Training Reports for TWF Investigators

Njemanze photo

Philip C. Njemanze, M.D.


Chidicon Medical Center
International Institute of Advanced Research & Training
Imo State, Nigeria

Project and Training Dates

Diarrheal diseases in Nigeria (Focus on Imo and Abia States)
June 1996, June 1997


To apply remote sensing and geographic information system technologies to health system and planning in Nigeria. Specifically, to apply remote sensing and geographic information system technologies to the prevention of diarrheal diseases in Nigeria.


In Africa, Asia and South America, acute diarrheal illnesses is responsible for 4 to 6 million deaths per year, or 12,600 deaths per day. In some areas in sub-Saharan Africa, more than 50 percent of deaths of children are directly attributable to acute diarrheal illnesses. In addition, by contributing to malnutrition and thereby reducing resistance to other infections, acute diarrheal illnesses may increase the severity of presentation of other disease conditions.

This problem is spatially related to the lack of pure water at different sites. Identification of the areas with poor water facilities and high incidence of diarrhea is crucial to solving this problem. Conventional approaches used in Nigeria do not take into account the spatial relationship between water availability and disease patterns.

This project will use remote sensing (RS) and geographic information system (GIS) technologies to determine the optimal location for bore holes and other clean water resources to prevent (water-borne) diseases. The initial study will focus on old Imo State (presently Imo and Abia States), Nigeria. The RS images of the area will be used to map land cover, vegetation, hydrology and towns. The GIS database will also include spatial and quantitative information on diarrheal disease patterns, population data, transportation infrastructure, existing clean water facilities, human waste dumps, industrial pollution sites, and other sources of contamination of water supply locations. The location of potential clean water resources will be determined based on analysis of the database. Computer modeling will enable determination of the impact of contamination, infrastructure malfunction, population changes, and seasonal fluctuations. The experience gained in this study could be used on a regional scale to guide funding agencies to implement water development schemes. Such an approach could significantly reduce infant mortality due to diarrheal diseases.

Objectives of CHAART Visit

  1. Acquire hands on experience on the use of image processing software ERDAS Imagine and GIS software ARCINFO.
  2. To process Images of AVHRR satellite acquired via INTERNET from USGS database.
  3. To digitize maps on related GIS layers useful for implementation of project phased 1.
  4. Develop organizational plan of a locally implementable image processing unit for actualization of the aforementioned project.

Accomplishments during Visit

Objectives 1 and 2 were accomplished after multiple sessions using ERDAS IMAGINE software. AVHRR NDVI 10 days composite images were downloaded from the homepage of the USGS and captured for processing in the IMAGINE software. The images were colored to display geological formations, vegetation and land cover respectively. The seasonal variation of vegetation was examined by comparing images of dry and wet seasons with less than 5% cover.The digital chart of the world data of Nigeria (borders and drainage) were used for ground control point registration. The thrid objective was met by digitizing maps of Imo State, including the borders, geology and hydrology, using ARCINFO software.

Future Activities

Phase 2 will commence in summer of 1998, for two months in June/July. Landsat TM images and IRS Pan < 10m resolution images will be used for location of town and regional water resources. For Phase 3, preliminary discussions were held on organization of an RS/GIS center in Nigeria for health applications. The hardware and software requirements were discussed. It will be necessary to submit a grant to this effect. The following guiding principles were helpful:
  • Projects should be designed for national health goals but can be accomplished as multilateral international programs. It will be best to develop collaboration with CHAART in order to provide the necessary expert consultations for the startup.
  • Projects will have 100% national manpower provision for planning and implementation.
  • Projects must be developed on easy to maintain hardware and software. The cost estimate (shown below) for a fully functional unit is $5000. Such a unit could be provided to the investigator or coinvestigator for use in his/her home country.

Publications Based on This Work

Njemanze, P.C., J. Anozie, J.O. Ihenacho, M.J. Russell, and A.B. Uwaeziozi. 1999. Am. J. Trop. Med. Hyg. 61(3)356-360. PDF

Last updated: 16 Nov 1999.