[Using ELISA for identifying Triatominae feeding behaviour in Colombia]

Standardising the ELISA technique for identifying triatomine insects' feeding behaviour.

The ELISA test was standardised by preparing 12 animal anti-specie polyclonal antisera by immunising rabbits with sera from domestic and wild animals; the sera were titred and absorbed to improve specificity. The intestinal content of fifth-instar Rhodnius prolixus (previously fed on each host) was used as positive control; negative controls were obtained from triatomines without feeding. The intestinal content from 60 intradomicile R. prolixus collected in the field was processed to determine the test's effectiveness.

The high-reactivity ELISA technique was standardised in detecting every blood protein in the positive controls used here. Blood proteins from one or more domestic and wild hosts were detected in 70% of the intestinal content of triatomines collected in homes. Bird, human, pig and goat blood were the most frequent feeding sources; blood proteins from wild animals were identified in 9.5% of them.

The technique was shown to be effective in detecting blood proteins from different hosts in the intestinal content of triatomines taken from the laboratory and the field. Even though domestic animals' blood was preferentially determined, the findings from wild animals' blood could indicate insect mobility probably from the wild to the domicile. This tool helps in understanding triatomines' behaviour regarding their hosts, thereby contributing to understanding Chagas' disease eco-epidemiology.