|
Memórias do Instituto Oswaldo Cruz
Fundação Oswaldo Cruz, Fiocruz
ISSN: 1678-8060 EISSN: 1678-8060
Vol. 90, Num. 5, 1995, pp. 557-558
|
Mem. Inst. Oswaldo Cruz, Rio de Janeiro, Vol. 90
(5), sep./oct. 1995
RESEARCH NOTE
Preliminary Survey of Phlebotomine Sandflies (Diptera:
Psychodidae) in Northern Nigeria
Simon M Agwale+, Dung D Pam, Blaise Dondji, Dochka D
Duhlinska
Applied Entomology and Parasitology Unit, Department of
Zoology, University of Jos, P.M.B. 2084 Jos, Plateau State,
Nigeria
Code Number: OC95111
Size of Files:
Text: 7K
No associated graphics
Key words: Nigeria - sandflies - Phlebotomus
-Sergentomyia
In this paper we report a preliminary survey of the species
composition of sandflies in northern Nigeria, particularly in
Keana village of Plateau State, an endemic area for
leishmaniasis (SM Agwale et al 1993 Mem Inst Oswaldo
Cruz 88: 347).
Although data on the sandflies fauna of northern Nigeria has
been accumulated (DJ Lewis, B McMillan 1961 Proc R Entomol Soc
Lond Ser B Taxon 30: 29-37, EJ Asimeng 1985 Insect Sci Appl 6:
27-31), this is the first report on the species composition of
sandflies in this active focus of leishmaniasis in Nigeria.
A survey of phlebotomine sandlflies was carried out in
northern Nigeria particularly in Keana village to determine
the species composition and their relative abundance.
Sandflies from Zaria, Kaduna and Kano were exclusively
collected by sticky traps prepared from parchment paper (18 by
24cm) coated on both surfaces with engine oil, whereas both
mouth aspiration and sticky traps methods were used to collect
sandflies from Katsina and Keana. Single collection was made
during October 1993 at Zaria, Kaduna, Kano and Katsina,
whereas a monthly collection was made at Keana village
(October 1993 to October 1994), but collections were not made
from May through July in this area. Species identification of
the sandflies was made using the standard keys (E Abonnec 1972
Bull Br Mus Nat Hist Ent 45: 121-209, DJ Lewis 1982 Bull Br
Mus Nat Hist Ent 45: 121-209).
Eight species of phlebotomine sandflies belonging to the Old
World genera namely Sergentomyia and Phlebotomus
were collected. The species of the genus Sergentomyia
constituted the major proportion of the entire sandflies
collected. They consisted of 678 (63.66%) S. (S.)
africana Newstead, 319 (29.95%) S. (S.) antennata
Newstead, 16 (1.50%) S. (S.) clydei Sinton, 14 (1.32%)
S. (G.) squamipleuris Newstead, 5 (0.45%) S. (S.)
bedfordi Newstead and 5 (0.45%) S. (S.) schwitzi
Adler et al Only two species of the genus
Phlebotomus were discovered; they consisted of 23
(2.16%) P. (P.) duboscqi Neveu-Lemaire from Katsina and
5 (0.45%) P. (A.) rhodaini Parrot from Keana. Of the 23
specimens of P. duboscqi, 20 were collected by mouth
aspirator on walls indoors and 3 by sticky traps.
TABLE. The species composition of sandfly samples collected at
different sites in Northern Nigeria
-------------------------------------------------------------
Geographical Sandflies species
area -------------------------------------------------
P. dubosqi P. rhodaini S. africana S. antennata
m f m f m f m f
No Gv Inf No Gv Inf No Gv Inf No Gv Inf
-------------------------------------------------------------
Katsina 16 7 3 3 7 1
Kano 1
Zaria 1
Kaduna 7 4
Keana 4 1 401 260 166 4 219 96 76
-------------------------------------------------------------
Total 23 5 678 319
-------------------------------------------------------------
-------------------------------------------------------------
Geographical Sandflies species
area -------------------------------------------------
S. clydei S. squamipleuris S. bedfordi S. schwitzi
m f m f m f m f
No Gv Inf No Gv Inf No Gv Inf No Gv Inf
-------------------------------------------------------------
Katsina
Kano
Zaria
Kaduna
Keana 4 12 5 13 1 4 1 3 2 2
-------------------------------------------------------------
Total 16 14 5 5
-------------------------------------------------------------
m: male; f: female; No: number Gv: gravid; infected
Although S. africana and S. antennata persisted
throughtout the year, none of the species has been
incriminated in the transmission of human leishmaniasis. The
highest number of species was recorded in August through
October. The study confirmed that the phlebotomine fauna in
the leishmaniasis endemic area consists mainly of Sergentomyia
species.
In northern Nigeria, P. duboscqi has been identified in
the Sahel and Sudan Savanna bioclimatic zones (Asimeng loc.
cit., Lewis loc. cit.). It appears from this study that the
distribution of this species does not extend into the Guinea
Savanna as was also reported (EJ Asimeng 1991 Insect Sci Appli
28: 578-580). The only sandfly of the genus Phlebotomus
collected from the endemic focus (P. rhodaini) has not
been incriminated in the transmission of human
leishmaniasis.
This findings so far may trigger a suspicion and further
investigation of the role of sandflies of the genus
Sergentomyia in the transmission of leishmaniasis. Molecular
characterization of Leishmania isolates from humans
living in the focus (Keana village) is now in progress, and
when completed will give new information of this public health
significance in Nigeria. Active search of sandflies species
composition in this region is still in progress in order to
isolate Leishmania parasites from infected specimens.
Colonization of species of the genus Sergentomyia and
subsequent experimental infection will also be interesting to
complement this study.
Acknowledgements: to Prof. R Killick-Kendrick for reading the
manuscript.
This work was supported by the UNDP/WORLD BANK/WHO Special
Program for Research and Training in Tropical Diseases. This
study fulfils part of the requirement for the award of a PhD
degree to SM Agwale by the University of Jos, Nigeria.
+ Corresponding author
Received 21 November 1994
Accepted 23 May 1995
Copyright 1995 Fundacao Oswaldo Cruz
|