Malaria en España: aspectos entomológicos y perspectivas de futuro

Abstract

RESUMENLa malaria fue erradicada de España oficialmente en 1964. Sin embargo, en la actualidad en nuestro país se registran anualmente cientos de casos importados. En este sentido, el estudio del vector se postula de gran importancia para inferir posibles escenarios de transmisión, ya sea de tipo esporádico o regular. Si bien el nivel socio-económico del país no parece secundar una posible reemergencia de la enfermedad a corto o medio plazo, la presencia de poblaciones de anofelinos bien establecidas y gametocitos de plasmodios circulando entre cierto porcentaje de la población humana parecen avalar, con suficiente crédito, el mantenimiento del estado de vigilancia epidemiológica. Además, la globalización de mercados y el emergente proceso de cambio climático, pueden permitir la colonización de nuestro territorio por parte de especies de Anopheles transmisoras de plasmodiosis humana en regiones tropicales y subtropicales. Con el objetivo de profundizar en el conocimiento de la riqueza faunística, distribución espacial y bioecología de los culícidos anofelinos, se llevaron a cabo diversos muestreos larvarios intensivos la Comunidad Valenciana, región con suficiente heterogeneidad hídrica y datos históricos de prevalencia palúdica, como para respaldar su elección. Cinco especies del género Anopheles, con distinta trascendencia en la difusión de la enfermedad, fueron identificadas.Palabras clave: Malaria. Anopheles. España. Mosquitos. Biodiversidad. Vector. Plasmodium. ABSTRACT Malaria in Spain: Entomological Aspects and Future OutlookMalaria was officially eradicated in Spain in 1964. However, at the present time, hundreds of imported cases are registered in our country each year. In this context, the study of the vector is seen to be highly significant in order to infer possible transmission scenarios, whether of a sporadic or a regular nature. Although the socio-economic level of the country does not appear to foreshadow the possible reemergence of the disease in the short and medium term, the presence of well-established populations of anophelini and plasmodium gametocytes circulating in a certain percentage of the human population does appear to warrant the continuation of the current status of epidemiological surveillance. Moreover, the globalisation of markets and the emerging process of climate change could enable the colonisation of our territory by part of the Anopheles species that transmit human plasmodiosis in tropical and subtropical regions. In order to obtain a more thorough knowledge of the range of fauna, spatial distribution and bioecology of the anopheline Culicoides, a number of intensive larval samplings were taken in the Community of Valencia, a region with sufficient surface water heterogeneity and historical data of malaria prevalence to substantiate the decision to choose it for this study. Five species of the Anopheles genus, with varying degrees of impact in the dissemination of the disease, were identified.

The Historical Distribution of Main Malaria Foci in Spain as Related to Water Bodies

“…This distribution was stable in a similar manner, even during the outbreak of the Spanish post-war period [13]. These results are consistent with the mapping elaborated in 1933 by Hernández Pacheco for Spain, who regards as severely endemic areas the regions of Extremadura, the Betis valley and the crops of Alicante and Murcia [3]. According to Hernández Pacheco, the Hills of Toledo and Sierra Morena had intense endemic character, and the Mediterranean coast and the Castilian plateau were regarded as slightly endemic.…”

“…In order to do this, we calculated the mean value of the spring rainfall recorded in the observatories of Southwestern Spain with long pluviometric sets: Córdoba, Seville, San Fernando (Cádiz) and Riotinto (Huelva), since the southwest of Spain is a region with many wetlands [29] and it is also historically considered as a severely endemic area [3]. The weather station of Seville was used for the seasonal analysis of the average minimum temperatures.…”

“…Other European countries managed to eradicate autochthonous malaria not long after the Second World War [2,3], such as Germany in 1950, Holland in 1961, Italy in 1970, and Portugal and Greece in 1973 [4]. More recently, the WHO has reported cases of malaria in Georgia, Azerbaijan, Kyrgyzstan, Tajikistan, Uzbekistan and Turkey [5], and there have been sporadic locally acquired cases in Mediterranean European countries like France, Italy, Greece [5] and Spain [6].…”

Anopheles plumbeus Stephens, 1828: a neglected malaria vector in Europe

“…Additionally, malaria eradication programs in southern Europe usually included intense mosquito control not only through the use of insecticides, but also through environmental modifications, resulting in changes in the Anopheles fauna. 15 The disappearance of Anopheles labranchiae (Falleroni, 1926) from Spain 16 or Anopheles sacharovi (Favre, 1903) from Malta and Romania 17 are examples of such a faunistic change. Thirdly, there is a worrying decrease in the number of specialists in medical entomology in numerous countries and this may lead to a decline in the number of field studies on mosquitoes.…”

Practical Diagnosis of Red Cell Disorders in Southern Spain

“…Nonetheless, heterozygous Hb AS and Hb AC have been detected in native patients. Malaria was officially eradicated in Spain in 1964, and some impact on the hemoglobin status could have occurred as has been proposed with thalassemias [15]. …”