THE EMERGING SYNDROME OF ENVENOMING BY THE NEW-GUINEA SMALL-EYED SNAKE MICROPECHIS-IKAHEKA

The New Guinea small-eyed or Ikaheka snake, Micropechis ikaheka, which occurs throughout New Guinea and some adjacent islands, is feared by the indigenes. The first proven human fatality was in the 1950s and th is species has since been implicated in many other cases of severe and fatal envenoming. Reliable attribution of envenoming to this species in victims unable to capture or kill the snake recently became possibl e by the use of enzyme immunoassay. Eleven cases of proven envenoming by M. ikaheka, with two fatalities, were identified in Papua New Guine a and Irian Jaya. Five patients showed no clinical signs of envenoming . The other six patients showed symptoms typical of envenoming by othe r Australasian elapids: mild local swelling, local lymphadenopathy, ne urotoxicity, generalized myalgia, spontaneous systemic bleeding, incoa gulable blood and passage of dark urine (haemoglobinuria or myoglobinu ria). Two patients developed hypotension and two died of respiratory p aralysis 19 and 38 h after being bitten. In vitro studies indicate tha t the venom is rich in phospholipase A(2), is indirectly haemolytic, a nticoagulant and inhibits platelets, but is not procoagulant or fibrin olytic. It shows predominantly post-synaptic neurotoxic and myotoxic a ctivity. Anecdotally, Commonwealth Serum Laboratories' (CSL) death add er antivenom has proved ineffective whereas CSL polyvalent antivenom m ay be beneficial. Anticholinesterase drugs might prove effective in im proving neuromuscular transmission and should be tested in patients wi th neurotoxic envenoming.