Having blood drawn can traumatize captive primates. Typically, the animal is caught, restrained and anaesthetised. This stress, along with the anaesthesia can cloud the desired measurement. A group of Germans decided to go the “all natural” way and employ the services of Dipetalogaster maximus (pictured) to do their blood drawing. We’re big fans of bugs as medgadgets, and Ruth Thomsen and Christian C. Voigt of the Institute of Zoo and Wildlife Research in Berlin have given us more work to admire…
When possible effects of the bug’s haemolymph or saliva on the blood sample were studied, it was shown that the sample remains unchanged if it is redrawn from the bug’s crop within approximately 30 min after the bug has finished its blood meal. The blood then can be used for a variety of analysis, including lymphocyte cultures (Volleth 1985), doubly-labelled water experiments (Voigt et al. 2003), antibodies (Voigt et al. 2006), determining the concentration of steroid hormones (Voigt et al. 2004) and haematology (R. Thomsen and C.C. Voigt, in preparation).
Dipetalogaster maximus (Reduviidae, Heteroptera) develops in five larval stages (L1-5) until the imago (I) hatches. Since each stage has a characteristic size (e.g. L1 = 0.4 cm, Imago = 4 cm), the quantity of blood required can be defined precisely from 0.1 to 4.0 ml (for details, see Voigt et al. 2004). After the bug has recognised the victim, it punctures the skin with its proboscis, which is 32-fold smaller in diameter than a common 26-gauge needle, and then starts to suck blood. Immediately after the initial sting, the bug releases pain-reducing substances so that the host does not notice the parasite (von Helversen et al. 1986).
Since the bug releases heparinising substances into the ingested blood, any further preparation of the blood is unnecessary (Voigt et al. 2003).
That is some cool stuff. This seems remarkably practical, particularly in animals for which drawing blood is a big pain (for both the animal and the grad student). Drawing blood on a hard-to-stick or a mentally retarded patient, similarly would go a long way for a sensitive medical student.
The research comes to us from the journal Primates, and has only recently been published online.
The authors are awarded 1000 Medgadget Points™ for sticking with the term “blood-sucking bugs” throughout the paper.
More from the PubMed abstract…
