Longevity and viability of Taenia solium eggs in the digestive system of the beetle Ammophorus rubripes

Abstract

The present study evaluated the capacity of Ammophorus rubripes beetles to carry Taenia solium eggs, in terms of duration and viability of eggs in their digestive system. One hundred beetles were distributed into five polyethylene boxes, and then they were infected with T. solium eggs. Gravid proglottids of T. solium were crushed and then mixed with cattle feces. One gram of this mixture was placed in each box for 24 hours, after which each group of beetles was transferred into a new clean box. Then, five beetles were dissected every three days. Time was strongly associated with viability (r=0.89; P<0.001) and the calculated time to cero viability is 36 days. The eggs in the intestinal system of each beetle were counted and tested for viability. Taenia solium eggs were present in the beetle’s digestive system for up to 39 days (13th sampling day out of 20), gradually reducing in numbers and viability, which was 0 on day 36 post-infection. Egg viability was around 40% up to day 24 post-infection, with a median number of eggs of 11 per beetle at this time. Dung beetles may potentially contribute towards dispersing T. solium eggs in endemic areas.

Spatial relationship between Taenia solium tapeworm carriers and necropsy cyst burden in pigs

“…It is also possible that pigs appearing distant from tapeworm carriers were infected through egg dispersion mechanisms, such as dung beetles and flies, which have been identified as possible mechanical vectors capable of dispersing T . solium eggs over long distances [27–31]. Finally, it is possible that we did not identify all tapeworm carriers in the study area.…”

Molecular Detection of Taeniid Eggs in Beetles Collected in an Area Endemic for Taenia solium

“…The role of beetles as mechanical vectors for some species of Taenia has been studied since several years ago, probably because these beetles feel a natural attraction to the feces and are part of the cycle of other parasites. 12,15 Some species of beetles can ingest the eggs of the genus Taenia and keep them viable in their guts [8][9][10][11] ; however, the present study is the first to show the presence of T. solium and T. hydatigena in beetles under natural conditions, molecularly.…”

“…10 Also, Ammophorus rubripes beetles can have viable T. solium eggs until 27 days postinfection. 11 As is known, several species of beetles are obligate intermediate hosts of some Spiruridae nematodes such as Ascarops strongylina and Physocephalus sexalatus, which are common parasites of pigs. 12 An association between these parasites and porcine cysticercosis has been demonstrated, thus also supporting a possible role for beetles in the transmission of Taenia eggs.…”

Climate Change and the Neglected Tropical Diseases

“…It has been previously suggested that blow flies could distribute eggs (Lawson and Gemmell, 1990) but this has not been demonstrated other than experimentally with dead flies being ingested by lambs (Lawson and Gemmell, 1990). More recently, Ammophorus rubripes, a dung beetle, has been implemented as a potential carrier through experiments that demonstrated carriage of viable eggs by the beetles for up to 24 days (Gomez-Puerta et al, 2014). A broad range of synergistic and competing factors is likely to affect the ecology of any organism capable of dispersing eggs, leading perhaps to localised extinction (Brook et al, 2008), among other effects related to anthropogenic disruption of established ecosystems (Cable et al, 2017).…”