In my view, serology is in a stage where it is warranted to study its introduction into control programmes especially for early detection of the most infectious form of the disease. Optimal operational procedures should be defined, and performance and cost-efficiency investigated. The skin tests which are now under development have the potential to detect most individuals infected with M. leprae, and perhaps in conjunction with serology, will also be useful for the early diagnosis of disease. I expect these skin tests especially to be useful, contrary to serological assays, for the early detection of paucibacillary leprosy patients. Other diagnostic assays, which make use of other approaches especially molecular amplification assays, have potentially numerous applications, but are still at a level of sophistication in terms of necessary skills and costs, which limits their application to well-equipped laboratories. Nevertheless, it would be regrettable if leprosy control would not benefit the promising development in this field to miniaturise and simplify these techniques.
Both operational and technical approaches towards improvement of diagnosis are needed and one or the other should not be excluded. As early diagnosis is concerned, there are developments which are very promising, both in terms of scientific merit and in potential usefulness for leprosy control. Let us together strive for these developments to continue.
Paul Klatser (delivered by Stella van Beers)
P. Klatser, Royal Tropical Institute (KIT), Amsterdam, THE NETHERIANDS
