Transmission of Water-Borne Infections
Study of Transmission of Water-Borne Infections by Application of Computer Modeling (GIS) and Field Experiments Implemented with Tracer Phages
Tech Area / Field
- MED-DIS/Disease Surveillance/Medicine
- ENV-MRA/Modelling and Risk Assessment/Environment
3 Approved without Funding
Georgian Academy of Sciences / Institute of Bacteriophage, Microbiology and Virology, Georgia, Tbilisi
- Tbilisi State University / Geophysics Institute, Georgia, Tbilisi
- Public Health Agency of Canada / Laboratory for Foodborne Zoonoses, Canada, ON, Guelph\nUniversity of North Carolina / Carolina Environmental Program, USA, NC, Chapel Hill\nHealth Protection Agency / CAMR (Centre for Applied Microbiology & Research), UK, Porton Down
Project summaryWater-borne epidemics are especially frequent in developing countries with low economic support. A number of incidence of infections caused by different types of enteric viruses, bacterial pathogens, such as Salmonella sp., Shigella sp, E. coli and protozoans, like Entamoeba hystolitica has drastically increased during the past 5 years in Georgia as well. All these cases are mostly registered in the valley of the river Mtkvari, in the cities: Tbilisi, Rustavi, Borjomi. Recently the outbreaks caused by the damages of canalization systems have been registered in the cities Zugdidi and Poti located in the Kolkheti Valley.
High prevalence of enteric infections in Georgia, first of all, is associated with the economic shortage existing in this country due to which the treatment regimens of drinking water are disabled. Immediate measures such as repairs of the faulty distribution systems and/or other water supply system infrastructure are failing. Warm climate especially facilitates rapid spread of infections.
Damages of the water supply and canalization systems also occur as the results of natural hazards, however the epidemic follow-up of these events practically does not exist. The territory of Georgia is prone to natural disasters as earthquakes, floods, landslides, mud flow, etc. The burst of seismic activity was observed in Georgia and adjacent area in the last decade. Three major earthquakes of magnitude M~6.5-7 and several moderate events occurred in the region (Spitack 1988, Racha 1991, Barisakho 1992, Tbilisi, 2002) with catastrophic consequences both to population and economics.
The main goal of the present project is the evaluation of the methods for assessment of post- hazard epidemic (due to earthquakes, or other natural disasters). The basis of the hazard estimation are the hazard maps, population density maps, information about the water supply systems, water reservoirs, and the pattern of spread of epidemics due to damages caused by: a) the ordinary failures of the water systems, and, b) the natural disasters. Simultaneously with the predictive computer-modeling aiming monitoring of development of epidemics in urban environment the field experiments based on application of tracer phages will be accomplished. The results of computer modeling and filed experiments will be compared.
The focus will be made on application of coliphages - alternative indicators to the traditional coliform bacteria. Coliform bacteriophages will be used as tracers in the field ecological experiments. Application of bacteriophages as tracers provides information about the initial source of contamination and ways of its further transmission in environment. Therefore, it is easy to model epidemic process and follow up its development in nature. It is well-known that F-specific RNA bacteriophages are adequate model organisms for enteric viruses in fresh waters. It was shown that somatic coliphages are the best indicators of the efficiency of drinking water treatment for viruses and protozoan cysts. The same approaches have been successfully used by the USA partner involved in this project.
In the 80’s and 90’s the IBMV scientists have worked out an original indicator system, which has been previously successfully applied by the IBMV group on the Black Sea shore and other regions in Georgia. Use of the simple and precise methods for identification of the smallest amounts of the tracer-phages amongst the similar objects encountered in environment, without application of expensive and sophisticated techniques, like PCR, is one of the most important advantage of this approach.
The major objectives of the project are:
a) to assess due to computer modeling a potential risk of infection caused by enteric viruses, bacterial pathogens and protozoans. These models will make it possible to predict spread of infection in initial and boundary conditions.
b) to determine the possible ways of spread of infection via computer modeling in the particular urban regions of Tbilisi e.g. a region Chugureti known for a high prevalence of enteric infections (Entamoeba hystolitica, Salmonella typhimurium, Shigella dysenteria) and a region Saburtalo, where these infections have never been registered;
c) to design an appropriate indicator/tracer phage-based model for field experiments;
d) to prove the indicator/tracer phage-based model in the field experiments in the same regions (see, paragraph b);
e) to compare the results obtained by predictive mathematical model and those obtained by the field experiments.
The project consists of the following steps, which will be mostly overlapping and/or accomplished simultaneously:
Step I - Delineation of zones of maximal risk and numerical modeling of epidemic distribution process will be carried out on the basis of solution of appropriate equations for different initial and boundary conditions. The epidemic spread velocity will be studied experimentally.
Step II - Assessment of extent of disaster and planning of countermeasures. The action of phage will be modeled numerically as well. All databases and maps will be compiled using GIS technology. ArcView 3.1 software will be used for this purpose. The scenarios of epidemics due to earthquakes for selected areas will be compiled. The prevention and/or mitigation and preparedness plans will be evaluated. The plans include economic aspects (estimation of loses without countermeasures, the cost of these measures, etc.).
Steps I-II will be accomplished by a mixed group of specialists including microbiologists, and geophysics;
Step III - Investigation of the background epidemic situation in the population living in Tbilisi on the right bank of the river Mtkvari (region Chugureti) known for a high prevalence of enteric infections (Entamoeba hystolitica, Salmonella typhimurium, Shigella dysenteria) and a region Saburtalo, where these infections have never been registered;
Step IV – Study of biological traits of indicator and tracer bacteriophages is based on detailed genetic and molecular biologic characterization of the selected tracer-phages and implies a variety of modern methods.
Step V – Establishment of the small scale industry for provision of phage-tracers.
Step VI - Assessment of development of epidemics in environment due to application of tracer bacteriophages. The results of the field experiments implemented during this step will be compared with those provided through computer modeling.
The data will be analyzed and appropriate conclusions will be drawn out. The most valuable practical results will be patented.
It is necessary to stress that the results of this project may not be limited by the field of Technology Demonstration. Many of these results could have a certain value for the Basic Research as well, especially the assessment of the reliability of predictive computer models. The present project may have a significant economic impact to development of effective preventive measures against the spread of epidemics. These results will be put into the foundation of the future projects.
The main expected outcomes of the present project are:
The present project is the first one in the series of projects planned by IBMV (GE), which will be directed to the problem of infection and its prevention and control by using of bio-preventive measures. Due to the results of the present project the conclusions concerning: a) the safety of the water supply system in different regions of Tbilisi will be elucidated; b) the theoretical and practical approval for application of bacteriophages as tracers will be provided, which will be based on the results of computer modeling and practical data. The project will also demonstrate if it is reasonable to have a stock of enteric bacteriophages for extreme epidemic situations.
This project basically addresses to two fields, in particular: Technology Demonstration and Applied Research, because the effectiveness of the indicator phage-based technique is intended to be proved in field conditions in Georgia. Mimic of the natural hazard after-effect with the focus on assessment of the potential of the phage-based techniques in determining of the possible ways of development of is a totally new direction in this field. The outcomes of the present project will serve to solution of the issues related to human health and ecology. The project results are closely related to environmental protection as well.
Because the computer modeling will simulate after-effect conditions of epidemics caused by natural hazards, these will be suitable model for the after-effects occurring during wars and mass migrations. Therefore, we believe this technology may find its practical application worldwide in the regions with high risks of earthquakes, floods, etc. as well as those with high incidence of epidemics due to other factors causing population displacements and other disruptions. It contributes to solution of national and international problems, such as epidemics associated with economic shortages as well damage and destruction occurring during natural hazards, mass migrations, wars, ethnic conflicts, etc. The studies of consequences of natural hazards are essential, because safety concerns not only engineering constructions, but first and foremost the health and well-being of population. Against this background one should remember that impact of natural hazards is much more disastrous for developing countries, because the long-term effects may last decades and adsorb considerable part of a small national budget. Thus, the present project will have economically significant outcome for Georgia and the whole Caucasian region.
The present project will involve the scientists from the IBMV that in former times were responsible for elaboration of the treatment and prophylactic phage preparations to the Soviet Army. Involvement of Georgian scientists representing different fields promotes their integration into the international scientific community. These scientists would contribute to development of applied and basic research and would apply technology developments for peaceful purposes.
The project will be accomplished jointly by the: IBMV (GE), UNSSP (GE), University of North Carolina (USA) and CAMR (UK). Each of these institutions has remarkable professional experience, which will provide complementary contribution for realization of the project.
The US partners will provide comments to the technical reports, which will be submitted by project participants annually to the ISTC. A number of phages selected as indicators/tracers will be tested by the US. collaborator as well, in particular by genomic studies. These tests will be accomplished jointly. For this purpose at least one young scientist from CIS country will visit the U.S. partner and stay in his lab for a period of 3-4 months. The US partner will be involved into preparation of the articles and/or patents as well.
The UK collaborator will provide the consultations on a geo-spatial correlation modeling of the potential interactions between risk factors and ultimate human risk, and will help to develop risk models, both inside and outside of GIS, based around population dynamic models of disease. The UK collaborator will advise also on application of a range of computer software, for example Oracle 9i for data warehousing, the full ArcGIS suite for GIS applications, as well as bespoke modeling in @RISK, C and C++ programs. The UK collaborator will be involved into the whole process of preparation and reviewing of the reports and articles. One of the Georgian scientists responsible for computer risk assessment will travel for a short visit (7-14 days) to the UK laboratory for sharing the information and exchanging the materials.
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.