Biotecnologia Aplicada Elfos Scientiae ISSN: 0684-4551 Vol. 12, Num. 2, 1995, pp. 80-81

REPORTE CORTO/SHORT REPORT

Presented in the Congress Biotecnologia Habana'94. La Habana, Cuba, Nov. 28 - Dec. 3, 1994

INTRODUCTION AND IMPLEMENTATION OF MOLECULAR TECHNOLOGY FOR THE DIAGNOSIS AND EPIDEMIOLOGY OF INFECTIOUS DISEASES IN LATIN AMERICA

Eva Harris^1, Alejandro Belli^2 and Nina Agabian^1

^1Intercampus Program in Molecular Parasitology, University of California at San Francisco, 3333 California Avenue, Suite 150, San Francisco, CA 94118; ^2National Diagnostics and Reference Center, Ministry of Health, Managua, Nicaragua.

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INTRODUCTION

Molecular techniques, such as the polymerase chain reaction (PCR) and nonradioactive DNA probes, can be applied to the diagnosis and epidemiology of infectious diseases in countries of limited resources. When appropriately implemented, these molecular techniques are more rapid, more sensitive, more specific, safer, and less costly than existing methods. We have developed a successful format for the transfer of molecular technology to Latin American countries through the use of on-site hands-on workshops (1).

The program is comprised of sequentially staged and progressively more complex courses which provide participants with solid experience in the theory and practice of molecular technology, epidemiology and proposal development. The courses progress from the introduction of molecular technology (Phase I) to its implementation by local scientists (Phase II and beyond) and are accessible to a wide range of participants, since prior training is not a pre-requisite. Course I is designed in consultation with local scientists, who select the pathogens to be detected based on national health priorities. Participants in the first workshop then design the pilot studies they will conduct in Course II and collect the appropriate samples. These pilot studies from the basis of grant proposals detailing larger studies which are developed during Course II. These courses have been conducted in Nicaragua and Ecuador and are planned in a number of additional countries in the region.

MATERIALS AND METHODS

Existing methodologies (PCR and nonradioactive DNA probes) for detection of a range of pathogens were adapted for country- specific applications, allowing course participants to detect Leishmania, V. cholerae, M. tuberculosis, dengue virus, Shigella and enterotoxigenic E. coli, and P. falciparum in clinical and environmental samples. Extraction procedures were simplified for rapid processing, and PCR was carried out by manual amplification or with a thermocycler, if available. Simple but effective precautions were used to minimize the chance of cross-contamination of samples, including frequent treatment of bench surfaces and micropipettor shafts with sodium hypochlorite (household bleach) and the use of separate rooms and separate sets of micropipettors for the preparation of PCR reactions, DNA extraction, and analysis of amplified products.

RESULTS AND DISCUSSION

These workshops have received enthusiastic responses from participating scientists, physicians, and medical technicians. Each course includes 20 participants from throughout the country; for instance, in the most recent Phase I course in Ecuador, participants came from 8 cities representing 15 different institutions. As a result, important contacts and collaborations have emerged between individuals and institutions, at the national, regional and international level.

As a consequence of these courses, several projects have been initiated in such areas as the molecular epidemiology of Leishmania in Central America and the molecular diagnosis of tuberculosis. An ongoing study in Nicaragua funded by the European Economic Community involves the identification of Central American strains of Leishmania by molecular means (PCR, RAPD, RFLP) and the molecular characterization of putative hybrid strains (2). Pilot projects for the upcoming Phase II course in Ecuador planned for May, 1995, include the molecular diagnosis and epidemiology of tuberculosis, the detection of dengue virus in clinical samples and in the rapid typing of Leishmania strains from clinical specimens. Similar courses are currently planned in Bolivia, Honduras, Argentina and Brazil as well.

REFERENCES

1. HARRIS, E. et al . (1993). Biochemical Education 21(1): 16-22

2. BELLI, A. A. et al. Parasitology, in press.

Copyright 1995 Sociedad Iberolatinoamericana de Biotecnologia Aplicada a la Salud