Iraq and Zimbabwe. In February 2009, the Ministry of Health of Zimbabwe reported over 65,000 cases of cholera, killing around 2,000 people across the country. The epidemic then spread to neighbouring countries, particularly in South Africa and Botswana. In July 2012, WHO reported cholera epidemics in Cuba, reporting 158 cases with 3 deaths and finally another epidemic was reported in Sierra Leone in October where the total number of cases reported was 20,736 with 280 deaths.
In Italy, the last major cholera epidemic dates back to 1973 in Campania and Puglia. In 1994 an epidemic of limited proportions occurred in Bari, in which less than 10 cases were reported. Since then, the only episode described dates back to August 2008 in a male subject who had returned from a trip abroad (Egypt).
Sierra Leone: epidemia colera, 10 mila casi e 176 morti
There is a cholera emergency in Sierra Leone where 10,000 cases and 176 deaths have been recorded since the beginning of the year. The most affected area is Freetown, the capital of the small West-African country, where 100 people have died in the last month (repubblica.it - 21 August 2012).
- Foto 1-2: Sierra Leone
- Foto 3-4: Sierra Leone
- Foto 5: Haiti
- Foto 6: Kinshasa
Sources / Bibliography
- David L et. All. Manuale per il Controllo delle Malattie trasmissibili
- EpiCentro- Portale di epidemiologia
- Istituto Superiore di Sanità
- Signorelli C. Igiene Epidemiologia Sanità Pubblica .Società Editrice Universo IV edizione 2008