Control of filariasis vector using Ovillanta in Gwale local Government area of Kano State, Nigeria

Abstract

The study was aimed at finding the effectiveness of a physical method of controlling filariasis vector larvae. Four ovillanta traps were placed in four different sites (north, south, west and east) of Gwale Local Government area of Kano state. The eggs and immature stage (larvae) of the filariasis vector were collected and destroyed. A total of 134667 larvae were collected altogether. 25% from site A, 23% from site B, 28% from site C and 24% from site D.The finding of the study shows that ovillanta trap is an effective method in controlling filariasis vector.

Full text

Journal of Ecobiotechnology 2020, 12: 014-016
doi: 10.25081/jebt.2020.v12.6434
http://updatepublishing.com/journal/index.php/jebt
14 JEcobiotechnol • 2020 • Vol12
INTRODUCTION
Culex mosquito commonly known as the “southern house
mosquito”is a medium-sized brown mosquito that exists
throughout the tropics and the lower latitudes of temperate
regions. This species is found in the southern United States and
is present throughout Florida. In Nigeria they are found in several
areas such as Kano, Akure, Ondo, Ibadan and Edo [1]. This
night time-active, opportunistic blood feeder is a vector of many
pathogens, several of which affect humans.Culex mosquitoes are
the chief vectors of Wuchereria bancrofti that cause a disease
known as bancroftian filariasis [2]. Culex mosquitomay also cause
protozoan, viral, parasitic and helminthic diseases.
Lymphatic filariasis stands next to malaria as the most important
vector-borne disease in India. Culex quinquefasciatus (Cx.
quinquefasciatus), a vector of lymphatic filariasis affects 119
million people living in 73 countries, with India accounting
for 40% of the global prevalence of infection[3]. Japanese
encephalitis (JE) a mosquito-borne viral disease is a serious public
health problem in Asia[4] and it is highly endemic in few districts
of Tamil Nadu, Southern India. To prevent mosquito- borne
diseases and improve public health, it is necessary to control
them. Malaria and filarial vectors in Nigeria are resistant to
dichlorodiphenyltrichloroethane (DDT), hexachlorocyclohexane
(HCH), malathion, and deltamethrin[5]. In this situation, the
change of insecticides has hampered the program with increased
costs. Thus, the future of vector control mainly relies on the
strategies for the management of existing insecticide resistance
in the vectors and to limit its further spread. Therefore, it is the
hour to launch extensive search to explore eco-friendly biological
materials for control [6].
MATERIAL AND METHODS
Sample Area
Kano is the largest city in the Sudan Region of Nigeria. It is located
between latitude 12o 25 to 12o 40N and longitude 8o 35N to 8o 45E.
Kano city has for centuries been the most important commercial
and industrial nerve centre of Northern Nigeria attracting millions
from all parts of the country and beyond. Immigration and
natural growth rate of 3% is expected to continue to increase
the population and waste stream in the years to come. With a
population presently estimated at 3.5 million, Kano metropolis
is among the fastest growing cities in Nigeria. With a population
density of about 1000 inhabitants per km2 within the Kano closed
settled zone compared to the national average of 267 inhabitants
per km2. It is also one of the most crowded. The city also has a
large migrant worker population which has been increasing at the
rate of 30 to 40 per cent per annum.
Gwale Local Government area was chosen and a total of four
siteswere randomly selected from north, south, west and east
area to constitute the Sampling Areas. Each site was labeled.
OVILLANTA SET UP
Ovillanta was created from two 50 cm sections of an old car tire,
fashioned into a mouth-like shape, with a fluid release valve at
Control of lariasis vector using
Ovillanta in Gwale local Government
area of Kano State, Nigeria
A. B. Umar, A. H. Dankaka and M. Manjur Shah*
Department of Biological Sciences, Yusuf Maitama Sule University, Kano, Nigeria
ABSTRACT
The study was aimed at finding the effectiveness of a physical method of controlling filariasis vector larvae. Four ovillanta
traps were placed in four different sites (north, south, west and east) of Gwale Local Government area of Kano state.
The eggs and immature stage (larvae) of the filariasis vector were collected and destroyed. A total of 134667 larvae
were collected altogether. 25% from site A, 23% from site B, 28% from site C and 24% from site D.The finding of the
study shows that ovillanta trap is an effective method in controlling filariasis vector.
KEYWORDS: Culex larvae, Filariasis, Ovillanta, vector
Copyright: © The authors. This article is open access and licensed under the terms of the Creative Commons Attribution License
(http://creativecommons.org/licenses/by/4.0/) which permits unrestricted, use, distribution and reproduction in any medium, or format for any purpose,
even commercially provided the work is properly cited. Attribution — You must give appropriate credit, provide a link to the license, and indicate if
changes were made.
Short Communication
ISS N:2077-0464
Received: August 13, 2020
Accepted: October 18, 2020
Published: October 22, 2020
*Corresponding Author:
M. Manjur Shah,
Email: mmanjurshah@gmail.
com

JEcobiotechnol • 2020 • Vol12  15
Umar,
et al
.
the bottom. Inside the lower tire cavity, a milk-based, non-toxic
solution was developed. Inserted to float in the artificial pond
was a wooden or paper strip on which the female insect lays her
eggs. The strip was removed twice weekly.
The solution, which now includes mosquito pheromone (the
female insect’s chemical perfume that helps others identify a
safe breeding site)was drained, filtered, and recycled back into
the tire. The pheromone was concentrates over time, making
the ovillanta even more attractive for mosquitoes [7].
COLLECTION OF LARVAE
Culex mosquitoe larvae were collected twice weekly using
filtering method as described by Gerardo et al. 2016 [8]. This
was done by placing the kitchen filter on top of a clean plastic
bottle of more than 2 litres. By opening the valve on the trap
the water was drained at the centre of the filter and the larvae
was retain as the water flow through the filter. The filter was
removed containing larvae from the bottle and the valve was
closed so as to replace the water. The number of larvae in each
trap was counted and recorded, then poured into white plastic
containers (Table 1).
Identification of Filariasis Vector Larvae
The filariasis vector larvae were identified by their simple
morphological features as well as their behavior in water
according to Linton et al. 2001 [9]. The larval head is short and
stout, becoming darker toward the base. The mouth brushes
have long yellow filaments that are used for filtering organic
materials. The abdomen consists of eight segments, siphon, and
saddle. Each segment has a unique setae pattern. The larvae
of Culex mosquito tend to position themselves at an angle due
to presence of siphon in which they use for respiration [10].
Destruction of Filariasis Vector
The filariasis vector larvae were destroyed using concentrated
70-80% ethanol as described by [11].
SCOPE OF THE STUDY
Culex mosquitoes was collected twice weekly for period of eight
months from January 2018 to September 2018, using Ovillanta
RESULTS
A total of 134667 filariasis vector larvae were collected from the
four sites in Gwale Local Government area of Kano state. 25%
from site A, 23% from site B, 28% from site C and 24% from
site D (Table 2).
During the first week of sample collection, small dark spots were
observed on the top of the landing strip in all of the ovillanta
traps. The presence of dark spots which later developed into
Culex mosquito larvae after three days indicated the dark spots
where the eggs were laid by the adult female culicine mosquito
which was in accordance with Bates,1949 [12].He stated that
eggs are laid in raft which float on the surface of water and
become darken after few hours of deposition that normally
hatched within 24-30 hours.
The number of Culex mosquito larval instars collected from
four ovillanta traps shows the effectiveness of the trap as a new
technique of targeting the immatured stage of filariasis vector
larvae which was in line with Lee et al. 1989 [13].observations
which stated that Culex mosquito breeds in man-made artificial
container such as septic tanks, stock draining tought, oxidation
pond and tyres. The increase in number of the mosquito larvae
in the trap may be due to re-used of the water rather than
discarding as the mosquito released oviposition pheromones
when they lay eggs which is in accordance with Gerardo et al.
2016 finding [8].
CONCLUSION
The findings of the study shows that, ovillanta trap is an
effective trap which when placed in close proximity can be
used to target the immature stage of filariasis vector larvae and
destructing them might reduce the rate of transmission.
REFERENCES
1. Hotez, P. J., Asojo, O. A. and Adesino, A. M. “ Zero ground” for the
high prevalence neglated tropical diseases. Plots Negl Trop Dis.
2012:6(7):e1600.
2. Abdel-Hameed, A.A., Dura, W.T. and Alkhalife, I.S. An inguinal mass
with local vascular lesions induced by a lymphatic filaria. Saudi
Medical Journal, 2004;25:1106-1108.
3. Ramaiah, K.D., Das, P.K., Michael, E. and Guyatt H. The economic
burden of lymphatic filariasis in India. ParasitolToday, 2000;16:
251-253.
4. Libraty, D.H., Nisalak, A., Endy, T.P., Suntayakorn, S., Vaughn, D.W. and
Innis, B.L.(). Clinical and Immunological risk factors for severe disease
in Japanese encephalitis. Trans R Soc Trop Med Hyg 2002;96:173-8.
5. Ravi, V., Vanajakshi, S., Gowda, A. and Chandramuki, A. A laboratory
diagnosis of Japanese encephalitis using monoclonal antibodies and
Table 2: Monthly numbers of culex larvae caught in each site
Month Site A Site B Site C Site D
January 2296 1976 2310 2101
Febuary 2548 2001 2452 2458
March 2601 2203 2710 2415
April 3101 2801 3204 3105
May 3001 2934 3292 3115
June 3521 3052 3537 3431
July 3982 3450 3841 3615
August 4021 3854 4003 4013
September 4321 4031 4201 4215
October 4601 4131 4701 4321
33993 30429 37455 32790
Table 1: Sampling sites
SITE Labeled
GWALE NORTH A
GWALE WEST B
GWALE EAST C
GWALE SOUTH D

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et al
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correlation of findings with the outcome. J Med Virol., 1989;29:221-3.
6. Raghavendra, K. and Subbarao, S.K. Chemical insecticides in malaria
vector control in India. ICMR Bull, 2002;32: 1-7.
7. Hwag, Y. S., Kramer, W. l. and Mulla, M. S. Oviposition Attractants and
Repellents of Mosquitoes.Isolation and Identification of Oviposition
repellents for Culex Mosquitoes. J Chem Ecol., 1980;6:71-80.
8. Gerardo, U. C., Jonathan, M. H. and Colton, Y. M. “Canadian mosquito
trap offers hope in fight against zika spread”. Medical and Veterinary
Entomology, 2016;17: 195-204.
9. Linton, Y. M., Harbach, R. E., Chang, M.S., Anthony T.G. and
Matusop A. Mophological and Molecular identity of anopheles
(Diptera: culicidae) the nominotypical member of a malaria vector
species complex in South Asia. Systentomo, 2001;26:357-366.
10. Sirivanakarn, S. and White, G. B. (). Neotype designation of Culex
quinquefasciatus Say (Diptera: Culicidae). Proceedings of the
Entomological Society of Washington 80,360–372.
11. Schauff, M. E.Collecting and preserving insects and mites. USDA
miscellaneous publication. 1986;1443: 68 Pp
12. Bates, M. The Natural History of Mosquitoes. Macmillian Company.
New York, NY. 1949;379 pp.
13. Lee, D.J., Hicks, M. M., Debenham, M.L., Griffiths, M., Marks, E.N.,
Bryan, J.H. and Russell, R.C. The culicidae of the Australian region.
volume 7. Canberra, Australia; Australian government publishing
service 1989;281pp.