Choanotaenia infundibulum is a parasitic tapeworm that has chicken and other domestic and wild gallinaceous birds (e.g. turkey, pheasants, quails, etc.) as final hosts. They are found worldwide, with variable incidence, but are less frequent than other parasitic tapeworms of birds (e.g. Davainea proglottina, Raillietina spp). Other species of the genus Choanotaenia affect mainly wild birds.
Choanotaenia infundibulum does not affect dogs, cats, cattle, sheep, pigs, horses or other mammals.
Are birds infected with Choanotaenia infundibulum contagious for humans?
NO. The reason is that this tapeworm species is not a human parasite.
Final location of Choanotaenia infundibulum
The predilection site of adult Choanotaenia infundibulum is the small intestine
Anatomy of Choanotaenia infundibulum
Adult tapeworms are up to 25 cm long and 3 mm wide. The head (scolex) is small and has suckers and hooks for attaching to the host's gut wall. Usually it has not more than 30 segments (proglottids), which are wider than long. Each segment has its own reproductive organs of both sexes (i.e. they are hermaphroditic). Each segment has also excretory cells known as flame cells (protonephridia). The reproductive organs in each segment have a common opening called the genital pore. In young segments all these organs are still rudimentary. They develop progressively, which increases the size of the segment as it is pushed towards the tail. Otherwise, as other tapeworms, they have neither a digestive tube, nor circulatory respiratory systems. They don't need them because each segment absorbs what it needs directly through its tegument.
The eggs have an ovoid shape, measure about 35x45 micrometers, and contain an embryo (oncosphere).
Life cycle and biology of Choanotaenia infundibulum
Choanotaenia infundibulum has an indirect life cycle with domestic and wild birds as final hosts, and several fly species (e.g. Musca domestica), locusts, ants and termites as intermediate hosts.
The gravid segments of adult tapeworms that contain the eggs are shed with the birds' feces. They are motile and migrate quickly odd the feces into the surrounding vegetation. The intermediate hosts ingest the gravid segments, which release the eggs in their gut after digestion. The eggs then develop to cysticercoids in the body cavity of the intermediate hosts. The birds ingest flies, locusts, ants, etc. and after digestion, the cysticercoids release the young tapeworms that attach to the wall of the bird's gut.
The time between infection and shedding of the first eggs (prepatent period) about 2 to 4 weeks.
Harm caused by Choanotaenia infundibulum, symptoms and diagnosis
Choanotaenia infundibulum infections are moderately pathogenic. In most cases affected birds do not show serious clinical signs. Massive infections can cause reduced growth, especially in young birds. Affected birds can become apathetic and isolated.
Diagnosis is done through detection of gravid segments in the feces. Fecal examination must be done on fresh feces, because the gravid segments migrate quickly outside the droppings. Eggs are usually not found in the feces because they remain inside the migrating gravid segments. After necropsy the adult worms can be seen detected in the intestine.
Prevention and control of Choanotaenia infundibulum infections
Frequent change of the birds' bedding and keeping it dry can help to avoid infections because it shortens the survival of the gravid segments and the eggs.
Measures to avoid contamination of feed with ants or beetles are advisable. Chemical control of flies, ants and termites in poultry houses can be advisable. However, for both economic and ecologic reasons outdoor use of insecticides against ants, beetles or termites is not justified.
Flocks at risk can be treated with anthelmintics effective against tapeworms. They contain either broad-spectrum benzimidazoles (e.g. albendazole, febantel, fenbendazole, mebendazole, oxfendazole, etc.) or specific taenicides (e.g., niclosamide, praziquantel, etc.). Most of these active ingredients are available as additives for feed or drinking water, or as tablets for oral delivery.
WARNING: niclosamide is toxic for geese, and the combination of praziquantel with pyrantel tartrate is toxic for chicken!
Other classic livestock anthelmintics such as macrocyclic lactones (e.g. ivermectin, doramectin, moxidectin, etc.), levamisole, tetrahydropyrimidines (e.g. pyrantel, morantel) and piperazine derivatives are not effective at all against Choanotaenia infundibulum or whatever tapeworm.
There are so far no vaccines against Choanotaenia infundibulum. To learn more about vaccines against parasites of livestock and pets click here.
Biological control of Choanotaenia infundibulum (i.e. using its natural enemies) is so far not feasible.
You may be interested in an article in this site on medicinal plants against external and internal parasites.
Resistance of Choanotaenia infundibulum to anthelmintics
So far there are no reports on resistance of Choanotaenia infundibulum tapeworms to anthelmintics.
This means that if an anthelmintic fails to achieve the expected efficacy, chance is very high that either the product was unsuited for the control of Choanotaenia infundibulum, or it was used incorrectly.
Ask your veterinary doctor! If available, follow more specific national or regional recommendations for Choanotaenia infundibulum control.