Anopheles plumbeus (Diptera: Culicidae) in Europe: a mere nuisance mosquito or potential malaria vector?

Abstract

BackgroundAnopheles plumbeus has been recognized as a minor vector for human malaria in Europe since the beginning of the 20th century. In recent years this tree hole breeding mosquito species appears to have exploited novel breeding sites, including large and organically rich man-made containers, with consequently larger mosquito populations in close vicinity to humans. This lead to investigate whether current populations of An. plumbeus would be able to efficiently transmit Plasmodium falciparum, the parasite responsible for the most deadly form of malaria.MethodsAnopheles plumbeus immatures were collected from a liquid manure pit in Switzerland and transferred as adults to the CEPIA (Institut Pasteur, France) where they were fed on P. falciparum gametocytes produced in vitro. Anopheles gambiae mosquitoes served as controls. Development of P. falciparum in both mosquito species was followed by microscopical detection of oocysts on mosquito midguts and by sporozoite detection in the head/thorax by PCR and microscopy.ResultsA total of 293 wild An. plumbeus females from four independent collections successfully fed through a membrane on blood containing P. falciparum gametocytes. Oocysts were observed in mosquito midguts and P. falciparum DNA was detected in head-thorax samples in all four experiments, demonstrating, on a large mosquito sample, that An. plumbeus is indeed receptive to P. falciparum NF54 and able to produce sporozoites. Importantly, the proportion of sporozoites-infected An. plumbeus was almost similar to that of An. gambiae (31 to 88% An. plumbeus versus 67 to 97% An. gambiae). However, the number of sporozoites produced was significantly lower in infected An. plumbeus.ConclusionThe results show that a sample of field-caught An. plumbeus has a moderate to high receptivity towards P. falciparum. Considering the increased mobility of humans between Europe and malaria endemic countries and changes in environment and climate, these data strongly suggest that An. plumbeus could act as a vector for malaria and thus significantly contribute to increasing the malaria transmission risk in Central-Western Europe. In locations showing high vulnerability to the presence of gametocyte carriers, the risk of transmission of malaria by An. plumbeus should be considered.

Evolution of sexually-transferred steroids inAnophelesmosquitoes

“…Indeed, its refractoriness or low susceptibility to the human malaria parasite has been experimentally determined (18,19), confirming epidemiological data (20). Conversely, production of 20E was undetected in male mosquitoes from the two other Anopheles subgenera, Anopheles and Nyssorhynchus of which all tested members are registered as DVS and/or experimentally shown to be highly susceptible to Plasmodium falciparum (21,22). not peer-reviewed) is the author/funder.…”

Updated checklist of the mosquitoes (Diptera: Culicidae) of Belgium

“…plumbeus was the most abundant adult species captured. Other recent data indicate a strong population expansion of this species all over Belgium (Versteirt et al and confirm the aggressive biting and daytime activity of this species which is a highly competent vector of Plasmodium falciparum Welch 1897 (Schaffner et al and a potential vector of West Nile virus (Dekoninck et al …”

Two Cases of Plasmodium falciparum Malaria in the Netherlands without Recent Travel to a Malaria-Endemic Country

“…There are no indications of autochthonous transmission. 15 The latest reported cases of locally acquired tropical malaria in the Netherlands could be explained by airport malaria in patients staying near Schiphol Airport. 16,17 This so-called airport malaria could be another possible route of transmission in our patients.…”