Download Plants associated with aquatic stages of

Seediscussions,stats,andauthorprofilesforthispublicationat:https://www.researchgate.net/publication/235965056
Plantsassociatedwithaquaticstagesof
OnchocerciasisvectorSimuliumdamnosum
sensulatoinAbuHamedandGalabatFociin
Sudan
DATASET·FEBRUARY2013
READS
22
9AUTHORS,INCLUDING:
IsamMAZarroug
ArwaElaagip
9PUBLICATIONS47CITATIONS
UniversityofKhartoum
SEEPROFILE
13PUBLICATIONS11CITATIONS
SEEPROFILE
Allin-textreferencesunderlinedinbluearelinkedtopublicationsonResearchGate,
lettingyouaccessandreadthemimmediately.
Availablefrom:ArwaElaagip
Retrievedon:11January2016
Journal of Public Health and Epidemiology Vol. 5(2), pp. 83-86, February 2013
Available online at http://www.academicjournals.org/JPHE
DOI: 10.5897/JPHE12.089
ISSN 2141-2316 ©2013 Academic Journals
Full Length Research Paper
Plants associated with aquatic stages of
Onchocerciasis vector Simulium damnosum sensu lato
in AbuHamed and Galabat Foci in Sudan
Isam M. A. Zarroug1*, Arwa H. Elaagip2, Hanan A. Mohamed1, Wigdan A. Mubarak1, Kamal H.
Osman3, Tong Chor M. Deran3, Nabil Aziz4 and A. D. Nugud5
1
Onchocerciasis Control/Elimination Program, National Program for Prevention of Blindness (NPPB),
Federal Ministry of Health, Sudan.
2
Department of Parasitology and Medical Entomology, Faculty of Medical Laboratory Sciences,
University of Khartoum, Sudan.
3
National Program for Prevention of Blindness (NPPB), Federal Ministry of Health, Sudan.
4
The Carter Center, Sudan.
5
National Public Health Laboratory, Sudan.
Accepted 8 January, 2013
Onchocerciasis vector, Simulium (Edwardsellum) damnsoum sensu lato (Diptera: Simuliidae), breeds
near rapids and cataracts in running water rich in oxygen and are usually found attached to water
plants, trailing roots and branches, stones and rocks. This study was conducted to identify the plant
species associated with the aquatic stages of S. damnosum s. l. vectors in two foci: AbuHamed in
northern Sudan and Galabat in eastern Sudan during 2007 to 2009. All collected aquatic stages were
identified as S. damnosum s. l. The plants collected are identified as follows: Digitaria ciliaris (Retz.)
Koel. Family: Poaceae, Polygonum glabrum Willd. Family: Polygonaceae and Phragmites australis
(Cav.) Family: Poaceae in AbuHamed focus, and Cynodon dactylon (L.) Pers Family: Poaceae, Kanahia
laniflora (Forssk.) R.Br. Family: Asclepiadaceae and Digitaria ciliaris (Retz.) Koel. Family: Poaceae in
Galabat focus. This is the first documentation and identification of plants associated with breeding of S.
damnosum s. l. in Sudan.
Key words: Simulium damnosum s. l., Onchocerca volvulus, plants association, onchocerciasis, Sudan.
INTRODUCTION
Onchocerciasis is a parasitic infection caused by the
filarial nematode Onchocerca volvulus. It is a major
endemic disease throughout a wide belt of Sub-Saharan
Africa. Sudan is the northernmost country in the world
endemic for onchocerciasis (Baker and Abdelnur, 1985;
Davies and Crosskey, 1991; Higazi et al., 2000, 2001).
Onchocerciasis in Sudan is found in three foci reflecting
the distribution of swiftly flowing rivers and streams in the
country: Northern Sudan (AbuHamed focus), between the
*Corresponding author. E-mail: [email protected]. Tel:
+249923061600.
3rd and 5th cataracts of the Nile; Eastern Sudan (Galabat
Focus), near the Ethiopian border and south and
southwest Sudan between the Bahr ElArab and the Nile.
The vast majority of this endemic area is now part of the
new state of South Sudan due the recent split of the
country in 2011. Northern and southern Sudan foci have
been well studied (Baker and Abdelnur, 1985) but
onchocerciasis in Eastern Sudan has been little studied
and knowledge of its distribution is incomplete (Baker and
Abdelnur, 1985; Higazi et al., 2000). The disease in
AbuHamed focus is non-blinding and associated with
severe skin manifestations, low microfilarial rates and few
palpable nodules with infection rates up to 37% (Williams
et al., 1985), where in Galabat it reaches up to 63% but
84
J. Public Health Epidemiol.
Figure 1. Study sites in AbuHamed and Galabat foci in Sudan.
the disease is non-blinding and characterized by severe
localized skin manifestations including the sowda form of
the skin disease (Ghalib et al., 1987).
Simulium damnosum is widely distributed in tropical
Africa, particularly near rapids and cataracts, and is found
nd
as far north as the 2 cataract of the Nile. In the Sudan, it
occurs chiefly on the middle courses of the western Nile
tributaries, on the Ethiopian frontier, near Roseires,
Sennar and other places on the Blue Nile system, and on
the main Nile from Khartoum northwards (Lewis, 1954).
Since Simuliidae require permanent or nearly permanent
running water which is rich in oxygen, the areas which
they occupy in Sudan, mainly an arid country, are well
defined. Among the factors which determine breeding
places of simuliidae, several writers have considered
water speed to be the most important. This factor usually
appears to determine the breeding places in Sudan, but,
in the absence of numerous measurements of water
speed, it is convenient to classify breeding places in
terms of approximate size (Lewis, 1953).
Larvae and pupae are found attached to water plants,
trailing roots and branches, fallen leaves, stones, inclined
rock surfaces and lips of waterfalls. It is possible that
certain species have a preference for particular objects,
but no definite information on this is available (Freeman
and de Meillon, 1953; Davies and Crosskey, 1991).
This study was conducted to record and to identify the
plant species associated with the breeding of S.
damnosum s.l. the vector of onchocerciasis in two
endemic foci: AbuHamed in northern Sudan and Galabat
in Eastern Sudan.
MATERIALS AND METHODS
The study was conducted in two endemic foci, AbuHamed and
Galabat in Sudan (Figure 1) during 2007 to 2009. AbuHamed focus
lies in Northern Sudan (N 19° 32.495`- 18° 17.293`, E 32° 13.867` 33° 55.00`) between the 3rd and 5th cataracts in the River Nile, at
altitude 920 to 260 km (Figure 1). On the two banks of the Nile grow
hundreds of thousands of palm trees which provide ideal shelter
forest, suitable for survival of S. damnosum s. l. in unique northern
Zarroug et al.
85
Table 1. The list of endemic villages and collected plants in AbuHamed and Galabat foci in Sudan.
Area
AbuHamed Focus
Galabat Focus
Village
Alsarsaf (N 19° 31.350`, E 33° 17.112`), Karrni (N 18° 25.530`, E 33°
45.588`), Sheriek (N 18° 46.278`, E 33° 37.441`)
Alogda (N 18° 54.056`, E 32° 16.263`), Karrni,
Alsarsaf
Plant +ve S. damnosum
Digitaria ciliaris
Hilat Khatier (N 13° 13.102` E 36° 01.771`), Jumiaza (N 13°25.940` E
36° 05.705`) Aldahaab (N 13° 55.399`, E 36° 04.017`), Aldarabi (N 13°
57.217`, E 36° 03.274`)
Albahker (N 14° 06.578`, E 35° 56.570`), Mushraa’ Alfursan (N 13°
29.806`, E 36° 10.201`), Ajab Seidu (N 14° 03.409`, E 35° 59.487`)
Albahker, Mushraa’ Alfursan, Hilat Khatier, Jumiaza
Cynodon dactylon
most focus in the world. Galabat focus is found in eastern Sudan (N
14° 06`- 12° 57`, E 35° 56`- 36° 09`) on Atbara River, at altitude 540
to 1040 km (Figure 1), which is a seasonal river originating from the
highlands of Ethiopia and joining the River Nile at Atbara town. Its
banks covered with high density of vegetation mostly of Acacia sp.
It is a very fast flowing river supporting a high density of S.
damnosum s. l. during the rainy season (July to October).
Aquatic stages (eggs, larvae and pupae) of black flies were
collected from different plants at AbuHamed and Galabat foci
(Table 1). The collected larvae and pupae were preserved in 80%
ethyl alcohol for morphological identification which was following
the keys of Freeman and de Meillon (1953), Crosskey (1962) and
Davies and Crosskey (1991).
The stems, leaves and flowers of collected plants to which the
eggs, larvae and pupae of black fly were attached, were cut using
sharp surgical blades and forceps and preserved as dry specimens
for species identification following Bebawi and Neugebohrn (1991).
Polygonum glabrum
Phragmites australis
Kanahia laniflora
Digitaria ciliaris
During this study, D. ciliaris was found between cataracts rocks in AbuHamed and Galabat foci, P. glabrum
and P. australis were found in AbuHamed only breeding
on banks of shallow slow running water, while Kanahia
laniflora was found distributed along Atbara River and C.
dactylon was found in banks of fast shallow running water
in Galabat focus (Table 1). In this study, the density of
aquatic stages of S. damnosum s. l. was found the
highest in D. ciliaris in both foci, while the lowest density
found in P. glabrum and P. australis respectively. In all
associated plants S. damnosum s. l. density was higher
on underside of submerged leaves rather than stems and
other parts.
DISCUSSION
RESULTS
All the collected black fly samples were morphologically
identified as being S. damnosum s.l. which was
characterized the pupa by its diagnostic respiratory filaments (Freeman and de Meillon, 1953) and the larva by
its diagnostic flattened setae of proleg and head-capsule
with strong pigmentation and spots (Crosskey, 1962).
The collected plants were identified according to
morphological characteristics of flowers, leaves and geographical distribution of the collected plant. The results
were as follows:
Kanahia laniflora (Forssk.) R.Br. Family: Asclepiadaceae:
known locally as “Guweer”
Polygonum glabrum Willd. Family: Polygonaceae: known
locally as “Tumsahia”
Cynodon dactylon (L.) Pers Family: Poaceae: known
locally as “Nageela”
Phragmites australis (Cav.) Family: Poaceae: known
locally as “Bous”
Digitaria ciliaris (Retz.) Koel. Family: Poaceae: known
locally as “Dees”.
Onchocerciasis, or river blindness is endemic in Sudan in
three main foci. The oldest and largest focus exists in the
South and Southwest of Sudan, the most recent focus
exists in Galabat Province along Atbara River close to
borders with Ethiopia (Abdalla and Baker, 1975). The
Northern Focus was discovered in 1958 and centered on
the banks of River Nile around the town of AbuHamed in
the Nubian Desert (Morgan, 1958). Molecular studies
showed that the parasites and vectors from this focus
were significantly different from all isolates examined to
date including those from the rest of Sudan and West
Africa (Higazi et al., 2000, 2001).
In spite of the importance of plant species associated
with breeding of black fly vectors in epidemiology and
vector control studies, little is known about the association of these plants with hundreds of pupae and larvae
attached to stems, leaves and roots of many species
(Snow et al., 1958; Hocking and Hocking, 1962; Hamada
et al., 2003). The identification of plants associated with
aquatic stages ofS. damnosum s.l. vectors in AbuHamed
and Galabat foci has been determined for the first time in
Sudan.
86
J. Public Health Epidemiol.
was found to be the highest in D. ciliaris and K. laniflora
plants in Galabat focus and in D. ciliaris in AbuHamid
focus. These plants were embedded strongly and deeply
in the ground, in rocky, cataracts and in very fast flowing
water, which may be more suitable breeding places
rather than floating, fragile plants, like P. glabrum and P.
australis found in shallow slow running water along river
banks of River Nile and Atbara River, and may be swift
by strong current and speed of water. So, this may
indicated that there was a preference for particular plant
species like D. ciliaris and K. laniflora in Galabat focus
and D. ciliaris in AbuHamed focus as breeding places of
onchocerciasis vector.
This study may help in understanding the importance of
plant species in epidemiology, biology, behaviour and
ecology of S. damnosum s.l. vectors and may lead to
successful control interventions of the disease in Sudan.
More studies will be needed to measure water speed and
water current flow in relation to associated plants.
ACKNOWLEDGEMENTS
The authors thank Dr. Ikram Ahmed, Department of
Botany, Faculty of Science, University of Khartoum for
identification of plant species.
REFERENCES
Abdalla R, Baker EA (1975). A new focus of onchocerciasis in the
Sudan. Trop. Geo. Med. 27:365-370.
Baker RHA, Abdelnur OM (1986). Onchocerciasis in Sudan: the
distribution of the disease and its vectors. Trop. Med. Parasitol.
37:341-355.
Bebawi FF, Neugebohrn L (1991). A review of plants of Northern
Sudan, with special reference to their uses. Technical Cooperation –
Federal Republic of Germany, Eschborn. pp. 1-294.
Crosskey RW (1962). The identification of the larvae of Africa Simulium.
Bull. World Health Org. 27:483-489.
Davies JB, Crosskey RW (1991). Simulium vectors of onchocerciasis.
World Health Organization. WHO/VBC/91.992.
Freeman P, de Meillon B (1953). Simuliidae of the Ethiopian Region.
William Clowes and Sons Limited, London and Beccles. p. 1-224.
Ghalib H, Mackenzie C, Williams J, Elsheikh H, Kron M (1987). Severe
onchocercal dermatitis in Ethiopian border region of Sudan. Ann.
Trop. Med. Parasitol. 81:405-419.
Hamada N, Ale-Rocha R, Bessa LS (2003). Description of Simulium
damascenoi (Diptera: Simuliidae) male and the black-fly species from
the State of Amapá, Brazil. Mem Inst Oswaldo Cruz 98:353-360.
Higazi TB, Boakye DA, Wilson MD, Mahmoud BM, Baraka OZ, Mukhtar
MM (2000). Cytotaxonomic and molecular analysis of Simulium
(Edwardsellum) damnosum sensu lato (Diptera: Simuliidae) from
AbuHamed, Sudan. J. Med. Entomol. 37:547–553.
Higazi TB, Katholi CR, Mahmoud BM, Baraka OZ, Mukhtar MM,
AlQubati Y (2001). Onchocerca volvulus: Genetic diversity of parasite
isolates from Sudan. Exp. Parasitol. 97:24–34.
Hocking B, Hocking JM (1962). Entomological aspects of African
onchocerciasis and observations on Simulium in the Sudan. Bull
World Heallth Org. 27:465–472.
Lewis DJ (1954). Nimitti and some other small annoying flies in the
Sudan. Sudan Notes Rec. XXXV: 76–89.
Lewis DJ (1953). Simuliidae in the Anglo-Egyptian Sudan. Rev Zool
Bot. Afr. XLVIII. 3–4:269–286.
Morgan HV (1958). Onchocerciasis in the Northern Sudan. J. Trop.
Med. Hyg. 61:145-147.
Snow WE, Pickard E, Moore JB (1958). Observations on blackflies
(Simuliidae) in the Tennessee River Basin. J. Tennessee Acad. Sci.
33:5–23.
Williams JF, Abu Yousif AH, Ballard M, Awad R Tayeb M, Rasheed M
(1985). Onchocerciasis in Sudan: the Abu Hamed focus. Trans. R.
Soc. Trop. Med. Hyg. 79(4):464-468.