Volume 23, Number 9—September 2017
Dispatch
Possible Role of Fish as Transport Hosts for Dracunculus spp. Larvae
Table
Results of ferret exposure trials with 3 different fish species exposed to copepods infected with Dracunculus medinensis or D. insignis worms
Fish species | Dracunculus sp. | No. fish consumed/no. offered* | Total no. copepods† | Days until euthanasia of ferret‡ | Dracunculus infection status of ferret | No. worms recovered and sex§ |
---|---|---|---|---|---|---|
Mosquitofish (Gambusia affinis) | D. insignis | 28/30 | 300 | 91 and 134 | – | 0 |
D. medinensis |
30/30 |
300 |
77 |
+ |
1M/11F |
|
Tilapia (Oreochromis niloticus) |
D. insignis |
27/30 |
300 |
91 and 134 |
+ |
6F¶ |
Fathead minnow (Pimephales promelas) | D. insignis | 30/30 | 300 | 91 and 118 | + | 1M |
*In groups of 5 fish/day for 6 days.
†>25% of copepods infected.
‡The D. insignis worm–exposed ferrets have 2 entries for days until euthanasia because these animals were exposed to fish at 2 different time points with copepods infected with larvae from 2 different worms.
§All worms were recovered from the subcutaneous tissues of the limbs.
¶Of these 6 female worms, 5 were gravid, indicating a male worm either was missed or had died before necropsy.