Monday 27 December 2010

MALARIA: Spain: Historical aspects


Every summer thousands of us travel to exotic climes with mosquito nets, jungle-strength cream and anti-malarial drugs. But how 'foreign' really is Malaria to Spain and Europe ?
Despite all the concern about climate change enabling malaria to spread to the West, the weather is by no means the biggest factor in determining the presence of malarial mosquitoes. Europe was until the last century rife with the disease. In fact, the last country in Western Europe to eradicate malaria was cold, damp Holland in the late nineteen-sixties.
Malaria, or 'paludismo' as it is also known in Castilian, was endemic to Spain until well into the 20th century. Its existence has had a huge effect on the landscape in certain areas. Much of Spain 's wetland surface area has been drained in the fight to eradicate it. On the flip side, some sites like Doñana have to some extent been saved from extensive rice farming by the presence of malarial mosquitoes.
The disease probably took off from its ancestral enclaves with the Neolithic revolution between 8,000 and 10,000 BC. Sedentary life, the formation of the first villages, land clearance and crops irrigation, the increase in human population (thanks notably to the improvement in living conditions and food availability) certainly favoured the spread of malaria. New strands of resistant parasites would have been brought by the waves of invasions that swept across the Peninsula . We know for example that malaria followed Hannibal in his wake.
By the Middle Ages, kings and noblemen had gained control of the best wetlands for themselves, where they could hunt and earn lucrative profits by exploiting their natural resources (everything from rice cultivation to leech farming). However, these advantages were offset by the fear of marshes as breeding grounds of plagues and incurable fevers. As way of illustration, while the common European word comes from the Latin for 'bad airs', 'paludismo' comes from the Latin 'Palus' for lagoon. Such was the dread of these sites that a royal decree was passed in 11th-century Valencia sentencing any farmer to death who planted rice too close to villages and towns. For centuries afterwards, there was conflict between rice growers and the authorities who passed law after law restricting rice fields to wetlands that were unsuitable for other types of crops.
The disease continued to decimate local populations throughout the centuries and was to spread over the centuries with the increase in rice farming. The only areas relatively free of the disease were the colder northern statelets (Asturias, northern Navarra and Leon.). This north-south divide was patent in the organisation of the ventures of the Conquistadors; soldiers from Asturias , Galicia or Vizcaya would often be rejected for their tendency to suffer chapoteadas - marsh fevers. It was believed that people from malarial zones had developed a certain lucky immunity (I am unaware as to whether there is any real immunity among Spaniards as this is say among Sub-Saharan Africans). There is a long list of famous people who have died here from malaria ( Hannibal 's wife and son-see above, Emperor Isabel, Felipe II, Felipe IV, Felipe V, Fernando VI, Carlos II, Santa Teresa de Jesús, Hernán Cortés.).


Distribution of malaria in Spain in 1786.

An outbreak hit Barcelona in the 1880's as the city ran out of money to finish the Eixample, as is described by Robert Hughes in 'Barcelona'. As speculation sent prices sky high, thousands of investors went bust when the bubble burst and hundreds of plots were left bare for a decade. Here stagnant waters built up, a ripe environ for mosquito larva.
At the turn of the 20th century, malaria was considered the biggest single health risk by the Spanish authorities, and an estimated 800,000 people had malaria in Spain , with some 4,000 dying every year. This concern led to the passing of the Cambó Law in 1918, which gave legal backing to the already strong trend of wetland drainage since the mid-19th century. The law was often ineffective as it allowed for wetlands to be converted into rice fields, though it was responsible for the destruction of much of Spain 's wetland surface area until its repeal in the early 1980's.
Along with drainage, one of the most effective controls was the release in 1921 of a fish called 'gambusia' or mosquitofish, incidentally probably now the most widespread freshwater fish in the world. This little fish is a voracious devourer of mosquito larva and rapidly took to Iberian waters. Improvements in housing, public health and sanitation, and a falling rural population all helped to cut back the parasite, though the Civil War meant a temporary halt to its retreat. Four years after it finished, in 1943, a final serious outbreak hit the country with 400,000 people affected and 1,250 deaths, but by the end of the forties it had been effectively controlled and restricted to a few pockets, with the use of DDT from 1947 onwards delivering the coup de grace .
The defeat of malaria
Malaria was declared officially eradicated in 1964, which was just in time for mass tourism, which certainly would not have taken off had it not been for the parasite's prior eradication. It also coincided nicely with the UN no longer classifying Spain as a Third World country. As all development workers know, malaria is eradicated by means of progress, not by a change in the temperature or necessarily draining all wetlands.
Malaria could indeed return to Europe , but the real trigger would be a massive economic meltdown rather than any rise in temperature, which would only make matters worse.

  Spanish first-day cover in support of the UN's world anti-malarial campaign of 1962, just before the disease was delared erradicated from the country.
Malaria update
Nothing to do with Spain, but following on from the 'Malaria in Spain' thing, I've discovered that Holland wasn't the last place in Europe to be declared malaria-free. Thus: It was not until 1975 that the last pocket of indigenous malaria in Greek Macedonia was considered eliminated and the World Health Organization declared the continent free of the disease. [http://www.swissinfo.org/sen/swissinfo.html?siteSect=671&sid=1746755]
However, so called 'imported' as opposed to autochthonous malaria is an increasing problem in Spain and the EU. According to the WHO
Throughout Europe, imported malaria is a growing medical and health issue. Since the early 1970s, the reported number of imported cases increased ten-fold, from 1 500 cases in 1972 to more than 15 000 in 2000.
http://www.iberianature.com/material/malaria.html

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