Analysis of climate and extrinsic incubation of Dirofilaria immitis in southern South America

Cuervo, Pablo F. and Fantozzi, M. Cecilia and Di Cataldo, Sophia and Cringoli, Giuseppe and Mera y Sierra, Roberto and Rinaldi, Laura (2013) Analysis of climate and extrinsic incubation of Dirofilaria immitis in southern South America. Geospatial Health, 8 (1). pp. 175-181. ISSN 1970-7096

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Dirofilariosis, caused by Dirofilaria immitis and D. repens, is spreading in several geographic regions. The development of infective larvae in the mosquito vector (extrinsic incubation) needs an accumulated total of 130 degree-days above the 14 ºC threshold, normally expressed as heartworm development units (HDUs). Based on this information, temperature- based models have been developed and applied to evaluate the distribution and spread of Dirofilaria infections in various countries and continents. Despite the confirmed presence of D. immitis in most South American countries, the available information about its epidemiology remains scarce. We analysed the temporal and spatial extrinsic incubation of this parasite in Argentina, Chile and Uruguay, taking into account daily temperatures from 49 meteorological stations during a 30-year period (1982-2012). The theoretically possible number of D. immitis generations was calculated based on the number of meteorological stations that reached the 130-HDUs threshold. The resulting information was spatially interpolated using the inverse weighted distance (IWD) model to produce thematic maps. The model shows that 41 of the meteorological stations reach the threshold needed and that D. immitis transmission is markedly seasonal with a peak in late spring (December), stable during summer (January to March) and declining in the autumn (April and May). Suitable temperatures exist in Uruguay and most of Argentina, whereas D. immitis transmission in Chile is only possible in the north and in the central inlands. The results suggest that the climatic impact on D. immitis transmission must have been minimal in the countries investigated since the annual meteorological records did not change much during the 30-year period analysed.

Item Type: Article
Uncontrolled Keywords: Dirofilaria immitis, extrinsic incubation period, geographical information system, temperature, South America
Subjects: 600 Tecnologia - Scienze applicate > 610 Medicina e salute (Classificare qui la tecnologia dei servizi medici) > 614 Medicina legale; incidenza delle malattie; Medicina preventiva pubblica > 614.4 Incidenza delle malattie e misure pubblica per prevenirle (classificare qui l'Epidemiologia, l'Epidemiologia clinica)
Depositing User: Chiara D'Arpa
Date Deposited: 30 Jul 2014 14:02
Last Modified: 30 Jul 2014 14:02

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