Onchocerca volvulus : comparison of field collection methods for the preservation of parasite and vector samples for PCR analysis

• Published in: Bulletin of the World Health Organization Vol. 75; no. 5; pp. 443 - 447
• Main Authors: TOE, L, BACK, C, ADJAMI, A. G, TANG, J. M, UNNASCH, T. R
• Format: Journal Article
• Language: English
• Published: Genève Organisation mondiale de la santé 01.01.1997; World Health Organization
• Subjects: Animals; Biological and medical sciences; Collections and collecting; Dehydrogenases; Deoxyribonucleic acid; Diagnosis; Diagnostic specimens; Dissection; DNA; DNA - isolation & purification; DNA, Helminth - isolation & purification; Female; Fundamental and applied biological sciences. Psychology; Insect Vectors - genetics; Insect Vectors - parasitology; Laboratories; Medically important nuisances and vectors, pests of stored products and materials: population survey and control; Methods; Nitrogen; Onchocerca volvulus - genetics; Onchocerciasis; Onchocerciasis - prevention & control; Ovaries; Parasites; Polymerase Chain Reaction; Simuliidae - genetics; Simuliidae - parasitology; Skin; Vectors. Intermediate hosts; Simuliidae; Preservation; Insecta; Simulium damnosum; Onchocerca volvulus; Parasite; Parasitosis; Method; Helminthiasis; Onchocerciasis; Infection; Polymerase chain reaction; Arthropoda; Nematode disease; Helmintha; Nemathelminthia; Specific identification; Filariosis; Gathering; Invertebrata; Nematoda; Vector; Diptera; Comparative study
• ISSN: 0042-9686; 1564-0604

In recent years, methods for the identification of the filarial worm Onchocerca volvulus and its vector, blackflies of the Simulium damnosum complex (S. damnosum sensu lato (s.l.)), based on the amplification of parasite and vector DNA sequences with the polymerase chain reaction (PCR), have been developed. Routine application of these methods requires techniques for sample collection and preservation that are compatible with the limitations of field collection, yet preserve DNA in a form suitable for PCR. Two different methods for sample preservation were evaluated by the field collection teams and the DNA probe laboratory of the Onchocerciasis Control Programme in West Africa. The most successful involved the preservation of material from O. volvulus and its associated vectors in a dried state on microscope slides. Of over 1200 parasite samples preserved in this manner, more than 93% retained DNA yielding positive results in PCR analysis (1208/1291). Vector material (malpighian tubules and ovaries) preserved in the same manner on the same microscope slides also yielded DNA that was suitable for PCR.