The epidemiological and Geographical Information System (GIS) mapping of mosquito species in Nigeria intends to develop a comprehensive state of the art web based GIS database by integrating contemporary entomological field surveillance and the use of remote sensing to achieve multiple objectives, focusing on mosquito spp management as a potential approach to assist in minimizing disease (arboviral) risks and outbreaks in Nigeria. The project will inform and educate (professionals and the public); empower decision-making at all levels; help in planning and tweaking clinically and cost-effective actions, in predicting outcomes before making any financial commitments and ascribing priorities in a climate of finite resources; change practices; and continually monitor and analyse changes, as well as sentinel events involved in malaria and Arboviral disease control programmes. Consequently, the project will develop reliable baseline data that will help in implementing and monitoring the progress of various intervention measures deployed to combat malaria and Arbovirus diseases in the country. The ultimate goal is to illuminate the road towards implementing a comprehensive national, multi-agency spatio-temporal health information infrastructure functioning proactively in real time.

1. VECTOR SURVEILLANCE & CONTROL IN NIGERIA:
MAPPING OF MOSQUITO SPECIES IN THE SIX GEOPOLITICAL ZONES.
BY
ANUMBA JOSEPH UCHE
NATIONAL ARBOVIRUS AND VECTORS RESEARCH CENTRE (NAVRC).
BACKGROUND.
The National Arbovirus and Vectors Research Centre (NAVRC) in Nigeria is set to launch a
mosquito (Anopheles, Culex and Aedes) species surveillance map to help detect the spread/
vector distribution of various arthropod borne viruses (Arbovirus) in the six geopolitical zones
of Nigeria.
A pilot study kicked off in the South Eastern part of Nigeria (Enugu and Anambra State). The
proposed methodology of the project is the integration of Geo-informatics (Geographical
Information Systems- GIS) in real time vector surveillance. This novel approach intends to
forecast the tendencies for Arbovirus disease outbreaks in communities across the geopolitical
zones in Nigeria as such, the National Arbovirus and Vectors Research Centre in Nigeria will be
able to monitor mosquito population and provide early warning signals against impending
threats from malaria and Arbovirus disease outbreaks.
This has become pertinent due to the re-emergence of yellow fever and other Arboviral diseases
outbreaks in some parts of the country.
This approach has been tested and successfully implemented by the Venezuelan Government
and some countries (http://dengue.pchrd.dost.gov.ph/).
JUSTIFICATION.
In lieu of the unrelenting efforts of the Nigerian Government to combat the scourge of malaria
and various Arbovirus caused by the mosquito spp vectors, a need exists to further develop new
technologies, such as remote sensing and geographic information systems analysis, for
estimating arthropod vector abundance in aquatic habitats and predicting adult vector
population outbreaks around the 36 states including the Federal Capital Territory, Nigeria. This
is in line with the mandate and core objectives of the National Arbovirus and Vectors Research
Centre under the Jurisdiction of the Federal Ministry of Health.
VECTOR SURVEILLANCE & CONTROL IN NIGERIA: Mapping Of Mosquito Species In the Six Geopolitical Zones.
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2. GOALS & OBJECTIVES.
The epidemiological and Geographical Information System (GIS) mapping of mosquito species
in Nigeria intends to develop a comprehensive state of the art web based GIS database by
integrating contemporary entomological field surveillance and the use of remote sensing to
achieve multiple objectives, focusing on mosquito spp management as a potential approach to
assist in minimizing disease (arboviral) risks and outbreaks in Nigeria.
The project will inform and educate (professionals and the public); empower decision-making
at all levels; help in planning and tweaking clinically and cost-effective actions, in predicting
outcomes before making any financial commitments and ascribing priorities in a climate of
finite resources; change practices; and continually monitor and analyse changes, as well as
sentinel events involved in malaria and Arboviral disease control programmes.
Consequently, the project will develop reliable baseline data that will help in implementing and
monitoring the progress of various intervention measures deployed to combat malaria and
Arbovirus diseases in the country.
The ultimate goal is to illuminate the road towards implementing a comprehensive national,
multi-agency spatio-temporal health information infrastructure functioning proactively in real
time.
VECTOR SURVEILLANCE & CONTROL IN NIGERIA: Mapping Of Mosquito Species In the Six Geopolitical Zones.
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3. METHODOLOGY & REQUIREMENTS.
Consensus
The format and contents of the intended surveillance and control system will be designed in
consultation with experts in public health surveillance, disease control and prevention from the
Federal level and their respective counterparts in the State Ministry of Health (SMoH), as well
as Information Technology (IT) developers. A detailed analysis of the available epidemiologic
surveillance and vector control information systems, data and results from pilot studies (in
South East Nigeria) will be used to assess the performance of the Ministry’s Health Information
System so as to debug and identify shortcomings prior to nationwide deployment and use.
Conceptual Framework.
Epidemiological and entomological data will be entered and analysed to produce risk maps
which are then used to direct vector control activities. New epidemiological and entomological
data will be used to assess the impact of control activities thus generating a knowledge database
which can be used to evaluate cost-effectiveness of control measures, accountability and
operational research. Control interventions will be directed according to the risk maps and
entered into the system for impact evaluation in the reduction of disease cases and/or vector
population.
System Development
The GIS for surveillance and control mosquito spp will be constructed in three phases. In the
first phase, an interoperable geocoding web based tool with a mapping application, designed to
work with the Epidemiologic Surveillance Platform (EPS) will be developed to geocode the
place of residence (town blocks level) of probable arbovirus and vector cases. Then, a
modification may be made on the EPS to enable geocoding through online calls in order to georeference the residence of probable cases. The EPS shall be operated nationwide by the
jurisdictional, state and social security system epidemiologists in coordination with the
National Arbovirus and Vectors Research Centre (NAVRC).
The second phase will include the development of a set of modules for entomological
surveillance, planning and monitoring control activities, as well as a module for downloading
information to the hard drive of local entomologists’ and epidemiologists’ computers. Vector
surveillance is based on contemporary field surveillance and ovitrap data; for this purpose, a
VECTOR SURVEILLANCE & CONTROL IN NIGERIA: Mapping Of Mosquito Species In the Six Geopolitical Zones.
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4. modification of the geocoding tool will be developed to geocode ovitraps. After an ovitrap is
geo-referenced, data on egg counts are entered into Vector GIS via web based formularies.
Another set of web based formularies will be developed to allow entering data on vector control
activities carried out at the local level. Also, the platform will allow entering data gathered in
entomological surveys, such as the number of water containers per house, the number of
positive containers per house and the number of pupae- positive containers per house as well as
adult mosquitoes gotten via Pyrethrum Knockdown Collection (PKC) and dummy human bait
if necessary.
These formularies shall be linked to town blocks using the National Geo- statistical Framework
(NGF) and the federal electoral identification codes if available. The modules for control and
planning include tools to visualize temporal and geographical accumulation of cases (clusters of
malaria/arbovirus transmission) in order to direct vector control activities. It will also include a
tool to print maps to be used in field activities; these maps shall have the id code of each block
to allow recording of surveillance/control activities.
The third phase shall be completed with a reporting module and an improved geographic
visualization tool that combines epidemiologic, entomological and control data into a single
mapping window.
Each of these phases will be implemented gradually in the States with most arbovirus/vector
incidence, and group of researchers and IT specialists, along with NAVRC personnel trained
state and jurisdictional epidemiologist in its use.
Statistical Analysis.
Identification of areas of probable cases accumulation in time (clusters) will be carried out using
a nearest neighbor hierarchical clustering algorithm. This statistical methodology is used in
epidemiology to detect areas of high accumulation of cases based on the distance between them.
For its application in malaria/arbovirus transmission, a minimum number of cases to conform a
cluster will be set. The algorithm shall be run every week using the EPS geo-referenced
epidemiological data of the three previous weeks. In this way the entire national territory could
scanned every week in search for areas with an accumulation of at least five cases separated by
500 meters or less within a three weeks’ time window.
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5. At the end of the each surveillance and data analysis, a standard transmission risk index shall
be produced for malaria and arbovirus disease causing mosquitoes:

High transmission risk=high entomological risk and presence of arbovirus probable
cases

Moderate high transmission=Moderate high entomological risk and presence of
arbovirus probable cases.

Moderate low transmission=Moderate low entomological risk and presence of
arbovirus probable cases

Low transmission risk=no arbovirus probable cases detected.
Enquiries: National Arbovirus and Vectors
Research Centre, Enugu State- Nigeria.
Contact: Anumba Joseph Uche
anumbajoe@gmail.com(2348032173955)
http://linkedin.com/in/anumbajoe
VECTOR SURVEILLANCE & CONTROL IN NIGERIA: Mapping Of Mosquito Species In the Six Geopolitical Zones.
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