Tantari Delta Dunarii

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Sc. Annals of DDI Tulcea, Romaniavol. 14 2008

SCIENTIFIC ANNALS OF THE DANUBE DELTA INSTITUTE, TULCEA ROMANIA, 2008 15

Investigations of the Anopheline (Diptera: Culicidae) fauna fromthree areas belonging to the Danube Delta Biosphere Reserve inorder to evaluate the risk of malaria re-emergence

FALCUTA Elena, PRIOTEASA Florian-Liviu, NICOLESCU Gabriela

Address: Cantacuzino National Institute of Research and Development for Microbiology and Immunology, 103 SplaiulIndependentei, Bucharest 050096, Romania.

Address of author responsible for correspondence: Elena Falcuta - Cantacuzino National Institute of Research andDevelopment for Microbiology and Immunology, 103 Splaiul Independentei, Bucharest 050096, Romania.; email:[email protected], [email protected]

BSTRACT. The survey focused on the comparative analyses of the anopheline fauna belonging to themaculipennis group between three areas of the Danube Delta Biosphere Reserve, two of them situated near theRazim-Sinoe lagoonal complex and one belonging to the fluvial delta. The study that was carried out during 2006

and 2007 intended to establish the composition of the anopheline fauna as well as the longevity of the various species inorder to evaluate the risk of malaria re-emergence. A number of 2437 mosquitoes, belonging to Anopheles maculipennisgroup were collected. The presence of the former vector species was pointed up: Anopheles atroparvus, Anophelesmesseaeand Anopheles maculipennis sensu stricto. The investigations of the number of egg batches laid by a femalehave shown the physiological age of the respective female and namely if the female could infect or not the humans.

Key words: Malaria, Danube Delta, Anopheles maculipennisgroup, Physiological age

INTRODUCTION

The climate of the planet follows a warming-up period. Different models suggest that this phenomenon willcontinue and will have more prominent effects in temperate regions. Both local and global changes may,independently or combined, have a negative impact on humans health, by emergence of some diseases in

Europe, or by re-emerging long-time sleeping diseases from this area.

Malaria is one of the most important vector-diseases on the globe and kills almost 1.5 3 million peopleevery year. During last century, malaria was eradicated from almost all European countries, but it hasalready reappeared in regions in which it had previously been eradicated. The main vectors of malaria inPalaearctic region including Europe belong to Anopheles maculipennis group. Romania is a malaria-freecountry since 1962.

Mosquitoes of the genus Anopheles are widely spread in Romania [16], but few is known about theirdistribution and vector potential in current conditions of environmental changing. Four species of Anopheleswere involved in malaria transmission in the former endemic areas in Romania: Anopheles atroparvus,Anopheles sacharovi, Anopheles maculipennis sensu strictoand Anopheles messeae[25].

During the first half of the last century the localities in the neighbourhood of the lagoonal complex Razim-Sinoe represented areas with high incidence of malaria. These areas were the only ones in the countrywhere two important and strong vectors transmitted malaria, Anopheles atroparvus and Anophelessacharovi, the latter beeing the main vector in this area [24, 26].

The fluvial delta was described by Zotta [23, 24] as an area of anophelism without malaria.

The survey is intended to monitor the Anopheles fauna belonging to the maculipennis group in order toevaluate the risk of re-emergence of malaria under the present environmental condition.

MATERIALS AND METHODS

The survey was carried out during the years 2006 (between April and October) and 2007 (between Marchand September) in three areas of the Danube Delta Biosphere Reserve, two of them belonging to the Razim

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- Sinoe lagoonary complex and one being situated in the fluvial delta at Mila 26. From these study areasvery few recent data concerning Anopheleswere available.

Slcioara is a vilage situated in the western part of the Razim-Sinoe lacustine complex. Here we collectedmosquitoes in two investigational sites with adjoining locations:

Site A is represented by the vilage. Here we investigated some animal shelters (2 pigsties and onechicken coops), a house and the outdoor.

Site B is a fishpond located near Slcioara village. Here are some buildings used by fishermans.

Grindul Lupilor is a marine sand bank situated in the central part of the Razim-Sinoe lacustrine complex. Isa large area were the vertebrate fauna is very well represented and anthropic settlements are very few.Here mosquitoes were collected inside of a pigsty, in a house and outdoor.

Mila 26 is located in Maliuc area on the Sulina branch of the Danube. The mosquitoes were collected in twoinvestigational sites:

Site A is represented by an anthropic habitat, limited to a courtyard situated on the bank of Sulinabranch.

Site B is represented by a large area with many reed-beds chanels which are populated by many

water-birds. A large number of domestic animals (pigs, cattle, horses) are living in a semi-wildstate here. In this area there is a stable in which some of these animals find shelter during thenight.

Capturing methods:

Indoor capturing

Inside of the houses and animal shelters the anophelines were captured using entomological aspirators [17](Fig 4.). The anophelines species can be differentiated from other species during capturing by their obliqueposition on the substrate with the proboscis, the head and the body on the same line.Indoor capturing was the main method because in the resting sites the anophelines are fed and they areable to lay egg batches. This fact is very important because the species of maculipennis complex can bedifferentiated among themselves by the appearance of the eggs. If the anophelines females dont lay egg

batches it is impossible to differentiate morphologicaly the species belonging to maculipennis group.Outdoor capturing

Outside of the human or animal shelters the anophelines were caught along other species using CDC light traps (Fig 5.), entomological handnet and entomological aspirators [17].

Species identification: Fully fed females belonging to the maculipennis complex were kept in cloth cagesat a temperature of approximately 27 2C and a high relative humidity of 7080% for optimal ovariandevelopment. After having laid egg batches, the Anopheles individuals were determined on a species levelby the morphological characters of their eggs (Fig. 6. and Fig. 7.) using a Nikon dissecting microscope.

Estimation of the physiological age of females: Simultaneously with the monitoring of the anophelinefauna, we estimated the physiological age of the females via dissections and observation of the stages oftheir ovaries [21].

RESULTS AND DISCUSSION

Year 2006

The general climate characteristics from year 2006 have influenced the mosquito fauna and they may bedescribed as following:

- very cold spring-time with unusual low-temperatures until end of May;- frequently abundant rainfalls and floods on spring-time and autumn;- very high relative humidity.


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Salcioara 2007

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%

Anopheles messeae Anopheles atroparvu

Fig. 2. - Seasonal dynamics of the maculipennisgroup species in Slcioara in 2007

Grindul Lupilor 2007

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Anopheles messeae Anopheles atroparv

Fig 3. - Seasonal dynamics of the maculipennisgroup species in Grindul Lupilor in 2007

CONCLUSIONS

The presence of Anopheles messeae (which has been in the past the weakest malaria vector in ourcountry) in pure or almost pure populations at Mila 26, the lack of Anopheles sacharovi(as the main vectorfor malaria in the past) and the weak representation of Anopheles atroparvusduring the summer in thearea of the Razim - Sinoe lagoonal complex, as well as the very short life span of anopheline females,indicate a very low risk of malaria re-emergence in these parts of RBDD.


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Acknowledgements. We are grateful to Dr. Vasile Otel and Dr. J. B. Kiss from Danube Delta NationalInstitute for their support. This work was supported by EU grant GOCE-2003-010284 EDEN and waspartially funded by Cantacuzino NIRDMI. The contents of this publication are the responsibility of theauthors and don't necessarily reflect the views of the European Commission.

REFERENCES

1. BLBE (I.), CRISTESCU (A.), ENESCU (A.), TCU (V.), GIURC (I.), CRISTODORESCU - NICOLESCU (G.), 1978 -Up to date entomological aspects in the previously endemic areas of malaria in the Danube Plain and Dobrudja . IN:Archives Roumaines de Pathologie experimentale et de Microbiologie, vol. 37, No. 3 - 4, page 389.

2. BLBE (I.), NICOLESCU (G.), 1986 - Insecte vectoare i generatoare de disconfort. Ed. Medical, Bucureti.3.CIOLPAN (O.), 1988 - Culicidele ca vectori ai unor ageni patogeni. IN: Bacteriologia, Virusologia, Parazitologia,

Epidemiologia., vol. XXXIII (3), 207 - 223.4. CLEMENTS (A. N.), 1963 The physiology of mosquitoes. IN: International Series of Monographs on Pure and

Applied Biology. Division Zoology Gen. (Ed. G. A. Kerkut), vol. 17. Pergamon Press.5. DUPORT (M.), ATHANASIU (M.), 1949 Cercetri asupra bionomiei i distribuiei geografice a lui Anopheles

maculipennis n jud. Tulcea. IN: Academia R.P.R., Buletintiintific, t. 1, No. 3, pp. 267 274.6. EDWARDS (F. W.), 1921 - A revision of the mosquitoes of the Palearctic region. IN: Bull. Ent. Res., vol. 12, pp. 236 -

351.

7. EPSTEIN (P. R.), 1995 - Emergind Diseases and Ecosystems Instability: New Threats to Public Health . IN: AmericanJournal of Public Health, vol. 85, No. 2, pp. 168 172.8. KNIGHT (K. L.), 1978 - Suppl. I to A Catalog of the Mosquitoes of the World (Diptera : Culicidae). In: Th. Say

Foundation, Supp. 6, page 107.9. KNIGHT (K. L.), STONE (A.), 1977 - A Catalog of the Mosquitoes of the World (Diptera : Culicidae) . IN: Th. Say

Found., vol. VI. Entom. Soc. Amer. Baltimore, USA.10. MARTINI (E.), ZOTTA (G.), 1934 - Races dAnopheles maculipennis en Roumanie. IN: Archives Roumaines de

Pathologie experimentale et de Microbiologie, vol. VII, No. 2, pp. 135 - 205.11. MEZINCESCU (D.), 1904 - Despre culicidele din Delta Dunrii [About the culicids in the Danube Delta]. IN: Buletinul

Serviciului Sanitar12. MINAR (J.), 1990 - Family Culicidae, Psychodidae, Chironomidae. IN: Catalogue of Palaearctic Diptera (eds. A. Soos

and L. Papp). Elsevier, Budapest.13. MORSE (S. S.), 1995 - Factors in the emergence of infectious diseases. IN: Emerg. Infect. Diseases, vol. 1, No. 1,

pp. 7 - 15.14. NICOLESCU (G.), 1983 Aspecte actuale privind fauna de insecte vectoare i generatoare de disconfort. IN:

Bacteriologia, Virusologia, Parazitologia, Epidemiologia., vol. 28, no. 1, page 83.

15. NICOLESCU (G.), 1995 The mosquitoes (Diptera: Culicidae) from Romania: an annotated checklist andbibliography. IN: Roumanian Archives of Microbiology and Immunology, vol. 54, No. 1 - 2, pp. 75 109.16.NICOLESCU (G.), VLADIMIRESCU (A.), CIOLPAN (O.), 2002 The distribution of mosquitoes in Romania (Diptera :

Culicidae). Part I: Anopheles, Aedesand Culex. IN: European Mosquito Bulletin, vol. 13, pp. 17 26.17. PRIOTEASA (F. L.), FALCUTA (E.), MARINOV (E. M.), NICOLESCU (G.), 2007 - Mosquitoes (Diptera: Culicidae) in

Mila 26 Maliuc area (Danube Delta, Romania) preliminary data. IN: Scientific Annals of the Danube Delta Institute,vol. 13, pp. 89 96.

18. SERVICE (M. W.), 1976 Mosquito ecology. Field sampling methods. Appl. Science Publish. London.19. STONE (A.), KNIGHT (K. L.), STARCKE (H.), 1959 - A Synoptic Catalogue of the mosquitoes of the World. Thomas

Say Foundation.20. UNGUREANU (E. M.), ILIES (M.), 1959 Contribution a letude des Culicides dans le Delta du Danube. IN:

Proceeding of the Scientific Session of Marine Zoological Station Ion Borcea, September 15 17th, Agigea, 1956,pp. 487 494.

21. UNGUREANU (E. M.), 1972 Methods for dissecting dry insects and insects preserved in fixative solutions or byrefrigeration. IN: Bulletin of the World Health Organization, vol. 47, No. 2, pp. 239 244.

22. VELEHORSCHI (N.), NICOLESCU (G.), CEIANU (C.), GIURCA (I.), BLBE (I.), 1990 -The mosquitoes (Diptera:

Culicidae) in Maliuc (Danube Delta) faunistical and ecological data. IN: Archives Roumaines de Pathologieexperimentale et de Microbiologie, t. 49, no. 3, pp. 269 - 282.23. ZOTTA (G.), 1927 - Considrations sur lAnophlisme du Delta du Danube. IN: Bulletin de la Societe de Pathologie

exotique, t. XX, No. 8, pp. 801 811.24. ZOTTA (G.), 1932 - Etudes sur le paludisme dans le Delta du Danube (I. Anophelisme sans paludisme). IN: Archives

Roumaines de Pathologie experimentale et de Microbiologie, vol. 1, pp. 133 176.25. ZOTTA (G.), 1938 Contribution a letude de la distribution des races dA. maculipennisen rapport avec les grandes

lignes de repartition du paludisme en Roumanie. IN: Archives Roumaines de Pathologie experimentale et deMicrobiologie, vol. XI, No. 2, pp. 209 246.

26. ZOTTA (G.), RADACOVICI (E.), TEODORESCU (A.M.), GEORGESCU (M.), MARDARE (I.), DEMETRESCU (C.),ATANASIU (M.), TRIFON (A.), 1944 - Evolutia endemiei palustre in judetul Tulcea [Malaria endemic in Tulceacountry]. IN: Revista Stiintelor Medicale, t. XXXIII, No. 3 6, pp. 341 396.

Manuscript received: February, 2008Manuscript accepted: June, 2008

Printed: October 2008


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